[CI Skip] 0.98.1

skip-checks: true

.123trigger

@@ -1 +1 @@
-6
+13

.github/workflows/push-master.yml

@@ -14,6 +14,8 @@ jobs:
         node-version: [12.x]
     steps:
     - uses: actions/checkout@v1
+      with:
+        token: ${{ secrets.GH_PAT }}
     - name: Use Node.js ${{ matrix.node-version }}
       uses: actions/setup-node@v1
       with:
@@ -27,7 +29,7 @@ jobs:
         NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
       run: |
         yarn install --frozen-lockfile
-        CI_NO_BETA=true yarn polkadot-dev-ghact-build
+        yarn polkadot-dev-ghact-build
 
   build_docs:
     name: Build Docs
@@ -51,3 +53,15 @@ jobs:
       run: |
         yarn install --frozen-lockfile
         yarn polkadot-dev-ghact-docs
+
+  dummy:
+    name: Dummy
+    if: "contains(github.event.head_commit.message, '[CI Skip]')"
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node-version: [12.x]
+    steps:
+    - name: dummy
+      run: |
+        echo "Dummy skip step"

CHANGELOG.md

@@ -1,3 +1,38 @@
+# 0.98.1
+
+- Make the TypeScript generation script mor re-usable (Thanks to @xlc)
+- Add `.entries()` for all map-types, returning storage keys and values
+- Add `.signAsync` to submittable extrinsics (Thanks to @c410-f3r)
+- Cleanup circular references between internal dependencies
+- Support for new Substrate democracy with preimages in derive
+- Alignment of types with Substrate/Polkadot master branches
+
+# 0.97.1
+
+- **Breaking change** Add the passing on an explicit `Registry` to all calls to `createType` as well as all codec classes. If you are upgrading form an older version, use the [migration guide](UPGRADING.md) to walk through the changes required.
+- **Breaking change** The metadata classes have been moved from `@polkadot/types` into `@polkadot/metadata`. If you explicitly create `Metadata` classes, you now would need to do so with the `import Metadata from '@polkadot/metadata';` This is a decorated class, where the previous metadata is now available on `Metadata.metadata`, alongside decorated `consts.*`', `tx.*` and `query.*`.
+- **Breaking change** Session `Keys` defaults to 4 keys now (Substrate master), depending on your node config, you would want to override with e.g. `Keys: 'SessionKeys3'` (1, 2, 3, 4, 5 & 6)
+- **Breaking change** `ValidatorPrefs` now default to the new percentage commission model, to use the previous `validatorPayment`, you can override with `ValidatorPrefs: 'ValidatorPrefsTo196'`
+- `api.derive.*` now has built-in memomization
+- Various fixes and cleanups to `api.derive.*` including era length progress and vesting calculations
+- Aligned all types with the latest Polkadot & Substrate, including Kusama CC3
+- Support for Metadata V9, which adjusts the hashing methods of storage entries
+- Support for Metadata V10 (still un-released), which includes prefixed map support
+
+# 0.96.1
+
+- Updated types for latest Kusama
+- Add `filterRecords` (in addition to `findRecord`) on submittable results
+- Various ABI v2 contract fixes
+- Update derive for elections (incl. RunnersUp) and heartbeat derives (with blocks & messages)
+- Add vesting totals & locked breakdowns to derive balances
+- Update council derives for the latest Substrate master support (with constants)
+- Derive cleanups, including sharing of instances between the API and internal to derives
+
+# 0.95.2
+
+- Temporary removal of `account_nextIndex` use, will be re-added in a future release
+
 # 0.95.1
 
 - Support Extrinsic V4 with additional signature indicator (Latest Polkadot/Substrate/Kusama)

UPGRADING.md

@@ -2,7 +2,91 @@
 
 This is an upgrade guide for users of the API. It does not attempt to detail each version (the [CHANGELOG](CHANGELOG.md) has all the changes between versions), but rather tries to explain the rationale behind major breaking changes and how users of the API should handle this.
 
-While we try to keep the user-facing interfaces as stable as possible, sometimes you just need to make additions to move forward and improve things down the road, as painful as they may be. Like you, we are also users of the API, and eat our own dogfood - and as such, feel any pains introduced first.
+While we try to keep the user-facing interfaces as stable as possible, sometimes you just need to make additions to move forward and improve things down the road, as painful as they may be. Like you, we are also users of the API, and eat our own dog food - and as such, feel any pains introduced first.
+
+
+## 0.97.1 (and newer)
+
+The 0.97 series lays the groundwork to allow type registration  to be ties to a specific chain and a specific Api instance. In the past, 2 Api instances in the same process would share types, which mean that you could not connect to 2 independent chains with different types. This is very problematic for Polkadot chains, where the idea is to connect to multiple chains.
+
+When using the Api, a new `Registry` will be created on using `new Api(...)` or `Api.create(...)` and this will be transparently passed when creating types. In the cases where you create type instances explicitly or create type classes for injection, you would need to make adjustments.
+
+### Type classes
+
+In a number of instances, developers are creating classes and making these available for interacting with their chains. For instance, an example of a custom type could be -
+
+```js
+import { Struct, Text, u32 } from '@polkadot/types';
+
+export class Preferences extends Struct {
+  constructor (value?: ahy) {
+    super({
+      name: Text,
+      id: u32
+    }, value);
+  }
+
+  ...
+}
+```
+
+In the current iteration, the underlying `@polkadot/types` bases structures now require a `Registry` to be passed as the first parameter. This means that the above signature would be adjusted to -
+
+```js
+// the next import is only required for TypeScript
+import { Registry } from '@polkadot/types/types';
+import { Struct, Text, u32 } from '@polkadot/types';
+
+export class Preferences extends Struct {
+  constructor (registry: Registry, value?: ahy) {
+    super(registry, {
+      name: Text,
+      id: u32
+    }, value);
+  }
+
+  ...
+}
+```
+
+Where the type is used or returned from the API, the `Registry` will be automatically passed to class creation.
+
+### createType
+
+Previously, when creating a type instance such as `BlockNumber`, you would do `api.createType('BlockNumber', <initValue>)`, this is unchanged. In the cases where you directly import from `@polkadot/types`, the following pattern is required -
+
+```js
+import { createType } from '@polkadot/types';
+
+...
+const blockNumber = createType(api.registry, 'BlockNumber', 12345);
+```
+
+In some cases, you would want to explicitly pass a `Registry` interface to the API, instead of relying on it explicitly. This is generally applicable in the cases where you want to use the `createType` independently from the API -
+
+```js
+import { ApiPromise } from '@polkadot/api';
+import { TypeRegistry, createType } from '@polkadot/types';
+
+...
+const registry = new TypeRegistry();
+const blockNumber = createType(registry, 'BlockNumber', 12345);
+const api = await ApiPromise.create({ registry });
+```
+
+### Extrinsic metadata
+
+In some applications, the undocumented `findFunction` has been used to determine the Api has the metadata for a specific extrinsic. The has been exposed on top of `GenericCall`, and it typically used in applications such as signers. Along with the compulsory registry, the above functions have been moved to the `Registry` itself, so if you previously had -
+
+```js
+const { meta, method, section } = GenericCall.findFunction(extrinsic.callIndex);
+```
+
+You need to change it to -
+
+```js
+const { meta, method, section } = registry.findMetaCall(extrinsic.callIndex);
+```
 
 ## 0.90.1 (and newer), from 0.81.1 (and older)
 
@@ -29,10 +113,10 @@ To better align with the actual types from the metadata, and avoid (too much) co
 
 The [@polkadot/api](packages/api) has always handled the conversion of types for parameters when making calls or queries. For example, when making a transfer to `BOB` (address), any of the following is valid -
 
-- `api.tx.balances.transfer(BOB, 12345)` - value specied as a number
-- `api.tx.balances.transfer(BOB, '12345')` - value specied as a string
-- `api.tx.balances.transfer(BOB, '0x3039')` - value specied as a hex
-- `api.tx.balances.transfer(BOB, new BN(12345))` - value specied as a [BN](https://github.com/indutny/bn.js/)
+- `api.tx.balances.transfer(BOB, 12345)` - value specified as a number
+- `api.tx.balances.transfer(BOB, '12345')` - value specified as a string
+- `api.tx.balances.transfer(BOB, '0x3039')` - value specified as a hex
+- `api.tx.balances.transfer(BOB, new BN(12345))` - value specified as a [BN](https://github.com/indutny/bn.js/)
 
 Internally the API will take the input and convert the value into a `Balance`, serialize it using the SCALE codec and transfer it to the node. In some cases users would construct the `Balance` type manually, by importing the class and calling `new` on it. This last approach has now been removed, and where classes are still available (limited reach), discouraged.
 
@@ -108,7 +192,7 @@ export class MyStruct extends Struct {
 }
 ```
 
-Internally the [@polkadot/types](packages/types) package now only defines classes where there are specific encoding logic applied. For all other types, the definitions are done via a JSON-like format and then the TypeScript definitions are generated from these. (In a world where nodes inject types and the type definitions are not needed, this functionality will be useful to allow TS devs to auto-generate type definitions based on what the node defines.)
+Internally the [@polkadot/types](packages/types) package now only defines classes where there are specific encoding logic applied. For all other types, the definitions are done via a JSON-like format and then the TypeScript definitions are generated from these. (In a world where nodes inject types and the type definitions are not needed, this functionality will be useful to allow TS developers to auto-generate type definitions based on what the node defines.)
 
 ### Signing transactions (Signer interface)
 

copy-to-apps.sh

@@ -15,7 +15,7 @@ yarn polkadot-dev-build-ts
 copy_folder "api" "api"
 copy_folder "api-contract" "api-contract"
 copy_folder "api-derive" "api-derive"
-copy_folder "api-metadata" "api-metadata"
+copy_folder "metadata" "metadata"
 copy_folder "rpc-core" "rpc-core"
 copy_folder "rpc-provider" "rpc-provider"
 copy_folder "type-jsonrpc" "jsonrpc"

jest.config.js

@@ -6,8 +6,8 @@ module.exports = Object.assign({}, config, {
   moduleNameMapper: {
     '@polkadot/api-contract(.*)$': '<rootDir>/packages/api-contract/src/$1',
     '@polkadot/api-derive(.*)$': '<rootDir>/packages/api-derive/src/$1',
-    '@polkadot/api-metadata(.*)$': '<rootDir>/packages/api-metadata/src/$1',
     '@polkadot/api(.*)$': '<rootDir>/packages/api/src/$1',
+    '@polkadot/metadata(.*)$': '<rootDir>/packages/metadata/src/$1',
     '@polkadot/rpc-(core|provider)(.*)$': '<rootDir>/packages/rpc-$1/src/$2',
     '@polkadot/jsonrpc(.*)$': '<rootDir>/packages/type-jsonrpc/src/$1',
     '@polkadot/types(.*)$': '<rootDir>/packages/types/src/$1'
@@ -16,7 +16,7 @@ module.exports = Object.assign({}, config, {
     '<rootDir>/packages/api/build',
     '<rootDir>/packages/api-derive/build',
     '<rootDir>/packages/api-contract/build',
-    '<rootDir>/packages/api-metadata/build',
+    '<rootDir>/packages/metadata/build',
     '<rootDir>/packages/rpc-core/build',
     '<rootDir>/packages/rpc-provider/build',
     '<rootDir>/packages/type-jsonrpc/build',

lerna.json

@@ -9,5 +9,5 @@
   "packages": [
     "packages/*"
   ],
-  "version": "0.95.2"
+  "version": "0.98.1"
 }

package.json

@@ -1,5 +1,5 @@
 {
-  "version": "0.95.2",
+  "version": "0.98.1",
   "private": true,
   "engines": {
     "yarn": "^1.10.1"
@@ -9,11 +9,12 @@
   ],
   "resolutions": {
     "babel-core": "^7.0.0-bridge.0",
-    "typescript": "^3.6.4"
+    "typescript": "^3.7.2"
   },
   "scripts": {
     "build": "yarn build:interfaces && polkadot-dev-build-ts",
     "build:interfaces": "node packages/types/src/scripts/interfacesTsWrapper.js",
+    "circular": "madge --circular --extensions ts ./",
     "docs": "node packages/types/src/scripts/MetadataMdWrapper.js && polkadot-dev-build-docs",
     "chain:info": "node packages/types/src/scripts/extractChainWrapper.js",
     "lint": "eslint --ext .js,.jsx,.ts,.tsx . && tsc --noEmit --pretty",
@@ -28,10 +29,10 @@
     "test:watch": "jest --coverage --watch"
   },
   "devDependencies": {
-    "@babel/core": "^7.6.4",
-    "@babel/register": "^7.6.2",
-    "@babel/runtime": "^7.6.3",
-    "@polkadot/dev": "^0.32.0-beta.11",
-    "@polkadot/ts": "^0.1.82"
+    "@babel/core": "^7.7.4",
+    "@babel/register": "^7.7.4",
+    "@babel/runtime": "^7.7.4",
+    "@polkadot/dev": "^0.32.0-beta.15",
+    "@polkadot/ts": "^0.1.86"
   }
 }

packages/api-contract/README.md

@@ -3,9 +3,12 @@
 Interfaces to allow for the encoding and decoding of Substrate contract ABIs.
 
 ```js
+import {ApiPromise, WsProvider } from '@polkadot/api';
 import { Abi } from '@polkadot/api-contract';
 
-const abi = new Abi(<...JSON ABI...>);
+const wsProvider = new WsProvider(<...Node Url...>);
+const api = await ApiPromise.create({ provider: wsProvider });
+const abi = new Abi(api.registry, <...JSON ABI...>);
 
 api.tx.contracts
   .call(<contract addr>, <value>, <max gas>, abi.messages.<method name>(<...params...>))

packages/api-contract/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@polkadot/api-contract",
-  "version": "0.95.2",
+  "version": "0.98.1",
   "description": "Interfaces for interacting with contracts and contract ABIs",
   "main": "index.js",
   "keywords": [
@@ -26,7 +26,7 @@
   },
   "homepage": "https://github.com/polkadot-js/api/tree/master/packages/api-contract#readme",
   "dependencies": {
-    "@babel/runtime": "^7.6.3",
-    "@polkadot/types": "^0.95.2"
+    "@babel/runtime": "^7.7.4",
+    "@polkadot/types": "^0.98.1"
   }
 }

packages/api-contract/src/Abi.spec.ts

@@ -2,21 +2,24 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import erc20Abi from '../test/contracts/Erc20.json';
+import { TypeRegistry } from '@polkadot/types';
 
+import incrementerAbi from '../test/contracts/incrementer.json';
 import { Abi } from '.';
 
 describe('Abi', (): void => {
-  describe('erc20', (): void => {
+  const registry = new TypeRegistry();
+
+  describe('incrementer', (): void => {
     let abi: Abi;
 
     beforeEach((): void => {
-      abi = new Abi(erc20Abi);
+      abi = new Abi(registry, incrementerAbi);
     });
 
     it('has the attached methods', (): void => {
-      expect(Object.keys(abi.messages)).toEqual(
-        ['totalSupply', 'balanceOf', 'allowance', 'transfer', 'approve', 'transferFrom']
+      expect(Object.values(abi.abi.contract.messages).map(({ name }): string => name)).toEqual(
+        ['inc', 'get', 'compare']
       );
     });
   });

packages/api-contract/src/Abi.ts

@@ -2,7 +2,9 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import { ContractABI, ContractABIPre, ContractABIFn, InterfaceAbi, AbiMessages } from './types';
+import { Registry } from '@polkadot/types/types';
+import { AbiConstructors, AbiMessages, ContractABI, ContractABIPre, ContractABIFn, InterfaceAbi } from './types';
+
 import { stringCamelCase } from '@polkadot/util';
 
 import ContractRegistry from './ContractRegistry';
@@ -10,12 +12,12 @@ import ContractRegistry from './ContractRegistry';
 export default class ContractAbi extends ContractRegistry implements InterfaceAbi {
   public readonly abi: ContractABI;
 
-  public readonly constructors: ContractABIFn[];
+  public readonly constructors: AbiConstructors;
 
-  public readonly messages: AbiMessages = {};
+  public readonly messages: AbiMessages;
 
-  public constructor (abi: ContractABIPre) {
-    super(abi);
+  constructor (registry: Registry, abi: ContractABIPre) {
+    super(registry, abi);
     [this.abi, this.constructors, this.messages] = this.decodeAbi(abi);
   }
 
@@ -25,16 +27,21 @@ export default class ContractAbi extends ContractRegistry implements InterfaceAb
     const abi = this.convertAbi(abiPre);
     const constructors = abi.contract.constructors.map(
       (constructor, index): ContractABIFn => {
-        return this.createMethod(`constructor ${index}`, constructor);
+        return this.createMessage(`constructor ${index}`, constructor);
       }
     );
 
-    const messages: AbiMessages = {};
-    abi.contract.messages.forEach((method): void => {
-      const name = stringCamelCase(method.name);
+    const messages: AbiMessages = abi.contract.messages.reduce(
+      (result: AbiMessages, message): AbiMessages => {
+        const name = stringCamelCase(message.name);
 
-      messages[name] = this.createMethod(`messages.${name}`, method);
-    });
+        return {
+          ...result,
+          [name]: this.createMessage(`messages.${name}`, message)
+        };
+      },
+      {}
+    );
 
     return [abi, constructors, messages];
   }

packages/api-contract/src/ContractRegistry.ts

@@ -2,14 +2,55 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import { CodecArg, TypeDef } from '@polkadot/types/types';
-import { ContractABIArgBasePre, ContractABIContract, ContractABIContractPre, ContractABIEvent, ContractABIEventPre, ContractABIFn, ContractABIFnArg, ContractABIMethod, ContractABIMethodBase, ContractABIMethodPre, ContractABI, ContractABIPre, ContractABIRange, ContractABIRangePre, ContractABIStorage, ContractABIStorageLayout, ContractABIStorageLayoutPre, ContractABIStoragePre, ContractABIStorageStruct, ContractABIStorageStructPre, ContractABITypePre } from './types';
-import { Compact } from '@polkadot/types';
+import { CodecArg, Constructor, Registry, TypeDef } from '@polkadot/types/types';
+import { ContractABIArgBasePre, ContractABIContract, ContractABIContractPre, ContractABIEvent, ContractABIEventPre, ContractABIFn, ContractABIFnArg, ContractABIMessage, ContractABIMessageBase, ContractABIMessagePre, ContractABI, ContractABIMessageCommon, ContractABIPre, ContractABIRange, ContractABIRangePre, ContractABIStorage, ContractABIStorageLayout, ContractABIStorageLayoutPre, ContractABIStoragePre, ContractABIStorageStruct, ContractABIStorageStructPre, ContractABITypePre } from './types';
 
-import { assert, isNumber, isString, isNull, isObject, isUndefined, stringCamelCase } from '@polkadot/util';
+import { Compact, u32, createClass, createType, encodeType } from '@polkadot/types';
+import { assert, hexToU8a, isNumber, isString, isNull, isObject, isUndefined, stringCamelCase, isHex, hexToNumber } from '@polkadot/util';
 
 import MetaRegistry from './MetaRegistry';
-import { createArgClass } from './method';
+
+// parse a selector, this can be a number (older) or of [<hex>, <hex>, ...]. However,
+// just catch everything (since this is now non-standard for u32 anyway)
+function parseSelector (registry: Registry, fnname: string, input: ContractABIMessageCommon['selector']): u32 {
+  if (isNumber(input)) {
+    return createType(registry, 'u32', input);
+  } else if (isHex(input)) {
+    return createType(registry, 'u32', hexToU8a(input));
+  } else if (typeof input === 'string') {
+    try {
+      const array = JSON.parse(input);
+
+      assert(array.length === 4, `${fnname}: Invalid selector length`);
+
+      return createType(registry, 'u32', Uint8Array.from(
+        // the as number[] is here to pacify TS, it doesn't quite know how to handle the cb
+        (array as number[]).map((value: string | number): number =>
+          isHex(value)
+            ? hexToNumber(value.toString())
+            : value
+        )
+      ));
+    } catch (e) {
+      console.error(e);
+    }
+  }
+
+  throw new Error(`${fnname}: Unable to parse selector`);
+}
+
+function createArgClass (registry: Registry, args: ContractABIFnArg[], baseDef: Record<string, string>): Constructor {
+  return createClass(
+    registry,
+    JSON.stringify(
+      args.reduce((base: Record<string, any>, { name, type }): Record<string, any> => {
+        base[name] = type.displayName || encodeType(type);
+
+        return base;
+      }, baseDef)
+    )
+  );
+}
 
 export default class ContractRegistry extends MetaRegistry {
   // Contract ABI helpers
@@ -26,7 +67,7 @@ export default class ContractRegistry extends MetaRegistry {
   }
 
   public validateConstructors ({ contract: { constructors } }: ContractABIPre): void {
-    constructors.forEach((constructor: ContractABIMethodPre, index): void => {
+    constructors.forEach((constructor: ContractABIMessagePre, index): void => {
       const unknownKeys = Object.keys(constructor).filter((key): boolean => !['args', 'docs', 'name', 'selector'].includes(key));
 
       assert(unknownKeys.length === 0, `Unknown keys ${unknownKeys.join(', ')} found in ABI constructor`);
@@ -35,45 +76,51 @@ export default class ContractRegistry extends MetaRegistry {
     });
   }
 
-  public validateMethods ({ contract: { messages } }: ContractABIPre): void {
-    messages.forEach((method): void => {
-      const unknownKeys = Object.keys(method).filter((key): boolean => !['args', 'docs', 'mutates', 'name', 'selector', 'return_type'].includes(key));
+  public validateMessages ({ contract: { messages } }: ContractABIPre): void {
+    messages.forEach((message): void => {
+      const unknownKeys = Object.keys(message).filter((key): boolean => !['args', 'docs', 'mutates', 'name', 'selector', 'return_type'].includes(key));
+      const fnname = `messages.${message.name}`;
 
-      assert(unknownKeys.length === 0, `Unknown keys ${unknownKeys.join(', ')} found in ABI args for messages.${method.name}`);
-      const { name, selector, return_type: returnType } = method;
-      assert(isNumber(name) && isString(this.stringAt(name)), `Expected name for messages.${method.name}`);
-      assert(isNumber(selector), `Expected selector for messages.${method.name}`);
-      assert(isNull(returnType) || (isNumber(returnType.ty) && isObject(this.typeDefAt(returnType.ty))), `Expected return_type for messages.${method.name}`);
+      assert(unknownKeys.length === 0, `Unknown keys ${unknownKeys.join(', ')} found in ABI args for messages.${message.name}`);
 
-      this.validateArgs(`messages.${method.name}`, method.args);
+      const { name, selector, return_type: returnType } = message;
+
+      assert(isNumber(name) && isString(this.stringAt(name)), `Expected name for ${fnname}`);
+      assert(isNull(returnType) || (isNumber(returnType.ty) && isObject(this.typeDefAt(returnType.ty))), `Expected return_type for ${fnname}`);
+
+      parseSelector(this.registry, fnname, selector);
+      this.validateArgs(fnname, message.args);
     });
   }
 
   public validateAbi (abi: ContractABIPre): void {
     const unknownKeys = Object.keys(abi.contract).filter((key): boolean => !['constructors', 'docs', 'events', 'messages', 'name'].includes(key));
+
     assert(unknownKeys.length === 0, `Unknown fields ${unknownKeys.join(', ')} found in ABI`);
 
     const { contract: { constructors, messages, name } } = abi;
+
     assert(constructors && messages && isString(this.stringAt(name)), 'ABI should have constructors, messages & name sections');
 
     this.validateConstructors(abi);
-    this.validateMethods(abi);
+    this.validateMessages(abi);
   }
 
-  public createMethod (name: string, method: Partial<ContractABIMethod> & ContractABIMethodBase): ContractABIFn {
-    const args = method.args.map(({ name, type }): ContractABIFnArg => {
+  public createMessage (name: string, message: Partial<ContractABIMessage> & ContractABIMessageBase): ContractABIFn {
+    const args = message.args.map(({ name, type }): ContractABIFnArg => {
       assert(isObject(type), `Invalid type at index ${type}`);
       return {
         name: stringCamelCase(name),
         type
       };
     });
-    const Clazz = createArgClass(args, isUndefined(method.selector) ? {} : { __selector: 'u32' });
-    const baseStruct: { [index: string]: any } = { __selector: method.selector };
+    const Clazz = createArgClass(this.registry, args, isUndefined(message.selector) ? {} : { __selector: 'u32' });
+    const baseStruct: { [index: string]: any } = { __selector: isUndefined(message.selector) ? undefined : parseSelector(this.registry, name, message.selector) };
     const encoder = (...params: CodecArg[]): Uint8Array => {
       assert(params.length === args.length, `Expected ${args.length} arguments to contract ${name}, found ${params.length}`);
 
       const u8a = new Clazz(
+        this.registry,
         args.reduce((mapped, { name }, index): Record<string, CodecArg> => {
           mapped[name] = params[index];
 
@@ -87,9 +134,8 @@ export default class ContractRegistry extends MetaRegistry {
     const fn = (encoder as ContractABIFn);
 
     fn.args = args;
-    fn.isConstant = !(method.mutates || false);
-    fn.type = method.returnType || null;
-
+    fn.isConstant = !(message.mutates || false);
+    fn.type = message.returnType || null;
     return fn;
   }
 
@@ -112,7 +158,7 @@ export default class ContractRegistry extends MetaRegistry {
   public convertContract ({ constructors, messages, name, events, ...contract }: ContractABIContractPre): ContractABIContract {
     return {
       constructors: this.convertConstructors(constructors),
-      messages: messages.map(method => this.convertMethod(method)),
+      messages: messages.map(message => this.convertMessage(message)),
       name: this.stringAt(name),
       ...(events
         ? { events: events.map(event => this.convertEvent(event)) }
@@ -121,17 +167,17 @@ export default class ContractRegistry extends MetaRegistry {
     };
   }
 
