chore: support deprecating controller by controller

app/core/Engine/controllers/account-tracker-controller-init.test.ts

@@ -11,6 +11,7 @@
 import { MOCK_ANY_NAMESPACE, MockAnyNamespace } from '@metamask/messenger';
 import { selectAssetsAccountApiBalancesEnabled } from '../../../selectors/featureFlagController/assetsAccountApiBalances';
 import { selectBasicFunctionalityEnabled } from '../../../selectors/settings';
+import { selectIsControllerDeprecated } from '../../../selectors/featureFlagController/assetsUnifyState';
 
 jest.mock('@metamask/assets-controllers');
 
@@ -25,6 +26,14 @@
   selectBasicFunctionalityEnabled: jest.fn().mockReturnValue(true),
 }));
 
+jest.mock('../../../selectors/featureFlagController/assetsUnifyState', () => ({
+  selectIsControllerDeprecated: jest.fn().mockReturnValue(() => false),
+}));
+
+jest.mock('../../../store', () => ({
+  store: { getState: jest.fn().mockReturnValue({}) },
+}));
+
 function getInitRequestMock(): jest.Mocked<
   MessengerClientInitRequest<AccountTrackerControllerMessenger>
 > {
@@ -68,6 +77,7 @@
         accountsApiChainIds: expect.any(Function),
         allowExternalServices: expect.any(Function),
         isHomepageSectionsV1Enabled: expect.any(Function),
+        isDeprecated: expect.any(Function),
       }),
     );
   });
@@ -113,4 +123,35 @@
     expect(allowExternalServices()).toBe(false);
     expect(selectBasicFunctionalityEnabled).toHaveBeenCalled();
   });
+
+  describe('isDeprecated', () => {
+    it('returns false when AccountTrackerController is not deprecated', () => {
+      jest.mocked(selectIsControllerDeprecated).mockReturnValue(() => false);
+
+      accountTrackerControllerInit(getInitRequestMock());
+
+      const controllerMock = jest.mocked(AccountTrackerController);
+      const { isDeprecated } = controllerMock.mock.calls[0][0] as {
+        isDeprecated: () => boolean;
+      };
+
+      expect(isDeprecated()).toBe(false);
+      expect(selectIsControllerDeprecated).toHaveBeenCalledWith(
+        'AccountTrackerController',
+      );
+    });
+
+    it('returns true when AccountTrackerController is deprecated', () => {
+      jest.mocked(selectIsControllerDeprecated).mockReturnValue(() => true);
+
+      accountTrackerControllerInit(getInitRequestMock());
+
+      const controllerMock = jest.mocked(AccountTrackerController);
+      const { isDeprecated } = controllerMock.mock.calls[0][0] as {
+        isDeprecated: () => boolean;
+      };
+
+      expect(isDeprecated()).toBe(true);
+    });
+  });
 });

app/core/Engine/controllers/account-tracker-controller-init.ts

@@ -5,6 +5,9 @@ import {
 } from '@metamask/assets-controllers';
 import { selectAssetsAccountApiBalancesEnabled } from '../../../selectors/featureFlagController/assetsAccountApiBalances';
 import { selectBasicFunctionalityEnabled } from '../../../selectors/settings';
+import { selectIsControllerDeprecated } from '../../../selectors/featureFlagController/assetsUnifyState';
+import { store } from '../../../store';
+
 /**
  * Initialize the accountTracker controller.
  *
@@ -34,6 +37,10 @@ export const accountTrackerControllerInit: MessengerClientInitFunction<
       selectAssetsAccountApiBalancesEnabled(getState()) as `0x${string}`[],
     allowExternalServices: () => selectBasicFunctionalityEnabled(getState()),
     isHomepageSectionsV1Enabled: () => true,
+    isDeprecated: () =>
+      selectIsControllerDeprecated('AccountTrackerController')(
+        store.getState(),
+      ),
   });
 
