feat: add KeyringV2 wrapper and adapters

README.md

@@ -52,6 +52,7 @@ linkStyle default opacity:0.5
   account_api --> keyring_api;
   account_api --> keyring_utils;
   keyring_api --> keyring_utils;
+  eth_hd_keyring --> keyring_api;
   eth_hd_keyring --> keyring_utils;
   eth_ledger_bridge_keyring --> keyring_utils;
   eth_qr_keyring --> keyring_utils;

packages/keyring-api/CHANGELOG.md

@@ -7,6 +7,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- Add `KeyringWrapper` base class to adapt legacy keyrings to `KeyringV2` ([#398](https://github.com/MetaMask/accounts/pull/398))
+- Add unified `KeyringV2` interface ([#397](https://github.com/MetaMask/accounts/pull/397))
+
 ## [21.2.0]
 
 ### Added

packages/keyring-api/README.md

@@ -230,6 +230,10 @@ A unified keyring interface, designed to work for both native (EVM) keyrings and
 - Interface name: `KeyringV2`
 - Location: `@metamask/keyring-api/src/api/v2/keyring.ts`
 
+### Keyring wrapper
+
+The `KeyringWrapper` helper adapts existing keyrings that implement the legacy `Keyring` interface to the new `KeyringV2` interface. It is intended to be subclassed in concrete keyrings, overriding the account management and request-handling methods to delegate to the underlying implementation.
+
 ## Migrating from 0.1.x to 0.2.x
 
 The following changes were made to the API, which may require changes to your

packages/keyring-api/package.json

@@ -49,7 +49,9 @@
     "@metamask/keyring-utils": "workspace:^",
     "@metamask/superstruct": "^3.1.0",
     "@metamask/utils": "^11.1.0",
-    "bitcoin-address-validation": "^2.2.3"
+    "@types/uuid": "^9.0.8",
+    "bitcoin-address-validation": "^2.2.3",
+    "uuid": "^9.0.1"
   },
   "devDependencies": {
     "@lavamoat/allow-scripts": "^3.2.1",

packages/keyring-api/src/api/v2/index.ts

@@ -4,3 +4,4 @@ export * from './keyring-type';
 export * from './create-account';
 export * from './export-account';
 export * from './private-key';
+export * from './wrapper';

packages/keyring-api/src/api/v2/wrapper/index.ts

@@ -0,0 +1,2 @@
+export * from './keyring-wrapper';
+export * from './keyring-address-resolver';

packages/keyring-api/src/api/v2/wrapper/keyring-address-resolver.test.ts

@@ -0,0 +1,28 @@
+import { InMemoryKeyringAddressResolver } from './keyring-address-resolver';
+
+describe('InMemoryKeyringAddressResolver', () => {
+  it('registers and resolves account IDs and addresses', () => {
+    const resolver = new InMemoryKeyringAddressResolver();
+
+    const address = '0xaBc';
+    const id = resolver.register(address);
+
+    expect(typeof id).toBe('string');
+
+    const resolvedAddress = resolver.getAddress(id);
+    expect(resolvedAddress).toBe(address);
+
+    const resolvedId = resolver.getAccountId(address);
+    expect(resolvedId).toBe(id);
+  });
+
+  it('reuses the same ID when registering the same address', () => {
+    const resolver = new InMemoryKeyringAddressResolver();
+
+    const address = '0xaBc';
+    const firstId = resolver.register(address);
+    const secondId = resolver.register(address);
+
+    expect(firstId).toBe(secondId);
+  });
+});