-  public convertConstructors (constructors: ContractABIMethodPre[]): ContractABIMethod[] {
+  public convertConstructors (constructors: ContractABIMessagePre[]): ContractABIMessage[] {
     return constructors.map(
-      (constructor: ContractABIMethodPre): ContractABIMethod => {
-        return this.convertMethod(constructor);
+      (constructor: ContractABIMessagePre): ContractABIMessage => {
+        return this.convertMessage(constructor);
       }
     );
   }
 
-  public convertMethod ({ args, name, return_type: returnType, ...method }: ContractABIMethodPre): ContractABIMethod {
+  public convertMessage ({ args, name, return_type: returnType, ...message }: ContractABIMessagePre): ContractABIMessage {
     return {
-      ...method,
+      ...message,
       args: this.convertArgs(args),
       name: this.stringAt(name),
       returnType: returnType ? this.convertType(returnType) : null

packages/api-contract/src/MetaRegistry.spec.ts

@@ -2,32 +2,41 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import fs from 'fs';
-import path from 'path';
+import { TypeRegistry } from '@polkadot/types';
 
 import MetaRegistry from './MetaRegistry';
 
 import erc20Abi from '../test/contracts/Erc20.json';
+import erc20Cmp from '../test/compare/erc20.test.json';
 import sharedVecAbi from '../test/contracts/SharedVecV2.json';
+import sharedVecCmp from '../test/compare/shared-vec.test.json';
+import test001Abi from '../test/abi/test001.json';
+import test001Cmp from '../test/compare/test001.cmp.json';
+
+function compare (meta: MetaRegistry, other: any): void {
+  try {
+    expect(meta.typeDefs).toEqual(other);
+  } catch (error) {
+    console.error(JSON.stringify(meta.typeDefs));
+
+    throw error;
+  }
+}
 
 describe('MetaRegistry', (): void => {
+  const registry = new TypeRegistry();
+
   describe('construction', (): void => {
     it('initializes from a contract ABI (ERC20)', (): void => {
-      const metaRegistry = new MetaRegistry(erc20Abi);
-      fs.writeFile(path.join(__dirname, '../test/compare/erc20.test.json'), JSON.stringify(metaRegistry.typeDefs, null, 2), function (err): void {
-        if (err) throw err;
-      });
-
-      expect(true).toBe(true);
+      compare(new MetaRegistry(registry, erc20Abi), erc20Cmp);
     });
 
     it('initializes from a contract ABI (SharedVec)', (): void => {
-      const metaRegistry = new MetaRegistry(sharedVecAbi);
-      fs.writeFile(path.join(__dirname, '../test/compare/shared-vec.test.json'), JSON.stringify(metaRegistry.typeDefs, null, 2), function (err): void {
-        if (err) throw err;
-      });
+      compare(new MetaRegistry(registry, sharedVecAbi), sharedVecCmp);
+    });
 
-      expect(true).toBe(true);
+    it('initializes from a contract ABI (Other, test001)', (): void => {
+      compare(new MetaRegistry(registry, test001Abi), test001Cmp);
     });
   });
 });

packages/api-contract/src/MetaRegistry.ts

@@ -2,7 +2,7 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import { MetaRegistryItem, MetaRegistryJson, MetaTypeDefClikeEnum, MetaType, MetaTypeDefEnum, MetaTypeDefEnumVariant, MetaTypeDefEnumVariantStruct, MetaTypeDefEnumVariantTupleStruct, MetaTypeDefEnumVariantUnit, MetaTypeDefStruct, MetaTypeDefStructField, MetaTypeDefTupleStruct, MetaTypeDefUnion, MetaTypeIdCustom, MetaTypeIdVec, MetaTypeIdVecFixed, MetaTypeInfo, StringIndex, TypeDef, TypeDefInfo, TypeIndex } from '@polkadot/types/types';
+import { MetaRegistryItem, MetaRegistryJson, MetaTypeDefClikeEnum, MetaType, MetaTypeDefEnum, MetaTypeDefEnumVariant, MetaTypeDefEnumVariantStruct, MetaTypeDefEnumVariantTupleStruct, MetaTypeDefEnumVariantUnit, MetaTypeDefStruct, MetaTypeDefStructField, MetaTypeDefTupleStruct, MetaTypeDefUnion, MetaTypeIdCustom, MetaTypeIdVec, MetaTypeIdVecFixed, MetaTypeInfo, Registry, StringIndex, TypeDef, TypeDefInfo, TypeIndex } from '@polkadot/types/types';
 
 import { assert } from '@polkadot/util';
 import { displayType, withTypeString } from '@polkadot/types';
@@ -34,13 +34,16 @@ function detectedType ({ def, id }: MetaType): MetaTypeInfo {
 }
 
 class MetadataRegistryLookup {
+  public readonly registry: Registry;
+
   protected _strings: string[] = [];
 
   protected _types: MetaType[] = [];
 
   public typeDefs: TypeDef[] = [];
 
-  public constructor ({ registry: { strings, types } }: MetaRegistryJson) {
+  constructor (registry: Registry, { registry: { strings, types } }: MetaRegistryJson) {
+    this.registry = registry;
     this._strings = strings;
     this._types = types;
   }
@@ -102,8 +105,8 @@ class MetadataRegistryLookup {
 }
 
 export default class MetaRegistry extends MetadataRegistryLookup {
-  public constructor (json: MetaRegistryJson) {
-    super(json);
+  constructor (registry: Registry, json: MetaRegistryJson) {
+    super(registry, json);
 
     // Generate TypeDefs for each provided registry type
     this._types.forEach((_, index: number): void => this.setTypeDefAtIndex(index + 1));

packages/api-contract/src/RxBase.ts

@@ -1,31 +0,0 @@
-// Copyright 2017-2019 @polkadot/api-contract authors & contributors
-// This software may be modified and distributed under the terms
-// of the Apache-2.0 license. See the LICENSE file for details.
-
-import { SubmittableModuleExtrinsics } from '@polkadot/api/types';
-import { ApiObject, ContractABIPre, ContractBase } from './types';
-
-import { assert } from '@polkadot/util';
-
-import Abi from './Abi';
-
-// NOTE Experimental, POC, bound to change
-export default abstract class RxBase implements ContractBase<'rxjs'> {
-  public readonly abi: Abi;
-
-  public readonly api: ApiObject<'rxjs'>;
-
-  public readonly apiContracts: SubmittableModuleExtrinsics<'rxjs'>;
-
-  public constructor (api: ApiObject<'rxjs'>, abi: ContractABIPre | Abi) {
-    this.abi = abi instanceof Abi
-      ? abi
-      : new Abi(abi);
-    this.api = api;
-
-    // cater for substrate 2.x & 1.x (in order)
-    this.apiContracts = api.tx.contracts || api.tx.contract;
-
-    assert(this.apiContracts && this.apiContracts.putCode, 'You need to connect to a node with the contracts module, the metadata does not enable api.tx.contracts on this instance');
-  }
-}

packages/api-contract/src/RxBlueprint.ts

@@ -1,72 +0,0 @@
-// Copyright 2017-2019 @polkadot/api-contract authors & contributors
-// This software may be modified and distributed under the terms
-// of the Apache-2.0 license. See the LICENSE file for details.
-
-import { SubmittableResultImpl } from '@polkadot/api/types';
-import { AccountId, Address, Hash } from '@polkadot/types/interfaces';
-import { IKeyringPair } from '@polkadot/types/types';
-import { ContractABIPre } from './types';
-
-import BN from 'bn.js';
-import { Observable } from 'rxjs';
-import { map } from 'rxjs/operators';
-import { ApiRx, SubmittableResult } from '@polkadot/api';
-import { createType } from '@polkadot/types';
-import { assert } from '@polkadot/util';
-
-import Abi from './Abi';
-import RxBase from './RxBase';
-import RxContract from './RxContract';
-
-type BlueprintCreateResultSubscription = Observable<BlueprintCreateResult>;
-
-export interface BlueprintCreate {
-  signAndSend (account: IKeyringPair | string | AccountId | Address): BlueprintCreateResultSubscription;
-}
-
-class BlueprintCreateResult extends SubmittableResult {
-  public readonly contract?: RxContract;
-
-  public constructor (result: SubmittableResultImpl, contract?: RxContract) {
-    super(result);
-
-    this.contract = contract;
-  }
-}
-
-// NOTE Experimental, POC, bound to change
-export default class Blueprint extends RxBase {
-  public readonly codeHash: Hash;
-
-  public constructor (api: ApiRx, abi: ContractABIPre | Abi, codeHash: string | Hash) {
-    super(api, abi);
-
-    this.codeHash = createType('Hash', codeHash);
-  }
-
-  public deployContract (constructorIndex = 0, endowment: number | BN, maxGas: number | BN, ...params: any[]): BlueprintCreate {
-    assert(!!this.abi.constructors[constructorIndex], `Specified constructor index ${constructorIndex} does not exist`);
-    const signAndSend = (account: IKeyringPair | string | AccountId | Address): BlueprintCreateResultSubscription => {
-      return this.apiContracts
-        .create(endowment, maxGas, this.codeHash, this.abi.constructors[constructorIndex](...params))
-        .signAndSend(account)
-        .pipe(map(this.createResult));
-    };
-
-    return { signAndSend };
-  }
-
-  private createResult = (result: SubmittableResult): BlueprintCreateResult => {
-    let contract: RxContract | undefined;
-
-    if (result.isFinalized) {
-      const record = result.findRecord('contract', 'Instantiated');
-
-      if (record) {
-        contract = new RxContract(this.api, this.abi, record.event.data[1] as Address);
-      }
-    }
-
-    return new BlueprintCreateResult(result, contract);
-  }
-}

packages/api-contract/src/RxCode.ts

@@ -1,83 +0,0 @@
-// Copyright 2017-2019 @polkadot/api-contract authors & contributors
-// This software may be modified and distributed under the terms
-// of the Apache-2.0 license. See the LICENSE file for details.
-
-import { SubmittableResultImpl } from '@polkadot/api/types';
-import { AccountId, Address, Hash } from '@polkadot/types/interfaces';
-import { IKeyringPair } from '@polkadot/types/types';
-import { ContractABIPre } from './types';
-
-import BN from 'bn.js';
-import { Observable } from 'rxjs';
-import { map } from 'rxjs/operators';
-import { ApiRx, SubmittableResult } from '@polkadot/api';
-import { compactAddLength, u8aToU8a } from '@polkadot/util';
-
-import Abi from './Abi';
-import RxBase from './RxBase';
-import RxBlueprint from './RxBlueprint';
-
-// Ok, tried, failed, eventually ... well, we are only trying with RxJs as a
-// start, so take a big fat shortcut with this version, real intended version
-// follows this and is commented out
-type CodePutCodeResultSubscription = Observable<CodePutCodeResult>;
-// type ICodePutCodeResultSubscription<ApiType> =
-//   ApiType extends 'rxjs'
-//     ? Observable<CodePutCodeResult>
-//     : Promise<() => void>;
-
-// unlike the ISubmittableExtrinsic, it doesn't extend IExtrinsic and only
-// implements one var iant of signAndSend - this is purely done to see what
-// is hanging where, with the bare-mainimum from a simplicity perspective
-// Very obvious is that it supports only 1 version of signAndSend
-// (we need to revisit this, but probably ok for initial?)
-// eslint-disable-next-line @typescript-eslint/interface-name-prefix
-export interface CodePutCode {
-  signAndSend (account: IKeyringPair | string | AccountId | Address): CodePutCodeResultSubscription;
-}
-
-class CodePutCodeResult extends SubmittableResult {
-  public readonly blueprint?: RxBlueprint;
-
-  public constructor (result: SubmittableResultImpl, blueprint?: RxBlueprint) {
-    super(result);
-
-    this.blueprint = blueprint;
-  }
-}
-
-// NOTE Experimental, POC, bound to change
-export default class RxCode extends RxBase {
-  public readonly code: Uint8Array;
-
-  public constructor (api: ApiRx, abi: ContractABIPre | Abi, wasm: string | Uint8Array) {
-    super(api, abi);
-
-    this.code = u8aToU8a(wasm);
-  }
-
-  public createBlueprint (maxGas: number | BN): CodePutCode {
-    const signAndSend = (account: IKeyringPair | string | AccountId | Address): CodePutCodeResultSubscription => {
-      return this.apiContracts
-        .putCode(maxGas, compactAddLength(this.code))
-        .signAndSend(account)
-        .pipe(map(this.createResult));
-    };
-
-    return { signAndSend };
-  }
-
-  private createResult = (result: SubmittableResultImpl): CodePutCodeResult => {
-    let blueprint: RxBlueprint | undefined;
-
-    if (result.isFinalized) {
-      const record = result.findRecord('contract', 'CodeStored');
-
-      if (record) {
-        blueprint = new RxBlueprint(this.api, this.abi, record.event.data[0] as Hash);
-      }
-    }
-
-    return new CodePutCodeResult(result, blueprint);
-  }
-}

packages/api-contract/src/RxContract.ts

@@ -1,41 +0,0 @@
-// Copyright 2017-2019 @polkadot/api-contract authors & contributors
-// This software may be modified and distributed under the terms
-// of the Apache-2.0 license. See the LICENSE file for details.
-
-import { AccountId, Address } from '@polkadot/types/interfaces';
-import { IKeyringPair } from '@polkadot/types/types';
-import { ContractABIPre, ContractABIFn, InterfaceContract, InterfaceContractCalls } from './types';
-
-import BN from 'bn.js';
-import { Observable } from 'rxjs';
-import { ApiRx, SubmittableResult } from '@polkadot/api';
-import { createType } from '@polkadot/types';
-import Abi from './Abi';
-import RxBase from './RxBase';
-
-export type ContractCallResultSubscription = Observable<SubmittableResult>;
-
-export interface ContractCall {
-  signAndSend (account: IKeyringPair | string | AccountId | Address): ContractCallResultSubscription;
-}
-
-type CallResult = (value: BN | number, maxGas: BN | number, ...params: any[]) => ContractCall;
-
-// NOTE Experimental, POC, bound to change
-export default class RxContract extends RxBase implements InterfaceContract {
-  public readonly address: Address;
-
-  public readonly calls: InterfaceContractCalls = {};
-
-  public constructor (api: ApiRx, abi: ContractABIPre | Abi, address: string | AccountId | Address) {
-    super(api, abi);
-
-    this.address = createType('Address', address);
-
-    Object.entries(this.abi.messages).forEach(([name]): void => {
-      this.calls[name] = (fn: ContractABIFn): CallResult =>
-        (value: BN | number, maxGas: BN | number, ...params: any[]): ContractCall =>
-          this.apiContracts.call(this.address, value, maxGas, fn(...params));
-    });
-  }
-}

packages/api-contract/src/base/Blueprint.ts

@@ -0,0 +1,75 @@
+// Copyright 2017-2019 @polkadot/api-contract authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+import { ApiTypes, DecorateMethod, SubmittableResultImpl } from '@polkadot/api/types';
+import { AccountId, Address, Hash } from '@polkadot/types/interfaces';
+import { IKeyringPair } from '@polkadot/types/types';
+import { ApiObject, ContractABIPre } from '../types';
+
+import BN from 'bn.js';
+import { Observable } from 'rxjs';
+import { map } from 'rxjs/operators';
+import { SubmittableResult } from '@polkadot/api';
+import { createType } from '@polkadot/types';
+import { assert } from '@polkadot/util';
+
+import Abi from '../Abi';
+import Contract from './Contract';
+import { BaseWithTx } from './util';
+
+type BlueprintCreateResultSubscription<ApiType extends ApiTypes> = Observable<BlueprintCreateResult<ApiType>>;
+
+export interface BlueprintCreate<ApiType extends ApiTypes> {
+  signAndSend (account: IKeyringPair | string | AccountId | Address): BlueprintCreateResultSubscription<ApiType>;
+}
+
+class BlueprintCreateResult<ApiType extends ApiTypes> extends SubmittableResult {
+  public readonly contract?: Contract<ApiType>;
+
+  constructor (result: SubmittableResultImpl, contract?: Contract<ApiType>) {
+    super(result);
+
+    this.contract = contract;
+  }
+}
+
+// NOTE Experimental, POC, bound to change
+export default class Blueprint<ApiType extends ApiTypes> extends BaseWithTx<ApiType> {
+  public readonly codeHash: Hash;
+
+  constructor (api: ApiObject<ApiType>, abi: ContractABIPre | Abi, decorateMethod: DecorateMethod<ApiType>, codeHash: string | Hash) {
+    super(api, abi, decorateMethod);
+
+    this.codeHash = createType(this.registry, 'Hash', codeHash);
+  }
+
+  public deployContract (constructorIndex = 0, endowment: number | BN, maxGas: number | BN, ...params: any[]): BlueprintCreate<ApiType> {
+    assert(!!this.abi.constructors[constructorIndex], `Specified constructor index ${constructorIndex} does not exist`);
+
+    return {
+      signAndSend: this.decorateMethod(
+        (account: IKeyringPair | string | AccountId | Address): BlueprintCreateResultSubscription<ApiType> => {
+          return this.apiContracts
+            .create(endowment, maxGas, this.codeHash, this.abi.constructors[constructorIndex](...params))
+            .signAndSend(account)
+            .pipe(map(this.createResult));
+        }
+      )
+    };
+  }
+
+  private createResult = (result: SubmittableResult): BlueprintCreateResult<ApiType> => {
+    let contract: Contract<ApiType> | undefined;
+
+    if (result.isFinalized) {
+      const record = result.findRecord('contract', 'Instantiated');
+
+      if (record) {
+        contract = new Contract<ApiType>(this.api, this.abi, this.decorateMethod, record.event.data[1] as Address);
+      }
+    }
+
+    return new BlueprintCreateResult(result, contract);
+  }
+}

packages/api-contract/src/base/Code.ts

@@ -0,0 +1,71 @@
+// Copyright 2017-2019 @polkadot/api-contract authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+import { ApiTypes, DecorateMethod, SubmittableResultImpl } from '@polkadot/api/types';
+import { AccountId, Address, Hash } from '@polkadot/types/interfaces';
+import { IKeyringPair } from '@polkadot/types/types';
+import { ApiObject, ContractABIPre } from '../types';
+
+import BN from 'bn.js';
+import { Observable } from 'rxjs';
+import { map } from 'rxjs/operators';
+import { SubmittableResult } from '@polkadot/api';
+import { compactAddLength, u8aToU8a } from '@polkadot/util';
+
+import Abi from '../Abi';
+import Blueprint from './Blueprint';
+import { BaseWithTx } from './util';
+
+type CodePutCodeResultSubscription<ApiType extends ApiTypes> = Observable<CodePutCodeResult<ApiType>>;
+
+// eslint-disable-next-line @typescript-eslint/interface-name-prefix
+export interface CodePutCode<ApiType extends ApiTypes> {
+  signAndSend (account: IKeyringPair | string | AccountId | Address): CodePutCodeResultSubscription<ApiType>;
+}
+
+class CodePutCodeResult<ApiType extends ApiTypes> extends SubmittableResult {
+  public readonly blueprint?: Blueprint<ApiType>;
+
+  constructor (result: SubmittableResultImpl, blueprint?: Blueprint<ApiType>) {
+    super(result);
+
+    this.blueprint = blueprint;
+  }
+}
+
+// NOTE Experimental, POC, bound to change
+export default class Code<ApiType extends ApiTypes> extends BaseWithTx<ApiType> {
+  public readonly code: Uint8Array;
+
+  constructor (api: ApiObject<ApiType>, abi: ContractABIPre | Abi, decorateMethod: DecorateMethod<ApiType>, wasm: string | Uint8Array) {
+    super(api, abi, decorateMethod);
+
+    this.code = u8aToU8a(wasm);
+  }
+
+  public createBlueprint = (maxGas: number | BN): CodePutCode<ApiType> => {
+    return {
+      signAndSend: this.decorateMethod(
+        (account: IKeyringPair | string | AccountId | Address): CodePutCodeResultSubscription<ApiType> => this.apiContracts
+          .putCode(maxGas, compactAddLength(this.code))
+          .signAndSend(account)
+          .pipe(map(this.createResult))
+      )
+    };
+  }
+
+  private createResult = (result: SubmittableResultImpl): CodePutCodeResult<ApiType> => {
+    let blueprint: Blueprint<ApiType> | undefined;
+
+    if (result.isFinalized) {
+      const record = result.findRecord('contract', 'CodeStored');
+
+      if (record) {
+        blueprint = new Blueprint<ApiType>(this.api, this.abi, this.decorateMethod, record.event.data[0] as Hash);
+      }
+    }
+
+    return new CodePutCodeResult(result, blueprint);
+  }
+}

packages/api-contract/src/base/Contract.ts

@@ -0,0 +1,97 @@
+// Copyright 2017-2019 @polkadot/api-contract authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+import { ApiTypes, DecorateMethod, ObsInnerType } from '@polkadot/api/types';
+import { AccountId, Address, ContractExecResult } from '@polkadot/types/interfaces';
+import { Codec, IKeyringPair } from '@polkadot/types/types';
+import { ApiObject, ContractABIMessage, ContractABIPre, ContractCallOutcome } from '../types';
+
+import BN from 'bn.js';
+import { Observable } from 'rxjs';
+import { map } from 'rxjs/operators';
+import { SubmittableResult } from '@polkadot/api';
+import { createType } from '@polkadot/types';
+import Abi from '../Abi';
+import { formatData } from '../util';
+import { BaseWithTxAndRpcCall } from './util';
+
+type ContractCallTypes = 'tx' | 'rpc';
+
+type ContractCallResultSubscription<ApiType extends ApiTypes, CallType extends ContractCallTypes> = ApiType extends 'rxjs'
+  ? Observable<ContractCallResult<CallType>>
+  : Promise<ObsInnerType<ContractCallResult<CallType>>>;
+
+// eslint-disable-next-line @typescript-eslint/interface-name-prefix
+export interface ContractCall<ApiType extends ApiTypes, CallType extends ContractCallTypes> {
+  send (account: IKeyringPair | string | AccountId | Address): ContractCallResultSubscription<ApiType, CallType>;
+}
+
+export type ContractCallResult<CallType extends ContractCallTypes> = CallType extends 'rpc'
+  ? Observable<ContractCallOutcome>
+  : Observable<SubmittableResult>;
+
+export default class Contract<ApiType extends ApiTypes> extends BaseWithTxAndRpcCall<ApiType> {
+  public readonly address: Address;
+
+  public call (as: 'rpc', message: string, value: BN | number, gasLimit: BN | number, ...params: any[]): ContractCall<ApiType, 'rpc'>;
+  public call (as: 'tx', message: string, value: BN | number, gasLimit: BN | number, ...params: any[]): ContractCall<ApiType, 'tx'>;
+  public call<CallType extends ContractCallTypes> (as: CallType, message: string, value: BN | number, gasLimit: BN | number, ...params: any[]): ContractCall<ApiType, CallType> {
+    const { fn, def } = this.getMessage(message);
+
+    return {
+      send: this.decorateMethod(
+        as === 'rpc'
+          ? (account: IKeyringPair | string | AccountId | Address): ContractCallResult<'rpc'> => {
+            return this.rpcContractsCall(
+              createType(this.registry, 'ContractCallRequest', {
+                origin: account,
+                dest: this.address.toString(),
+                value,
+                gasLimit,
+                inputData: fn(...params)
+              })
+            )
+              .pipe(
+                map((result: ContractExecResult): ContractCallOutcome =>
+                  this.createOutcome(result, createType(this.registry, 'AccountId', account), def, params)
+                )
+              );
+          }
+          : (account: IKeyringPair | string | AccountId | Address): ContractCallResult<'tx'> => {
+            return this.apiContracts
+              .call(this.address, value, gasLimit, fn(...params))
+              .signAndSend(account);
+          }
+      )
+    };
+  }
+
+  private createOutcome (result: ContractExecResult, origin: AccountId, message: ContractABIMessage, params: any[]): ContractCallOutcome {
+    let output: Codec | null = null;
+
+    if (result.isSuccess) {
+      const { data } = result.asSuccess;
+
+      output = message.returnType
+        ? formatData(this.registry, data, message.returnType)
+        : createType(this.registry, 'Data', data);
+    }
+
+    return {
+      time: Date.now(),
+      message,
+      origin,
+      params,
+      result,
+      isSuccess: result.isSuccess,
+      output
+    };
+  }
+
+  constructor (api: ApiObject<ApiType>, abi: ContractABIPre | Abi, decorateMethod: DecorateMethod<ApiType>, address: string | AccountId | Address) {
+    super(api, abi, decorateMethod);
+
+    this.address = createType(this.registry, 'Address', address);
+  }
+}

packages/api-contract/src/base/index.ts

@@ -0,0 +1,7 @@
+// Copyright 2017-2019 @polkadot/api authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+export { default as Blueprint } from './Blueprint';
+export { default as Code } from './Code';
+export { default as Contract } from './Contract';

packages/api-contract/src/base/util.ts

@@ -0,0 +1,78 @@
+// Copyright 2017-2019 @polkadot/api authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+import { ApiTypes, DecorateMethod, DecoratedRpc, SubmittableModuleExtrinsics } from '@polkadot/api/types';
+import { ApiObject, ContractABIMessage, ContractABIPre, ContractBase, ContractMessage } from '../types';
+import { RpcInterface } from '@polkadot/rpc-core/jsonrpc.types';
+import { Registry } from '@polkadot/types/types';
+
+import { assert, stringCamelCase } from '@polkadot/util';
+import Abi from '../Abi';
+
+export abstract class Base<ApiType extends ApiTypes> implements ContractBase<ApiType> {
+  public readonly abi: Abi;
+
+  public readonly api: ApiObject<ApiType>;
+
+  public readonly decorateMethod: DecorateMethod<ApiType>;
+
+  public readonly registry: Registry;
+
+  constructor (api: ApiObject<ApiType>, abi: ContractABIPre | Abi, decorateMethod: DecorateMethod<ApiType>) {
+    this.abi = abi instanceof Abi
+      ? abi
+      : new Abi(api.registry, abi);
+    this.registry = api.registry;
+    this.api = api;
+    this.decorateMethod = decorateMethod;
+  }
+
+  public get messages (): ContractMessage[] {
+    return this.abi.abi.contract.messages
+      .map(
+        (def: ContractABIMessage, index): ContractMessage => ({
+          index,
+          def,
+          fn: this.abi.messages[def.name] || this.abi.messages[stringCamelCase(name)]
+        })
+      );
+  }
+
+  public getMessage (nameOrIndex?: string | number): ContractMessage {
+    const index = nameOrIndex
+      ? typeof nameOrIndex === 'number'
+        ? nameOrIndex
+        : this.abi.abi.contract.messages.findIndex((message): boolean => nameOrIndex === message.name || nameOrIndex === stringCamelCase(message.name))
+      : 0;
+    const def = this.abi.abi.contract.messages[index];
+    assert(!!def, `Attempted to access a contract message that does not exist: ${typeof nameOrIndex === 'number' ? `index ${nameOrIndex}` : nameOrIndex}`);
+
+    const fn = this.abi.messages[def.name] || this.abi.messages[stringCamelCase(def.name)];
+    return { index, def, fn };
+  }
+}
+
+export abstract class BaseWithTx<ApiType extends ApiTypes> extends Base<ApiType> {
+  protected get apiContracts (): SubmittableModuleExtrinsics<'rxjs'> {
+    return this.api.rx.tx.contracts;
+  }
+
+  constructor (api: ApiObject<ApiType>, abi: ContractABIPre | Abi, decorateMethod: DecorateMethod<ApiType>) {
+    super(api, abi, decorateMethod);
+
+    assert(this.api.rx.tx.contracts && this.api.rx.tx.contracts.putCode, 'You need to connect to a node with the contracts module, the metadata does not enable api.tx.contracts on this instance');
+  }
+}
+
+export abstract class BaseWithTxAndRpcCall<ApiType extends ApiTypes> extends BaseWithTx<ApiType> {
+  protected get rpcContractsCall (): DecoratedRpc<'rxjs', RpcInterface>['contracts']['call'] {
+    return this.api.rx.rpc.contracts.call;
+  }
+
+  constructor (api: ApiObject<ApiType>, abi: ContractABIPre | Abi, decorateMethod: DecorateMethod<ApiType>) {
+    super(api, abi, decorateMethod);
+
+    assert(this.api.rx.rpc.contracts && this.api.rx.tx.contracts.call, 'You need to connect to a node with the contracts module, the metadata does not enable api.rpc.contracts.call on this instance');
+  }
+}

packages/api-contract/src/index.ts

@@ -3,6 +3,5 @@
 // of the Apache-2.0 license. See the LICENSE file for details.
 
