chore: return error message on search

packages/assets-controllers/CHANGELOG.md

@@ -15,6 +15,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 
 - Changed Plasma native token ([#7939](https://github.com/MetaMask/core/pull/7939))
+- `searchTokens` now returns an optional `error` field when requests fail, allowing consumers to detect and handle search failures instead of silently receiving empty results ([#7938](https://github.com/MetaMask/core/pull/7938))
 
 ## [99.3.2]
 

packages/assets-controllers/src/token-service.test.ts

@@ -637,7 +637,7 @@ describe('Token service', () => {
       });
     });
 
-    it('should return empty array if the fetch fails with a network error', async () => {
+    it('should return empty array with error if the fetch fails with a network error', async () => {
       const searchQuery = 'USD';
       nock(TOKEN_END_POINT_API)
         .get(
@@ -648,10 +648,14 @@ describe('Token service', () => {
 
       const result = await searchTokens([sampleCaipChainId], searchQuery);
 
-      expect(result).toStrictEqual({ count: 0, data: [] });
+      expect(result).toStrictEqual({
+        count: 0,
+        data: [],
+        error: expect.stringContaining('Example network error'),
+      });
     });
 
-    it('should return empty array if the fetch fails with 400 error', async () => {
+    it('should return empty array with error if the fetch fails with 400 error', async () => {
       const searchQuery = 'USD';
       nock(TOKEN_END_POINT_API)
         .get(
@@ -662,10 +666,14 @@ describe('Token service', () => {
 
       const result = await searchTokens([sampleCaipChainId], searchQuery);
 
-      expect(result).toStrictEqual({ count: 0, data: [] });
+      expect(result).toStrictEqual({
+        count: 0,
+        data: [],
+        error: expect.stringContaining("Fetch failed with status '400'"),
+      });
     });
 
-    it('should return empty array if the fetch fails with 500 error', async () => {
+    it('should return empty array with error if the fetch fails with 500 error', async () => {
       const searchQuery = 'USD';
       nock(TOKEN_END_POINT_API)
         .get(
@@ -676,7 +684,35 @@ describe('Token service', () => {
 
       const result = await searchTokens([sampleCaipChainId], searchQuery);
 
-      expect(result).toStrictEqual({ count: 0, data: [] });
+      expect(result).toStrictEqual({
+        count: 0,
+        data: [],
+        error: expect.stringContaining("Fetch failed with status '500'"),
+      });
+    });
+
+    it('should return error for malformed API response', async () => {
+      const searchQuery = 'USD';
+      const malformedResponse = {
+        count: 5,
+        // Missing 'data' array - this is malformed
+        someOtherField: 'value',
+      };
+
+      nock(TOKEN_END_POINT_API)
+        .get(
+          `/tokens/search?networks=${encodeURIComponent(sampleCaipChainId)}&query=${searchQuery}&limit=10&includeMarketData=false&includeRwaData=true`,
+        )
+        .reply(200, malformedResponse)
+        .persist();
+
+      const result = await searchTokens([sampleCaipChainId], searchQuery);
+
+      expect(result).toStrictEqual({
+        count: 0,
+        data: [],
+        error: 'Unexpected API response format',
+      });
     });
 
     it('should handle empty search results', async () => {
@@ -731,8 +767,12 @@ describe('Token service', () => {
 
       const result = await searchTokens([sampleCaipChainId], searchQuery);
 
-      // Non-array responses should be converted to empty object with count 0
-      expect(result).toStrictEqual({ count: 0, data: [] });
+      // Non-array responses should be converted to empty object with count 0 and error message
+      expect(result).toStrictEqual({
+        count: 0,
+        data: [],
+        error: 'Unexpected API response format',
+      });
     });
 
     it('should handle supported CAIP format chain IDs', async () => {

packages/assets-controllers/src/token-service.ts

@@ -204,7 +204,7 @@ type SearchTokenOptions = {
  * @param options.limit - The maximum number of results to return.
  * @param options.includeMarketData - Optional flag to include market data in the results (defaults to false).
  * @param options.includeRwaData - Optional flag to include RWA data in the results (defaults to false).
- * @returns Object containing count and data array. Returns { count: 0, data: [] } if request fails.
+ * @returns Object containing count, data array, and an optional error message if the request failed.
  */
 export async function searchTokens(
   chainIds: CaipChainId[],
@@ -214,7 +214,7 @@ export async function searchTokens(
     includeMarketData = false,
     includeRwaData = true,
   }: SearchTokenOptions = {},
-): Promise<{ count: number; data: TokenSearchItem[] }> {
+): Promise<{ count: number; data: TokenSearchItem[]; error?: string }> {
   const tokenSearchURL = getTokenSearchURL({
     chainIds,
     query,
@@ -236,11 +236,10 @@ export async function searchTokens(
     }
 
     // Handle non-expected responses
-    return { count: 0, data: [] };
+    return { count: 0, data: [], error: 'Unexpected API response format' };
   } catch (error) {
-    // Handle 400 errors and other failures by returning count 0 and empty array
-    console.log('Search request failed:', error);
-    return { count: 0, data: [] };
+    const errorMessage = error instanceof Error ? error.message : String(error);
+    return { count: 0, data: [], error: errorMessage };
   }
 }