   return {

app/selectors/featureFlagController/assetsUnifyState/index.test.ts

@@ -1,6 +1,8 @@
 import {
   selectIsAssetsUnifyStateEnabled,
   isAssetsUnifyStateFeatureEnabled,
+  getIsDeprecatedController,
+  selectIsControllerDeprecated,
   AssetsUnifyStateFeatureFlag,
   ASSETS_UNIFY_STATE_FLAG,
   ASSETS_UNIFY_STATE_FEATURE_VERSION_1,
@@ -95,3 +97,109 @@ describe('selectIsAssetsUnifyStateEnabled', () => {
     expect(selectIsAssetsUnifyStateEnabled(mockedState)).toBe(false);
   });
 });
+
+describe('getIsDeprecatedController', () => {
+  it('returns true when the controller is listed in deprecatedControllers', () => {
+    const flag: AssetsUnifyStateFeatureFlag = {
+      enabled: true,
+      featureVersion: ASSETS_UNIFY_STATE_FEATURE_VERSION_1,
+      deprecatedControllers: ['AccountTrackerController'],
+    };
+
+    expect(getIsDeprecatedController(flag, 'AccountTrackerController')).toBe(
+      true,
+    );
+  });
+
+  it('returns false when the controller is not listed in deprecatedControllers', () => {
+    const flag: AssetsUnifyStateFeatureFlag = {
+      enabled: true,
+      featureVersion: ASSETS_UNIFY_STATE_FEATURE_VERSION_1,
+      deprecatedControllers: ['SomeOtherController'],
+    };
+
+    expect(getIsDeprecatedController(flag, 'AccountTrackerController')).toBe(
+      false,
+    );
+  });
+
+  it('returns false when deprecatedControllers is empty', () => {
+    const flag: AssetsUnifyStateFeatureFlag = {
+      enabled: true,
+      featureVersion: ASSETS_UNIFY_STATE_FEATURE_VERSION_1,
+      deprecatedControllers: [],
+    };
+
+    expect(getIsDeprecatedController(flag, 'AccountTrackerController')).toBe(
+      false,
+    );
+  });
+
+  it('returns false when deprecatedControllers is absent', () => {
+    const flag: AssetsUnifyStateFeatureFlag = {
+      enabled: true,
+      featureVersion: ASSETS_UNIFY_STATE_FEATURE_VERSION_1,
+    };
+
+    expect(getIsDeprecatedController(flag, 'AccountTrackerController')).toBe(
+      false,
+    );
+  });
+
+  it('returns false when flagValue is undefined', () => {
+    expect(
+      getIsDeprecatedController(undefined, 'AccountTrackerController'),
+    ).toBe(false);
+  });
+
+  it('returns false when flagValue is null', () => {
+    expect(getIsDeprecatedController(null, 'AccountTrackerController')).toBe(
+      false,
+    );
+  });
+});
+
+describe('selectIsControllerDeprecated', () => {
+  it('returns true when the controller is listed in deprecatedControllers', () => {
+    const mockedState = mockStateWith({
+      enabled: true,
+      featureVersion: ASSETS_UNIFY_STATE_FEATURE_VERSION_1,
+      deprecatedControllers: ['AccountTrackerController'],
+    });
+
+    expect(
+      selectIsControllerDeprecated('AccountTrackerController')(mockedState),
+    ).toBe(true);
+  });
+
+  it('returns false when deprecatedControllers is empty', () => {
+    const mockedState = mockStateWith({
+      enabled: true,
+      featureVersion: ASSETS_UNIFY_STATE_FEATURE_VERSION_1,
+      deprecatedControllers: [],
+    });
+
+    expect(
+      selectIsControllerDeprecated('AccountTrackerController')(mockedState),
+    ).toBe(false);
+  });
+
+  it('returns false when deprecatedControllers is absent', () => {
+    const mockedState = mockStateWith({
+      enabled: true,
+      featureVersion: ASSETS_UNIFY_STATE_FEATURE_VERSION_1,
+    });
+
+    expect(
+      selectIsControllerDeprecated('AccountTrackerController')(mockedState),
+    ).toBe(false);
+  });
+
+  it('returns false when the flag is missing from state', () => {
+    expect(
+      selectIsControllerDeprecated('AccountTrackerController')(
+        mockedUndefinedFlagsState,
+      ),
+    ).toBe(false);
+  });
+});

app/selectors/featureFlagController/assetsUnifyState/index.ts

@@ -7,6 +7,7 @@ import { selectRemoteFeatureFlags } from '..';
 export interface AssetsUnifyStateFeatureFlag {
   enabled: boolean;
   featureVersion: string | null;
+  deprecatedControllers?: string[];
 }
 
 export const ASSETS_UNIFY_STATE_FLAG = 'assetsUnifyState';
@@ -35,6 +36,33 @@ export const isAssetsUnifyStateFeatureEnabled = (
   );
 };
 
+/**
+ * Checks if a controller is deprecated based on the assets unify state feature flag.
+ *
+ * @param flagValue - The raw feature flag value.
+ * @param controllerName - The name of the controller to check.
+ * @returns True if the controller is listed in deprecatedControllers, false otherwise.
+ */
+export const getIsDeprecatedController = (
+  flagValue: unknown,
+  controllerName: string,
+): boolean => {
+  if (!flagValue || typeof flagValue !== 'object') return false;
+  const parsed = flagValue as AssetsUnifyStateFeatureFlag;
+  return parsed.deprecatedControllers?.includes(controllerName) ?? false;
+};
+
+/**
+ * Selector factory to check if a specific controller is deprecated.
+ *
+ * @param controllerName - The name of the controller to check.
+ * @returns A selector that returns true if the controller is deprecated.
+ */
+export const selectIsControllerDeprecated = (controllerName: string) =>
+  createSelector(selectRemoteFeatureFlags, (flags) =>
+    getIsDeprecatedController(flags[ASSETS_UNIFY_STATE_FLAG], controllerName),
+  );
+
 /**
  * Selector to check if the assets unify state feature is enabled.
  * @returns Boolean indicating if the assets unify state feature is enabled.

tests/feature-flags/feature-flag-registry.ts

@@ -250,6 +250,13 @@ export const FEATURE_FLAG_REGISTRY: Record<string, FeatureFlagRegistryEntry> = {
           enabled: false,
           featureVersion: null,
           minimumVersion: null,
+          deprecatedControllers: [],
+        },
+        '8.3.0': {
+          enabled: true,
+          featureVersion: '1',
+          minimumVersion: '8.3.0',
+          deprecatedControllers: [],
         },
       },
     },