Handle storage with optional modifiers (#717)

* Handle storage with optional modifiers

* Storage docs indicate Option

* Cleanup Option logic

* Convert Optional derive to use Option

* Bump version, update changelog

* Update CHANGELOG description

* Enum.spec.js -> Enum.spec.ts

* Add isEmpty to primitive types

packages/types/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@polkadot/types",
-  "version": "0.44.1",
+  "version": "0.45.0",
   "description": "Implementation of the Parity codec",
   "main": "index.js",
   "keywords": [

packages/types/src/Metadata/v0/Modules.ts

@@ -124,7 +124,14 @@ export class ModuleMetadata extends Struct {
 
 export class StorageFunctionModifier extends Enum {
   constructor (value?: any) {
-    super(['None', 'Default', 'Required'], value);
+    super(['Optional', 'Default', 'Required'], value);
+  }
+
+  /**
+   * @description `true` if the storage entry is optional
+   */
+  get isOptional (): boolean {
+    return this.toNumber() === 0;
   }
 }
 

packages/types/src/Metadata/v1/toV0.ts

@@ -16,10 +16,10 @@ function storageV0 (mod: MetadataModuleV1): StorageMetadata | null {
 
   return new StorageMetadata({
     prefix: mod.prefix,
-    functions: mod.storage.unwrap().map(({ docs, fallback, name, type }) =>
+    functions: mod.storage.unwrap().map(({ docs, fallback, modifier, name, type }) =>
       new StorageFunctionMetadata({
         name,
-        modifier: 0, // unused, don't specify
+        modifier: modifier.toNumber(),
         type,
         default: fallback,
         documentation: docs

packages/types/src/codec/AbstractInt.ts

@@ -65,6 +65,13 @@ export default abstract class AbstractInt extends BN implements Codec {
     return this._bitLength / 8;
   }
 
+  /**
+   * @description Checks if the value is a zero value (align elsewhere)
+   */
+  get isEmpty (): boolean {
+    return this.isZero();
+  }
+
   /**
    * @description Returns the number of bits in the value
    */

packages/types/src/codec/Compact.ts

@@ -73,6 +73,13 @@ export default class Compact extends Base<UInt | Moment> implements Codec {
     return this.toU8a().length;
   }
 
+  /**
+   * @description Checks if the value is an empty value
+   */
+  get isEmpty (): boolean {
+    return this.raw.isEmpty;
+  }
+
   /**
    * @description Returns the number of bits in the value
    */

packages/types/src/codec/Enum.spec.ts

@@ -4,15 +4,16 @@
 
 import Enum from './Enum';
 
-const testDecode = (type, input, expected) =>
+const testDecode = (type: string, input: any, expected: any) =>
   it(`can decode from ${type}`, () => {
     const e = new Enum(['foo', 'bar'], input);
     expect(e.toString()).toBe(expected);
   });
 
-const testEncode = (to, expected) =>
+const testEncode = (to: 'toJSON' | 'toNumber' | 'toString' | 'toU8a', expected: any) =>
   it(`can encode ${to}`, () => {
     const e = new Enum(['foo', 'bar'], 1);
+
     expect(e[to]()).toEqual(expected);
   });
 

packages/types/src/codec/Enum.ts

@@ -65,6 +65,13 @@ export default class Enum extends Base<number> implements Codec {
     return 1;
   }
 
+  /**
+   * @description Checks if the value is an empty value (always false)
+   */
+  get isEmpty (): boolean {
+    return false;
+  }
+
   /**
    * @description Compares the value of the input to see if there is a match
    */

packages/types/src/codec/EnumType.ts

@@ -122,6 +122,13 @@ export default class EnumType<T> extends Base<Codec> implements Codec {
     return this._index;
   }
 
+  /**
+   * @description Checks if the value is an empty value
+   */
+  get isEmpty (): boolean {
+    return this.isEmpty;
+  }
+
   /**
    * @description Checks if the Enum points to a [[Null]] type
    */

packages/types/src/codec/Option.ts

@@ -53,6 +53,13 @@ export default class Option<T extends Codec> extends Base<T> implements Codec {
     return 1 + this.raw.encodedLength;
   }
 
+  /**
+   * @description Checks if the Option has no value
+   */
+  get isEmpty (): boolean {
+    return this.isNone;
+  }
+
   /**
    * @description Checks if the Option has no value
    */

packages/types/src/codec/Struct.ts

@@ -139,6 +139,21 @@ export default class Struct<
     };
   }
 
+  /**
+   * @description Checks if the value is an empty value
+   */
+  get isEmpty (): boolean {
+    const items = this.toArray();
+
+    for (let i = 0; i < items.length; i++) {
+      if (!items[i].isEmpty) {
+        return false;
+      }
+    }
+
+    return true;
+  }
+
   /**
    * @description Returns the Type description to sthe structure
    */

packages/types/src/codec/Tuple.ts

@@ -62,6 +62,13 @@ export default class Tuple extends Array<Codec> implements Codec {
     }, 0);
   }
 
+  /**
+   * @description Checks if the value is an empty value
+   */
+  get isEmpty (): boolean {
+    return this.length === 0;
+  }
+
   /**
    * @description The types definition of the tuple
    */

packages/types/src/codec/Vector.ts

@@ -53,6 +53,16 @@ export default class Vector<
     };
   }
 
+  /**
+   * @description Checks if the value is an empty value
+   */
+  get isEmpty (): boolean {
+    return this.length === 0;
+  }
+
+  /**
+   * @description The type for the items
+   */
   get Type (): string {
     return this._Type.name;
   }

packages/types/src/codec/index.ts

@@ -22,5 +22,5 @@ export { default as U8a } from './U8a';
 export { default as UInt } from './UInt';
 