 export { default as Abi } from './Abi';
-export { default as RxBlueprint } from './RxBlueprint';
-export { default as RxCode } from './RxCode';
-export { default as RxContract } from './RxContract';
+export * from './rx';
+export * from './promise';

packages/api-contract/src/method.ts

@@ -1,20 +0,0 @@
-// Copyright 2017-2019 @polkadot/api-contract authors & contributors
-// This software may be modified and distributed under the terms
-// of the Apache-2.0 license. See the LICENSE file for details.
-
-import { Constructor } from '@polkadot/types/types';
-import { ContractABIFnArg } from './types';
-
-import { createClass, encodeType } from '@polkadot/types';
-
-export function createArgClass (args: ContractABIFnArg[], baseDef: Record<string, string>): Constructor {
-  return createClass(
-    JSON.stringify(
-      args.reduce((base: Record<string, any>, { name, type }): Record<string, any> => {
-        base[name] = encodeType(type);
-
-        return base;
-      }, baseDef)
-    )
-  );
-}

packages/api-contract/src/promise/PromiseBlueprint.ts

@@ -0,0 +1,18 @@
+// Copyright 2017-2019 @polkadot/api-contract authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+import { Hash } from '@polkadot/types/interfaces';
+import { ContractABIPre } from '../types';
+
+import { ApiPromise } from '@polkadot/api';
+import { decorateMethod } from '@polkadot/api/promise';
+
+import Abi from '../Abi';
+import Blueprint from '../base/Blueprint';
+
+export default class PromiseBlueprint extends Blueprint<'promise'> {
+  constructor (api: ApiPromise, abi: ContractABIPre | Abi, codeHash: string | Hash) {
+    super(api, abi, decorateMethod, codeHash);
+  }
+}

packages/api-contract/src/promise/PromiseCode.ts

@@ -0,0 +1,17 @@
+// Copyright 2017-2019 @polkadot/api-contract authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+import { ContractABIPre } from '../types';
+
+import { ApiPromise } from '@polkadot/api';
+import { decorateMethod } from '@polkadot/api/promise';
+
+import Abi from '../Abi';
+import Code from '../base/Code';
+
+export default class PromiseCode extends Code<'promise'> {
+  constructor (api: ApiPromise, abi: ContractABIPre | Abi, wasm: string | Uint8Array) {
+    super(api, abi, decorateMethod, wasm);
+  }
+}

packages/api-contract/src/promise/PromiseContract.ts

@@ -0,0 +1,18 @@
+// Copyright 2017-2019 @polkadot/api-contract authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+import { AccountId } from '@polkadot/types/interfaces';
+import { ContractABIPre } from '../types';
+
+import { ApiPromise } from '@polkadot/api';
+import { decorateMethod } from '@polkadot/api/promise';
+
+import Abi from '../Abi';
+import Contract from '../base/Contract';
+
+export default class PromiseContract extends Contract<'promise'> {
+  constructor (api: ApiPromise, abi: ContractABIPre | Abi, address: string | AccountId) {
+    super(api, abi, decorateMethod, address);
+  }
+}

packages/api-contract/src/promise/index.ts

@@ -0,0 +1,7 @@
+// Copyright 2017-2019 @polkadot/api-contract authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+export { default as PromiseBlueprint } from './PromiseBlueprint';
+export { default as PromiseCode } from './PromiseCode';
+export { default as PromiseContract } from './PromiseContract';

packages/api-contract/src/rx/RxBlueprint.ts

@@ -0,0 +1,18 @@
+// Copyright 2017-2019 @polkadot/api-contract authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+import { Hash } from '@polkadot/types/interfaces';
+import { ContractABIPre } from '../types';
+
+import { ApiRx } from '@polkadot/api';
+import { decorateMethod } from '@polkadot/api/rx';
+
+import Abi from '../Abi';
+import Blueprint from '../base/Blueprint';
+
+export default class RxBlueprint extends Blueprint<'rxjs'> {
+  constructor (api: ApiRx, abi: ContractABIPre | Abi, codeHash: string | Hash) {
+    super(api, abi, decorateMethod, codeHash);
+  }
+}

packages/api-contract/src/rx/RxCode.ts

@@ -0,0 +1,17 @@
+// Copyright 2017-2019 @polkadot/api-contract authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+import { ContractABIPre } from '../types';
+
+import { ApiRx } from '@polkadot/api';
+import { decorateMethod } from '@polkadot/api/rx';
+
+import Abi from '../Abi';
+import Code from '../base/Code';
+
+export default class RxCode extends Code<'rxjs'> {
+  constructor (api: ApiRx, abi: ContractABIPre | Abi, wasm: string | Uint8Array) {
+    super(api, abi, decorateMethod, wasm);
+  }
+}

packages/api-contract/src/rx/RxContract.ts

@@ -0,0 +1,18 @@
+// Copyright 2017-2019 @polkadot/api-contract authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+import { AccountId } from '@polkadot/types/interfaces';
+import { ContractABIPre } from '../types';
+
+import { ApiRx } from '@polkadot/api';
+import { decorateMethod } from '@polkadot/api/rx';
+
+import Abi from '../Abi';
+import Contract from '../base/Contract';
+
+export default class RxContract extends Contract<'rxjs'> {
+  constructor (api: ApiRx, abi: ContractABIPre | Abi, address: string | AccountId) {
+    super(api, abi, decorateMethod, address);
+  }
+}

packages/api-contract/src/rx/index.ts

@@ -0,0 +1,7 @@
+// Copyright 2017-2019 @polkadot/api-contract authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+export { default as RxBlueprint } from './RxBlueprint';
+export { default as RxCode } from './RxCode';
+export { default as RxContract } from './RxContract';

packages/api-contract/src/types.ts

@@ -2,17 +2,26 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import { SubmittableModuleExtrinsics } from '@polkadot/api/types';
-import { Address } from '@polkadot/types/interfaces';
-import { CodecArg } from '@polkadot/types/types';
+import { ApiTypes, DecorateMethod } from '@polkadot/api/types';
+import { AccountId, Address, ContractExecResult } from '@polkadot/types/interfaces';
+import { Codec, CodecArg } from '@polkadot/types/types';
 import { MetaRegistryJson, StringIndex, TypeIndex, TypeDef } from '@polkadot/types/codec/create/types';
 
+// import { Observable } from 'rxjs';
 import { ApiPromise, ApiRx } from '@polkadot/api';
 
-export type ApiObject<ApiType> = ApiType extends 'rxjs'
+export type ApiObject<ApiType extends ApiTypes> = ApiType extends 'rxjs'
   ? ApiRx
   : ApiPromise;
 
+export interface ContractBase<ApiType extends ApiTypes> {
+  readonly abi: InterfaceAbi;
+  readonly api: ApiObject<ApiType>;
+  readonly decorateMethod: DecorateMethod<ApiType>;
+  getMessage: (name: string) => ContractMessage;
+  messages: ContractMessage[];
+}
+
 export interface ContractABITypePre {
   ty: TypeIndex;
   display_name: StringIndex[];
@@ -28,31 +37,31 @@ export interface ContractABIArgBase {
   type: TypeDef;
 }
 
-export type ContractABIMethodArgPre = ContractABIArgBasePre;
+export type ContractABIMessageArgPre = ContractABIArgBasePre;
 
-export type ContractABIMethodArg = ContractABIArgBase;
+export type ContractABIMessageArg = ContractABIArgBase;
 
-export interface ContractABIMethodBase {
-  args: ContractABIMethodArg[];
+export interface ContractABIMessageBase {
+  args: ContractABIMessageArg[];
 }
 
-export interface ContractABIMethodBasePre {
-  args: ContractABIMethodArgPre[];
+export interface ContractABIMessageBasePre {
+  args: ContractABIMessageArgPre[];
 }
 
-export interface ContractABIMethodCommon {
+export interface ContractABIMessageCommon {
   docs?: ContractABIDocs;
   mutates?: boolean;
-  selector: number;
+  selector: string | number;
 }
 
-export interface ContractABIMethodPre extends ContractABIMethodCommon, ContractABIMethodBasePre {
+export interface ContractABIMessagePre extends ContractABIMessageCommon, ContractABIMessageBasePre {
   name: StringIndex;
   return_type: ContractABITypePre | null;
 }
 
-export interface ContractABIMethod extends ContractABIMethodCommon {
-  args: ContractABIMethodArg[];
+export interface ContractABIMessage extends ContractABIMessageCommon {
+  args: ContractABIMessageArg[];
   name: string;
   returnType: TypeDef | null;
 }
@@ -62,16 +71,16 @@ export interface ContractABIContractCommon {
 }
 
 export interface ContractABIContractPre extends ContractABIContractCommon {
-  constructors: ContractABIMethodPre[];
-  messages: ContractABIMethodPre[];
+  constructors: ContractABIMessagePre[];
+  messages: ContractABIMessagePre[];
   name: StringIndex;
   events?: ContractABIEventPre[];
   docs?: ContractABIDocs;
 }
 
 export interface ContractABIContract extends ContractABIContractCommon {
-  constructors: ContractABIMethod[];
-  messages: ContractABIMethod[];
+  constructors: ContractABIMessage[];
+  messages: ContractABIMessage[];
   name: string;
   events?: ContractABIEvent[];
   docs?: ContractABIDocs;
@@ -121,7 +130,8 @@ export interface ContractABIEvent {
 }
 
 export interface ContractABIRangeBase {
-  'range.offset': number[];
+  // can be number[] (old) or hex (new)
+  'range.offset': number[] | string;
   'range.len': number;
 }
 
@@ -161,20 +171,22 @@ export type ContractABIStoragePre = ContractABIStorageStructPre;
 
 export type ContractABIStorage = ContractABIStorageStruct;
 
+export interface ContractMessage {
+  index: number;
+  fn: ContractABIFn;
+  def: ContractABIMessage;
+}
+
+export type AbiConstructors = ContractABIFn[];
+
 export type AbiMessages = Record<string, ContractABIFn>;
 
 export interface InterfaceAbi {
   readonly abi: ContractABI;
-  readonly constructors: ContractABIFn[];
+  readonly constructors: AbiConstructors;
   readonly messages: AbiMessages;
 }
 
-export interface ContractBase<ApiType> {
-  readonly abi: InterfaceAbi;
-  readonly api: ApiObject<ApiType>;
-  readonly apiContracts: SubmittableModuleExtrinsics<ApiType>;
-}
-
 export interface InterfaceContractCalls {
   [index: string]: Function;
 }
@@ -183,3 +195,13 @@ export interface InterfaceContract {
   readonly address: Address;
   readonly calls: InterfaceContractCalls;
 }
+
+export interface ContractCallOutcome {
+  time: number;
+  result: ContractExecResult;
+  origin: AccountId;
+  output: Codec | null;
+  params: any[];
+  isSuccess: boolean;
+  message: ContractABIMessage;
+}

packages/api-contract/src/util.ts

@@ -0,0 +1,22 @@
+// Copyright 2017-2019 @polkadot/rpc-core authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+import { Codec, Registry, TypeDefInfo, TypeDef } from '@polkadot/types/types';
+
+import { Data, Option, createClass } from '@polkadot/types';
+import { createTypeUnsafe } from '@polkadot/types/codec';
+
+export function formatData (registry: Registry, data: Data, { info, type }: TypeDef): Codec {
+  const u8a = data.toU8a();
+
+  if (info === TypeDefInfo.Option) {
+    return new Option(
+      registry,
+      createClass(registry, type),
+      createTypeUnsafe(registry, type, [u8a], true)
+    );
+  }
+
+  return createTypeUnsafe(registry, type, [u8a], true);
+}

packages/api-contract/test/abi/test001.json

@@ -0,0 +1,467 @@
+{
+  "registry": {
+    "strings": [
+      "StorageAndEnv",
+      "app",
+      "__ink_private",
+      "__ink_storage",
+      "__storage",
+      "Storage",
+      "value",
+      "Value",
+      "ink_core",
+      "storage",
+      "cell",
+      "SyncCell",
+      "sync_cell",
+      "Key",
+      "key",
+      "name",
+      "vec",
+      "Vec",
+      "elems",
+      "__env",
+      "EnvAccess",
+      "env2",
+      "env_access",
+      "immutable",
+      "TestEnv",
+      "test",
+      "accessor",
+      "DefaultSrmlTypes",
+      "types",
+      "access",
+      "EnvAccessMut",
+      "mutable",
+      "env",
+      "PhantomData",
+      "buffer",
+      "has_interacted",
+      "has_returned_value",
+      "new",
+      "init_value",
+      "bool",
+      "default",
+      "flip",
+      "get"
+    ],
+    "types": [
+      {
+        "id": {
+          "custom.name": 1,
+          "custom.namespace": [
+            2,
+            2,
+            3,
+            4
+          ],
+          "custom.params": []
+        },
+        "def": {
+          "struct.fields": [
+            {
+              "name": 5,
+              "type": 2
+            },
+            {
+              "name": 20,
+              "type": 14
+            }
+          ]
+        }
+      },
+      {
+        "id": {
+          "custom.name": 6,
+          "custom.namespace": [
+            2,
+            2,
+            3,
+            4
+          ],
+          "custom.params": []
+        },
+        "def": {
+          "struct.fields": [
+            {
+              "name": 7,
+              "type": 3
+            },
+            {
+              "name": 16,
+              "type": 9
+            }
+          ]
+        }
+      },
+      {
+        "id": {
+          "custom.name": 8,
+          "custom.namespace": [
+            9,
+            10,
+            7
+          ],
+          "custom.params": [
+            4
+          ]
+        },
+        "def": {
+          "struct.fields": [
+            {
+              "name": 11,
+              "type": 5
+            }
+          ]
+        }
+      },
+      {
+        "id": "bool",
+        "def": "builtin"
+      },
+      {
+        "id": {
+          "custom.name": 12,
+          "custom.namespace": [
+            9,
+            10,
+            11,
+            13
+          ],
+          "custom.params": [
+            4
+          ]
+        },
+        "def": {
+          "struct.fields": [
+            {
+              "name": 11,
+              "type": 6
+            }
+          ]
+        }
+      },
+      {
+        "id": {
+          "custom.name": 14,
+          "custom.namespace": [
+            9,
+            10,
+            15
+          ],
+          "custom.params": []
+        },
+        "def": {
+          "tuple_struct.types": [
+            7
+          ]
+        }
+      },
+      {
+        "id": {
+          "array.len": 32,
+          "array.type": 8
+        },
+        "def": "builtin"
+      },
+      {
+        "id": "u8",
+        "def": "builtin"
+      },
+      {
+        "id": {
+          "custom.name": 8,
+          "custom.namespace": [
+            9,
+            10,
+            7
+          ],
+          "custom.params": [
+            10
+          ]
+        },
+        "def": {
+          "struct.fields": [
+            {
+              "name": 11,
+              "type": 13
+            }
+          ]
+        }
+      },
+      {
+        "id": "str",
+        "def": {
+          "struct.fields": [
+            {
+              "name": 17,
+              "type": 11
+            }
+          ]
+        }
+      },
+      {
+        "id": {
+          "custom.name": 18,
+          "custom.namespace": [],
+          "custom.params": [
+            8
+          ]
+        },
+        "def": {
+          "struct.fields": [
+            {
+              "name": 19,
+              "type": 12
+            }
+          ]
+        }
+      },
+      {
+        "id": {
+          "slice.type": 8
+        },
+        "def": "builtin"
+      },
+      {
+        "id": {
+          "custom.name": 12,
+          "custom.namespace": [
+            9,
+            10,
+            11,
+            13
+          ],
+          "custom.params": [
+            10
+          ]
+        },
+        "def": {
+          "struct.fields": [
+            {
+              "name": 11,
+              "type": 6
+            }
+          ]
+        }
+      },
+      {
+        "id": {
+          "custom.name": 21,
+          "custom.namespace": [
+            9,
+            22,
+            23,
+            24
+          ],
+          "custom.params": [
+            15
+          ]
+        },
+        "def": {
+          "struct.fields": [
+            {
+              "name": 30,
+              "type": 17
+            }
+          ]
+        }
+      },
+      {
+        "id": {
+          "custom.name": 25,
+          "custom.namespace": [
+            9,
+            22,
+            26,
+            27
+          ],
+          "custom.params": [
+            16
+          ]
+        },
+        "def": {
+          "struct.fields": []
+        }
+      },
+      {
+        "id": {
+          "custom.name": 28,
+          "custom.namespace": [
+            9,
+            22,
+            29
+          ],
+          "custom.params": []
+        },
+        "def": {
+          "clike_enum.variants": []
+        }
+      },
+      {
+        "id": {
+          "custom.name": 31,
+          "custom.namespace": [
+            9,
+            22,
+            23,
+            32
+          ],
+          "custom.params": [
+            15
+          ]
+        },
+        "def": {
+          "struct.fields": [
+            {
+              "name": 33,
+              "type": 18
+            },
+            {
+              "name": 35,
+              "type": 11
+            },
+            {
+              "name": 36,
+              "type": 4
+            },
+            {
+              "name": 37,
+              "type": 4
+            }
+          ]
+        }
+      },
+      {
+        "id": {
+          "custom.name": 34,
+          "custom.namespace": [],
+          "custom.params": [
+            15
+          ]
+        },
+        "def": {
+          "tuple_struct.types": []
+        }
+      }
+    ]
+  },
+  "storage": {
+    "struct.type": 1,
+    "struct.fields": [
+      {
+        "name": 10,
+        "layout": {
+          "struct.type": 2,
+          "struct.fields": [
+            {
+              "name": 7,
+              "layout": {
+                "struct.type": 3,
+                "struct.fields": [
+                  {
+                    "name": 11,
+                    "layout": {
+                      "range.offset": "0x0000000000000000000000000000000000000000000000000000000000000000",
+                      "range.len": 1,
+                      "range.elem_type": 4
+                    }
+                  }
+                ]
+              }
+            },
+            {
+              "name": 16,
+              "layout": {
+                "struct.type": 9,
+                "struct.fields": [
+                  {
+                    "name": 11,
+                    "layout": {
+                      "range.offset": "0x0000000000000000000000000000000000000000000000000000000000000001",
+                      "range.len": 1,
+                      "range.elem_type": 10
+                    }
+                  }
+                ]
+              }
+            }
+          ]
+        }
+      }
+    ]
+  },
+  "contract": {
+    "name": 2,
+    "constructors": [
+      {
+        "name": 38,
+        "selector": "[\"0x5E\",\"0xBD\",\"0x88\",\"0xD6\"]",
+        "args": [
+          {
+            "name": 16,
+            "type": {
+              "ty": 11,
+              "display_name": [
+                18
+              ]
+            }
+          },
+          {
+            "name": 39,
+            "type": {
+              "ty": 4,
+              "display_name": [
+                40
+              ]
+            }
+          }
+        ],
+        "docs": [
+          "Constructor that initializes the `bool` value to the given `init_value`."
+        ]
+      },
+      {
+        "name": 41,
+        "selector": "[\"0x02\",\"0x22\",\"0xFF\",\"0x18\"]",
+        "args": [],
+        "docs": [
+          "Constructor that initializes the `bool` value to `false`.",
+          "",
+          "Constructors can delegate to other constructors."
+        ]
+      }
+    ],
+    "messages": [
+      {
+        "name": 42,
+        "selector": "[\"0x8C\",\"0x97\",\"0xDB\",\"0x39\"]",
+        "mutates": true,
+        "args": [],
+        "return_type": null,
+        "docs": [
+          "A message that can be called on instantiated contracts.",
+          "This one flips the value of the stored `bool` from `true`",
+          "to `false` and vice versa."
+        ]
+      },
+      {
+        "name": 43,
+        "selector": "[\"0x25\",\"0x44\",\"0x4A\",\"0xFE\"]",
+        "mutates": false,
+        "args": [],
+        "return_type": {
+          "ty": 4,
+          "display_name": [
+            40
+          ]
+        },
+        "docs": [
+          "Simply returns the current value of our `bool`."
+        ]
+      }
+    ],
+    "events": [],
+    "docs": []
+  }
+}

packages/api-contract/test/compare/incrementer.test.json

@@ -0,0 +1,188 @@
+[
+  {
+    "info": 9,
+    "type": "{ \"value\": \"{ \"cell\": \"{ \"cell\": \"([u8;32])\"} }<u32>\"} }<u32>\"} }",
+    "sub": [
+      {
+        "info": 9,
+        "type": "{ \"cell\": \"{ \"cell\": \"([u8;32])\"} }<u32>\"} }",
+        "sub": [
+          {
+            "info": 9,
+            "type": "{ \"cell\": \"([u8;32])\"} }",
+            "sub": [
+              {
+                "info": 10,
+                "type": "([u8;32])",
+                "sub": [
+                  {
+                    "info": 12,
+                    "type": "[u8;32]",
+                    "ext": {
+                      "length": 32,
+                      "type": "u8"
+                    },
+                    "sub": {
+                      "info": 6,
+                      "type": "u8"
+                    },
+                    "index": 0
+                  }
+                ],
+                "name": "cell",
+                "namespace": "ink_core::storage::key"
+              }
+            ],
+            "name": "cell",
+            "namespace": "ink_core::storage::cell::sync_cell",
+            "params": [
+              {
+                "info": 6,
+                "type": "u32"
+              }
+            ]
+          }
+        ],
+        "name": "value",
+        "namespace": "ink_core::storage::value",
+        "params": [
+          {
+            "info": 6,
+            "type": "u32"
+          }
+        ]
+      }
+    ],
+    "name": "Incrementer",
+    "namespace": "incrementer::normal"
+  },
+  {
+    "info": 9,
+    "type": "{ \"cell\": \"{ \"cell\": \"([u8;32])\"} }<u32>\"} }",
+    "sub": [
+      {
+        "info": 9,
+        "type": "{ \"cell\": \"([u8;32])\"} }",
+        "sub": [
+          {
+            "info": 10,
+            "type": "([u8;32])",
+            "sub": [
+              {
+                "info": 12,
+                "type": "[u8;32]",
+                "ext": {
+                  "length": 32,
+                  "type": "u8"
+                },
+                "sub": {
+                  "info": 6,
+                  "type": "u8"
+                },
+                "index": 0
+              }
+            ],
+            "name": "cell",
+            "namespace": "ink_core::storage::key"
+          }
+        ],
+        "name": "cell",
+        "namespace": "ink_core::storage::cell::sync_cell",
+        "params": [
+          {
+            "info": 6,
+            "type": "u32"
+          }
+        ]
+      }
+    ],
+    "name": "Value",
+    "namespace": "ink_core::storage::value",
+    "params": [
+      {
+        "info": 6,
+        "type": "u32"
+      }
+    ]
+  },
+  {
+    "info": 6,
+    "type": "u32"
+  },
+  {
+    "info": 9,
+    "type": "{ \"cell\": \"([u8;32])\"} }",
+    "sub": [
+      {
+        "info": 10,
+        "type": "([u8;32])",
+        "sub": [
+          {
+            "info": 12,
+            "type": "[u8;32]",
+            "ext": {
+              "length": 32,
+              "type": "u8"
+            },
+            "sub": {
+              "info": 6,
+              "type": "u8"
+            },
+            "index": 0
+          }
+        ],
+        "name": "cell",
+        "namespace": "ink_core::storage::key"
+      }
+    ],
+    "name": "SyncCell",
+    "namespace": "ink_core::storage::cell::sync_cell",
+    "params": [
+      {
+        "info": 6,
+        "type": "u32"
+      }
+    ]
+  },
+  {
+    "info": 10,
+    "type": "([u8;32])",
+    "sub": [
+      {
+        "info": 12,
+        "type": "[u8;32]",
+        "ext": {
+          "length": 32,
+          "type": "u8"
+        },
+        "sub": {
+          "info": 6,
+          "type": "u8"
+        },
+        "index": 0
+      }
+    ],
+    "name": "Key",
+    "namespace": "ink_core::storage::key"
+  },
+  {
+    "info": 12,
+    "type": "[u8;32]",
+    "ext": {
+      "length": 32,
+      "type": "u8"
+    },
+    "sub": {
+      "info": 6,
+      "type": "u8"
+    }
+  },
+  {
+    "info": 6,
+    "type": "u8"
+  },
+  {
+    "info": 6,
+    "type": "bool"
+  }
+]