packages/keyring-api/src/api/v2/wrapper/keyring-address-resolver.ts

@@ -0,0 +1,54 @@
+import type { AccountId } from '@metamask/keyring-utils';
+import { v4 as uuidv4 } from 'uuid';
+
+/**
+ * Mapping between an internal AccountId and the underlying keyring address.
+ */
+export type KeyringAddressResolver = {
+  /**
+   * Resolve an AccountId into an underlying address.
+   */
+  getAddress(accountId: AccountId): string | undefined;
+
+  /**
+   * Resolve an underlying address into an AccountId.
+   */
+  getAccountId(address: string): AccountId | undefined;
+
+  /**
+   * Register a new mapping. Implementations are free to decide how the
+   * AccountId is generated (e.g. UUIDv4).
+   */
+  register(address: string): AccountId;
+};
+
+/**
+ * Simple in-memory AccountId/address resolver used by default. This is mostly
+ * intended for controller-managed lifecycles where wrappers live in memory.
+ */
+export class InMemoryKeyringAddressResolver implements KeyringAddressResolver {
+  readonly #idByAddress = new Map<string, AccountId>();
+
+  readonly #addressById = new Map<AccountId, string>();
+
+  getAddress(accountId: AccountId): string | undefined {
+    return this.#addressById.get(accountId);
+  }
+
+  getAccountId(address: string): AccountId | undefined {
+    return this.#idByAddress.get(address);
+  }
+
+  register(address: string): AccountId {
+    const existing = this.#idByAddress.get(address);
+    if (existing) {
+      return existing;
+    }
+    const id = uuidv4();
+
+    this.#idByAddress.set(address, id);
+    this.#addressById.set(id, address);
+
+    return id;
+  }
+}