 // Type management helper functions
-export { default as createType, getTypeClass, getTypeDef, TypeDef, TypeDefInfo } from './createType';
+export { default as createType, createClass, getTypeClass, getTypeDef, TypeDef, TypeDefInfo } from './createType';
 export { default as typeRegistry } from './typeRegistry';

packages/types/src/primitive/Bool.ts

@@ -36,6 +36,13 @@ export default class Bool extends Boolean implements Codec {
     return 1;
   }
 
+  /**
+   * @description Checks if the value is an empty value (always false)
+   */
+  get isEmpty (): boolean {
+    return false;
+  }
+
   /**
    * @description Compares the value of the input to see if there is a match
    */

packages/types/src/primitive/Moment.ts

@@ -52,6 +52,13 @@ export default class Moment extends Date implements Codec {
     return BITLENGTH / 8;
   }
 
+  /**
+   * @description Checks if the value is an empty value
+   */
+  get isEmpty (): boolean {
+    return this.getTime() === 0;
+  }
+
   /**
    * @description Compares the value of the input to see if there is a match
    */

packages/types/src/primitive/Null.ts

@@ -18,6 +18,13 @@ export default class Null implements Codec {
     return 0;
   }
 
+  /**
+   * @description Checks if the value is an empty value (always true)
+   */
+  get isEmpty (): boolean {
+    return true;
+  }
+
   /**
    * @description Compares the value of the input to see if there is a match
    */

packages/types/src/primitive/Text.ts

@@ -46,6 +46,13 @@ export default class Text extends String implements Codec {
     return this.toU8a().length;
   }
 
+  /**
+   * @description Checks if the value is an empty value
+   */
+  get isEmpty (): boolean {
+    return this.length === 0;
+  }
+
   /**
    * @description The length of the value
    */

packages/types/src/scripts/MetadataMd.ts

@@ -145,7 +145,10 @@ function addStorage (metadata: MetadataV0) {
       const methodName = stringLowerFirst(func.name.toString());
       const arg = func.type.isMap ? ('`' + func.type.asMap.key.toString() + '`') : '';
       const doc = func.documentation.reduce((md, doc) => `${md} ${doc}`, '');
-      const renderSignature = `${md}\n▸ **${methodName}**(${arg}): ` + '`' + func.type + '`';
+      const type = func.modifier.isOptional
+        ? `Option<${func.type}>`
+        : func.type;
+      const renderSignature = `${md}\n▸ **${methodName}**(${arg}): ` + '`' + type + '`';
       const renderSummary = `${doc ? `\n- **summary**: ${doc}\n` : '\n'}`;
 
       return renderSignature + renderSummary;

packages/types/src/type/Address.ts

@@ -6,6 +6,7 @@ import BN from 'bn.js';
 import { decodeAddress } from '@polkadot/keyring';
 import { hexToU8a, isBn, isHex, isNumber, isU8a, u8aConcat, u8aToHex, u8aToU8a, u8aToBn } from '@polkadot/util';
 
+import { Codec } from '../types';
 import Base from '../codec/Base';
 import AccountId from './AccountId';
 import AccountIndex from './AccountIndex';
@@ -22,7 +23,7 @@ export const ACCOUNT_ID_PREFIX = new Uint8Array([0xff]);
  * we extend from Base with an AccountId/AccountIndex wrapper. Basically the Address
  * is encoded as `[ <prefix-byte>, ...publicKey/...bytes ]` as per spec
  */
-export default class Address extends Base<AccountId | AccountIndex> {
+export default class Address extends Base<AccountId | AccountIndex> implements Codec {
   constructor (value: AnyAddress = new Uint8Array()) {
     super(
       Address.decodeAddress(value)
@@ -75,6 +76,13 @@ export default class Address extends Base<AccountId | AccountIndex> {
     );
   }
 
+  /**
+   * @description Checks if the value is an empty value
+   */
+  get isEmpty (): boolean {
+    return this.raw.isEmpty;
+  }
+
   /**
    * @description The length of the raw value, either AccountIndex or AccountId
    */

packages/types/src/type/ChainProperties.ts

@@ -30,6 +30,13 @@ export default class ChainProperties extends Map<string, any> implements Codec {
     return 0;
   }
 
+  /**
+   * @description Checks if the value is an empty value
+   */
+  get isEmpty (): boolean {
+    return [...this.keys()].length === 0;
+  }
+
   /**
    * @description The token decimals, if defined (de-facto standard only)
    */

packages/types/src/types.ts

@@ -33,6 +33,11 @@ export interface Codec {
    */
   encodedLength: number;
 
+  /**
+   * @description Checks if the value is an empty value
+   */
+  isEmpty: boolean;
+
   /**
    * @description Compares the value of the input to see if there is a match
    */
@@ -62,7 +67,9 @@ export interface Codec {
 
 export type CodecTo = 'toHex' | 'toJSON' | 'toString' | 'toU8a';
 
-export type Constructor<T = Codec> = { new(value?: any): T };
+export interface Constructor<T = Codec> {
+  new(...value: Array<any>): T;
+}
 
 export type ConstructorDef<T = Codec> = { [index: string]: Constructor<T> };