diff --git a/plugins/app-backend/package.json b/plugins/app-backend/package.json
index 4e682851bf..a7fb51f772 100644
--- a/plugins/app-backend/package.json
+++ b/plugins/app-backend/package.json
@@ -51,6 +51,7 @@
     "@backstage/cli": "^0.11.0",
     "@backstage/types": "^0.1.1",
     "@types/supertest": "^2.0.8",
+    "mock-fs": "^5.1.0",
     "msw": "^0.35.0",
     "supertest": "^6.1.3"
   },
diff --git a/plugins/app-backend/src/lib/assets/findStaticAssets.test.ts b/plugins/app-backend/src/lib/assets/findStaticAssets.test.ts
new file mode 100644
index 0000000000..6527c28ea4
--- /dev/null
+++ b/plugins/app-backend/src/lib/assets/findStaticAssets.test.ts
@@ -0,0 +1,78 @@
+/*
+ * Copyright 2021 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import mockFs from 'mock-fs';
+import { findStaticAssets } from './findStaticAssets';
+
+describe('findStaticAssets', () => {
+  afterEach(() => {
+    mockFs.restore();
+  });
+
+  it('should find assets', async () => {
+    mockFs({
+      '/test': {
+        'a.js': 'alert("hello")',
+        'a.js.map': '',
+        'b.js': 'b',
+        'b.js.map': '',
+        js: {
+          'd.js': 'd',
+          'd.js.map': '',
+          x: {
+            'e.map': '',
+            y: {
+              'e.map': '',
+              z: {
+                'e.js': 'e',
+                'e.map': '',
+              },
+            },
+          },
+        },
+        styles: { 'c.css': 'body { color: red; }' },
+      },
+    });
+
+    const assets = await findStaticAssets('/test');
+    expect(assets.length).toBe(5);
+    expect(assets.map(a => a.path)).toEqual(
+      expect.arrayContaining([
+        'a.js',
+        'b.js',
+        'styles/c.css',
+        'js/d.js',
+        'js/x/y/z/e.js',
+      ]),
+    );
+
+    await expect(
+      assets.find(a => a.path === 'a.js')!.content(),
+    ).resolves.toEqual(Buffer.from('alert("hello")'));
+    await expect(
+      assets.find(a => a.path === 'b.js')!.content(),
+    ).resolves.toEqual(Buffer.from('b'));
+    await expect(
+      assets.find(a => a.path === 'styles/c.css')!.content(),
+    ).resolves.toEqual(Buffer.from('body { color: red; }'));
+    await expect(
+      assets.find(a => a.path === 'js/d.js')!.content(),
+    ).resolves.toEqual(Buffer.from('d'));
+    await expect(
+      assets.find(a => a.path === 'js/x/y/z/e.js')!.content(),
+    ).resolves.toEqual(Buffer.from('e'));
+  });
+});