packages/api-contract/test/contracts/Incrementer.json

@@ -1 +0,0 @@
-{"name":"Incrementer","deploy":{"args":[{"name":"init_value","type":"u32"}]},"messages":[{"name":"inc","selector":257544423,"mutates":true,"args":[{"name":"by","type":"u32"}],"return_type":null},{"name":"get","selector":4266279973,"mutates":false,"args":[],"return_type":"u32"},{"name":"compare","selector":363906316,"mutates":false,"args":[{"name":"with","type":"u32"}],"return_type":"bool"}]}

packages/api-contract/test/contracts/incrementer.json

@@ -0,0 +1,233 @@
+{
+  "registry": {
+    "strings": [
+      "Incrementer",
+      "incrementer",
+      "normal",
+      "value",
+      "Value",
+      "ink_core",
+      "storage",
+      "cell",
+      "SyncCell",
+      "sync_cell",
+      "Key",
+      "key",
+      "on_deploy",
+      "init_value",
+      "u32",
+      "inc",
+      "by",
+      "get",
+      "compare",
+      "with",
+      "bool"
+    ],
+    "types": [
+      {
+        "id": {
+          "custom.name": 1,
+          "custom.namespace": [
+            2,
+            3
+          ],
+          "custom.params": []
+        },
+        "def": {
+          "struct.fields": [
+            {
+              "name": 4,
+              "type": 2
+            }
+          ]
+        }
+      },
+      {
+        "id": {
+          "custom.name": 5,
+          "custom.namespace": [
+            6,
+            7,
+            4
+          ],
+          "custom.params": [
+            3
+          ]
+        },
+        "def": {
+          "struct.fields": [
+            {
+              "name": 8,
+              "type": 4
+            }
+          ]
+        }
+      },
+      {
+        "id": "u32",
+        "def": "builtin"
+      },
+      {
+        "id": {
+          "custom.name": 9,
+          "custom.namespace": [
+            6,
+            7,
+            8,
+            10
+          ],
+          "custom.params": [
+            3
+          ]
+        },
+        "def": {
+          "struct.fields": [
+            {
+              "name": 8,
+              "type": 5
+            }
+          ]
+        }
+      },
+      {
+        "id": {
+          "custom.name": 11,
+          "custom.namespace": [
+            6,
+            7,
+            12
+          ],
+          "custom.params": []
+        },
+        "def": {
+          "tuple_struct.types": [
+            6
+          ]
+        }
+      },
+      {
+        "id": {
+          "array.len": 32,
+          "array.type": 7
+        },
+        "def": "builtin"
+      },
+      {
+        "id": "u8",
+        "def": "builtin"
+      },
+      {
+        "id": "bool",
+        "def": "builtin"
+      }
+    ]
+  },
+  "storage": {
+    "struct.type": 1,
+    "struct.fields": [
+      {
+        "name": 4,
+        "layout": {
+          "struct.type": 2,
+          "struct.fields": [
+            {
+              "name": 8,
+              "layout": {
+                "range.offset": "0x0000000000000000000000000000000000000000000000000000000000000000",
+                "range.len": 1,
+                "range.elem_type": 3
+              }
+            }
+          ]
+        }
+      }
+    ]
+  },
+  "contract": {
+    "name": 1,
+    "constructors": [
+      {
+        "name": 13,
+        "selector": "[\"0x00\",\"0x00\",\"0x00\",\"0x00\"]",
+        "args": [
+          {
+            "name": 14,
+            "type": {
+              "ty": 3,
+              "display_name": [
+                15
+              ]
+            }
+          }
+        ],
+        "docs": [
+          "Initializes the value to the initial value."
+        ]
+      }
+    ],
+    "messages": [
+      {
+        "name": 16,
+        "selector": "[\"0x0F\",\"0x59\",\"0xD0\",\"0xE7\"]",
+        "mutates": true,
+        "args": [
+          {
+            "name": 17,
+            "type": {
+              "ty": 3,
+              "display_name": [
+                15
+              ]
+            }
+          }
+        ],
+        "return_type": null,
+        "docs": [
+          "Flips the current state of our smart contract."
+        ]
+      },
+      {
+        "name": 18,
+        "selector": "[\"0xFE\",\"0x4A\",\"0x44\",\"0x25\"]",
+        "mutates": false,
+        "args": [],
+        "return_type": {
+          "ty": 3,
+          "display_name": [
+            15
+          ]
+        },
+        "docs": [
+          "Returns the current state."
+        ]
+      },
+      {
+        "name": 19,
+        "selector": "[\"0x15\",\"0xB0\",\"0xC5\",\"0x0C\"]",
+        "mutates": false,
+        "args": [
+          {
+            "name": 20,
+            "type": {
+              "ty": 3,
+              "display_name": [
+                15
+              ]
+            }
+          }
+        ],
+        "return_type": {
+          "ty": 8,
+          "display_name": [
+            21
+          ]
+        },
+        "docs": [
+          "Returns `true` if the internal value is greater than or equal to the provided value."
+        ]
+      }
+    ],
+    "events": [],
+    "docs": []
+  }
+}

packages/api-derive/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@polkadot/api-derive",
-  "version": "0.95.2",
+  "version": "0.98.1",
   "description": "Common functions used across Polkadot, derived from RPC calls and storage queries.",
   "main": "index.js",
   "keywords": [
@@ -27,11 +27,11 @@
   },
   "homepage": "https://github.com/polkadot-js/api/tree/master/packages/api-derive#readme",
   "dependencies": {
-    "@babel/runtime": "^7.6.3",
-    "@polkadot/api": "^0.95.2",
-    "@polkadot/types": "^0.95.2"
+    "@babel/runtime": "^7.7.4",
+    "@polkadot/api": "^0.98.1",
+    "@polkadot/types": "^0.98.1"
   },
   "devDependencies": {
-    "@polkadot/keyring": "^1.6.1"
+    "@polkadot/keyring": "^1.7.1"
   }
 }

packages/api-derive/src/accounts/idAndIndex.ts

@@ -5,17 +5,41 @@
 import { AccountId, AccountIndex, Address } from '@polkadot/types/interfaces';
 
 import { Observable, of } from 'rxjs';
-import { map, startWith } from 'rxjs/operators';
+import { map } from 'rxjs/operators';
 import { ApiInterfaceRx } from '@polkadot/api/types';
+import { createType } from '@polkadot/types';
 import { isU8a } from '@polkadot/util';
 import { decodeAddress } from '@polkadot/util-crypto';
-import { createType } from '@polkadot/types';
-import { idToIndex } from './idToIndex';
-import { indexToId } from './indexToId';
-import { drr } from '../util/drr';
+
+import { memo } from '../util';
 
 export type AccountIdAndIndex = [AccountId?, AccountIndex?];
 
+function retrieve (api: ApiInterfaceRx, address: Address | AccountId | AccountIndex | string | null | undefined): Observable<AccountIdAndIndex> {
+  try {
+    // yes, this can fail, don't care too much, catch will catch it
+    const decoded = isU8a(address)
+      ? address
+      : decodeAddress((address || '').toString());
+
+    if (decoded.length === 32) {
+      const accountId = createType(api.registry, 'AccountId', decoded);
+
+      return api.derive.accounts.idToIndex(accountId).pipe(
+        map((accountIndex): AccountIdAndIndex => [accountId, accountIndex] as AccountIdAndIndex)
+      );
+    }
+
+    const accountIndex = createType(api.registry, 'AccountIndex', decoded);
+
+    return api.derive.accounts.indexToId(accountIndex).pipe(
+      map((accountId): AccountIdAndIndex => [accountId, accountIndex] as AccountIdAndIndex)
+    );
+  } catch (error) {
+    return of([undefined, undefined] as AccountIdAndIndex);
+  }
+}
+
 /**
  * @name idAndIndex
  * @param {(Address | AccountId | AccountIndex | string | null)} address - An accounts address in various formats.
@@ -30,32 +54,6 @@ export type AccountIdAndIndex = [AccountId?, AccountIndex?];
  * ```
  */
 export function idAndIndex (api: ApiInterfaceRx): (address?: Address | AccountId | AccountIndex | string | null) => Observable<AccountIdAndIndex> {
-  return (address?: Address | AccountId | AccountIndex | string | null): Observable<AccountIdAndIndex> => {
-    try {
-      // yes, this can fail, don't care too much, catch will catch it
-      const decoded = isU8a(address)
-        ? address
-        : decodeAddress((address || '').toString());
-
-      if (decoded.length === 32) {
-        const accountId = createType('AccountId', decoded);
-
-        return idToIndex(api)(accountId).pipe(
-          startWith(undefined),
-          map((accountIndex): AccountIdAndIndex => [accountId, accountIndex] as AccountIdAndIndex),
-          drr()
-        );
-      }
-
-      const accountIndex = createType('AccountIndex', decoded);
-
-      return indexToId(api)(accountIndex).pipe(
-        startWith(undefined),
-        map((accountId): AccountIdAndIndex => [accountId, accountIndex] as AccountIdAndIndex),
-        drr()
-      );
-    } catch (error) {
-      return of([undefined, undefined] as AccountIdAndIndex).pipe(drr());
-    }
-  };
+  return memo((address?: Address | AccountId | AccountIndex | string | null): Observable<AccountIdAndIndex> =>
+    retrieve(api, address));
 }

packages/api-derive/src/accounts/idToIndex.ts

@@ -3,13 +3,13 @@
 // of the Apache-2.0 license. See the LICENSE file for details.
 
 import { AccountId, AccountIndex } from '@polkadot/types/interfaces';
+import { AccountIndexes } from '../types';
 
 import { Observable } from 'rxjs';
 import { map, startWith } from 'rxjs/operators';
 import { ApiInterfaceRx } from '@polkadot/api/types';
 
-import { indexes, AccountIndexes } from './indexes';
-import { drr } from '../util/drr';
+import { memo } from '../util';
 
 /**
  * @name idToIndex
@@ -26,13 +26,11 @@ import { drr } from '../util/drr';
  * ```
  */
 export function idToIndex (api: ApiInterfaceRx): (accountId: AccountId | string) => Observable<AccountIndex | undefined> {
-  return (accountId: AccountId | string): Observable<AccountIndex | undefined> =>
-    indexes(api)()
-      .pipe(
-        startWith({}),
-        map((indexes: AccountIndexes): AccountIndex | undefined =>
-          (indexes || {})[accountId.toString()]
-        ),
-        drr()
-      );
+  return memo((accountId: AccountId | string): Observable<AccountIndex | undefined> =>
+    api.derive.accounts.indexes().pipe(
+      startWith({}),
+      map((indexes: AccountIndexes): AccountIndex | undefined =>
+        (indexes || {})[accountId.toString()]
+      )
+    ));
 }

packages/api-derive/src/accounts/index.ts

@@ -6,3 +6,4 @@ export * from './idAndIndex';
 export * from './idToIndex';
 export * from './indexToId';
 export * from './indexes';
+export * from './info';

packages/api-derive/src/accounts/indexToId.ts

@@ -8,9 +8,9 @@ import { Observable } from 'rxjs';
 import { map, startWith } from 'rxjs/operators';
 import { ApiInterfaceRx } from '@polkadot/api/types';
 import { ENUMSET_SIZE } from '@polkadot/types/primitive/Generic/AccountIndex';
-import { createType, ClassOf, Vec } from '@polkadot/types';
+import { ClassOf, Vec, createType } from '@polkadot/types';
 
-import { drr } from '../util/drr';
+import { memo } from '../util';
 
 /**
  * @name indexToId
@@ -26,19 +26,18 @@ import { drr } from '../util/drr';
  * ```
  */
 export function indexToId (api: ApiInterfaceRx): (accountIndex: AccountIndex | string) => Observable<AccountId | undefined> {
-  return (_accountIndex: AccountIndex | string): Observable<AccountId | undefined> => {
-    const querySection = api.query.indices || api.query.balances;
-    const accountIndex = _accountIndex instanceof ClassOf('AccountIndex')
-      ? _accountIndex
-      : createType('AccountIndex', _accountIndex);
+  const querySection = api.query.indices || api.query.balances;
 
-    return (querySection.enumSet<Vec<AccountId>>(accountIndex.div(ENUMSET_SIZE)))
-      .pipe(
-        startWith([]),
-        map((accounts): AccountId | undefined =>
-          (accounts || [])[accountIndex.mod(ENUMSET_SIZE).toNumber()]
-        ),
-        drr()
-      );
-  };
+  return memo((_accountIndex: AccountIndex | string): Observable<AccountId | undefined> => {
+    const accountIndex = _accountIndex instanceof ClassOf(api.registry, 'AccountIndex')
+      ? _accountIndex
+      : createType(api.registry, 'AccountIndex', _accountIndex);
+
+    return querySection.enumSet<Vec<AccountId>>(accountIndex.div(ENUMSET_SIZE)).pipe(
+      startWith([]),
+      map((accounts): AccountId | undefined =>
+        (accounts || [])[accountIndex.mod(ENUMSET_SIZE).toNumber()]
+      )
+    );
+  });
 }

packages/api-derive/src/accounts/indexes.ts

@@ -2,17 +2,16 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
+import { ApiInterfaceRx } from '@polkadot/api/types';
 import { AccountId, AccountIndex } from '@polkadot/types/interfaces';
+import { AccountIndexes } from '../types';
 
 import { Observable } from 'rxjs';
 import { map, switchMap } from 'rxjs/operators';
-import { ApiInterfaceRx } from '@polkadot/api/types';
 import { ENUMSET_SIZE } from '@polkadot/types/primitive/Generic/AccountIndex';
-import { createType } from '@polkadot/types';
+import { Vec, createType } from '@polkadot/types';
 
-import { drr } from '../util/drr';
-
-export type AccountIndexes = Record<string, AccountIndex>;
+import { memo } from '../util';
 
 const enumsetSize = ENUMSET_SIZE.toNumber();
 
@@ -32,29 +31,26 @@ const enumsetSize = ENUMSET_SIZE.toNumber();
  * ```
  */
 export function indexes (api: ApiInterfaceRx): () => Observable<AccountIndexes> {
-  return (): Observable<AccountIndexes> => {
-    return (api.query.indices.nextEnumSet<AccountIndex>())
-      .pipe(
-        // use the nextEnumSet (which is a counter of the number of sets) to construct
-        // a range of values to query [0, 1, 2, ...]. Retrieve the full enum set for the
-        // specific index - each query can return up to ENUMSET_SIZE (64) records, each
-        // containing an AccountId
-        switchMap((next: AccountIndex): Observable<any> =>
-          api.query.indices.enumSet.multi([...Array(next.toNumber() + 1).keys()]) as Observable<any>
-        ),
-        map((all: (AccountId[] | undefined)[]): AccountIndexes =>
-          (all || []).reduce((result, list, outerIndex): AccountIndexes => {
-            (list || []).forEach((accountId, innerIndex): void => {
-              // re-create the index based on position 0 is [0][0] and likewise
-              // 64 (0..63 in first) is [1][0] (the first index value in set 2)
-              const index = (outerIndex * enumsetSize) + innerIndex;
+  return memo((): Observable<AccountIndexes> =>
+    api.query.indices.nextEnumSet<AccountIndex>().pipe(
+      // use the nextEnumSet (which is a counter of the number of sets) to construct
+      // a range of values to query [0, 1, 2, ...]. Retrieve the full enum set for the
+      // specific index - each query can return up to ENUMSET_SIZE (64) records, each
+      // containing an AccountId
+      switchMap((next: AccountIndex): Observable<Vec<AccountId>[]> =>
+        api.query.indices.enumSet.multi<Vec<AccountId>>([...Array(next.toNumber() + 1).keys()])
+      ),
+      map((all: AccountId[][]): AccountIndexes =>
+        all.reduce((result: AccountIndexes, list, outerIndex): AccountIndexes => {
+          (list || []).forEach((accountId, innerIndex): void => {
+            // re-create the index based on position 0 is [0][0] and likewise
+            // 64 (0..63 in first) is [1][0] (the first index value in set 2)
+            const index = (outerIndex * enumsetSize) + innerIndex;
 
-              result[accountId.toString()] = createType('AccountIndex', index);
-            });
+            result[accountId.toString()] = createType(api.registry, 'AccountIndex', index);
+          });
 
-            return result;
-          }, {} as AccountIndexes)),
-        drr()
-      );
-  };
+          return result;
+        }, {}))
+    ));
 }

packages/api-derive/src/accounts/info.ts

@@ -0,0 +1,48 @@
+// Copyright 2017-2019 @polkadot/api-derive authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+import { ApiInterfaceRx } from '@polkadot/api/types';
+import { AccountId, AccountIndex, Address, Balance } from '@polkadot/types/interfaces';
+import { ITuple } from '@polkadot/types/types';
+import { DeriveAccountInfo } from '../types';
+
+import { Observable, combineLatest, of } from 'rxjs';
+import { map, switchMap } from 'rxjs/operators';
+import { Bytes, Option, u32 } from '@polkadot/types';
+import { u8aToString } from '@polkadot/util';
+
+import { memo } from '../util';
+
+function retrieveNick (api: ApiInterfaceRx, accountId?: AccountId): Observable<string | undefined> {
+  return ((
+    accountId && api.query.nicks
+      ? api.query.nicks.nameOf<Option<ITuple<[Bytes, Balance]>>>(accountId)
+      : of(undefined)
+  ) as Observable<Option<ITuple<[Bytes, Balance]>> | undefined>).pipe(
+    map((nameOf): string | undefined =>
+      nameOf?.isSome
+        ? u8aToString(nameOf.unwrap()[0]).substr(0, (api.consts.nicks.maxLength as u32).toNumber())
+        : undefined
+    )
+  );
+}
+
+/**
+ * @name info
+ * @description Returns aux. info with regards to an account, current that includes the accountId, accountIndex and nickname
+ */
+export function info (api: ApiInterfaceRx): (address?: AccountIndex | AccountId | Address | string | null) => Observable<DeriveAccountInfo> {
+  return memo((address?: AccountIndex | AccountId | Address | string | null): Observable<DeriveAccountInfo> =>
+    api.derive.accounts.idAndIndex(address).pipe(
+      switchMap(([accountId, accountIndex]): Observable<[DeriveAccountInfo, string?]> =>
+        combineLatest([
+          of({ accountId, accountIndex }),
+          retrieveNick(api, accountId)
+        ])
+      ),
+      map(([{ accountId, accountIndex }, nickname]): DeriveAccountInfo => ({
+        accountId, accountIndex, nickname
+      }))
+    ));
+}

packages/api-derive/src/balances/all.ts

@@ -3,6 +3,7 @@
 // of the Apache-2.0 license. See the LICENSE file for details.
 
 import { AccountId, AccountIndex, Address, Balance, BalanceLock, BlockNumber, Index, VestingSchedule } from '@polkadot/types/interfaces';
+import { DerivedBalances } from '../types';
 
 import BN from 'bn.js';
 import { combineLatest, of, Observable } from 'rxjs';
@@ -11,50 +12,55 @@ import { ApiInterfaceRx } from '@polkadot/api/types';
 import { Option, Vec, createType } from '@polkadot/types';
 import { bnMax } from '@polkadot/util';
 
-import { idAndIndex } from '../accounts/idAndIndex';
-import { bestNumber } from '../chain/bestNumber';
-import { DerivedBalances } from '../types';
-import { drr } from '../util/drr';
+import { memo } from '../util';
 
 type ResultBalance = [Balance, Balance, BalanceLock[], Option<VestingSchedule>];
 type Result = [AccountId, BlockNumber, ResultBalance, Index];
 
-function calcBalances ([accountId, bestNumber, [freeBalance, reservedBalance, locks, vesting], accountNonce]: Result): DerivedBalances {
-  let lockedBalance = createType('Balance');
+function calcBalances (api: ApiInterfaceRx, [accountId, bestNumber, [freeBalance, reservedBalance, locks, vesting], accountNonce]: Result): DerivedBalances {
+  let lockedBalance = createType(api.registry, 'Balance');
+  let lockedBreakdown: BalanceLock[] = [];
 
   if (Array.isArray(locks)) {
     // only get the locks that are valid until passed the current block
-    const totals = locks.filter((value): boolean => bestNumber && value.until.gt(bestNumber));
+    lockedBreakdown = locks.filter(({ until }): boolean => bestNumber && until.gt(bestNumber));
 
     // get the maximum of the locks according to https://github.com/paritytech/substrate/blob/master/srml/balances/src/lib.rs#L699
-    lockedBalance = totals[0]
-      ? createType('Balance', bnMax(...totals.map(({ amount }): Balance => amount)))
-      : createType('Balance');
+    if (lockedBreakdown.length) {
+      lockedBalance = createType(api.registry, 'Balance', bnMax(...lockedBreakdown.map(({ amount }): Balance => amount)));
+    }
   }
 
-  // offset = balance locked at genesis, perBlock is the unlock amount
-  const { offset, perBlock } = vesting.unwrapOr(createType('VestingSchedule'));
-  const vestedNow = createType('Balance', perBlock.mul(bestNumber));
-  const vestedBalance = vestedNow.gt(offset)
-    ? freeBalance
-    : createType('Balance', freeBalance.sub(offset).add(vestedNow));
+  // Calculate the vesting balances,
+  //  - offset = balance locked at genesis,
+  //  - perBlock is the unlock amount
+  const { offset: vestingTotal, perBlock } = vesting.unwrapOr(createType(api.registry, 'VestingSchedule'));
+  const vestedBalance = createType(api.registry, 'Balance', perBlock.mul(bestNumber));
+  const isVesting = vestedBalance.lt(vestingTotal);
 
-  // NOTE Workaround for this account on Alex (one of a couple reported) -
-  //   5F7BJL6Z4m8RLtK7nXEqqpEqhBbd535Z3CZeYF6ccvaQAY6N
-  // The locked is > the vested and ended up with the locked > free,
-  // i.e. related to https://github.com/paritytech/polkadot/issues/225
-  // (most probably due to movements from stash -> controller -> free)
-  const availableBalance = createType('Balance', bnMax(new BN(0), vestedBalance.sub(lockedBalance)));
+  // The available balance & vested has an interplay here
+  // "
+  // vesting is a guarantee that the account's balance will never go below a certain amount. so it functions in the opposite way, a bit like a lock that is monotonically decreasing rather than a liquid amount that is monotonically increasing.
+  // locks function as the same guarantee - that a balance will not be lower than a particular amount.
+  // because of this you can see that if there is a "vesting lock" that guarantees the balance cannot go below 200, and a "staking lock" that guarantees the balance cannot drop below 300, then we just have two guarantees of which the first is irrelevant.
+  // i.e. (balance >= 200 && balance >= 300) == (balance >= 300)
+  // ""
+  const floating = freeBalance.sub(lockedBalance);
+  const extraReceived = isVesting ? freeBalance.sub(vestingTotal) : new BN(0);
+  const availableBalance = createType(api.registry, 'Balance', bnMax(new BN(0), isVesting && floating.gt(vestedBalance) ? vestedBalance.add(extraReceived) : floating));
 
   return {
     accountId,
     accountNonce,
     availableBalance,
     freeBalance,
+    isVesting,
     lockedBalance,
+    lockedBreakdown,
     reservedBalance,
     vestedBalance,
-    votingBalance: createType('Balance', freeBalance.add(reservedBalance))
+    vestingTotal,
+    votingBalance: createType(api.registry, 'Balance', freeBalance.add(reservedBalance))
   };
 }
 
@@ -83,13 +89,13 @@ function queryBalances (api: ApiInterfaceRx, accountId: AccountId): Observable<R
  * ```
  */
 export function all (api: ApiInterfaceRx): (address: AccountIndex | AccountId | Address | string) => Observable<DerivedBalances> {
-  return (address: AccountIndex | AccountId | Address | string): Observable<DerivedBalances> => {
-    return idAndIndex(api)(address).pipe(
-      switchMap(([accountId]): Observable<Result> =>
+  return memo((address: AccountIndex | AccountId | Address | string): Observable<DerivedBalances> =>
+    api.derive.accounts.info(address).pipe(
+      switchMap(({ accountId }): Observable<Result> =>
         (accountId
           ? combineLatest([
             of(accountId),
-            bestNumber(api)(),
+            api.derive.chain.bestNumber(),
             queryBalances(api, accountId),
             // FIXME This is having issues with Kusama, only use accountNonce atm
             // api.rpc.account && api.rpc.account.nextIndex
@@ -98,11 +104,9 @@ export function all (api: ApiInterfaceRx): (address: AccountIndex | AccountId |
             //   : api.query.system.accountNonce<Index>(accountId)
             api.query.system.accountNonce<Index>(accountId)
           ])
-          : of([createType('AccountId'), createType('BlockNumber'), [createType('Balance'), createType('Balance'), createType('Vec<BalanceLock>'), createType('Option<VestingSchedule>', null)], createType('Index')])
+          : of([createType(api.registry, 'AccountId'), createType(api.registry, 'BlockNumber'), [createType(api.registry, 'Balance'), createType(api.registry, 'Balance'), createType(api.registry, 'Vec<BalanceLock>'), createType(api.registry, 'Option<VestingSchedule>', null)], createType(api.registry, 'Index')])
         )
       ),
-      map(calcBalances),
-      drr()
-    );
-  };
+      map((result): DerivedBalances => calcBalances(api, result))
+    ));
 }

packages/api-derive/src/balances/fees.ts

@@ -9,7 +9,7 @@ import { DerivedFees } from '../types';
 import { Observable, of } from 'rxjs';
 import { map } from 'rxjs/operators';
 
-import { drr } from '../util/drr';
+import { memo } from '../util';
 
 type Result = [Balance, Balance, Balance, Balance, Balance];
 
@@ -19,9 +19,9 @@ function queryV2 (api: ApiInterfaceRx): Observable<Result> {
   return of([
     // get values from api.const for substrate versions post spec_version: 101
     // https://github.com/paritytech/substrate/pull/2883/files#diff-5e5e1c3aec9ddfde0a9054d062ab3db9R131
-    api.consts.balances.creationFee as Balance,
-    api.consts.balances.existentialDeposit as Balance,
-    api.consts.balances.transferFee as Balance,
+    api.consts.balances.creationFee,
+    api.consts.balances.existentialDeposit,
+    api.consts.balances.transferFee,
     paymentBase.transactionBaseFee as Balance,
     paymentBase.transactionByteFee as Balance
   ]);
@@ -52,20 +52,18 @@ function queryV1 (api: ApiInterfaceRx): Observable<Result> {
  * ```
  */
 export function fees (api: ApiInterfaceRx): () => Observable<DerivedFees> {
-  return (): Observable<DerivedFees> => {
-    return (
-      api.consts.balances
-        ? queryV2(api)
-        : queryV1(api)
-    ).pipe(
+  const query = api.consts.balances
+    ? queryV2
+    : queryV1;
+
+  return memo((): Observable<DerivedFees> =>
+    query(api).pipe(
       map(([creationFee, existentialDeposit, transferFee, transactionBaseFee, transactionByteFee]): DerivedFees => ({
         creationFee,
         existentialDeposit,
         transactionBaseFee,
         transactionByteFee,
         transferFee
-      })),
-      drr()
-    );
-  };
+      }))
+    ));
 }

packages/api-derive/src/balances/votingBalances.ts

@@ -3,22 +3,20 @@
 // of the Apache-2.0 license. See the LICENSE file for details.
 
