feat(wallet): wire ApprovalController into default initialization

.github/CODEOWNERS

@@ -129,6 +129,7 @@
 /packages/profile-metrics-controller            @MetaMask/mobile-platform @MetaMask/extension-platform
 
 ## Initialization
+/packages/wallet/src/initialization/instances/approval-controller/ @MetaMask/confirmations
 /packages/wallet/src/initialization/instances/keyring-controller.ts @MetaMask/accounts-engineers @MetaMask/core-platform
 
 ## Package Release related

README.md

@@ -567,7 +567,9 @@ linkStyle default opacity:0.5
   user_operation_controller --> polling_controller;
   user_operation_controller --> transaction_controller;
   user_operation_controller --> eth_block_tracker;
+  wallet --> approval_controller;
   wallet --> base_controller;
+  wallet --> controller_utils;
   wallet --> keyring_controller;
   wallet --> messenger;
   wallet --> storage_service;

packages/wallet/CHANGELOG.md

@@ -7,6 +7,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- **BREAKING:** Wire `ApprovalController` into the default wallet initialization ([#8953](https://github.com/MetaMask/core/pull/8953))
+  - The default `Wallet` now constructs an `ApprovalController` and registers its `ApprovalController:*` messenger actions. Consumers that pass their own `messenger` and already wire an `ApprovalController` must remove their own before upgrading, or the duplicate registration will collide.
+  - Adds an `approvalController` slot to `instanceOptions` with `showApprovalRequest` (the callback that surfaces pending approval requests to the user; defaults to a no-op) and `typesExcludedFromRateLimiting` (the approval types exempt from per-origin rate limiting; defaults to a baseline of EVM approval types). Both let consumers (extension, mobile, wallet-cli) inject their platform-specific values.
+
 ## [2.0.0]
 
 ### Added

packages/wallet/package.json

@@ -53,8 +53,10 @@
     "test:watch": "NODE_OPTIONS=--experimental-vm-modules jest --watch"
   },
   "dependencies": {
+    "@metamask/approval-controller": "^9.0.1",
     "@metamask/base-controller": "^9.1.0",
     "@metamask/browser-passworder": "^6.0.0",
+    "@metamask/controller-utils": "^12.1.0",
     "@metamask/keyring-controller": "^26.0.0",
     "@metamask/messenger": "^1.2.0",
     "@metamask/scure-bip39": "^2.1.1",

packages/wallet/src/initialization/instances/approval-controller/approval-controller.test.ts

