Fix resolution of assets inside node_modules

Summary: The resolution logic for assets didn't return a `failed` resolution when it checked a non-existant folder and instead threw an error. This caused the resolver to not check alternate locations which caused issues when trying to resolve assets from packages in `node_modules`.

Reviewed By: cpojer

Differential Revision: D13941700

fbshipit-source-id: 1c33eb3f9dea0788d1410fe37d299b44b5a6f7ac

packages/metro-resolver/src/resolve.js

@@ -433,10 +433,17 @@ function resolveAssetFiles(
   fileNameHint: string,
   platform: string | null,
 ): Result<AssetFileResolution, FileCandidates> {
-  const assetNames = resolveAsset(dirPath, fileNameHint, platform);
-  if (assetNames != null) {
-    const res = assetNames.map(assetName => path.join(dirPath, assetName));
-    return resolvedAs(res);
+  try {
+    const assetNames = resolveAsset(dirPath, fileNameHint, platform);
+
+    if (assetNames != null) {
+      const res = assetNames.map(assetName => path.join(dirPath, assetName));
+      return resolvedAs(res);
+    }
+  } catch (err) {
+    if (err.code === 'ENOENT') {
+      return failedFor({type: 'asset', name: fileNameHint});
+    }
   }
   return failedFor({type: 'asset', name: fileNameHint});
 }

packages/metro/src/DeltaBundler/__tests__/resolver-test.js

@@ -1209,6 +1209,24 @@ describe('traverseDependencies', function() {
             resolver.resolve(p('/root/index.js'), './asset2.png'),
           ).toThrow(UnableToResolveError);
         });
+
+        it('resolves assets from packages in node_modules', async () => {
+          setMockFileSystem({
+            folder: {'index.js': ''},
+            node_modules: {
+              foo: {
+                'package.json': JSON.stringify({name: 'foo'}),
+                'asset.png': '',
+              },
+            },
+          });
+
+          resolver = await createResolver();
+
+          expect(
+            resolver.resolve(p('/root/folder/index.js'), 'foo/asset.png'),
+          ).toBe(p('/root/node_modules/foo/asset.png'));
+        });
       });
 
       describe('global packages', () => {
@@ -1824,6 +1842,21 @@ describe('traverseDependencies', function() {
             p('/root/providesFoo/index-client.js'),
           );
         });
+
+        it('resolves assets', async () => {
+          setMockFileSystem({
+            folder: {'index.js': ''},
+            providesFoo: {'asset.png': ''},
+          });
+
+          resolver = await createResolver({
+            resolver: {extraNodeModules: {foo: p('/root/providesFoo')}},
+          });
+
+          expect(
+            resolver.resolve(p('/root/folder/index.js'), 'foo/asset.png'),
+          ).toBe(p('/root/providesFoo/asset.png'));
+        });
       });
 
       describe('resolveRequest config param', () => {