Additional MultiAddress testing paths (#3205)

* Additional MultiAddress testing paths

* Update packages/types/src/generic/MultiAddress.ts

packages/types/src/generic/MultiAddress.spec.ts

@@ -20,6 +20,20 @@ describe('MultiAddress', (): void => {
     expect(a.toString()).toEqual('5C62W7ELLAAfix9LYrcx5smtcffbhvThkM5x7xfMeYXCtGwF');
   });
 
+  it('correctly decodes an AccountIndex', (): void => {
+    const a = registry.createType('MultiAddress', '25GUyv');
+
+    expect(a.index).toEqual(1);
+    expect(a.toString()).toEqual('25GUyv');
+  });
+
+  it('correctly decodes an AccountIndex (AccountIndex input)', (): void => {
+    const a = registry.createType('MultiAddress', registry.createType('AccountIndex', '25GUyv'));
+
+    expect(a.index).toEqual(1);
+    expect(a.toString()).toEqual('25GUyv');
+  });
+
   it('correctly decodes an Address20', (): void => {
     const a = registry.createType('MultiAddress', '0x67f89207abe6e1b093befd84a48f033137659292');
 

packages/types/src/generic/MultiAddress.ts

@@ -3,23 +3,25 @@
 
 import type { Registry } from '../types';
 
-import { isBn, isNumber, isString, isU8a } from '@polkadot/util';
+import { isBn, isNumber, isString } from '@polkadot/util';
 import { decodeAddress } from '@polkadot/util-crypto';
 
 import { Enum } from '../codec/Enum';
 import { GenericAccountId } from './AccountId';
 import { GenericAccountIndex } from './AccountIndex';
 
-function decodeMultiU8a (value?: unknown): unknown {
-  if (isU8a(value) && value.length <= 32) {
-    if (value.length === 32) {
-      return { id: value };
-    } else if (value.length === 20) {
-      return { Address20: value };
-    }
+function decodeString (registry: Registry, value: string): unknown {
+  const u8a = decodeAddress(value.toString());
+
+  if (u8a.length === 32) {
+    return { Id: u8a };
+  } else if (u8a.length === 20) {
+    return { Address20: u8a };
+  } else if (u8a.length <= 8) {
+    return { Index: registry.createType('AccountIndex', u8a).toNumber() };
   }
 
-  return value;
+  return u8a;
 }
 
 function decodeMultiAny (registry: Registry, value?: unknown): unknown {
@@ -27,13 +29,13 @@ function decodeMultiAny (registry: Registry, value?: unknown): unknown {
     return value;
   } else if (value instanceof GenericAccountId) {
     return { Id: value };
-  } else if (value instanceof GenericAccountIndex || isNumber(value) || isBn(value)) {
-    return { Index: registry.createType('Compact<AccountIndex>', value) };
+  } else if (value instanceof GenericAccountIndex || isBn(value) || isNumber(value)) {
+    return { Index: isNumber(value) ? value : value.toNumber() };
   } else if (isString(value)) {
-    return decodeMultiU8a(decodeAddress(value.toString()));
+    return decodeString(registry, value.toString());
   }
 
-  return decodeMultiU8a(value);
+  return value;
 }
 
 export class GenericMultiAddress extends Enum {