Add tests for feature resolver

Signed-off-by: Eric Peterson <ericpeterson@spotify.com>
2025-03-10 10:14:42 +01:00
parent 55e8568ff5
commit a2544d59f5
1 changed files with 140 additions and 0 deletions
@@ -0,0 +1,140 @@
+/*
+ * Copyright 2025 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 {
+  createFrontendPlugin,
+  PageBlueprint,
+} from '@backstage/frontend-plugin-api';
+import { CreateAppFeatureLoader } from './createApp';
+import { resolveFeatures } from './resolveFeatures';
+import { mockApis } from '@backstage/test-utils';
+
+describe('resolveFeatures', () => {
+  it('returns empty array when no features are provided', async () => {
+    const features = await resolveFeatures({
+      config: mockApis.config(),
+    });
+
+    expect(features).toEqual([]);
+  });
+
+  it('returns expected array when features are directly provided', async () => {
+    const features = await resolveFeatures({
+      config: mockApis.config(),
+      features: [
+        createFrontendPlugin({
+          id: 'test-feature',
+          extensions: [
+            PageBlueprint.make({
+              params: {
+                defaultPath: '/',
+                loader: () => new Promise(() => {}),
+              },
+            }),
+          ],
+        }),
+      ],
+    });
+
+    expect(features).toMatchObject([
+      {
+        $$type: '@backstage/FrontendPlugin',
+        id: 'test-feature',
+        version: 'v1',
+        extensions: [
+          {
+            $$type: '@backstage/Extension',
+            id: 'page:test-feature',
+            version: 'v2',
+            attachTo: {
+              id: 'app/routes',
+              input: 'routes',
+            },
+          },
+        ],
+      },
+    ]);
+  });
+
+  it('supports feature loaders', async () => {
+    const loader: CreateAppFeatureLoader = {
+      getLoaderName() {
+        return 'test-loader';
+      },
+      async load() {
+        return {
+          features: [
+            createFrontendPlugin({
+              id: 'test',
+              extensions: [
+                PageBlueprint.make({
+                  params: {
+                    defaultPath: '/',
+                    loader: () => new Promise(() => {}),
+                  },
+                }),
+              ],
+            }),
+          ],
+        };
+      },
+    };
+
+    const features = await resolveFeatures({
+      config: mockApis.config(),
+      features: [loader],
+    });
+
+    expect(features).toMatchObject([
+      {
+        $$type: '@backstage/FrontendPlugin',
+        id: 'test',
+        version: 'v1',
+        extensions: [
+          {
+            $$type: '@backstage/Extension',
+            id: 'page:test',
+            version: 'v2',
+            attachTo: {
+              id: 'app/routes',
+              input: 'routes',
+            },
+          },
+        ],
+      },
+    ]);
+  });
+
+  it('should propagate errors thrown by feature loaders', async () => {
+    const loader: CreateAppFeatureLoader = {
+      getLoaderName() {
+        return 'test-loader';
+      },
+      async load() {
+        throw new TypeError('boom');
+      },
+    };
+
+    await expect(() =>
+      resolveFeatures({
+        config: mockApis.config(),
+        features: [loader],
+      }),
+    ).rejects.toThrowErrorMatchingInlineSnapshot(
+      `"Failed to read frontend features from loader 'test-loader', TypeError: boom"`,
+    );
+  });
+});