Add .keyPrefix for storage keys (#1809)

* Add .keyPrefix for storage keys

* Fix hex length

CHANGELOG.md

@@ -5,6 +5,7 @@
 - Add typings for `api.tx.*.*` - the `polkadot-types-from-chain` now also generates these
 - Remove additional V1-only derives `(staking.recentlyOffline`, `balances.nominatorsFor`)
 - Add `.isMax()` on int values, an opposite of `isZero()` (e.g. `u128`, as well as derived, e.g. `Balances`)
+- Add `.keyPrefix()` to all `api.query.*` complimenting the `.key()` call, both returning a hex string
 
 # 1.0.1
 

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

@@ -3,24 +3,23 @@
 // 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 { AccountId, Exposure, Keys, Nominations, RewardDestination, ValidatorPrefs } from '@polkadot/types/interfaces';
 import { DerivedStakingStash } from '../types';
 
 import { Observable } from 'rxjs';
 import { map } from 'rxjs/operators';
-import { Option, Vec } from '@polkadot/types';
+import { Option } from '@polkadot/types';
 
 import { memo } from '../util';
 
-type Result = [Option<AccountId>, [Vec<AccountId>], RewardDestination, Exposure, ValidatorPrefs, Option<Keys>?];
-type ResultV2 = [Option<AccountId>, ITuple<[Vec<AccountId>]>, RewardDestination, Exposure, ValidatorPrefs, Option<Keys>];
+type Result = [Option<AccountId>, Nominations, RewardDestination, Exposure, ValidatorPrefs, Option<Keys>];
 
-function parse (stashId: AccountId, [_controllerId, [nominators], rewardDestination, stakers, validatorPrefs, _nextKeys]: Result): DerivedStakingStash {
+function parse (stashId: AccountId, [_controllerId, nominators, rewardDestination, stakers, validatorPrefs, _nextKeys]: Result): DerivedStakingStash {
   return {
     controllerId: _controllerId.unwrapOr(undefined),
-    nextKeys: _nextKeys?.unwrapOr(undefined),
-    nominators,
+    nextKeys: _nextKeys.unwrapOr(undefined),
+    nominators: nominators.targets,
+    nominateAt: nominators.submittedIn,
     rewardDestination,
     stakers,
     stashId,
@@ -29,7 +28,7 @@ function parse (stashId: AccountId, [_controllerId, [nominators], rewardDestinat
 }
 
 function query (api: ApiInterfaceRx, stashId: AccountId): Observable<Result> {
-  return api.queryMulti<ResultV2>([
+  return api.queryMulti<Result>([
     [api.query.staking.bonded, stashId],
     [api.query.staking.nominators, stashId],
     [api.query.staking.payee, stashId],

packages/api-derive/src/types.ts

@@ -193,6 +193,7 @@ export interface DeriveStakingValidators {
 export interface DerivedStakingStash {
   controllerId?: AccountId;
   nominators?: AccountId[];
+  nominateAt?: EraIndex;
   rewardDestination?: RewardDestination;
   nextKeys?: Keys;
   stakers?: Exposure;

packages/api/src/base/Decorate.ts

@@ -285,6 +285,9 @@ export default abstract class Decorate<ApiType extends ApiTypes> extends Events
     decorated.key = (arg1?: Arg, arg2?: Arg): string =>
       u8aToHex(compactStripLength(creator(creator.meta.type.isDoubleMap ? [arg1, arg2] : arg1))[1]);
 
+    decorated.keyPrefix = (): string =>
+      u8aToHex(creator.keyPrefix);
+
     if (this.hasSubscriptions) {
       // When using double map storage function, user need to pass double map key as an array
       decorated.multi = decorateMethod((args: (Arg | Arg[])[]): Observable<Codec[]> =>

packages/api/src/types/storage.ts

@@ -29,6 +29,7 @@ export interface StorageEntryBase<ApiType extends ApiTypes, F extends AnyFunctio
   entries: () => PromiseOrObs<ApiType, [StorageKey, ObsInnerType<ReturnType<F>>][]>;
   hash: (...args: Parameters<F>) => PromiseOrObs<ApiType, Hash>;
   key: (...args: Parameters<F>) => string;
+  keyPrefix: () => string;
   size: (...args: Parameters<F>) => PromiseOrObs<ApiType, u64>;
   multi: ApiType extends 'rxjs' ? StorageEntryObservableMulti : StorageEntryPromiseMulti;
 }

packages/metadata/src/Decorated/storage/fromMetadata/createFunction.ts

@@ -8,7 +8,7 @@ import { Codec, Registry } from '@polkadot/types/types';
 import BN from 'bn.js';
 import { Compact, Raw, createType, createTypeUnsafe } from '@polkadot/types/codec';
 import StorageKey, { StorageEntry } from '@polkadot/types/primitive/StorageKey';
-import { assert, isNull, isUndefined, stringLowerFirst, stringToU8a, u8aConcat } from '@polkadot/util';
+import { assert, compactStripLength, isNull, isUndefined, stringLowerFirst, stringToU8a, u8aConcat } from '@polkadot/util';
 import { xxhashAsU8a } from '@polkadot/util-crypto';
 
 import getHasher, { HasherFunction } from './getHasher';
@@ -218,5 +218,7 @@ export default function createFunction (registry: Registry, itemFn: CreateItemFn
     extendDoubleMap(registry, itemFn, storageFn);
   }
 
+  storageFn.keyPrefix = storageFn.iterKey || compactStripLength(storageFn())[1];
+
   return storageFn;
 }

packages/types/src/primitive/StorageKey.ts

@@ -12,6 +12,7 @@ import Bytes from './Bytes';
 export interface StorageEntry {
   (arg?: any): Uint8Array;
   iterKey?: Uint8Array & Codec;
+  keyPrefix: Uint8Array;
   meta: StorageEntryMetadataLatest;
   method: string;
   prefix: string;