feat: PortfolioView: Add feature flag check for polling intervals (#2…

…8501)

## **Description**

Adds a remote endpoint check to see if the remote API wants us to update
the number of seconds between polling intervals for balances.

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also include relevant motivation and context. Have in mind the following
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## **Related issues**

Fixes:

## **Manual testing steps**

1. Open the extension
2. See the network request being made in the Networks devtools panel
3. Change conditional in response to `if (true) {` and hardcode a
`pollInterval` value
4. See `this.tokenBalancesController.setIntervalLength` successfully
called.

## **Screenshots/Recordings**

<!-- If applicable, add screenshots and/or recordings to visualize the
before and after of your change. -->

### **Before**

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### **After**

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## **Pre-merge author checklist**

- [ ] I've followed [MetaMask Contributor
Docs](https://github.com/MetaMask/contributor-docs) and [MetaMask
Extension Coding
Standards](https://github.com/MetaMask/metamask-extension/blob/develop/.github/guidelines/CODING_GUIDELINES.md).
- [ ] I've completed the PR template to the best of my ability
- [ ] I’ve included tests if applicable
- [ ] I’ve documented my code using [JSDoc](https://jsdoc.app/) format
if applicable
- [ ] I’ve applied the right labels on the PR (see [labeling
guidelines](https://github.com/MetaMask/metamask-extension/blob/develop/.github/guidelines/LABELING_GUIDELINES.md)).
Not required for external contributors.

## **Pre-merge reviewer checklist**

- [ ] I've manually tested the PR (e.g. pull and build branch, run the
app, test code being changed).
- [ ] I confirm that this PR addresses all acceptance criteria described
in the ticket it closes and includes the necessary testing evidence such
as recordings and or screenshots.

app/scripts/metamask-controller.js

@@ -195,7 +195,7 @@ import {
   ExcludedSnapEndowments,
 } from '../../shared/constants/permissions';
 import { UI_NOTIFICATIONS } from '../../shared/notifications';
-import { MILLISECOND, SECOND } from '../../shared/constants/time';
+import { MILLISECOND, MINUTE, SECOND } from '../../shared/constants/time';
 import {
   ORIGIN_METAMASK,
   POLLING_TOKEN_ENVIRONMENT_TYPES,
@@ -244,6 +244,7 @@ import { endTrace, trace } from '../../shared/lib/trace';
 // eslint-disable-next-line import/no-restricted-paths
 import { isSnapId } from '../../ui/helpers/utils/snaps';
 import { BridgeStatusAction } from '../../shared/types/bridge-status';
+import fetchWithCache from '../../shared/lib/fetch-with-cache';
 import { BalancesController as MultichainBalancesController } from './lib/accounts/BalancesController';
 import {
   ///: BEGIN:ONLY_INCLUDE_IF(build-mmi)
@@ -2637,6 +2638,29 @@ export default class MetamaskController extends EventEmitter {
     }
   }
 
+  // Provides a method for getting feature flags for the multichain
+  // initial rollout, such that we can remotely modify polling interval
+  getInfuraFeatureFlags() {
+    fetchWithCache({
+      url: 'https://swap.api.cx.metamask.io/featureFlags',
+      cacheRefreshTime: MINUTE * 20,
+    })
+      .then(this.onFeatureFlagResponseReceived)
+      .catch((e) => {
+        // API unreachable (?)
+        log.warn('Feature flag endpoint is unreachable', e);
+      });
+  }
+
+  onFeatureFlagResponseReceived(response) {
+    const { multiChainAssets = {} } = response;
+    const { pollInterval } = multiChainAssets;
+    // Polling interval is provided in seconds
+    if (pollInterval > 0) {
+      this.tokenBalancesController.setIntervalLength(pollInterval * SECOND);
+    }
+  }
+
   postOnboardingInitialization() {
     const { usePhishDetect } = this.preferencesController.state;
 
@@ -2669,6 +2693,7 @@ export default class MetamaskController extends EventEmitter {
   triggerNetworkrequests() {
     this.txController.startIncomingTransactionPolling();
     this.tokenDetectionController.enable();
+    this.getInfuraFeatureFlags();
   }
 
   stopNetworkRequests() {

app/scripts/metamask-controller.test.js

@@ -39,6 +39,7 @@ import { flushPromises } from '../../test/lib/timer-helpers';
 import { ETH_EOA_METHODS } from '../../shared/constants/eth-methods';
 import { createMockInternalAccount } from '../../test/jest/mocks';
 import { mockNetworkState } from '../../test/stub/networks';
+import { SECOND } from '../../shared/constants/time';
 import {
   BalancesController as MultichainBalancesController,
   BTC_BALANCES_UPDATE_TIME as MULTICHAIN_BALANCES_UPDATE_TIME,
@@ -2632,6 +2633,56 @@ describe('MetaMaskController', () => {
     });
   });
 
+  describe('onFeatureFlagResponseReceived', () => {
+    const metamaskController = new MetaMaskController({
+      showUserConfirmation: noop,
+      encryptor: mockEncryptor,
+      initState: cloneDeep(firstTimeState),
+      initLangCode: 'en_US',
+      platform: {
+        showTransactionNotification: () => undefined,
+        getVersion: () => 'foo',
+      },
+      browser: browserPolyfillMock,
+      infuraProjectId: 'foo',
+      isFirstMetaMaskControllerSetup: true,
+    });
+
+    beforeEach(() => {
+      jest.spyOn(
+        metamaskController.tokenBalancesController,
+        'setIntervalLength',
+      );
+    });
+
+    afterEach(() => {
+      jest.clearAllMocks();
+    });
+
+    it('should not set the interval length if the pollInterval is 0', () => {
+      metamaskController.onFeatureFlagResponseReceived({
+        multiChainAssets: {
+          pollInterval: 0,
+        },
+      });
+      expect(
+        metamaskController.tokenBalancesController.setIntervalLength,
+      ).not.toHaveBeenCalled();
+    });
+
+    it('should set the interval length if the pollInterval is greater than 0', () => {
+      const pollInterval = 10;
+      metamaskController.onFeatureFlagResponseReceived({
+        multiChainAssets: {
+          pollInterval,
+        },
+      });
+      expect(
+        metamaskController.tokenBalancesController.setIntervalLength,
+      ).toHaveBeenCalledWith(pollInterval * SECOND);
+    });
+  });
+
   describe('MV3 Specific behaviour', () => {
     beforeAll(async () => {
       mockIsManifestV3.mockReturnValue(true);