 import { AccountId, AccountIndex, Address } from '@polkadot/types/interfaces';
+import { DerivedBalances } from '../types';
 
 import { combineLatest, Observable, of } from 'rxjs';
 import { ApiInterfaceRx } from '@polkadot/api/types';
 
-import { DerivedBalances } from '../types';
-import { drr } from '../util/drr';
-import { all } from './all';
+import { memo } from '../util';
 
 export function votingBalances (api: ApiInterfaceRx): (addresses?: (AccountId | AccountIndex | Address | string)[]) => Observable<DerivedBalances[]> {
-  return (addresses?: (AccountId | AccountIndex | Address | string)[]): Observable<DerivedBalances[]> => {
-    return (
-      !addresses || !addresses.length
-        ? of([] as DerivedBalances[])
-        : combineLatest(addresses.map(all(api)))
-    ).pipe(
-      drr()
-    );
-  };
+  return memo((addresses?: (AccountId | AccountIndex | Address | string)[]): Observable<DerivedBalances[]> =>
+    !addresses || !addresses.length
+      ? of([] as DerivedBalances[])
+      : combineLatest(
+        addresses.map((accountId): Observable<DerivedBalances> =>
+          api.derive.balances.all(accountId))
+      )
+  );
 }

packages/api-derive/src/balances/votingBalancesNominatorsFor.ts

@@ -3,27 +3,25 @@
 // of the Apache-2.0 license. See the LICENSE file for details.
 
 import { AccountId, AccountIndex, Address } from '@polkadot/types/interfaces';
+import { DerivedBalances } from '../types';
 
 import { Observable, of } from 'rxjs';
 import { switchMap } from 'rxjs/operators';
 import { ApiInterfaceRx } from '@polkadot/api/types';
 import { Vec } from '@polkadot/types';
 
-import { idAndIndex } from '../accounts/idAndIndex';
-import { DerivedBalances } from '../types';
-import { drr } from '../util/drr';
-import { votingBalances } from './votingBalances';
+import { memo } from '../util';
 
 export function votingBalancesNominatorsFor (api: ApiInterfaceRx): (address: AccountId | AccountIndex | Address | string) => Observable<DerivedBalances[]> {
-  return (address: AccountId | AccountIndex | Address | string): Observable<DerivedBalances[]> => {
-    return idAndIndex(api)(address).pipe(
-      switchMap(([accountId]): Observable<AccountId[]> =>
+  return memo((address: AccountId | AccountIndex | Address | string): Observable<DerivedBalances[]> =>
+    api.derive.accounts.info(address).pipe(
+      switchMap(({ accountId }): Observable<AccountId[]> =>
         accountId
-          ? (api.query.staking.nominatorsFor<Vec<AccountId>>(accountId))
+          ? api.query.staking.nominatorsFor<Vec<AccountId>>(accountId)
           : of([] as AccountId[])
       ),
-      switchMap(votingBalances(api)),
-      drr()
-    );
-  };
+      switchMap((accounts): Observable<DerivedBalances[]> =>
+        api.derive.balances.votingBalances(accounts)
+      )
+    ));
 }

packages/api-derive/src/chain/bestNumber.ts

@@ -2,13 +2,13 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import { BlockNumber } from '@polkadot/types/interfaces';
+import { BlockNumber, Header } from '@polkadot/types/interfaces';
 
 import { Observable } from 'rxjs';
 import { map } from 'rxjs/operators';
 import { ApiInterfaceRx } from '@polkadot/api/types';
 
-import { drr } from '../util/drr';
+import { memo } from '../util';
 
 /**
  * @name bestNumber
@@ -23,9 +23,8 @@ import { drr } from '../util/drr';
  * ```
  */
 export function bestNumber (api: ApiInterfaceRx): () => Observable<BlockNumber> {
-  return (): Observable<BlockNumber> =>
-    api.rpc.chain.subscribeNewHeads().pipe(
-      map((header): BlockNumber => header.number.unwrap()),
-      drr()
-    );
+  return memo((): Observable<BlockNumber> =>
+    api.derive.chain.subscribeNewHeads().pipe(
+      map((header: Header): BlockNumber => header.number.unwrap())
+    ));
 }

packages/api-derive/src/chain/bestNumberFinalized.ts

@@ -8,7 +8,7 @@ import { Observable } from 'rxjs';
 import { map } from 'rxjs/operators';
 import { ApiInterfaceRx } from '@polkadot/api/types';
 
-import { drr } from '../util/drr';
+import { memo } from '../util';
 
 /**
  * @name bestNumberFinalized
@@ -24,9 +24,8 @@ import { drr } from '../util/drr';
  * ```
  */
 export function bestNumberFinalized (api: ApiInterfaceRx): () => Observable<BlockNumber> {
-  return (): Observable<BlockNumber> =>
+  return memo((): Observable<BlockNumber> =>
     api.rpc.chain.subscribeFinalizedHeads().pipe(
-      map((header): BlockNumber => header.number.unwrap()),
-      drr()
-    );
+      map((header): BlockNumber => header.number.unwrap())
+    ));
 }

packages/api-derive/src/chain/bestNumberLag.ts

@@ -9,9 +9,7 @@ import { map } from 'rxjs/operators';
 import { ApiInterfaceRx } from '@polkadot/api/types';
 import { createType } from '@polkadot/types';
 
-import { drr } from '../util/drr';
-import { bestNumber } from './bestNumber';
-import { bestNumberFinalized } from './bestNumberFinalized';
+import { memo } from '../util';
 
 /**
  * @name bestNumberLag
@@ -27,14 +25,13 @@ import { bestNumberFinalized } from './bestNumberFinalized';
  * ```
  */
 export function bestNumberLag (api: ApiInterfaceRx): () => Observable<BlockNumber> {
-  return (): Observable<BlockNumber> =>
+  return memo((): Observable<BlockNumber> =>
     combineLatest([
-      bestNumber(api)(),
-      bestNumberFinalized(api)()
+      api.derive.chain.bestNumber(),
+      api.derive.chain.bestNumberFinalized()
     ]).pipe(
       map(([bestNumber, bestNumberFinalized]): BlockNumber =>
-        createType('BlockNumber', bestNumber.sub(bestNumberFinalized))
-      ),
-      drr()
-    );
+        createType(api.registry, 'BlockNumber', bestNumber.sub(bestNumberFinalized))
+      )
+    ));
 }

packages/api-derive/src/chain/getHeader.ts

@@ -2,13 +2,16 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import { Observable, combineLatest, of } from 'rxjs';
-import { catchError, map } from 'rxjs/operators';
+import { AccountId } from '@polkadot/types/interfaces';
 import { ApiInterfaceRx } from '@polkadot/api/types';
 
+import { Observable, combineLatest, of } from 'rxjs';
+import { catchError, map } from 'rxjs/operators';
+
+import { Vec } from '@polkadot/types';
+
 import { HeaderExtended } from '../type';
-import { drr } from '../util/drr';
-import { HeaderAndValidators } from './subscribeNewHeads';
+import { memo } from '../util';
 
 /**
  * @name bestNumberFinalized
@@ -25,22 +28,21 @@ import { HeaderAndValidators } from './subscribeNewHeads';
  * ```
  */
 export function getHeader (api: ApiInterfaceRx): (hash: Uint8Array | string) => Observable<HeaderExtended | undefined> {
-  return (hash: Uint8Array | string): Observable<HeaderExtended | undefined> =>
-    (combineLatest([
+  return memo((hash: Uint8Array | string): Observable<HeaderExtended | undefined> =>
+    combineLatest([
       api.rpc.chain.getHeader(hash),
       api.query.session
-        ? api.query.session.validators.at(hash)
+        ? api.query.session.validators.at(hash) as Observable<Vec<AccountId>>
         : of([])
-    ]) as Observable<HeaderAndValidators>).pipe(
+    ]).pipe(
       map(([header, validators]): HeaderExtended =>
-        new HeaderExtended(header, validators)
+        new HeaderExtended(api.registry, header, validators)
       ),
       catchError((): Observable<undefined> =>
         // where rpc.chain.getHeader throws, we will land here - it can happen that
         // we supplied an invalid hash. (Due to defaults, storeage will have an
         // empty value, so only the RPC is affected). So return undefined
         of()
-      ),
-      drr()
-    );
+      )
+    ));
 }

packages/api-derive/src/chain/subscribeNewHeads.ts

@@ -3,15 +3,12 @@
 // of the Apache-2.0 license. See the LICENSE file for details.
 
 import { ApiInterfaceRx } from '@polkadot/api/types';
-import { AccountId, Header } from '@polkadot/types/interfaces';
 
-import { Observable, combineLatest, of } from 'rxjs';
-import { map, switchMap } from 'rxjs/operators';
+import { Observable, combineLatest } from 'rxjs';
+import { map } from 'rxjs/operators';
 
 import { HeaderExtended } from '../type';
-import { drr } from '../util/drr';
-
-export type HeaderAndValidators = [Header, AccountId[]];
+import { memo } from '../util';
 
 /**
  * @name subscribeNewHeads
@@ -27,22 +24,13 @@ export type HeaderAndValidators = [Header, AccountId[]];
  * ```
  */
 export function subscribeNewHeads (api: ApiInterfaceRx): () => Observable<HeaderExtended> {
-  return (): Observable<HeaderExtended> =>
-    api.rpc.chain.subscribeNewHeads().pipe(
-      switchMap((header: Header): Observable<HeaderAndValidators> =>
-        (combineLatest([
-          of(header),
-          // theoretically we could combine at the first call with session.validators(), however
-          // we make 100% sure we actually get the validators at a specific block so when these
-          // change at an era boundary, we have the previous values to ensure our indexes are correct
-          api.query.session
-            ? api.query.session.validators.at(header.hash)
-            : of([])
-        ]) as Observable<HeaderAndValidators>)
-      ),
-      map(([header, validators]): HeaderExtended =>
-        new HeaderExtended(header, validators)
-      ),
-      drr()
-    );
+  return memo((): Observable<HeaderExtended> =>
+    combineLatest([
+      api.rpc.chain.subscribeNewHeads(),
+      api.derive.staking.validators()
+    ]).pipe(
+      map(([header, { validators }]): HeaderExtended =>
+        new HeaderExtended(api.registry, header, validators)
+      )
+    ));
 }

packages/api-derive/src/contracts/fees.ts

@@ -9,7 +9,7 @@ import BN from 'bn.js';
 import { Observable, of } from 'rxjs';
 import { map } from 'rxjs/operators';
 
-import { drr } from '../util/drr';
+import { memo } from '../util';
 
 type ResultV2 = [BN, BN, BN, BN, BN, BN, BN, BN, BN, BN];
 
@@ -31,49 +31,6 @@ function parseResult ([callBaseFee, contractFee, createBaseFee, creationFee, ren
   };
 }
 
-// Only for 1.0 support. rentByteFee, rentDepositOffset, tombstoneDeposit are not available in substrate 1.0.
-// TODO remove this once 1.0 support is dropped
-function queryV1 (api: ApiInterfaceRx): Observable<DerivedContractFees> {
-  return (
-    api.queryMulti([
-      api.query.contract.callBaseFee,
-      api.query.contract.contractFee,
-      api.query.contract.createBaseFee,
-      api.query.contract.creationFee,
-      api.query.contract.transactionBaseFee,
-      api.query.contract.transactionByteFee,
-      api.query.contract.transferFee
-    ]) as unknown as Observable<BN[]>
-  ).pipe(
-    map(([callBaseFee, contractFee, createBaseFee, creationFee, transactionBaseFee, transactionByteFee, transferFee]): DerivedContractFees =>
-      // We've done this on purpose, i.e. so we can  just copy the name/order from the parse above and
-      // see gaps, in this case those are filled with `ZERO`
-      parseResult([
-        callBaseFee, contractFee, createBaseFee, creationFee, ZERO, ZERO, ZERO, transactionBaseFee, transactionByteFee, transferFee
-      ])
-    ),
-    drr()
-  );
-}
-
-// query via query (early v2, non-current, support to be dropped])
-function queryQuery (api: ApiInterfaceRx): Observable<ResultV2> {
-  const queryBase = api.query.contracts || api.query.contract;
-
-  return api.queryMulti([
-    queryBase.callBaseFee,
-    queryBase.contractFee,
-    queryBase.createBaseFee,
-    queryBase.creationFee,
-    queryBase.rentByteFee,
-    queryBase.rentDepositOffset,
-    queryBase.tombstoneDeposit,
-    queryBase.transactionBaseFee,
-    queryBase.transactionByteFee,
-    queryBase.transferFee
-  ]) as unknown as Observable<ResultV2>;
-}
-
 // query via constants (current applicable path)
 function queryConstants (api: ApiInterfaceRx): Observable<ResultV2> {
   return of([
@@ -104,23 +61,18 @@ function queryConstants (api: ApiInterfaceRx): Observable<ResultV2> {
  * ```
  */
 export function fees (api: ApiInterfaceRx): () => Observable<DerivedContractFees> {
-  return (): Observable<DerivedContractFees> => {
-    if (api.query.contract && !api.query.contract.rentByteFee) {
-      return queryV1(api);
-    }
-
+  return memo((): Observable<DerivedContractFees> => {
     return (
       api.consts.contracts
         ? queryConstants(api)
-        : queryQuery(api)
+        : of([ZERO, ZERO, ZERO, ZERO, ZERO, ZERO, ZERO, ZERO, ZERO, ZERO])
     ).pipe(
       map(([callBaseFee, contractFee, createBaseFee, creationFee, rentByteFee, rentDepositOffset, tombstoneDeposit, transactionBaseFee, transactionByteFee, transferFee]): DerivedContractFees =>
         // We've done this on purpose, i.e. so we can  just copy the name/order from the parse above and see gaps
         parseResult([
           callBaseFee, contractFee, createBaseFee, creationFee, rentByteFee, rentDepositOffset, tombstoneDeposit, transactionBaseFee, transactionByteFee, transferFee
         ])
-      ),
-      drr()
+      )
     );
-  };
+  });
 }

packages/api-derive/src/democracy/index.ts

@@ -2,6 +2,7 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
+export * from './proposals';
 export * from './referendumInfos';
 export * from './referendums';
 export * from './referendumVotesFor';

packages/api-derive/src/democracy/proposals.ts

@@ -0,0 +1,75 @@
+// Copyright 2017-2019 @polkadot/api-derive authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+import { AccountId, Balance, BlockNumber, Hash, PropIndex } from '@polkadot/types/interfaces';
+import { ITuple } from '@polkadot/types/types';
+import { DeriveProposal } from '../types';
+
+import { Observable, combineLatest, of } from 'rxjs';
+import { map, switchMap } from 'rxjs/operators';
+import { ApiInterfaceRx } from '@polkadot/api/types';
+import { Bytes, Option, Vec, createType } from '@polkadot/types';
+
+import { memo } from '../util';
+
+export type PreImage = Option<ITuple<[Bytes, AccountId, Balance, BlockNumber]>>;
+type Depositors = Option<ITuple<[Balance, Vec<AccountId>]>>;
+
+export function proposals (api: ApiInterfaceRx): () => Observable<DeriveProposal[]> {
+  return memo((): Observable<DeriveProposal[]> =>
+    api.query.democracy
+      .publicProps<Vec<ITuple<[PropIndex, Hash, AccountId]>>>()
+      .pipe(
+        switchMap((proposals) =>
+          combineLatest([
+            of(proposals),
+            combineLatest(
+              ...proposals.map(([, hash]) =>
+                api.query.democracy.preimages<PreImage>(hash)
+              )
+            )
+          ])
+        ),
+        switchMap(([proposals, preimages]) =>
+          combineLatest([
+            of(proposals),
+            of(preimages),
+            combineLatest(
+              ...proposals.map(([index]) =>
+                api.query.democracy.depositOf<Depositors>(index)
+              )
+            )
+          ])
+        ),
+        map(([proposals, _preImages, _depositors]): DeriveProposal[] =>
+          proposals
+            .filter(([, , proposer], index): boolean =>
+              !!(_preImages[index]?.isSome) && !!(_depositors[index]?.isSome) && !proposer.isEmpty
+            )
+            .map(([propIndex, hash, proposer], index): DeriveProposal => {
+              const preImage = _preImages[index].unwrapOr(null);
+              const depositors = _depositors[index].unwrap();
+
+              return {
+                balance: depositors[0],
+                hash,
+                index: propIndex,
+                preimage: preImage
+                  ? {
+                    at: preImage[3],
+                    balance: preImage[2],
+                    proposer: preImage[1]
+                  }
+                  : undefined,
+                proposal: preImage
+                  ? createType(api.registry, 'Proposal', preImage[0].toU8a(true))
+                  : undefined,
+                proposer,
+                seconds: depositors[1]
+              };
+            })
+        )
+      )
+  );
+}

packages/api-derive/src/democracy/referendumInfo.ts

@@ -3,38 +3,66 @@
 // of the Apache-2.0 license. See the LICENSE file for details.
 
 import { ReferendumInfo } from '@polkadot/types/interfaces/democracy';
+import { DerivedReferendum } from '../types';
+import { PreImage } from './proposals';
 
 import BN from 'bn.js';
-import { Observable } from 'rxjs';
-import { map } from 'rxjs/operators';
+import { Observable, of } from 'rxjs';
+import { map, switchMap } from 'rxjs/operators';
 import { ApiInterfaceRx } from '@polkadot/api/types';
-import { Option } from '@polkadot/types';
-import { isNull } from '@polkadot/util';
+import { Option, createType } from '@polkadot/types';
 
-import { ReferendumInfoExtended } from '../type';
-import { drr } from '../util/drr';
+import { memo } from '../util';
 
-export function constructInfo (index: BN | number, optionInfo?: Option<ReferendumInfo>): Option<ReferendumInfoExtended> {
-  const info = optionInfo
-    ? optionInfo.unwrapOr(null)
+function constructInfo (api: ApiInterfaceRx, index: BN | number, _info: Option<ReferendumInfo>, _preimage?: PreImage): DerivedReferendum | null {
+  console.log(JSON.stringify(_info), JSON.stringify(_preimage));
+
+  const preImage = _preimage?.isSome
+    ? _preimage.unwrap()
     : null;
+  const info = _info.unwrapOr(null);
 
-  return new Option<ReferendumInfoExtended>(
-    ReferendumInfoExtended,
-    isNull(info)
-      ? null
-      : new ReferendumInfoExtended(info, index)
+  if (!info) {
+    return null;
+  }
+
+  return {
+    index: createType(api.registry, 'PropIndex', index),
+    info,
+    hash: info.proposalHash,
+    proposal: preImage
+      ? createType(api.registry, 'Proposal', preImage[0].toU8a(true))
+      : undefined,
+    preimage: preImage
+      ? {
+        at: preImage[3],
+        balance: preImage[2],
+        proposer: preImage[1]
+      }
+      : undefined
+  };
+}
+
+export function retrieveInfo (api: ApiInterfaceRx, index: BN | number, info: Option<ReferendumInfo>): Observable<DerivedReferendum | null> {
+  console.log(JSON.stringify(info));
+
+  return ((
+    info?.isSome
+      ? api.query.democracy.preimages<PreImage>(info.unwrap().proposalHash)
+      : of(undefined)
+  ) as Observable<PreImage | undefined>).pipe(
+    map((preimage?: PreImage): DerivedReferendum | null =>
+      constructInfo(api, index, info, preimage)
+    )
   );
 }
 
-export function referendumInfo (api: ApiInterfaceRx): (index: BN | number) => Observable<Option<ReferendumInfoExtended>> {
-  return (index: BN | number): Observable<Option<ReferendumInfoExtended>> => {
-    return (api.query.democracy.referendumInfoOf<Option<ReferendumInfo>>(index))
-      .pipe(
-        map((optionInfo): Option<ReferendumInfoExtended> =>
-          constructInfo(index, optionInfo)
-        ),
-        drr()
-      );
-  };
+export function referendumInfo (api: ApiInterfaceRx): (index: BN | number) => Observable<DerivedReferendum | null> {
+  return memo((index: BN | number): Observable<DerivedReferendum | null> =>
+    api.query.democracy.referendumInfoOf<Option<ReferendumInfo>>(index).pipe(
+      switchMap((info): Observable<DerivedReferendum | null> =>
+        retrieveInfo(api, index, info)
+      )
+    )
+  );
 }

packages/api-derive/src/democracy/referendumInfos.ts

@@ -3,30 +3,33 @@
 // of the Apache-2.0 license. See the LICENSE file for details.
 
 import { ReferendumInfo } from '@polkadot/types/interfaces/democracy';
+import { DerivedReferendum } from '../types';
 
 import BN from 'bn.js';
-import { Observable, of } from 'rxjs';
-import { map } from 'rxjs/operators';
+import { Observable, combineLatest, of } from 'rxjs';
+import { map, switchMap } from 'rxjs/operators';
 import { ApiInterfaceRx } from '@polkadot/api/types';
 import { Option, Vec } from '@polkadot/types';
 
-import { ReferendumInfoExtended } from '../type';
-import { drr } from '../util/drr';
-import { constructInfo } from './referendumInfo';
+import { memo } from '../util';
+import { retrieveInfo } from './referendumInfo';
 
-export function referendumInfos (api: ApiInterfaceRx): (ids?: (BN | number)[]) => Observable<Option<ReferendumInfoExtended>[]> {
-  return (ids: (BN | number)[] = []): Observable<Option<ReferendumInfoExtended>[]> => {
-    return (
+export function referendumInfos (api: ApiInterfaceRx): (ids?: (BN | number)[]) => Observable<DerivedReferendum[]> {
+  return memo((ids: (BN | number)[] = []): Observable<DerivedReferendum[]> =>
+    (
       !ids || !ids.length
         ? of([] as Option<ReferendumInfo>[])
         : api.query.democracy.referendumInfoOf.multi(ids) as Observable<Vec<Option<ReferendumInfo>>>
     ).pipe(
-      map((infos): Option<ReferendumInfoExtended>[] =>
-        ids.map((id, index): Option<ReferendumInfoExtended> =>
-          constructInfo(id, infos[index])
+      switchMap((infos): Observable<(DerivedReferendum | null)[]> =>
+        combineLatest(
+          ...ids.map((id, index): Observable<DerivedReferendum | null> =>
+            retrieveInfo(api, id, infos[index])
+          )
         )
       ),
-      drr()
-    );
-  };
+      map((infos): DerivedReferendum[] =>
+        infos.filter((referendum): boolean => !!referendum) as DerivedReferendum[]
+      )
+    ));
 }

packages/api-derive/src/democracy/referendumVotesFor.ts

@@ -11,27 +11,24 @@ import { ApiInterfaceRx } from '@polkadot/api/types';
 import { Vec, createType } from '@polkadot/types';
 
 import { DerivedBalances, DerivedReferendumVote } from '../types';
-import { drr } from '../util/drr';
-import { votes } from './votes';
-import { votingBalances } from '../balances/votingBalances';
+import { memo } from '../util';
 
 export function referendumVotesFor (api: ApiInterfaceRx): (referendumId: BN | number) => Observable<DerivedReferendumVote[]> {
-  return (referendumId: BN | number): Observable<DerivedReferendumVote[]> =>
-    (api.query.democracy.votersFor<Vec<AccountId>>(referendumId)).pipe(
+  return memo((referendumId: BN | number): Observable<DerivedReferendumVote[]> =>
+    api.query.democracy.votersFor<Vec<AccountId>>(referendumId).pipe(
       switchMap((votersFor): Observable<[Vec<AccountId>, Vote[], DerivedBalances[]]> =>
         combineLatest([
           of(votersFor),
-          votes(api)(referendumId as BN, votersFor),
-          votingBalances(api)(votersFor)
+          api.derive.democracy.votes(referendumId as BN, votersFor),
+          api.derive.balances.votingBalances(votersFor)
         ])
       ),
       map(([votersFor, votes, balances]): DerivedReferendumVote[] =>
         votersFor.map((accountId, index): DerivedReferendumVote => ({
           accountId,
-          balance: balances[index].votingBalance || createType('Balance'),
-          vote: votes[index] || createType('Vote')
-        } as unknown as DerivedReferendumVote))
-      ),
-      drr()
-    );
+          balance: balances[index].votingBalance || createType(api.registry, 'Balance'),
+          vote: votes[index] || createType(api.registry, 'Vote')
+        } as DerivedReferendumVote))
+      )
+    ));
 }

packages/api-derive/src/democracy/referendums.ts

@@ -3,32 +3,29 @@
 // of the Apache-2.0 license. See the LICENSE file for details.
 
