chore: Simplify TokenListController initialization

packages/assets-controllers/src/TokenListController.test.ts

@@ -1414,6 +1414,7 @@ describe('TokenListController', () => {
         chainId: ChainId.mainnet,
         messenger: restrictedMessenger,
       });
+      await controller1.initialize();
 
       nock(tokenService.TOKEN_END_POINT_API)
         .get(getTokensPath(ChainId.mainnet))
@@ -1451,6 +1452,7 @@ describe('TokenListController', () => {
         chainId: ChainId.mainnet,
         messenger: restrictedMessenger,
       });
+      await controller.initialize();
 
       await controller.fetchTokenList(ChainId.mainnet);
 
@@ -1473,6 +1475,102 @@ describe('TokenListController', () => {
       controller.destroy();
     });
 
+    it('should not save to StorageService before initialization', async () => {
+      const messenger = getMessenger();
+      const restrictedMessenger = getRestrictedMessenger(messenger);
+
+      // Create controller and fetch tokens
+      const controller1 = new TokenListController({
+        chainId: ChainId.mainnet,
+        messenger: restrictedMessenger,
+      });
+      // skip initialization
+
+      nock(tokenService.TOKEN_END_POINT_API)
+        .get(getTokensPath(ChainId.mainnet))
+        .reply(200, sampleMainnetTokenList);
+
+      await controller1.fetchTokenList(ChainId.mainnet);
+      expect(
+        controller1.state.tokensChainsCache[ChainId.mainnet],
+      ).toBeDefined();
+
+      // Wait for debounced persistence to complete (500ms + buffer)
+      await new Promise((resolve) => setTimeout(resolve, 600));
+
+      controller1.destroy();
+
+      // Verify data is in StorageService (per-chain file)
+      const chainStorageKey = `tokensChainsCache:${ChainId.mainnet}`;
+      const { result } = await messenger.call(
+        'StorageService:getItem',
+        'TokenListController',
+        chainStorageKey,
+      );
+
+      expect(result).toBeUndefined();
+    });
+
+    it('should save data updated before initialization to StorageService', async () => {
+      // Setup stale mainnet data in storage
+      const validChainData: DataCache = {
+        data: sampleMainnetTokensChainsCache,
+        timestamp: 1,
+      };
+      mockStorage.set(
+        `TokenListController:tokensChainsCache:${ChainId.mainnet}`,
+        validChainData,
+      );
+      const messenger = getMessenger();
+      const restrictedMessenger = getRestrictedMessenger(messenger);
+
+      // Create controller with delayed initialization, and fetch tokens
+      const controller = new TokenListController({
+        chainId: ChainId.mainnet,
+        messenger: restrictedMessenger,
+      });
+
+      nock(tokenService.TOKEN_END_POINT_API)
+        .get(getTokensPath(ChainId.mainnet))
+        .reply(200, sampleMainnetTokenList);
+      nock(tokenService.TOKEN_END_POINT_API)
+        .get(getTokensPath(toHex(56)))
+        .reply(200, sampleBinanceTokenList);
+
+      await controller.fetchTokenList(ChainId.mainnet);
+      await controller.fetchTokenList(toHex(56));
+      const savedCache = controller.state.tokensChainsCache;
+      expect(savedCache[ChainId.mainnet]).toBeDefined();
+      expect(savedCache[toHex(56)]).toBeDefined();
+      await controller.initialize();
+
+      // Wait for debounced persistence to complete (500ms + buffer)
+      await new Promise((resolve) => setTimeout(resolve, 600));
+
+      controller.destroy();
+
+      // Verify data is in StorageService (per-chain file)
+      const mainnetStorageKey = `tokensChainsCache:${ChainId.mainnet}`;
+      const { result: mainnetResult } = await messenger.call(
+        'StorageService:getItem',
+        'TokenListController',
+        mainnetStorageKey,
+      );
+      const binanceStorageKey = `tokensChainsCache:${toHex(56)}`;
+      const { result: binanceResult } = await messenger.call(
+        'StorageService:getItem',
+        'TokenListController',
+        binanceStorageKey,
+      );
+
+      // Confirm fresh results overwrite stale
+      expect(mainnetResult).toBeDefined();
+      expect(mainnetResult).toStrictEqual(savedCache[ChainId.mainnet]);
+      // Confirm results not in storage previously are persisted
+      expect(binanceResult).toBeDefined();
+      expect(binanceResult).toStrictEqual(savedCache[toHex(56)]);
+    });
+
     it('should handle errors when loading individual chain cache files', async () => {
       // Pre-populate storage with two chains
       const validChainData: DataCache = {

packages/assets-controllers/src/TokenListController.ts

@@ -129,14 +129,6 @@ export class TokenListController extends StaticIntervalPollingController<TokenLi
    */
   readonly #changedChainsToPersist: Set<Hex> = new Set();
 
