Resolver: Don't resolve directories as assets

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

@@ -1649,6 +1649,45 @@ function dep(name: string): TransformResultDependency {
           filePath: p('/root/node_modules/foo/asset.png'),
         });
       });
+
+      test('resolves a package whose name ends in an asset extension', async () => {
+        setMockFileSystem({
+          'index.js': '',
+          node_modules: {
+            'lodash.zip': {
+              'package.json': JSON.stringify({name: 'lodash.zip'}),
+              'index.js': '',
+            },
+          },
+        });
+
+        resolver = await createResolver({
+          resolver: {assetExts: ['png', 'zip']},
+        });
+
+        expect(
+          resolver.resolve(p('/root/index.js'), dep('lodash.zip')),
+        ).toEqual({
+          type: 'sourceFile',
+          filePath: p('/root/node_modules/lodash.zip/index.js'),
+        });
+      });
+
+      test('resolves a directory whose name ends in an asset extension', async () => {
+        setMockFileSystem({
+          'index.js': '',
+          'icons.png': {'index.js': ''},
+        });
+
+        resolver = await createResolver();
+
+        expect(
+          resolver.resolve(p('/root/index.js'), dep('./icons.png')),
+        ).toEqual({
+          type: 'sourceFile',
+          filePath: p('/root/icons.png/index.js'),
+        });
+      });
     });
 
     describe('global packages', () => {

packages/metro/src/node-haste/DependencyGraph/createModuleResolver.js

@@ -77,7 +77,12 @@ export default function createModuleResolver({
           resolution => basePath + '@' + resolution + 'x' + extension,
         ),
       ]
-        .map(assetPath => fileSystemLookup(assetPath).realPath)
+        .map(assetPath => {
+          const result = fileSystemLookup(assetPath);
+          // A directory such as `node_modules/lodash.zip` is not an asset, and
+          // must fall through to directory (package) resolution.
+          return result.exists && result.type === 'f' ? result.realPath : null;
+        })
         .filter(Boolean);
 
       return assets.length ? assets : null;