 import { ReferendumIndex } from '@polkadot/types/interfaces/democracy';
+import { DerivedReferendum } from '../types';
 
 import BN from 'bn.js';
 import { Observable, of } from 'rxjs';
 import { switchMap } from 'rxjs/operators';
 import { ApiInterfaceRx } from '@polkadot/api/types';
-import { Option } from '@polkadot/types';
 
-import { ReferendumInfoExtended } from '../type';
-import { drr } from '../util/drr';
-import { referendumInfos } from './referendumInfos';
+import { memo } from '../util';
 
-export function referendums (api: ApiInterfaceRx): () => Observable<Option<ReferendumInfoExtended>[]> {
-  return (): Observable<Option<ReferendumInfoExtended>[]> =>
-    (api.queryMulti([
+export function referendums (api: ApiInterfaceRx): () => Observable<DerivedReferendum[]> {
+  return memo((): Observable<DerivedReferendum[]> =>
+    api.queryMulti<[ReferendumIndex, ReferendumIndex]>([
       api.query.democracy.nextTally,
       api.query.democracy.referendumCount
-    ]) as Observable<[ReferendumIndex?, ReferendumIndex?]>).pipe(
-      switchMap(([nextTally, referendumCount]): Observable<Option<ReferendumInfoExtended>[]> =>
+    ]).pipe(
+      switchMap(([nextTally, referendumCount]): Observable<DerivedReferendum[]> =>
         referendumCount && nextTally && referendumCount.gt(nextTally) && referendumCount.gtn(0)
-          ? referendumInfos(api)(
+          ? api.derive.democracy.referendumInfos(
             [...Array(referendumCount.sub(nextTally).toNumber())].map((_, i): BN =>
               nextTally.addn(i)
             )
           )
           : of([])
-      ),
-      drr()
-    );
+      )
+    ));
 }

packages/api-derive/src/democracy/votes.ts

@@ -7,20 +7,17 @@ import { AccountId, Vote } from '@polkadot/types/interfaces';
 import BN from 'bn.js';
 import { Observable, of } from 'rxjs';
 import { ApiInterfaceRx } from '@polkadot/api/types';
-import { Vec } from '@polkadot/types';
 
-import { drr } from '../util/drr';
+import { memo } from '../util';
 
 export function votes (api: ApiInterfaceRx): (referendumId: BN, accountIds?: AccountId[]) => Observable<Vote[]> {
-  return (referendumId: BN, accountIds: AccountId[] = []): Observable<Vote[]> => {
-    return ((
-      !accountIds || !accountIds.length
-        ? of([])
-        : api.query.democracy.voteOf.multi(
-          accountIds.map((accountId): [BN, AccountId] =>
-            [referendumId, accountId]
-          )
+  return memo((referendumId: BN, accountIds: AccountId[] = []): Observable<Vote[]> =>
+    !accountIds || !accountIds.length
+      ? of([] as Vote[])
+      : api.query.democracy.voteOf.multi<Vote>(
+        accountIds.map((accountId): [BN, AccountId] =>
+          [referendumId, accountId]
         )
-    ) as Observable<Vec<Vote>>).pipe(drr());
-  };
+      )
+  );
 }

packages/api-derive/src/elections/approvalsOf.ts

@@ -5,11 +5,28 @@
 import { AccountId, ApprovalFlag, SetIndex } from '@polkadot/types/interfaces';
 
 import { ApiInterfaceRx } from '@polkadot/api/types';
-import { Observable } from 'rxjs';
+import { Observable, of } from 'rxjs';
 import { Vec } from '@polkadot/types';
 import { switchMap, map } from 'rxjs/operators';
 import { approvalFlagsToBools } from '../util/approvalFlagsToBools';
-import { drr } from '../util/drr';
+import { memo } from '../util';
+
+function queryElections (api: ApiInterfaceRx, who: AccountId | string): Observable<boolean[][]> {
+  return api.query.elections.nextVoterSet<SetIndex>().pipe(
+    switchMap((nextVoterSet: SetIndex): Observable<Vec<ApprovalFlag>[]> =>
+      api.query.elections.approvalsOf.multi(
+        [...Array(nextVoterSet.toNumber() + 1).keys()].map((i): [string, number] =>
+          [who.toString(), i]
+        )
+      ) as any as Observable<Vec<ApprovalFlag>[]>
+    ),
+    map((votes: Vec<ApprovalFlag>[]): boolean[][] =>
+      votes.map((flags: Vec<ApprovalFlag>): boolean[] =>
+        approvalFlagsToBools(flags)
+      )
+    )
+  );
+}
 
 /**
  * @name approvalsOf
@@ -23,21 +40,10 @@ import { drr } from '../util/drr';
  * });
  * ```
  */
-export function approvalsOf (api: ApiInterfaceRx): (who: AccountId) => Observable<boolean[][]> {
-  return (who: AccountId | string): Observable<boolean[][]> =>
-    api.query.elections.nextVoterSet<SetIndex>().pipe(
-      switchMap((nextVoterSet: SetIndex): Observable<Vec<ApprovalFlag>[]> =>
-        api.query.elections.approvalsOf.multi(
-          [...Array(nextVoterSet.toNumber() + 1).keys()].map((i): [string, number] => [
-            who.toString(), i]
-          )
-        ) as any as Observable<Vec<ApprovalFlag>[]>
-      ),
-      map((votes: Vec<ApprovalFlag>[]): boolean[][] =>
-        votes.map((flags: Vec<ApprovalFlag>): boolean[] =>
-          approvalFlagsToBools(flags)
-        )
-      ),
-      drr()
-    );
+export function approvalsOf (api: ApiInterfaceRx): (who: AccountId | string) => Observable<boolean[][]> {
+  return memo((who: AccountId | string): Observable<boolean[][]> =>
+    api.query.elections
+      ? queryElections(api, who)
+      : of([])
+  );
 }

packages/api-derive/src/elections/approvalsOfAt.ts

@@ -5,13 +5,19 @@
 import { AccountId, ApprovalFlag, SetIndex } from '@polkadot/types/interfaces';
 
 import BN from 'bn.js';
-import { Observable } from 'rxjs';
+import { Observable, of } from 'rxjs';
 import { map } from 'rxjs/operators';
 import { ApiInterfaceRx } from '@polkadot/api/types';
 import { Vec } from '@polkadot/types';
 
 import { approvalFlagsToBools } from '../util/approvalFlagsToBools';
-import { drr } from '../util/drr';
+import { memo } from '../util';
+
+function queryElections (api: ApiInterfaceRx, who: AccountId | string, at: SetIndex | BN | number): Observable<boolean[]> {
+  return api.query.elections.approvalsOf<Vec<ApprovalFlag>>([who.toString(), at]).pipe(
+    map((flags: Vec<ApprovalFlag>): boolean[] => approvalFlagsToBools(flags))
+  );
+}
 
 /**
  * @name approvalsOfAt
@@ -26,9 +32,9 @@ import { drr } from '../util/drr';
  * ```
  */
 export function approvalsOfAt (api: ApiInterfaceRx): (who: AccountId, at: SetIndex) => Observable<boolean[]> {
-  return (who: AccountId | string, at: SetIndex | BN | number): Observable<boolean[]> =>
-    api.query.elections.approvalsOf<Vec<ApprovalFlag>>([who.toString(), at]).pipe(
-      map((flags: Vec<ApprovalFlag>): boolean[] => approvalFlagsToBools(flags)),
-      drr()
-    );
+  return memo((who: AccountId | string, at: SetIndex | BN | number): Observable<boolean[]> =>
+    api.query.elections
+      ? queryElections(api, who, at)
+      : of([])
+  );
 }

packages/api-derive/src/elections/info.ts

@@ -2,30 +2,82 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import { AccountId, BlockNumber, SetIndex, VoteIndex } from '@polkadot/types/interfaces';
-import { Codec } from '@polkadot/types/types';
+import { AccountId, Balance, BlockNumber, SetIndex, VoteIndex } from '@polkadot/types/interfaces';
+import { ITuple } from '@polkadot/types/types';
 
-import { Observable } from 'rxjs';
+import { Observable, combineLatest } from 'rxjs';
 import { map } from 'rxjs/operators';
 import { ApiInterfaceRx } from '@polkadot/api/types';
-import { Vec, u32 } from '@polkadot/types';
+import { createType, Vec, u32 } from '@polkadot/types';
 
 import { DerivedElectionsInfo } from '../types';
-import { drr } from '../util/drr';
+import { memo } from '../util';
 
-type Result = [Vec<[AccountId, BlockNumber] & Codec>, Vec<AccountId>, u32, u32, SetIndex, BlockNumber, VoteIndex, SetIndex];
+type ResultElectionsInner = [u32, u32, Vec<ITuple<[AccountId, BlockNumber]>>, SetIndex, BlockNumber, VoteIndex, SetIndex];
+type ResultElections = [Vec<AccountId>, ResultElectionsInner];
 
-function query (api: ApiInterfaceRx): Observable<Result> {
-  return api.queryMulti<Result>([
-    api.query.elections.members,
-    api.query.elections.candidates,
-    api.query.elections.candidateCount,
-    api.query.elections.desiredSeats,
-    api.query.elections.nextVoterSet,
-    api.query.elections.termDuration,
-    api.query.elections.voteCount,
-    api.query.elections.voterCount
-  ]);
+function deriveElections (api: ApiInterfaceRx, [candidates, [candidateCount, desiredSeats, members, nextVoterSet, termDuration, voteCount, voterCount]]: ResultElections): DerivedElectionsInfo {
+  return {
+    candidates,
+    candidateCount,
+    desiredSeats,
+    nextVoterSet,
+    members: members.map(([accountId]): [AccountId, Balance] => [accountId, createType(api.registry, 'Balance')]),
+    runnersUp: [],
+    termDuration,
+    voteCount,
+    voterCount
+  };
+}
+
+function queryElections (api: ApiInterfaceRx): Observable<DerivedElectionsInfo> {
+  // NOTE We have an issue where candidates can return `null` for an empty array
+  return combineLatest([
+    api.query.elections.candidates<Vec<AccountId>>(),
+    api.queryMulti<ResultElectionsInner>([
+      api.query.elections.candidateCount,
+      api.query.elections.desiredSeats,
+      api.query.elections.members,
+      api.query.elections.nextVoterSet,
+      api.query.elections.termDuration,
+      api.query.elections.voteCount,
+      api.query.elections.voterCount
+    ])
+  ]).pipe(map((result): DerivedElectionsInfo => deriveElections(api, result)));
+}
+
+function derivePhragmen (api: ApiInterfaceRx, candidates: AccountId[], members: [AccountId, Balance][], runnersUp: [AccountId, Balance][], candidacyBond: Balance, desiredSeats: u32, termDuration: BlockNumber, votingBond: Balance): DerivedElectionsInfo {
+  return {
+    candidates,
+    candidateCount: createType(api.registry, 'u32', candidates.length),
+    candidacyBond,
+    desiredSeats,
+    members: members.sort((a, b): number => b[1].cmp(a[1])),
+    runnersUp: runnersUp.sort((a, b): number => b[1].cmp(a[1])),
+    termDuration,
+    votingBond
+  };
+}
+
+function queryPhragmen (api: ApiInterfaceRx): Observable<DerivedElectionsInfo> {
+  // NOTE We have an issue where candidates can return `null` for an empty array, hence
+  // we are not using multi queries here, so empty array is empty (instead of space-filled)
+  return combineLatest([
+    api.query.electionsPhragmen.candidates<Vec<AccountId>>(),
+    api.query.electionsPhragmen.members<Vec<ITuple<[AccountId, Balance]>>>(),
+    api.query.electionsPhragmen.runnersUp<Vec<ITuple<[AccountId, Balance]>>>()
+  ]).pipe(
+    map(([candidates, members, runnersUp]): DerivedElectionsInfo => derivePhragmen(
+      api,
+      candidates,
+      members,
+      runnersUp,
+      api.consts.electionsPhragmen.candidacyBond as Balance,
+      api.consts.electionsPhragmen.desiredMembers as u32,
+      api.consts.electionsPhragmen.termDuration as BlockNumber,
+      api.consts.electionsPhragmen.votingBond as Balance
+    ))
+  );
 }
 
 /**
@@ -42,25 +94,9 @@ function query (api: ApiInterfaceRx): Observable<Result> {
  * ```
  */
 export function info (api: ApiInterfaceRx): () => Observable<DerivedElectionsInfo> {
-  return (): Observable<DerivedElectionsInfo> => {
-    return query(api).pipe(
-      map(([members, candidates, candidateCount, desiredSeats, nextVoterSet, termDuration, voteCount, voterCount]): DerivedElectionsInfo => ({
-        members: members.reduce(
-          (record: Record<string, BlockNumber>, [accountId, blockNumber]): Record<string, BlockNumber> => {
-            record[accountId.toString()] = blockNumber;
-            return record;
-          },
-          {}
-        ),
-        candidates,
-        candidateCount,
-        desiredSeats,
-        nextVoterSet,
-        termDuration,
-        voteCount,
-        voterCount
-      })),
-      drr()
-    );
-  };
+  return memo((): Observable<DerivedElectionsInfo> =>
+    api.query.electionsPhragmen
+      ? queryPhragmen(api)
+      : queryElections(api)
+  );
 }

packages/api-derive/src/elections/voterPositions.ts

@@ -4,13 +4,41 @@
 
 import { AccountId, SetIndex } from '@polkadot/types/interfaces';
 import { ApiInterfaceRx } from '@polkadot/api/types';
-import { Vec, Option, createType } from '@polkadot/types';
+import { Vec, Option, createType, u32 } from '@polkadot/types';
 import { DerivedVoterPositions } from '../types';
 
 import BN from 'bn.js';
-import { of, combineLatest, Observable } from 'rxjs';
+import { of, Observable } from 'rxjs';
 import { switchMap, map } from 'rxjs/operators';
-import { drr } from '../util/drr';
+
+import { memo } from '../util';
+
+function queryElections (api: ApiInterfaceRx): Observable<DerivedVoterPositions> {
+  return api.query.elections.nextVoterSet<SetIndex>().pipe(
+    switchMap((nextVoterSet: SetIndex): Observable<Vec<Option<AccountId>>[]> =>
+      api.query.elections.voters.multi<Vec<Option<AccountId>>>([...Array(+nextVoterSet + 1).keys()].map((_, i): [number] => [i]))
+    ),
+    map((voters: Vec<Option<AccountId>>[]): DerivedVoterPositions => {
+      return voters.reduce((result: DerivedVoterPositions, vec, setIndex): DerivedVoterPositions => {
+        vec.forEach((e, index): void => {
+          // re-create the index based on position 0 is [0][0] and likewise
+          // 64 (0..63 in first) is [1][0] (the first index value in set 2)
+          const accountId: AccountId | null = e.unwrapOr(null);
+
+          if (accountId) {
+            result[accountId.toString()] = {
+              globalIndex: (api.consts.elections.voterSetSize as u32).muln(setIndex).addn(index),
+              index: new BN(index),
+              setIndex: createType(api.registry, 'SetIndex', setIndex)
+            };
+          }
+        });
+
+        return result;
+      }, {});
+    })
+  );
+}
 
 /**
  * @name voterPositions
@@ -26,32 +54,9 @@ import { drr } from '../util/drr';
  * ```
  */
 export function voterPositions (api: ApiInterfaceRx): () => Observable<DerivedVoterPositions> {
-  return (): Observable<DerivedVoterPositions> =>
-    api.query.elections.nextVoterSet<SetIndex>().pipe(
-      switchMap((nextVoterSet: SetIndex): Observable<[BN, Vec<Option<AccountId>>[]]> => combineLatest(
-        of(api.consts.elections.voterSetSize) as any as Observable<BN>,
-        api.query.elections.voters.multi([...Array(+nextVoterSet + 1).keys()].map((_, i): [number] => [i])) as any as Observable<Vec<Option<AccountId>>[]>
-      )),
-      map((result: [BN, Vec<Option<AccountId>>[]]): DerivedVoterPositions => {
-        const [setSize, voters] = result;
-        return voters.reduce((result: DerivedVoterPositions, vec, setIndex): DerivedVoterPositions => {
-          vec.forEach((e, index): void => {
-            // re-create the index based on position 0 is [0][0] and likewise
-            // 64 (0..63 in first) is [1][0] (the first index value in set 2)
-            const accountId: AccountId | null = e.unwrapOr(null);
-
-            if (accountId) {
-              result[accountId.toString()] = {
-                globalIndex: setSize.muln(setIndex).addn(index),
-                index: new BN(index),
-                setIndex: createType('SetIndex', setIndex)
-              };
-            }
-          });
-
-          return result;
-        }, {});
-      }),
-      drr()
-    );
+  return memo((): Observable<DerivedVoterPositions> =>
+    api.query.elections
+      ? queryElections(api)
+      : of({})
+  );
 }

packages/api-derive/src/elections/voters.ts

@@ -6,13 +6,25 @@ import { ApiInterfaceRx } from '@polkadot/api/types';
 import { AccountId } from '@polkadot/types/interfaces';
 import { DerivedVoterPositions } from '../types';
 
-import { Observable } from 'rxjs';
+import { Observable, of } from 'rxjs';
 import { map } from 'rxjs/operators';
 import { createType, Vec } from '@polkadot/types';
 
-import { drr } from '../util/drr';
-import { voterPositions } from './voterPositions';
+import { memo } from '../util';
 