-  /**
-   * Tracks chains that were just loaded from storage and should skip
-   * the next persistence cycle. This prevents redundant writes where
-   * data loaded from storage would be immediately written back.
-   * Chains are removed from this set after being skipped once.
-   */
-  readonly #chainsLoadedFromStorage: Set<Hex> = new Set();
-
   /**
    * Previous tokensChainsCache for detecting which chains changed.
    */
@@ -211,13 +203,6 @@ export class TokenListController extends StaticIntervalPollingController<TokenLi
     this.#chainId = chainId;
     this.#abortController = new AbortController();
 
-    // Subscribe to state changes to automatically persist tokensChainsCache
-    this.messenger.subscribe(
-      'TokenListController:stateChange',
-      (newCache: TokensChainsCache) => this.#onCacheChanged(newCache),
-      (controllerState) => controllerState.tokensChainsCache,
-    );
-
     if (onNetworkStateChange) {
       // TODO: Either fix this lint violation or explain why it's necessary to ignore.
       // eslint-disable-next-line @typescript-eslint/no-misused-promises
@@ -244,6 +229,13 @@ export class TokenListController extends StaticIntervalPollingController<TokenLi
    */
   async initialize(): Promise<void> {
     await this.#synchronizeCacheWithStorage();
+
+    // Subscribe to state changes to automatically persist tokensChainsCache
+    this.messenger.subscribe(
+      'TokenListController:stateChange',
+      (newCache: TokensChainsCache) => this.#onCacheChanged(newCache),
+      (controllerState) => controllerState.tokensChainsCache,
+    );
   }
 
   /**
@@ -260,13 +252,7 @@ export class TokenListController extends StaticIntervalPollingController<TokenLi
 
       // Chain is new or timestamp changed (indicating data update)
       if (!prevData || prevData.timestamp !== newData.timestamp) {
-        // Skip persistence for chains that were just loaded from storage
-        // (they don't need to be written back immediately)
-        if (this.#chainsLoadedFromStorage.has(chainId)) {
-          this.#chainsLoadedFromStorage.delete(chainId); // Clean up - future updates should persist
-        } else {
-          this.#changedChainsToPersist.add(chainId);
-        }
+        this.#changedChainsToPersist.add(chainId);
       }
     }
 
@@ -388,17 +374,14 @@ export class TokenListController extends StaticIntervalPollingController<TokenLi
         }
       });
 
+      // Chains in state _before loading persisted state_, from a recent update
+      const chainsInState = new Set(
+        Object.keys(this.state.tokensChainsCache) as Hex[],
+      );
+
       // Merge loaded cache with existing state, preferring existing data
       // (which may be fresher if fetched during initialization)
       if (Object.keys(loadedCache).length > 0) {
-        // Track which chains we're actually loading from storage
-        // These will be skipped in the next #onCacheChanged to avoid redundant writes
-        for (const chainId of Object.keys(loadedCache) as Hex[]) {
-          if (!this.state.tokensChainsCache[chainId]) {
-            this.#chainsLoadedFromStorage.add(chainId);
-          }
-        }
-
         this.update((state) => {
           // Only load chains that don't already exist in state
           // This prevents overwriting fresh API data with stale cached data
@@ -408,24 +391,14 @@ export class TokenListController extends StaticIntervalPollingController<TokenLi
             }
           }
         });
-
-        // Note: The update() call above only triggers #onCacheChanged if chains
-        // were actually added to state. If initial state already contains chains
-        // from storage, the update() is a no-op and #onCacheChanged is never called.
       }
 
       // Persist chains that exist in state but were not loaded from storage.
       // This handles the case where initial state contains chains that don't exist
       // in storage yet (e.g., fresh data from API). Without this, those chains
       // would be lost on the next app restart.
-      const loadedChainIds = new Set(Object.keys(loadedCache) as Hex[]);
-      const chainsInState = new Set(
-        Object.keys(this.state.tokensChainsCache) as Hex[],
-      );
       for (const chainId of chainsInState) {
-        if (!loadedChainIds.has(chainId)) {
-          this.#changedChainsToPersist.add(chainId);
-        }
+        this.#changedChainsToPersist.add(chainId);
       }
 
       // Persist any chains that need to be saved
@@ -548,7 +521,6 @@ export class TokenListController extends StaticIntervalPollingController<TokenLi
       this.#persistDebounceTimer = undefined;
     }
     this.#changedChainsToPersist.clear();
-    this.#chainsLoadedFromStorage.clear();
   }
 
   /**