@@ -0,0 +1,148 @@
+import { ApprovalController } from '@metamask/approval-controller';
+import { ApprovalType } from '@metamask/controller-utils';
+import { Messenger } from '@metamask/messenger';
+
+import { defaultConfigurations } from '../../defaults';
+import type {
+  DefaultActions,
+  DefaultEvents,
+  RootMessenger,
+} from '../../defaults';
+import { approvalController } from './approval-controller';
+
+/**
+ * Creates a root messenger for use in tests.
+ *
+ * @returns A root messenger.
+ */
+function getRootMessenger(): RootMessenger<DefaultActions, DefaultEvents> {
+  return new Messenger({ namespace: 'Root' });
+}
+
+describe('approvalController', () => {
+  it('is registered as a default initialization configuration', () => {
+    // Proves the controller is part of the default ensemble that `initialize()`
+    // wires, without constructing a `Wallet` (which keeps this PR independent of
+    // the constructor-options shape).
+    expect(Object.values(defaultConfigurations)).toContain(approvalController);
+  });
+
+  it('initializes an ApprovalController with default state', () => {
+    const messenger = approvalController.getMessenger(getRootMessenger());
+
+    const instance = approvalController.init({
+      state: undefined,
+      messenger,
+      options: {},
+    });
+
+    expect(instance).toBeInstanceOf(ApprovalController);
+    expect(instance.state).toStrictEqual({
+      pendingApprovals: {},
+      pendingApprovalCount: 0,
+      approvalFlows: [],
+    });
+  });
+
+  it('forwards the provided state to the controller', () => {
+    const messenger = approvalController.getMessenger(getRootMessenger());
+
+    const instance = approvalController.init({
+      state: {
+        pendingApprovals: {},
+        pendingApprovalCount: 3,
+        approvalFlows: [],
+      },
+      messenger,
+      options: {},
+    });
+
+    expect(instance.state.pendingApprovalCount).toBe(3);
+  });
+
+  it('uses the provided showApprovalRequest callback', () => {
+    const messenger = approvalController.getMessenger(getRootMessenger());
+    const showApprovalRequest = jest.fn();
+
+    const instance = approvalController.init({
+      state: undefined,
+      messenger,
+      options: { showApprovalRequest },
+    });
+
+    instance.startFlow();
+
+    expect(showApprovalRequest).toHaveBeenCalledTimes(1);
+  });
+
+  it('defaults showApprovalRequest to a no-op when omitted', () => {
+    const messenger = approvalController.getMessenger(getRootMessenger());
+
+    const instance = approvalController.init({
+      state: undefined,
+      messenger,
+      options: {},
+    });
+
+    expect(() => instance.startFlow()).not.toThrow();
+  });
+
+  // Pins the exact default exclusion set (independent of the source constant):
+  // each of these types must allow multiple pending requests from one origin.
+  // The pending promises never settle here; `.catch` only marks them handled.
+  it.each([
+    ApprovalType.PersonalSign,
+    ApprovalType.EthSignTypedData,
+    ApprovalType.Transaction,
+    ApprovalType.WatchAsset,
+    ApprovalType.EthGetEncryptionPublicKey,
+    ApprovalType.EthDecrypt,
+  ])('excludes %s from rate limiting by default', (type) => {
+    const messenger = approvalController.getMessenger(getRootMessenger());
+
+    const instance = approvalController.init({
+      state: undefined,
+      messenger,
+      options: {},
+    });
+
+    instance.add({ origin: 'metamask.io', type }).catch(() => undefined);
+    instance.add({ origin: 'metamask.io', type }).catch(() => undefined);
+
+    // Both requests are queued rather than the second being rejected.
+    expect(instance.state.pendingApprovalCount).toBe(2);
+  });
+
+  it('honors a custom typesExcludedFromRateLimiting list that overrides the default', () => {
+    const messenger = approvalController.getMessenger(getRootMessenger());
+
+    const instance = approvalController.init({
+      state: undefined,
+      messenger,
+      // Empty override: nothing is excluded, not even the default types.
+      options: { typesExcludedFromRateLimiting: [] },
+    });
+
+    instance
+      .add({ origin: 'metamask.io', type: ApprovalType.Transaction })
+      .catch(() => undefined);
+
+    // A second request of the same origin and type is now rate-limited.
+    expect(() =>
+      instance.add({ origin: 'metamask.io', type: ApprovalType.Transaction }),
+    ).toThrow('already pending');
+  });
+
+  it('exposes its actions through the root messenger', () => {
+    const rootMessenger = getRootMessenger();
+    const messenger = approvalController.getMessenger(rootMessenger);
+
+    approvalController.init({ state: undefined, messenger, options: {} });
+
+    expect(rootMessenger.call('ApprovalController:getState')).toStrictEqual({
+      pendingApprovals: {},
+      pendingApprovalCount: 0,
+      approvalFlows: [],
+    });
+  });
+});

packages/wallet/src/initialization/instances/approval-controller/approval-controller.ts

@@ -0,0 +1,49 @@
+import {
+  ApprovalController,
+  ApprovalControllerMessenger,
+} from '@metamask/approval-controller';
+import { ApprovalType } from '@metamask/controller-utils';
+import { Messenger } from '@metamask/messenger';
+
+import { InitializationConfiguration } from '../../types';
+
+/**
+ * Approval types that are exempt from per-origin rate limiting, so more than one
+ * request of the same type can be pending at once. These are the common EVM
+ * types: signing, transactions, watch-asset, and encryption.
+ *
+ * Clients can replace this list via
+ * `instanceOptions.approvalController.typesExcludedFromRateLimiting` — the
+ * extension and mobile pass their own. `snap_dialog` will be added here once the
+ * wallet wires `SnapController`.
+ */
+const DEFAULT_TYPES_EXCLUDED_FROM_RATE_LIMITING = [
+  ApprovalType.PersonalSign,
+  ApprovalType.EthSignTypedData,
+  ApprovalType.Transaction,
+  ApprovalType.WatchAsset,
+  ApprovalType.EthGetEncryptionPublicKey,
+  ApprovalType.EthDecrypt,
+];
+
+export const approvalController: InitializationConfiguration<
+  ApprovalController,
+  ApprovalControllerMessenger
+> = {
+  name: 'ApprovalController',
+  init: ({ state, messenger, options }) =>
+    new ApprovalController({
+      state,
+      messenger,
+      showApprovalRequest:
+        options.showApprovalRequest ?? ((): void => undefined),
+      typesExcludedFromRateLimiting:
+        options.typesExcludedFromRateLimiting ??
+        DEFAULT_TYPES_EXCLUDED_FROM_RATE_LIMITING,
+    }),
+  getMessenger: (parent) =>
+    new Messenger({
+      namespace: 'ApprovalController',
+      parent,
+    }),
+};