+function queryElections (api: ApiInterfaceRx): Observable<AccountId[]> {
+  return api.derive.elections.voterPositions().pipe(
+    map((voterPositions: DerivedVoterPositions): Vec<AccountId> =>
+      createType(
+        api.registry,
+        'Vec<AccountId>',
+        Object.entries(voterPositions)
+          .sort((a, b): number => a[1].globalIndex.cmp(b[1].globalIndex))
+          .map(([accountId]): AccountId => createType(api.registry, 'AccountId', accountId))
+      )
+    )
+  );
+}
 /**
  * @name voters
  * @returns An array of all current voters from all sets.
@@ -25,18 +37,10 @@ import { voterPositions } from './voterPositions';
  * });
  * ```
  */
-export function voters (api: ApiInterfaceRx): () => Observable<Vec<AccountId>> {
-  return (): Observable<Vec<AccountId>> =>
-    voterPositions(api)().pipe(
-      map(
-        (voterPositions: DerivedVoterPositions): Vec<AccountId> =>
-          createType(
-            'Vec<AccountId>',
-            Object.entries(voterPositions)
-              .sort((a, b): 0 | 1 | -1 => a[1].globalIndex.cmp(b[1].globalIndex))
-              .map(([accountId]): AccountId => createType('AccountId', accountId))
-          )
-      ),
-      drr()
-    );
+export function voters (api: ApiInterfaceRx): () => Observable<AccountId[]> {
+  return memo((): Observable<AccountId[]> =>
+    api.query.elections
+      ? queryElections(api)
+      : of([])
+  );
 }

packages/api-derive/src/imOnline/receivedHeartbeats.ts

@@ -3,36 +3,39 @@
 // of the Apache-2.0 license. See the LICENSE file for details.
 
 import { AccountId, SessionIndex } from '@polkadot/types/interfaces';
+import { DerivedHeartbeats } from '../types';
 
-import { of, Observable } from 'rxjs';
+import { of, Observable, combineLatest } from 'rxjs';
 import { map, switchMap } from 'rxjs/operators';
 import { ApiInterfaceRx } from '@polkadot/api/types';
-import { Bytes, Vec } from '@polkadot/types';
+import { Bytes, Option, u32 } from '@polkadot/types';
 
-import { drr } from '../util/drr';
+import { memo } from '../util';
 
 /**
  * @description Return a boolean array indicating whether the passed accounts had received heartbeats in the current session
  */
-export function receivedHeartbeats (api: ApiInterfaceRx): (addresses: (AccountId | string)[]) => Observable<boolean[]> {
-  return (addresses: (AccountId | string)[]): Observable<boolean[]> => {
-    return api.query.imOnline && api.query.imOnline.receivedHeartbeats
-      ? api.queryMulti<[SessionIndex, Vec<AccountId>]>([
-        api.query.session.currentIndex,
-        api.query.imOnline.keys
-      ]).pipe(
-        switchMap(([currentIndex, keys]): Observable<Bytes[]> =>
-          api.query.imOnline.receivedHeartbeats.multi(
-            addresses.map((address): [SessionIndex, number] =>
-              [currentIndex, keys.indexOf(address)]
-            )
-          )
+export function receivedHeartbeats (api: ApiInterfaceRx): () => Observable<DerivedHeartbeats> {
+  return memo((): Observable<DerivedHeartbeats> =>
+    api.query.imOnline?.receivedHeartbeats && api.query.imOnline.authoredBlocks
+      ? api.derive.staking.overview().pipe(
+        switchMap(({ currentIndex, validators }): Observable<[AccountId[], Option<Bytes>[], u32[]]> =>
+          combineLatest([
+            of(validators),
+            api.query.imOnline.receivedHeartbeats.multi<Option<Bytes>>(validators.map((_address, index): [SessionIndex, number] => [currentIndex, index])),
+            api.query.imOnline.authoredBlocks.multi<u32>(validators.map((address): [SessionIndex, AccountId] => [currentIndex, address]))
+          ])
         ),
-        map((heartbeats): boolean[] =>
-          heartbeats.map((heartbeat): boolean => !heartbeat.isEmpty)
-        ),
-        drr()
+        map(([validators, heartbeats, numBlocks]): DerivedHeartbeats =>
+          validators.reduce((result: DerivedHeartbeats, validator, index): DerivedHeartbeats => ({
+            ...result,
+            [validator.toString()]: {
+              blockCount: numBlocks[index],
+              hasMessage: !heartbeats[index].isEmpty,
+              isOnline: !heartbeats[index].isEmpty || numBlocks[index].gtn(0)
+            }
+          }), {})
+        )
       )
-      : of([...new Array(addresses.length).keys()].map((): boolean => false));
-  };
+      : of({}));
 }

packages/api-derive/src/index.spec.ts

@@ -5,6 +5,7 @@
 import { Observable, from } from 'rxjs';
 import ApiRx from '@polkadot/api/rx/Api';
 import MockProvider from '@polkadot/rpc-provider/mock';
+import { TypeRegistry } from '@polkadot/types';
 
 import { ExactDerive } from '.';
 
@@ -26,8 +27,10 @@ const testFunction = (api: ApiRx): any => {
 };
 
 describe('derive', (): void => {
+  const registry = new TypeRegistry();
+
   describe('builtin', (): void => {
-    const api = new ApiRx({ provider: new MockProvider() });
+    const api = new ApiRx({ provider: new MockProvider(registry), registry });
 
     beforeAll((done): void => {
       api.isReady.subscribe((): void => done());
@@ -77,7 +80,8 @@ describe('derive', (): void => {
           test: (): any => (): Observable<any> => from([1, 2, 3])
         }
       },
-      provider: new MockProvider()
+      provider: new MockProvider(registry),
+      registry
     });
 
     beforeAll((done): void => {

packages/api-derive/src/session/eraLength.ts

@@ -2,18 +2,18 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import BN from 'bn.js';
+import { BlockNumber } from '@polkadot/types/interfaces';
+import { DerivedSessionInfo } from '../types';
+
 import { Observable } from 'rxjs';
 import { map } from 'rxjs/operators';
 import { ApiInterfaceRx } from '@polkadot/api/types';
 
-import { drr } from '../util/drr';
-import { info } from './info';
+import { memo } from '../util';
 
-export function eraLength (api: ApiInterfaceRx): () => Observable<BN> {
-  return (): Observable<BN> =>
-    info(api)().pipe(
-      map(({ eraLength }): BN => eraLength),
-      drr()
-    );
+export function eraLength (api: ApiInterfaceRx): () => Observable<BlockNumber> {
+  return memo((): Observable<BlockNumber> =>
+    api.derive.session.info().pipe(
+      map(({ eraLength }: DerivedSessionInfo): BlockNumber => eraLength)
+    ));
 }

packages/api-derive/src/session/eraProgress.ts

@@ -2,18 +2,18 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import BN from 'bn.js';
+import { BlockNumber } from '@polkadot/types/interfaces';
+import { DerivedSessionInfo } from '../types';
+
 import { Observable } from 'rxjs';
 import { map } from 'rxjs/operators';
 import { ApiInterfaceRx } from '@polkadot/api/types';
 
-import { drr } from '../util/drr';
-import { info } from './info';
+import { memo } from '../util';
 
-export function eraProgress (api: ApiInterfaceRx): () => Observable<BN> {
-  return (): Observable<BN> =>
-    info(api)().pipe(
-      map(({ eraProgress }): BN => eraProgress),
-      drr()
-    );
+export function eraProgress (api: ApiInterfaceRx): () => Observable<BlockNumber> {
+  return memo((): Observable<BlockNumber> =>
+    api.derive.session.info().pipe(
+      map(({ eraProgress }: DerivedSessionInfo): BlockNumber => eraProgress)
+    ));
 }

packages/api-derive/src/session/index.ts

@@ -4,5 +4,6 @@
 
 export * from './eraLength';
 export * from './eraProgress';
+export * from './indexes';
 export * from './info';
 export * from './sessionProgress';

packages/api-derive/src/session/indexes.ts

@@ -0,0 +1,31 @@
+// Copyright 2017-2019 @polkadot/api-derive authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+import { ApiInterfaceRx } from '@polkadot/api/types';
+import { EraIndex, SessionIndex } from '@polkadot/types/interfaces';
+import { DeriveSessionIndexes } from '../types';
+
+import { Observable, of } from 'rxjs';
+import { map } from 'rxjs/operators';
+import { createType, u32 as U32 } from '@polkadot/types';
+
+import { memo } from '../util';
+
+export function indexes (api: ApiInterfaceRx): () => Observable<DeriveSessionIndexes> {
+  return memo((): Observable<DeriveSessionIndexes> =>
+    (
+      // Some chains (eg. very limited node-template), does not have session
+      api.query.session && api.query.staking
+        ? api.queryMulti<[SessionIndex, EraIndex, U32]>([
+          api.query.session.currentIndex,
+          api.query.staking.currentEra,
+          api.query.staking.validatorCount
+        ])
+        : of([createType(api.registry, 'SessionIndex', 1), createType(api.registry, 'EraIndex', 1), createType(api.registry, 'u32')])
+    ).pipe(
+      map(([currentIndex, currentEra, validatorCount]): DeriveSessionIndexes => ({
+        currentIndex, currentEra, validatorCount
+      }))
+    ));
+}

packages/api-derive/src/session/info.ts

@@ -2,28 +2,26 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import { BlockNumber, EraIndex, SessionIndex } from '@polkadot/types/interfaces';
-import { DerivedSessionInfo } from '../types';
+import { BlockNumber, SessionIndex } from '@polkadot/types/interfaces';
+import { DerivedSessionInfo, DeriveSessionIndexes } from '../types';
 
-import { Observable, combineLatest, of } from 'rxjs';
+import { Observable, combineLatest } from 'rxjs';
 import { map } from 'rxjs/operators';
 import { ApiInterfaceRx } from '@polkadot/api/types';
 import { Option, u64, createType } from '@polkadot/types';
 
-import { drr } from '../util/drr';
-import { bestNumber } from '../chain';
+import { memo } from '../util';
 
-type Result94Session = [SessionIndex, Option<BlockNumber>, BlockNumber, BlockNumber, SessionIndex];
-type Result94 = [BlockNumber, Result94Session];
+type ResultV1Session = [Option<BlockNumber>, BlockNumber, BlockNumber, SessionIndex];
+type ResultV1 = [BlockNumber, DeriveSessionIndexes, ResultV1Session];
 
-type ResultIndex = [SessionIndex, EraIndex];
-type ResultSlots = [u64, u64, u64];
-type ResultType = [boolean, boolean, u64, SessionIndex];
-type Result = [ResultType, ResultSlots, ResultIndex];
+type ResultSlots = [u64, u64, u64, SessionIndex];
+type ResultType = [boolean, u64, SessionIndex];
+type Result = [ResultType, DeriveSessionIndexes, ResultSlots];
 
 // internal helper to just split the logic - take all inputs, do the calculations and combine
-function createDerived94 ([bestNumber, [currentIndex, _lastLengthChange, sessionLength, lastEraLengthChange, sessionsPerEra]]: Result94): DerivedSessionInfo {
-  const lastLengthChange = (_lastLengthChange && _lastLengthChange.unwrapOr(null)) || createType('BlockNumber');
+function createDerivedV1 (api: ApiInterfaceRx, [bestNumber, { currentIndex, validatorCount }, [_lastLengthChange, sessionLength, lastEraLengthChange, sessionsPerEra]]: ResultV1): DerivedSessionInfo {
+  const lastLengthChange = _lastLengthChange?.unwrapOr(null) || createType(api.registry, 'BlockNumber');
   const sessionProgress = bestNumber
     .sub(lastLengthChange)
     .add(sessionLength)
@@ -36,89 +34,80 @@ function createDerived94 ([bestNumber, [currentIndex, _lastLengthChange, session
     .add(sessionProgress);
 
   return {
-    currentEra: createType('EraIndex', currentEra),
+    currentEra: createType(api.registry, 'EraIndex', currentEra),
     currentIndex,
-    eraLength: createType('BlockNumber', sessionLength.mul(sessionsPerEra)),
-    eraProgress: createType('BlockNumber', eraProgress),
+    eraLength: createType(api.registry, 'BlockNumber', sessionLength.mul(sessionsPerEra)),
+    eraProgress: createType(api.registry, 'BlockNumber', eraProgress),
     isEpoch: false,
-    lastEraLengthChange,
-    lastLengthChange,
     sessionLength,
     sessionsPerEra,
-    sessionProgress: createType('BlockNumber', sessionProgress)
+    sessionProgress: createType(api.registry, 'BlockNumber', sessionProgress),
+    validatorCount
   };
 }
 
-function createDerivedLatest ([[hasBabe, isGenesisSlot, epochDuration, sessionsPerEra], [currentSlot, epochIndex, epochOrGenesisStartSlot], [currentIndex, currentEra]]: Result): DerivedSessionInfo {
-  const epochStartSlot = isGenesisSlot
-    ? epochIndex
-      .mul(epochDuration)
-      .add(epochOrGenesisStartSlot)
-    : epochOrGenesisStartSlot;
+function createDerivedLatest (api: ApiInterfaceRx, [[hasBabe, epochDuration, sessionsPerEra], { currentIndex, currentEra, validatorCount }, [currentSlot, epochIndex, epochOrGenesisStartSlot, currentEraStartSessionIndex]]: Result): DerivedSessionInfo {
+  const epochStartSlot = epochIndex.mul(epochDuration).add(epochOrGenesisStartSlot);
   const sessionProgress = currentSlot.sub(epochStartSlot);
-  const eraProgress = epochIndex
-    .mod(sessionsPerEra)
-    .mul(epochDuration)
-    .add(sessionProgress);
+  const eraProgress = currentIndex.sub(currentEraStartSessionIndex).mul(epochDuration).add(sessionProgress);
 
   return {
     currentEra,
     currentIndex,
-    eraLength: createType('BlockNumber', sessionsPerEra.mul(epochDuration)),
-    eraProgress: createType('BlockNumber', eraProgress),
+    eraLength: createType(api.registry, 'BlockNumber', sessionsPerEra.mul(epochDuration)),
+    eraProgress: createType(api.registry, 'BlockNumber', eraProgress),
     isEpoch: hasBabe,
-    lastEraLengthChange: createType('BlockNumber'),
-    lastLengthChange: createType('BlockNumber', epochStartSlot),
     sessionLength: epochDuration,
     sessionsPerEra,
-    sessionProgress: createType('BlockNumber', sessionProgress)
+    sessionProgress: createType(api.registry, 'BlockNumber', sessionProgress),
+    validatorCount
   };
 }
 
-function info94 (api: ApiInterfaceRx): Observable<DerivedSessionInfo> {
+function infoV1 (api: ApiInterfaceRx): Observable<DerivedSessionInfo> {
   return combineLatest([
-    bestNumber(api)(),
-    api.queryMulti<Result94Session>([
-      api.query.session.currentIndex,
+    api.derive.chain.bestNumber(),
+    api.derive.session.indexes(),
+    api.queryMulti<ResultV1Session>([
       api.query.session.lastLengthChange,
       api.query.session.sessionLength,
       api.query.staking.lastEraLengthChange,
       api.query.staking.sessionsPerEra
     ])
   ]).pipe(
-    map(createDerived94),
-    drr()
+    map((result): DerivedSessionInfo => createDerivedV1(api, result))
   );
 }
 
-function infoLatest (api: ApiInterfaceRx): Observable<DerivedSessionInfo> {
-  const hasBabe = !!api.consts.babe;
-
-  return combineLatest([
-    of([
-      hasBabe,
-      hasBabe && !!api.query.babe.genesisSlot,
-      hasBabe
-        ? api.consts.babe.epochDuration as u64
-        : createType('u64', 1),
-      api.consts.staking.sessionsPerEra as SessionIndex
-    ] as ResultType),
-    hasBabe
-      ? api.queryMulti<ResultSlots>([
-        api.query.babe.currentSlot,
-        api.query.babe.epochIndex,
-        api.query.babe.genesisSlot
-          ? api.query.babe.genesisSlot
-          : api.query.babe.epochStartSlot
+function infoLatestAura (api: ApiInterfaceRx): Observable<DerivedSessionInfo> {
+  return api.derive.session.indexes().pipe(
+    map((indexes): DerivedSessionInfo =>
+      createDerivedLatest(api, [
+        [false, createType(api.registry, 'u64', 1), api.consts.staking?.sessionsPerEra || createType(api.registry, 'SessionIndex', 1)],
+        indexes,
+        [createType(api.registry, 'u64', 1), createType(api.registry, 'u64', 1), createType(api.registry, 'u64', 1), createType(api.registry, 'SessionIndex', 1)]
       ])
-      : of([createType('u64', 1), createType('u64', 1), createType('u64', 1)] as ResultSlots),
-    api.queryMulti<ResultIndex>([
-      api.query.session.currentIndex,
-      api.query.staking.currentEra
+    )
+  );
+}
+
+function infoLatestBabe (api: ApiInterfaceRx): Observable<DerivedSessionInfo> {
+  return combineLatest([
+    api.derive.session.indexes(),
+    api.queryMulti<ResultSlots>([
+      api.query.babe.currentSlot,
+      api.query.babe.epochIndex,
+      api.query.babe.genesisSlot,
+      api.query.staking.currentEraStartSessionIndex
     ])
   ]).pipe(
-    map(createDerivedLatest),
-    drr()
+    map(([indexes, slots]: [DeriveSessionIndexes, ResultSlots]): DerivedSessionInfo =>
+      createDerivedLatest(api, [
+        [true, api.consts.babe.epochDuration, api.consts.staking.sessionsPerEra],
+        indexes,
+        slots
+      ])
+    )
   );
 }
 
@@ -126,12 +115,12 @@ function infoLatest (api: ApiInterfaceRx): Observable<DerivedSessionInfo> {
  * @description Retrieves all the session and era info and calculates specific values on it as the length of the session and eras
  */
 export function info (api: ApiInterfaceRx): () => Observable<DerivedSessionInfo> {
-  return (): Observable<DerivedSessionInfo> => {
-    // With substrate `spec_version 94`, the era and session has been explicitly exposed as `parameter_types`.
-    // pre-94 we had more info and needed to calculate (handle old/Alex first)
-    // https://github.com/paritytech/substrate/commit/dbf322620948935d2bbae214504e6c668c3073ed#diff-c29f42d6b931fa93ba038dbbbfec3055
-    return api.query.session.lastLengthChange
-      ? info94(api) // 1.x
-      : infoLatest(api); // 2.x
-  };
+  const query = api.consts.timestamp || api.consts.babe || api.consts.aura
+    ? api.consts.babe
+      ? infoLatestBabe // 2.x with Babe
+      : infoLatestAura // 2.x with Aura (not all info there)
+    : infoV1;
+
+  return memo((): Observable<DerivedSessionInfo> =>
+    query(api));
 }

packages/api-derive/src/session/sessionProgress.ts

@@ -2,18 +2,18 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import BN from 'bn.js';
+import { BlockNumber } from '@polkadot/types/interfaces';
+import { DerivedSessionInfo } from '../types';
+
 import { Observable } from 'rxjs';
 import { map } from 'rxjs/operators';
 import { ApiInterfaceRx } from '@polkadot/api/types';
 
-import { drr } from '../util/drr';
-import { info } from './info';
+import { memo } from '../util';
 
-export function sessionProgress (api: ApiInterfaceRx): () => Observable<BN> {
-  return (): Observable<BN> =>
-    info(api)().pipe(
-      map(({ sessionProgress }): BN => sessionProgress),
-      drr()
-    );
+export function sessionProgress (api: ApiInterfaceRx): () => Observable<BlockNumber> {
+  return memo((): Observable<BlockNumber> =>
+    api.derive.session.info().pipe(
+      map(({ sessionProgress }: DerivedSessionInfo): BlockNumber => sessionProgress)
+    ));
 }

packages/api-derive/src/staking/controllers.ts

@@ -2,31 +2,32 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import { AccountId } from '@polkadot/types/interfaces';
-import { Codec } from '@polkadot/types/types';
+import { ApiInterfaceRx } from '@polkadot/api/types';
+import { AccountId, ValidatorPrefs } from '@polkadot/types/interfaces';
+import { ITuple } from '@polkadot/types/types';
 
 import { Observable, combineLatest, of } from 'rxjs';
 import { switchMap } from 'rxjs/operators';
-import { ApiInterfaceRx } from '@polkadot/api/types';
-import { Option } from '@polkadot/types';
+import { Option, Vec } from '@polkadot/types';
 
-import { drr } from '../util/drr';
+import { memo } from '../util';
+
+type DeriveControllers = [AccountId[], Option<AccountId>[]];
 
 /**
  * @description From the list of stash accounts, retrieve the list of controllers
  */
-export function controllers (api: ApiInterfaceRx): () => Observable<[AccountId[], Option<AccountId>[]]> {
-  return (): Observable<[AccountId[], Option<AccountId>[]]> =>
-    api.query.staking
-      .validators<[AccountId[]] & Codec>()
-      .pipe(
-        switchMap(([stashIds]): Observable<[AccountId[], Option<AccountId>[]]> =>
-          combineLatest([
-            of(stashIds),
-            // eslint-disable-next-line @typescript-eslint/no-unnecessary-type-assertion
-            api.query.staking.bonded.multi(stashIds) as Observable<Option<AccountId>[]>
-          ])
-        ),
-        drr()
-      );
+export function controllers (api: ApiInterfaceRx): () => Observable<DeriveControllers> {
+  return memo((): Observable<[AccountId[], Option<AccountId>[]]> =>
+    api.query.staking.validators<ITuple<[Vec<AccountId>, Vec<ValidatorPrefs>]>>().pipe(
+      switchMap(([stashIds]): Observable<DeriveControllers> =>
+        combineLatest([
+          of(stashIds),
+          // for V2, don't return all the controllers, we call bonded at a later point
+          api.consts.session
+            ? of([])
+            : api.query.staking.bonded.multi<Option<AccountId>>(stashIds)
+        ])
+      )
+    ));
 }

packages/api-derive/src/staking/electedInfo.ts

@@ -0,0 +1,30 @@
+// Copyright 2017-2019 @polkadot/api-derive authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+import { ApiInterfaceRx } from '@polkadot/api/types';
+import { AccountId } from '@polkadot/types/interfaces';
+import { DerivedStaking, DerivedStakingElected } from '../types';
+
+import { Observable, combineLatest, of } from 'rxjs';
+import { map, switchMap } from 'rxjs/operators';
+
+import { memo } from '../util';
+
+export function electedInfo (api: ApiInterfaceRx): () => Observable<DerivedStakingElected> {
+  return memo((): Observable<DerivedStakingElected> =>
+    api.derive.staking.validators().pipe(
+      switchMap(({ currentElected }): Observable<[AccountId[], DerivedStaking[]]> =>
+        combineLatest([
+          of(currentElected),
+          combineLatest(currentElected.map((accountId): Observable<DerivedStaking> =>
+            api.derive.staking.info(accountId)
+          ))
+        ])
+      ),
+      map(([currentElected, info]): DerivedStakingElected => ({
+        currentElected, info
+      }))
+    )
+  );
+}

packages/api-derive/src/staking/index.ts

@@ -3,5 +3,8 @@
 // of the Apache-2.0 license. See the LICENSE file for details.
 
 export * from './controllers';
+export * from './electedInfo';
 export * from './info';
+export * from './overview';
 export * from './recentlyOffline';
+export * from './validators';

packages/api-derive/src/staking/info.ts

@@ -2,13 +2,10 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import { AccountId, Balance, BlockNumber } from '@polkadot/types/interfaces/runtime';
-import { Keys } from '@polkadot/types/interfaces/session';
-import { Exposure, RewardDestination, StakingLedger, UnlockChunk, ValidatorPrefs } from '@polkadot/types/interfaces/staking';
-import { Codec } from '@polkadot/types/types';
-
 import { ApiInterfaceRx } from '@polkadot/api/types';
-import { DerivedStaking, DerivedUnlocking } from '../types';
+import { AccountId, Balance, BlockNumber, Exposure, Keys, Nominations, RewardDestination, StakingLedger, UnlockChunk, ValidatorPrefs } from '@polkadot/types/interfaces';
+import { ITuple } from '@polkadot/types/types';
+import { DerivedRecentlyOffline, DerivedSessionInfo, DerivedStaking, DerivedUnlocking } from '../types';
 
 import BN from 'bn.js';
 import { combineLatest, Observable, of } from 'rxjs';
@@ -17,14 +14,23 @@ import { createType, Option, Vec } from '@polkadot/types';
 
 import { isUndefined } from '@polkadot/util';
 
-import { bestNumber } from '../chain/bestNumber';
-import { eraLength } from '../session/eraLength';
-import { recentlyOffline } from './recentlyOffline';
-import { drr } from '../util/drr';
+import { memo } from '../util';
 
-type MultiResult = [Option<Keys>, [
-  Option<AccountId> | Vec<[AccountId, Keys] & Codec>, Option<StakingLedger>, [AccountId[]], RewardDestination, Exposure, [ValidatorPrefs]
-]];
+interface ParseInput {
+  accountId: AccountId;
+  controllerId: AccountId;
+  recentlyOffline?: DerivedRecentlyOffline;
+  nominators: AccountId[];
+  rewardDestination: RewardDestination;
+  queuedKeys?: [AccountId, Keys][];
+  sessionInfo: DerivedSessionInfo;
+  stakers: Exposure;
+  stakingLedger: Option<StakingLedger>;
+  stashId: AccountId;
+  validatorPrefs: ValidatorPrefs;
+  nextKeys?: Option<Keys>;
+  nextKeyFor?: Option<AccountId>;
+}
 
 // groups the supplied chunks by era, i.e. { [era]: BN(total of values) }
 function groupByEra (list: UnlockChunk[]): Record<string, BN> {
@@ -39,52 +45,56 @@ function groupByEra (list: UnlockChunk[]): Record<string, BN> {
   }, {});
 }
 
-// calculate the remining blocks in a specific unlock era
-function remainingBlocks (era: BN, eraLength: BN, bestNumber: BlockNumber): BlockNumber {
-  const remaining = eraLength.mul(era).sub(bestNumber);
+// calculate the remaining blocks in a specific unlock era
+function remainingBlocks (api: ApiInterfaceRx, era: BN, sessionInfo: DerivedSessionInfo): BlockNumber {
+  const remaining = era.sub(sessionInfo.currentEra);
 
-  return createType('BlockNumber', remaining.lten(0)
-    ? new BN(0)
-    : remaining
+  // on the Rust side the current-era >= era-for-unlock (removal done on >)
+  return createType(api.registry, 'BlockNumber', remaining.gtn(0)
+    ? remaining
+      .subn(1)
+      .mul(sessionInfo.eraLength)
+      .add(sessionInfo.eraLength.sub(sessionInfo.eraProgress))
+    : 0
   );
 }
 
-function calculateUnlocking (stakingLedger: StakingLedger | undefined, eraLength: BN, bestNumber: BlockNumber): DerivedUnlocking[] | undefined {
+function calculateUnlocking (api: ApiInterfaceRx, stakingLedger: StakingLedger | undefined, sessionInfo: DerivedSessionInfo): DerivedUnlocking[] | undefined {
   if (isUndefined(stakingLedger)) {
     return undefined;
   }
 
   const unlockingChunks = stakingLedger.unlocking.filter(({ era }): boolean =>
-    remainingBlocks(era.unwrap(), eraLength, bestNumber).gtn(0)
+    remainingBlocks(api, era.unwrap(), sessionInfo).gtn(0)
   );
 
   if (!unlockingChunks.length) {
     return undefined;
   }
 
-  // group the Unlockchunks that have the same era and sum their values
+  // group the unlock chunks that have the same era and sum their values
   const groupedResult = groupByEra(unlockingChunks);
   const results = Object.entries(groupedResult).map(([eraString, value]): DerivedUnlocking => ({
-    value: createType('Balance', value),
-    remainingBlocks: remainingBlocks(createType('BlockNumber', eraString), eraLength, bestNumber)
+    value: createType(api.registry, 'Balance', value),
+    remainingBlocks: remainingBlocks(api, new BN(eraString), sessionInfo)
   }));
 
   return results.length ? results : undefined;
 }
 
-function redeemableSum (stakingLedger: StakingLedger | undefined, eraLength: BN, bestNumber: BlockNumber): Balance {
+function redeemableSum (api: ApiInterfaceRx, stakingLedger: StakingLedger | undefined, sessionInfo: DerivedSessionInfo): Balance {
   if (isUndefined(stakingLedger)) {
-    return createType('Balance');
+    return createType(api.registry, 'Balance');
   }
 
-  return createType('Balance', stakingLedger.unlocking.reduce((total, { era, value }): BN => {
-    return remainingBlocks(era.unwrap(), eraLength, bestNumber).eqn(0)
+  return createType(api.registry, 'Balance', stakingLedger.unlocking.reduce((total, { era, value }): BN => {
+    return remainingBlocks(api, era.unwrap(), sessionInfo).eqn(0)
       ? total.add(value.unwrap())
       : total;
   }, new BN(0)));
 }
 
-function unwrapSessionIds (stashId: AccountId, queuedKeys: Option<AccountId> | Vec<[AccountId, Keys] & Codec>, nextKeys: Option<Keys>): { nextSessionIds: AccountId[]; nextSessionId?: AccountId; sessionIds: AccountId[]; sessionId?: AccountId } {
+function unwrapSessionIds (stashId: AccountId, queuedKeys: Option<AccountId> | [AccountId, Keys][], nextKeys: Option<Keys>): { nextSessionIds: AccountId[]; sessionIds: AccountId[] } {
   // for 2.x we have a Vec<(ValidatorId,Keys)> of the keys
   if (Array.isArray(queuedKeys)) {
     const sessionIds = (queuedKeys.find(([currentId]): boolean =>
@@ -93,9 +103,7 @@ function unwrapSessionIds (stashId: AccountId, queuedKeys: Option<AccountId> | V
     const nextSessionIds = nextKeys.unwrapOr([] as AccountId[]);
 
     return {
-      nextSessionId: nextSessionIds[0],
       nextSessionIds,
-      sessionId: sessionIds[0],
       sessionIds
     };
   }