packages/keyring-api/src/api/v2/wrapper/keyring-wrapper.test.ts

@@ -0,0 +1,203 @@
+import type { Keyring, AccountId } from '@metamask/keyring-utils';
+import type { Hex, Json } from '@metamask/utils';
+import { v4 as uuidv4 } from 'uuid';
+
+import { InMemoryKeyringAddressResolver } from './keyring-address-resolver';
+import { KeyringWrapper } from './keyring-wrapper';
+import type { KeyringAccount } from '../../account';
+import type { KeyringCapabilities } from '../keyring-capabilities';
+import { KeyringType } from '../keyring-type';
+
+class TestKeyringWrapper extends KeyringWrapper<TestKeyring> {
+  async getAccounts(): Promise<KeyringAccount[]> {
+    const addresses = await this.inner.getAccounts();
+    const scopes = this.capabilities.scopes ?? ['eip155:1'];
+
+    return addresses.map((address) => {
+      const id = this.resolver.register(address);
+
+      const account: KeyringAccount = {
+        id,
+        type: 'eip155:eoa',
+        address,
+        scopes,
+        options: {},
+        methods: [],
+      };
+
+      return account;
+    });
+  }
+
+  public deletedAccountIds: AccountId[] = [];
+
+  async createAccounts(): Promise<KeyringAccount[]> {
+    return this.getAccounts();
+  }
+
+  async deleteAccount(accountId: AccountId): Promise<void> {
+    this.deletedAccountIds.push(accountId);
+  }
+
+  async submitRequest(): Promise<any> {
+    return {};
+  }
+}
+
+class TestKeyring implements Keyring {
+  static type = 'Test Keyring';
+
+  public type = TestKeyring.type;
+
+  readonly #accounts: Hex[];
+
+  public lastDeserializedState: Json | undefined;
+
+  constructor(addresses: Hex[] = []) {
+    this.#accounts = addresses;
+  }
+
+  async serialize(): Promise<Json> {
+    return { accounts: this.#accounts };
+  }
+
+  async deserialize(state: Json): Promise<void> {
+    this.lastDeserializedState = state;
+  }
+
+  async getAccounts(): Promise<Hex[]> {
+    return this.#accounts;
+  }
+
+  async addAccounts(_numberOfAccounts = 1): Promise<Hex[]> {
+    return this.#accounts;
+  }
+}
+
+const capabilities: KeyringCapabilities = {
+  scopes: ['eip155:10'],
+};
+
+const entropySourceId = 'test-entropy-source';
+
+describe('KeyringWrapper', () => {
+  it('serializes and deserializes via the inner keyring', async () => {
+    const inner = new TestKeyring(['0x1']);
+    const wrapper = new TestKeyringWrapper({
+      inner,
+      type: KeyringType.Hd,
+      capabilities,
+      entropySourceId,
+    });
+
+    const state = await wrapper.serialize();
+    expect(state).toStrictEqual({ accounts: ['0x1'] });
+
+    await wrapper.deserialize(state);
+    expect(inner.lastDeserializedState).toStrictEqual(state);
+  });
+
+  it('returns accounts with stable IDs and correct addresses', async () => {
+    const addresses = ['0x1' as const, '0x2' as const];
+    const inner = new TestKeyring(addresses);
+    const wrapper = new TestKeyringWrapper({
+      inner,
+      type: KeyringType.Hd,
+      capabilities,
+      entropySourceId,
+    });
+
+    const accounts = await wrapper.getAccounts();
+
+    expect(accounts).toHaveLength(addresses.length);
+
+    const ids = new Set<string>();
+    accounts.forEach((account: KeyringAccount, index) => {
+      expect(account.address).toBe(addresses[index]);
+      expect(account.type).toBe('eip155:eoa');
+      expect(account.scopes).toStrictEqual(capabilities.scopes);
+      expect(account.options).toStrictEqual({});
+      expect(account.methods).toStrictEqual([]);
+
+      ids.add(account.id);
+    });
+
+    // Ensure IDs are unique
+    expect(ids.size).toBe(addresses.length);
+
+    // getAccount should resolve by ID
+    const [firstAccount] = accounts;
+    expect(firstAccount).toBeDefined();
+    if (!firstAccount) {
+      throw new Error('Expected at least one account from the wrapper');
+    }
+    const resolved = await wrapper.getAccount(firstAccount.id);
+    expect(resolved.address).toBe(firstAccount.address);
+  });
+
+  it('throws when requesting an unknown account', async () => {
+    const inner = new TestKeyring([]);
+    const wrapper = new TestKeyringWrapper({
+      inner,
+      type: KeyringType.Hd,
+      capabilities,
+      entropySourceId,
+    });
+
+    await expect(wrapper.getAccount(uuidv4())).rejects.toThrow(
+      'Account not found for id',
+    );
+  });
+
+  it('throws when account mapping exists but account object cannot be found', async () => {
+    const addresses = ['0x1' as const];
+    const inner = new TestKeyring(addresses);
+    const resolver = new InMemoryKeyringAddressResolver();
+    const wrapper = new TestKeyringWrapper({
+      inner,
+      type: KeyringType.Hd,
+      capabilities,
+      resolver,
+      entropySourceId,
+    });
+
+    // Prime the resolver by calling getAccounts once
+    await wrapper.getAccounts();
+
+    // Now, simulate a missing account object by clearing the underlying
+    // accounts of the inner keyring.
+    const emptyInner = new TestKeyring([] as Hex[]);
+    const inconsistentWrapper = new TestKeyringWrapper({
+      inner: emptyInner,
+      type: KeyringType.Hd,
+      capabilities,
+      resolver,
+      entropySourceId,
+    });
+
+    const accountId = resolver.getAccountId(
+      addresses[0] as string,
+    ) as AccountId;
+
+    await expect(inconsistentWrapper.getAccount(accountId)).rejects.toThrow(
+      'Account not found for id',
+    );
+  });
+
+  it('falls back to mainnet scope when capabilities.scopes is not set', async () => {
+    const addresses = ['0x1' as const];
+    const inner = new TestKeyring(addresses);
+    const wrapper = new TestKeyringWrapper({
+      inner,
+      type: KeyringType.Hd,
+      entropySourceId,
+      // Explicitly omit scopes to exercise the default fallback.
+      capabilities: {} as KeyringCapabilities,
+    });
+
+    const accounts = await wrapper.getAccounts();
+
+    expect(accounts).toHaveLength(1);
+    expect(accounts[0]?.scopes).toStrictEqual(['eip155:1']);
+  });
+});