packages/wallet/src/initialization/instances/approval-controller/types.ts

@@ -0,0 +1,23 @@
+import type {
+  ApprovalControllerOptions,
+  ShowApprovalRequest,
+} from '@metamask/approval-controller';
+
+/**
+ * Per-instance options for the wallet's `ApprovalController`. Both fields are
+ * optional; see the controller's `init` for the defaults applied when omitted.
+ */
+export type ApprovalControllerInstanceOptions = {
+  /**
+   * Callback that surfaces a pending approval request to the user. Defaults to
+   * a no-op so the controller works headlessly.
+   */
+  showApprovalRequest?: ShowApprovalRequest;
+  /**
+   * Approval types exempt from per-origin rate limiting. Defaults to a baseline
+   * of EVM approval types.
+   */
+  typesExcludedFromRateLimiting?: NonNullable<
+    ApprovalControllerOptions['typesExcludedFromRateLimiting']
+  >;
+};

packages/wallet/src/initialization/instances/index.ts

@@ -1,2 +1,3 @@
+export { approvalController } from './approval-controller/approval-controller';
 export { keyringController } from './keyring-controller';
 export { storageService } from './storage-service';

packages/wallet/src/types.ts

@@ -7,6 +7,7 @@ import type {
   DefaultEvents,
   RootMessenger,
 } from './initialization/defaults';
+import type { ApprovalControllerInstanceOptions } from './initialization/instances/approval-controller/types';
 import { GenericEncryptor } from './initialization/instances/keyring-controller';
 import { InitializationConfiguration } from './initialization/types';
 
@@ -21,6 +22,7 @@ export type WalletOptions = {
 };
 
 export type InstanceSpecificOptions = {
+  approvalController?: ApprovalControllerInstanceOptions;
   keyringController?: {
     encryptor?: GenericEncryptor;
     keyringBuilders?: KeyringControllerOptions['keyringBuilders'];

packages/wallet/tsconfig.build.json

@@ -6,7 +6,9 @@
     "rootDir": "./src"
   },
   "references": [
+    { "path": "../approval-controller/tsconfig.build.json" },
     { "path": "../base-controller/tsconfig.build.json" },
+    { "path": "../controller-utils/tsconfig.build.json" },
     { "path": "../keyring-controller/tsconfig.build.json" },
     { "path": "../messenger/tsconfig.build.json" },
     { "path": "../storage-service/tsconfig.build.json" }

packages/wallet/tsconfig.json

@@ -4,7 +4,9 @@
     "baseUrl": "./"
   },
   "references": [
+    { "path": "../approval-controller/tsconfig.json" },
     { "path": "../base-controller/tsconfig.json" },
+    { "path": "../controller-utils/tsconfig.json" },
     { "path": "../keyring-controller/tsconfig.json" },
     { "path": "../messenger/tsconfig.json" },
     { "path": "../storage-service/tsconfig.json" }

yarn.lock

@@ -5885,9 +5885,11 @@ __metadata:
   version: 0.0.0-use.local
   resolution: "@metamask/wallet@workspace:packages/wallet"
   dependencies:
+    "@metamask/approval-controller": "npm:^9.0.1"
     "@metamask/auto-changelog": "npm:^6.1.0"
     "@metamask/base-controller": "npm:^9.1.0"
     "@metamask/browser-passworder": "npm:^6.0.0"
+    "@metamask/controller-utils": "npm:^12.1.0"
     "@metamask/keyring-controller": "npm:^26.0.0"
     "@metamask/messenger": "npm:^1.2.0"
     "@metamask/scure-bip39": "npm:^2.1.1"