@@ -106,85 +114,114 @@ function unwrapSessionIds (stashId: AccountId, queuedKeys: Option<AccountId> | V
     : [];
 
   return {
-    nextSessionId: nextSessionIds[0],
     nextSessionIds,
-    sessionId: nextSessionIds[0],
     sessionIds: nextSessionIds
   };
 }
 
-function retrieveMulti (api: ApiInterfaceRx, stashId: AccountId, controllerId: AccountId): Observable<MultiResult> {
+function parseResult (api: ApiInterfaceRx, { accountId, controllerId, stashId, sessionInfo, recentlyOffline = {}, nextKeyFor, queuedKeys, stakingLedger, nominators, rewardDestination, stakers, validatorPrefs, nextKeys }: ParseInput): DerivedStaking {
+  const _stakingLedger = stakingLedger.unwrapOr(undefined);
+  const _nextKeyFor = nextKeyFor || createType(api.registry, 'Option<AccountId>', null);
+  const _nextKeys = nextKeys || createType(api.registry, 'Option<Keys>', null);
+
+  return {
+    accountId,
+    controllerId,
+    nominators,
+    offline: recentlyOffline[stashId.toString()],
+    redeemable: redeemableSum(api, _stakingLedger, sessionInfo),
+    rewardDestination,
+    stakers,
+    stakingLedger: _stakingLedger,
+    stashId,
+    unlocking: calculateUnlocking(api, _stakingLedger, sessionInfo),
+    validatorPrefs,
+    ...unwrapSessionIds(stashId, queuedKeys || _nextKeyFor, _nextKeys)
+  };
+}
+
+type MultiResultV1 = [Option<AccountId>, Option<StakingLedger>, [Vec<AccountId>], RewardDestination, Exposure, ITuple<[ValidatorPrefs]>];
+
+function retrieveInfoV1 (api: ApiInterfaceRx, accountId: AccountId, stashId: AccountId, controllerId: AccountId): Observable<DerivedStaking> {
   return combineLatest([
-    // TODO We really want this as part of the multi, however can only do that
-    // once we drop substrate 1.x support (nulti requires values for all)
-    api.query.session.nextKeys
-      ? api.query.session.nextKeys<Option<Keys>>(api.consts.session.dedupKeyPrefix, stashId)
-      : of(createType('Option<Keys>', null)),
+    api.derive.session.info(),
+    api.derive.staking.recentlyOffline(),
     api.queryMulti([
-      api.query.session.queuedKeys
-        ? [api.query.session.queuedKeys]
-        : [api.query.session.nextKeyFor, controllerId],
+      [api.query.session.nextKeyFor, controllerId],
       [api.query.staking.ledger, controllerId],
       [api.query.staking.nominators, stashId],
       [api.query.staking.payee, stashId],
       [api.query.staking.stakers, stashId],
       [api.query.staking.validators, stashId]
-    ])
-  ]) as Observable<MultiResult>;
+    ]) as Observable<MultiResultV1>
+  ]).pipe(map(([sessionInfo, recentlyOffline, [nextKeyFor, stakingLedger, [nominators], rewardDestination, stakers, [validatorPrefs]]]: [DerivedSessionInfo, DerivedRecentlyOffline, MultiResultV1]): DerivedStaking =>
+    parseResult(api, {
+      accountId, controllerId, stashId, sessionInfo, recentlyOffline, nextKeyFor, stakingLedger, nominators, rewardDestination, stakers, validatorPrefs
+    })
+  ));
 }
 
-function retrieveInfo (api: ApiInterfaceRx, accountId: AccountId, stashId: AccountId, controllerId: AccountId): Observable<DerivedStaking> {
-  return combineLatest([
-    eraLength(api)(),
-    bestNumber(api)(),
-    recentlyOffline(api)(),
-    retrieveMulti(api, stashId, controllerId)
-  ]).pipe(
-    map(([eraLength, bestNumber, recentlyOffline, [nextKeys, [queuedKeys, _stakingLedger, [nominators], rewardDestination, stakers, [validatorPrefs]]]]): DerivedStaking => {
-      const stakingLedger = _stakingLedger.unwrapOr(undefined);
+type MultiResultV2 = [[Vec<AccountId>] | Option<ITuple<[Nominations]>>, RewardDestination, Exposure, [ValidatorPrefs], Option<Keys>, Option<StakingLedger>];
 
-      return {
-        accountId,
-        controllerId,
-        nominators,
-        offline: recentlyOffline[stashId.toString()],
-        redeemable: redeemableSum(stakingLedger, eraLength, bestNumber),
-        rewardDestination,
-        stakers,
-        stakingLedger,
-        stashId,
-        unlocking: calculateUnlocking(stakingLedger, eraLength, bestNumber),
-        validatorPrefs,
-        ...unwrapSessionIds(stashId, queuedKeys, nextKeys)
-      };
-    })
-  );
+function retrieveInfoV2 (api: ApiInterfaceRx, accountId: AccountId, stashId: AccountId, controllerId: AccountId): Observable<DerivedStaking> {
+  return combineLatest([
+    api.derive.session.info(),
+    api.query.session.queuedKeys<Vec<ITuple<[AccountId, Keys]>>>(),
+    api.queryMulti([
+      [api.query.staking.nominators, stashId],
+      [api.query.staking.payee, stashId],
+      [api.query.staking.stakers, stashId],
+      [api.query.staking.validators, stashId],
+      [api.query.session.nextKeys, [api.consts.session.dedupKeyPrefix, stashId]],
+      [api.query.staking.ledger, controllerId]
+    ]) as Observable<MultiResultV2>
+  ]).pipe(map(([sessionInfo, queuedKeys, [_nominators, rewardDestination, stakers, [validatorPrefs], nextKeys, stakingLedger]]: [DerivedSessionInfo, [AccountId, Keys][], MultiResultV2]): DerivedStaking => {
+    // if we have staking.storageVersion it indicates the new structure, unwrap as needed
+    // FIXME We really want to be pulling all the new (valuable) info along
+    const nominators: AccountId[] = api.query.staking.storageVersion
+      ? (_nominators as Option<ITuple<[Nominations]>>).isSome
+        ? (_nominators as Option<ITuple<[Nominations]>>).unwrap()[0].targets
+        : []
+      : (_nominators as [Vec<AccountId>])[0];
+
+    return parseResult(api, {
+      accountId, controllerId, stashId, sessionInfo, queuedKeys, stakingLedger, nominators, rewardDestination, stakers, validatorPrefs, nextKeys
+    });
+  }));
+}
+
+function retrieveV1 (api: ApiInterfaceRx, accountId: AccountId): Observable<DerivedStaking> {
+  // depending on where we come from, this may be a controller or stash
+  return combineLatest([
+    api.query.staking.bonded<Option<AccountId>>(accountId),
+    api.query.staking.ledger<Option<StakingLedger>>(accountId)
+  ]).pipe(switchMap(([bonded, stakingLedger]): Observable<DerivedStaking> =>
+    stakingLedger.isSome
+      ? retrieveInfoV1(api, accountId, stakingLedger.unwrap().stash, accountId)
+      : bonded.isSome
+        ? retrieveInfoV1(api, accountId, accountId, bonded.unwrap())
+        : of({ accountId: accountId, nextSessionIds: [], sessionIds: [] })
+  ));
+}
+
+function retrieveV2 (api: ApiInterfaceRx, stashId: AccountId): Observable<DerivedStaking> {
+  return api.query.staking
+    .bonded<Option<AccountId>>(stashId)
+    .pipe(switchMap((controllerId): Observable<DerivedStaking> =>
+      controllerId.isSome
+        ? retrieveInfoV2(api, stashId, stashId, controllerId.unwrap())
+        : of({ accountId: stashId, nextSessionIds: [], sessionIds: [] })
+    ));
 }
 
 /**
  * @description From a stash, retrieve the controllerId and fill in all the relevant staking details
  */
 export function info (api: ApiInterfaceRx): (_accountId: Uint8Array | string) => Observable<DerivedStaking> {
-  return (_accountId: Uint8Array | string): Observable<DerivedStaking> => {
-    const accountId = createType('AccountId', _accountId);
+  const query = api.consts.session
+    ? retrieveV2
+    : retrieveV1;
 
-    return (
-      // NOTE For 2.x-only support, only the first path is required, therefore we
-      // can replace this with `.bonded<Option<AccountId>>(accountId)` - in 2.x
-      // the session.validators return the stashes (as expected)
-      api.queryMulti<[Option<AccountId>, Option<StakingLedger>]>([
-        [api.query.staking.bonded, accountId], // try to map to controller
-        [api.query.staking.ledger, accountId] // try to map to stash (1.x only)
-      ])
-    ).pipe(
-      switchMap(([controllerId, stakingLedger]): Observable<DerivedStaking> =>
-        controllerId.isSome
-          ? retrieveInfo(api, accountId, accountId, controllerId.unwrap())
-          : stakingLedger.isSome
-            ? retrieveInfo(api, accountId, stakingLedger.unwrap().stash, accountId)
-            : of({ accountId, nextSessionIds: [], sessionIds: [] })
-      ),
-      drr()
-    );
-  };
+  return memo((accountId: Uint8Array | string): Observable<DerivedStaking> =>
+    query(api, createType(api.registry, 'AccountId', accountId)));
 }

packages/api-derive/src/staking/infoStash.ts

@@ -0,0 +1,64 @@
+// Copyright 2017-2019 @polkadot/api-derive authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+import { ApiInterfaceRx } from '@polkadot/api/types';
+import { AccountId, Exposure, Keys, RewardDestination, ValidatorPrefs } from '@polkadot/types/interfaces';
+import { ITuple } from '@polkadot/types/types';
+import { DerivedStakingStash } from '../types';
+
+import { Observable } from 'rxjs';
+import { map } from 'rxjs/operators';
+import { Option, Vec } from '@polkadot/types';
+
+import { memo } from '../util';
+
+// NOTE Unused ATM, preparing for V2-only
+
+type Result = [Option<AccountId>, [Vec<AccountId>], RewardDestination, Exposure, ValidatorPrefs, Option<Keys>?];
+type ResultV1 = [Option<AccountId>, ITuple<[Vec<AccountId>]>, RewardDestination, Exposure, ValidatorPrefs];
+type ResultV2 = [Option<AccountId>, ITuple<[Vec<AccountId>]>, RewardDestination, Exposure, ValidatorPrefs, Option<Keys>];
+
+function parse (stashId: AccountId, [_controllerId, [nominators], rewardDestination, stakers, validatorPrefs, _nextKeys]: Result): DerivedStakingStash {
+  return {
+    controllerId: _controllerId.unwrapOr(undefined),
+    nextKeys: _nextKeys?.unwrapOr(undefined),
+    nominators,
+    rewardDestination,
+    stakers,
+    stashId,
+    validatorPrefs
+  };
+}
+
+function retrieveV1 (api: ApiInterfaceRx, stashId: AccountId): Observable<Result> {
+  return api.queryMulti<ResultV1>([
+    [api.query.staking.bonded, stashId],
+    [api.query.staking.nominators, stashId],
+    [api.query.staking.payee, stashId],
+    [api.query.staking.stakers, stashId],
+    [api.query.staking.validators, stashId]
+  ]);
+}
+
+function retrieveV2 (api: ApiInterfaceRx, stashId: AccountId): Observable<Result> {
+  return api.queryMulti<ResultV2>([
+    [api.query.staking.bonded, stashId],
+    [api.query.staking.nominators, stashId],
+    [api.query.staking.payee, stashId],
+    [api.query.staking.stakers, stashId],
+    [api.query.staking.validators, stashId],
+    [api.query.session.nextKeys, [api.consts.session.dedupKeyPrefix, stashId]]
+  ]);
+}
+
+export function infoStash (api: ApiInterfaceRx): (stashId: AccountId) => Observable<DerivedStakingStash> {
+  const query = api.consts.session
+    ? retrieveV2
+    : retrieveV1;
+
+  return memo((stashId: AccountId): Observable<DerivedStakingStash> =>
+    query(api, stashId).pipe(
+      map((result): DerivedStakingStash => parse(stashId, result))
+    ));
+}

packages/api-derive/src/staking/overview.ts

@@ -0,0 +1,37 @@
+// Copyright 2017-2019 @polkadot/api-derive authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+import { EraPoints } from '@polkadot/types/interfaces';
+import { ApiInterfaceRx } from '@polkadot/api/types';
+import { DerivedStakingOverview } from '../types';
+
+import { Observable, combineLatest, of } from 'rxjs';
+import { map, switchMap } from 'rxjs/operators';
+import { createType } from '@polkadot/types';
+
+import { memo } from '../util';
+
+/**
+ * @description Retrieve the staking overview, including elected and points earned
+ */
+export function overview (api: ApiInterfaceRx): () => Observable<DerivedStakingOverview> {
+  return memo((): Observable<DerivedStakingOverview> =>
+    combineLatest([
+      api.derive.session.indexes(),
+      api.derive.staking.validators()
+    ]).pipe(
+      switchMap(([{ currentEra, currentIndex, validatorCount }, { currentElected, validators }]) =>
+        combineLatest([
+          of({ currentElected, currentEra, currentIndex, validators, validatorCount }),
+          // this will change on a per block basis, keep it innermost (and it needs eraIndex)
+          api.query.staking?.currentEraPointsEarned
+            ? api.query.staking.currentEraPointsEarned<EraPoints>(currentEra)
+            : of(createType(api.registry, 'EraPoints'))
+        ])
+      ),
+      map(([{ currentElected, currentEra, currentIndex, validators, validatorCount }, eraPoints]): DerivedStakingOverview => ({
+        currentElected, currentEra, currentIndex, eraPoints, validators, validatorCount
+      }))
+    ));
+}

packages/api-derive/src/staking/recentlyOffline.ts

@@ -2,18 +2,18 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import { AccountId, BlockNumber } from '@polkadot/types/interfaces';
-import { Codec } from '@polkadot/types/types';
-
-import BN from 'bn.js';
-import { Observable, of } from 'rxjs';
-import { map } from 'rxjs/operators';
 import { ApiInterfaceRx } from '@polkadot/api/types';
+import { AccountId, BlockNumber } from '@polkadot/types/interfaces';
+import { ITuple } from '@polkadot/types/types';
 import { DerivedRecentlyOffline } from '../types';
 
-import { drr } from '../util/drr';
+import { Observable, of } from 'rxjs';
+import { map } from 'rxjs/operators';
+import { Vec, u32 } from '@polkadot/types';
 
-type OfflineResult = [AccountId, BlockNumber, BN][] & Codec;
+import { memo } from '../util';
+
+type OfflineResult = Vec<ITuple<[AccountId, BlockNumber, u32]>>;
 
 function expandDerived (recentlyOffline: OfflineResult): DerivedRecentlyOffline {
   return recentlyOffline.reduce((result: DerivedRecentlyOffline, [accountId, blockNumber, count]): DerivedRecentlyOffline => {
@@ -36,7 +36,7 @@ function expandDerived (recentlyOffline: OfflineResult): DerivedRecentlyOffline
  * @description Retrieve a keyed record of accounts recently reported to be offline
  */
 export function recentlyOffline (api: ApiInterfaceRx): () => Observable<DerivedRecentlyOffline> {
-  return (): Observable<DerivedRecentlyOffline> =>
+  return memo((): Observable<DerivedRecentlyOffline> =>
     (
       // TODO recentlyOffline  has been dropped for 2.x and replaced, figure out the
       // replacement as actually use and implement it
@@ -44,7 +44,6 @@ export function recentlyOffline (api: ApiInterfaceRx): () => Observable<DerivedR
         ? api.query.staking.recentlyOffline<OfflineResult>()
         : of([] as unknown as OfflineResult)
     ).pipe(
-      map(expandDerived),
-      drr()
-    );
+      map(expandDerived)
+    ));
 }

packages/api-derive/src/staking/validators.ts

@@ -0,0 +1,34 @@
+// Copyright 2017-2019 @polkadot/api-derive authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+import { AccountId } from '@polkadot/types/interfaces';
+import { ApiInterfaceRx } from '@polkadot/api/types';
+import { DeriveStakingValidators } from '../types';
+
+import { Observable, of } from 'rxjs';
+import { map } from 'rxjs/operators';
+import { Vec } from '@polkadot/types';
+
+import { memo } from '../util';
+
+/**
+ * @description Retrieve latest list of validators
+ */
+export function validators (api: ApiInterfaceRx): () => Observable<DeriveStakingValidators> {
+  return memo((): Observable<DeriveStakingValidators> =>
+    (
+      // Sadly the node-template is (for some obscure reason) not comprehensive, so while the derive works
+      // in all actual real-world deployed chains, it does create some confusion for limited template chains
+      api.query.session && api.query.staking
+        ? api.queryMulti<[Vec<AccountId>, Vec<AccountId>]>([
+          api.query.session.validators,
+          api.query.staking.currentElected
+        ])
+        : of([[], []] as [AccountId[], AccountId[]])
+    ).pipe(
+      map(([validators, currentElected]): DeriveStakingValidators => ({
+        currentElected, validators
+      }))
+    ));
+}

packages/api-derive/src/type/HeaderExtended.ts

@@ -3,7 +3,7 @@
 // of the Apache-2.0 license. See the LICENSE file for details.
 
 import { AccountId, Header } from '@polkadot/types/interfaces';
-import { AnyJsonObject, Constructor } from '@polkadot/types/types';
+import { AnyJsonObject, Constructor, Registry } from '@polkadot/types/types';
 
 import runtimeTypes from '@polkadot/types/interfaces/runtime/definitions';
 import { Struct } from '@polkadot/types';
@@ -19,8 +19,8 @@ const _Header: Constructor<Header> = Struct.with(runtimeTypes.types.Header as an
 export default class HeaderExtended extends _Header {
   private _author?: AccountId;
 
-  public constructor (header?: Header, sessionValidators?: AccountId[]) {
-    super(header);
+  constructor (registry: Registry, header?: Header, sessionValidators?: AccountId[]) {
+    super(registry, header);
 
     this._author = this.extractAuthor(sessionValidators);
   }

packages/api-derive/src/type/ReferendumInfoExtended.ts

@@ -3,7 +3,7 @@
 // of the Apache-2.0 license. See the LICENSE file for details.
 
 import { ReferendumIndex, ReferendumInfo } from '@polkadot/types/interfaces/democracy';
-import { AnyJsonObject, Constructor } from '@polkadot/types/types';
+import { AnyJsonObject, Constructor, Registry } from '@polkadot/types/types';
 
 import BN from 'bn.js';
 import democracyTypes from '@polkadot/types/interfaces/democracy/definitions';
@@ -20,12 +20,12 @@ const _ReferendumInfo: Constructor<ReferendumInfo> = Struct.with(democracyTypes.
 export default class ReferendumInfoExtended extends _ReferendumInfo {
   private _index: ReferendumIndex;
 
-  public constructor (value: ReferendumInfo | ReferendumInfoExtended, index?: BN | number) {
-    super(value);
+  constructor (registry: Registry, value: ReferendumInfo | ReferendumInfoExtended, index?: BN | number) {
+    super(registry, value);
 
     this._index = value instanceof ReferendumInfoExtended
       ? value.index
-      : createType('ReferendumIndex', index);
+      : createType(registry, 'ReferendumIndex', index);
   }
 
   /**

packages/api-derive/src/types.ts

@@ -2,20 +2,31 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import { AccountId, Balance, BlockNumber, EraIndex, Exposure, Index, RewardDestination, SessionIndex, SetIndex, StakingLedger, ValidatorPrefs, Vote, VoteIndex } from '@polkadot/types/interfaces';
+import { AccountId, AccountIndex, Balance, BalanceLock, BlockNumber, EraIndex, EraPoints, Exposure, Hash, Index, Keys, Proposal, PropIndex, ReferendumInfo, RewardDestination, SessionIndex, SetIndex, StakingLedger, ValidatorPrefs, Vote, VoteIndex } from '@polkadot/types/interfaces';
 
 import BN from 'bn.js';
-import { u32 } from '@polkadot/types';
+import { u32, Vec } from '@polkadot/types';
+
+export type AccountIndexes = Record<string, AccountIndex>;
+
+export interface DeriveAccountInfo {
+  accountId?: AccountId;
+  accountIndex?: AccountIndex;
+  nickname?: string;
+}
 
 export interface DerivedBalances {
   accountId: AccountId;
   accountNonce: Index;
   freeBalance: Balance;
+  isVesting: boolean;
   lockedBalance: Balance;
+  lockedBreakdown: BalanceLock[];
   availableBalance: Balance;
   reservedBalance: Balance;
   votingBalance: Balance;
   vestedBalance: Balance;
+  vestingTotal: Balance;
 }
 
 export type DerivedBalancesMap = Record<string, DerivedBalances>;
@@ -34,14 +45,17 @@ export interface DerivedContractFees {
 }
 
 export interface DerivedElectionsInfo {
-  members: Record<string, BlockNumber>;
   candidates: AccountId[];
   candidateCount: u32;
+  candidacyBond?: Balance;
   desiredSeats: u32;
-  nextVoterSet: SetIndex;
+  members: [AccountId, Balance][];
+  nextVoterSet?: SetIndex;
+  runnersUp: [AccountId, Balance][];
   termDuration: BlockNumber;
-  voteCount: VoteIndex;
-  voterCount: SetIndex;
+  voteCount?: VoteIndex;
+  voterCount?: SetIndex;
+  votingBond?: Balance;
 }
 
 export interface DerivedFees {
@@ -52,11 +66,43 @@ export interface DerivedFees {
   transferFee: Balance;
 }
 
+export interface DerivedHeartbeatAuthor {
+  blockCount: u32;
+  hasMessage: boolean;
+  isOnline: boolean;
+}
+
+export type DerivedHeartbeats = Record<string, DerivedHeartbeatAuthor>;
+
 export interface RecentlyOffline {
   blockNumber: BlockNumber;
   count: BN;
 }
 
+export interface DeriveProposalPreImage {
+  at: BlockNumber;
+  balance: Balance;
+  proposer: AccountId;
+}
+
+export interface DeriveProposal {
+  balance?: Balance;
+  hash: Hash;
+  index: PropIndex;
+  preimage?: DeriveProposalPreImage;
+  proposal?: Proposal;
+  proposer: AccountId;
+  seconds: Vec<AccountId>;
+}
+
+export interface DerivedReferendum {
+  hash: Hash;
+  index: PropIndex;
+  info: ReferendumInfo;
+  preimage?: DeriveProposalPreImage;
+  proposal?: Proposal;
+}
+
 export type DerivedRecentlyOffline = Record<string, RecentlyOffline[]>;
 
 export interface DerivedReferendumVote {
@@ -65,14 +111,16 @@ export interface DerivedReferendumVote {
   vote: Vote;
 }
 
-export interface DerivedSessionInfo {
+export interface DeriveSessionIndexes {
   currentEra: EraIndex;
   currentIndex: SessionIndex;
+  validatorCount: u32;
+}
+
+export interface DerivedSessionInfo extends DeriveSessionIndexes {
   eraLength: BlockNumber;
   eraProgress: BlockNumber;
   isEpoch: boolean;
-  lastEraLengthChange: BlockNumber;
-  lastLengthChange: BlockNumber;
   sessionLength: BlockNumber;
   sessionsPerEra: SessionIndex;
   sessionProgress: BlockNumber;
@@ -82,6 +130,11 @@ export type DerivedStakingAccount = [AccountId, DerivedStakingOnlineStatus];
 
 export type DerivedStakingAccounts = DerivedStakingAccount[];
 
+export interface DerivedStakingElected {
+  currentElected: AccountId[];
+  info: DerivedStaking[];
+}
+
 export interface DerivedStakingOnlineStatus {
   online?: {
     isOnline: boolean;
@@ -93,25 +146,36 @@ export interface DerivedStakingOnlineStatus {
   }[];
 }
 
-export interface DerivedStaking extends DerivedStakingOnlineStatus {
-  accountId: AccountId;
+export interface DeriveStakingValidators {
+  currentElected: AccountId[];
+  validators: AccountId[];
+}
+
+export interface DerivedStakingStash {
   controllerId?: AccountId;
-  // @deprecated Use nextSessionIds instead
-  nextSessionId?: AccountId;
-  nextSessionIds: AccountId[];
   nominators?: AccountId[];
-  redeemable?: Balance;
   rewardDestination?: RewardDestination;
-  // @deprecated Use sessionIds instead
-  sessionId?: AccountId;
-  sessionIds: AccountId[];
+  nextKeys?: Keys;
   stakers?: Exposure;
-  stakingLedger?: StakingLedger;
   stashId?: AccountId;
-  unlocking?: DerivedUnlocking[];
   validatorPrefs?: ValidatorPrefs;
 }
 
+export interface DerivedStaking extends DerivedStakingOnlineStatus, DerivedStakingStash {
+  accountId: AccountId;
+  nextSessionIds: AccountId[];
+  redeemable?: Balance;
+  sessionIds: AccountId[];
+  stakingLedger?: StakingLedger;
+  unlocking?: DerivedUnlocking[];
+}
+
+export interface DerivedStakingOverview extends DeriveSessionIndexes {
+  currentElected: AccountId[];
+  eraPoints: EraPoints;
+  validators: AccountId[];
+}
+
 export type DerivedUnlocking = { remainingBlocks: BlockNumber; value: Balance };
 
 export interface VoterPosition {

packages/api-derive/src/util/approvalFlagToBools.spec.ts

@@ -4,11 +4,13 @@
 
 import { ApprovalFlag } from '@polkadot/types/interfaces';
 
-import { createType } from '@polkadot/types';
+import { createType, TypeRegistry } from '@polkadot/types';
 
 import { approvalFlagsToBools } from './approvalFlagsToBools';
 
 describe('approvalFlagsToBools', (): void => {
+  const registry = new TypeRegistry();
+
   it('translates and empty array to empty', (): void => {
     expect(
       approvalFlagsToBools([] as ApprovalFlag[])
@@ -18,7 +20,7 @@ describe('approvalFlagsToBools', (): void => {
   it('translates a single input', (): void => {
     expect(
       approvalFlagsToBools([
-        createType('ApprovalFlag', 0b1010)
+        createType(registry, 'ApprovalFlag', 0b1010)
       ])
     ).toEqual([false, true, false, true]);
   });
@@ -26,8 +28,8 @@ describe('approvalFlagsToBools', (): void => {
   it('translates multiple inputs', (): void => {
     expect(
       approvalFlagsToBools([
-        createType('ApprovalFlag', 0b0000),
-        createType('ApprovalFlag', 0b1100)
+        createType(registry, 'ApprovalFlag', 0b0000),
+        createType(registry, 'ApprovalFlag', 0b1100)
       ])
     ).toEqual([false, false, false, true, true]);
   });

packages/api-derive/src/util/drr.ts

@@ -1,30 +0,0 @@
-// Copyright 2017-2019 @polkadot/api-derive authors & contributors
-// This software may be modified and distributed under the terms
-// of the Apache-2.0 license. See the LICENSE file for details.
-
-import { catchError, distinctUntilChanged, publishReplay, refCount } from 'rxjs/operators';
-import { Observable } from 'rxjs';
-import { logger } from '@polkadot/util';
-
-type DrrResult = <T> (source$: Observable<T>) => Observable<T>;
-
-const l = logger('drr');
-
-/**
- * Shorthand for distinctUntilChanged(), publishReplay(1) and refCount().
- *
- * @ignore
- */
-export const drr = (): DrrResult => <T> (source$: Observable<T>): Observable<T> =>
-  source$.pipe(
-    catchError((error): Observable<never> => {
-      l.error(error);
-
-      throw error;
-    }),
-    distinctUntilChanged((a: any, b: any): boolean =>
-      JSON.stringify({ value: a }) === JSON.stringify({ value: b })
-    ),
-    publishReplay(1),
-    refCount()
-  );

packages/api-derive/src/util/index.ts

@@ -3,3 +3,4 @@
 // of the Apache-2.0 license. See the LICENSE file for details.
 
 export * from './approvalFlagsToBools';
+export * from './memo';

packages/api-derive/src/util/memo.ts

@@ -0,0 +1,33 @@
+// Copyright 2017-2019 @polkadot/api-derive authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.v
+
+import createMemo from 'memoizee';
+import { Observable, Observer } from 'rxjs';
+import { drr } from '@polkadot/rpc-core/rxjs';
+
+type ObsFn <T> = (...params: any[]) => Observable<T>;
+
+// Normalize via JSON.stringify, allow e.g. AccountId -> ss58
+// eslint-disable-next-line @typescript-eslint/unbound-method
+const normalizer = JSON.stringify;
+
+// Wraps a derive, doing 2 things to optimize calls -
+//   1. creates a memo of the inner fn -> Observable, removing when unsubscribed
+//   2. wraps the observable in a drr() (which includes an unsub delay)
+export function memo <T> (inner: ObsFn<T>): ObsFn<T> {
+  const cached = createMemo(
+    (...params: any[]): Observable<T> =>
+      Observable.create((observer: Observer<T>): VoidCallback => {
+        const sub = inner(...params).subscribe(observer);
+
+        return (): void => {
+          cached.delete(...params);
+          sub.unsubscribe();
+        };
+      }).pipe(drr()),
+    { normalizer }
+  );
+
+  return cached;
+}

packages/api-metadata/README.md

@@ -1 +0,0 @@
-# @polkadot/api-metadata

packages/api-metadata/src/consts/README.md

@@ -1,3 +0,0 @@
-# @polkadot/api-metadata/consts
-
-A base interface to the parameter types

packages/api-metadata/src/consts/static.ts

@@ -1,12 +0,0 @@
-// Copyright 2017-2019 @polkadot/api-metadata authors & contributors
-// This software may be modified and distributed under the terms
-// of the Apache-2.0 license. See the LICENSE file for details.
-
-import { Metadata } from '@polkadot/types';
-import metadataRpc from '@polkadot/types/Metadata/static';
-
-import fromMetadata from './fromMetadata';
-
-export default fromMetadata(
-  new Metadata(metadataRpc)
-);

packages/api-metadata/src/consts/types.ts

@@ -1,14 +0,0 @@
-// Copyright 2017-2019 @polkadot/api-metadata authors & contributors
-// This software may be modified and distributed under the terms
-// of the Apache-2.0 license. See the LICENSE file for details.
-
-import { Codec } from '@polkadot/types/types';
-import { ModuleConstantMetadataLatest } from '@polkadot/types/interfaces';
-
-export interface ConstantCodec extends Codec {
-  meta: ModuleConstantMetadataLatest;
-}
-
-export type ModuleConstants = Record<string, Codec>;
-
-export type Constants = Record<string, ModuleConstants>;

packages/api-metadata/src/extrinsics/README.md

@@ -1,3 +0,0 @@
-# @polkadot/api-metadata/extrinsics
-
-Base extrinsic definitions & codecs