frontend-defaults: removed deprecated CreateAppFeatureLoader

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

.changeset/fruity-rockets-rhyme.md

@@ -0,0 +1,5 @@
+---
+'@backstage/frontend-defaults': minor
+---
+
+**BREAKING**: Removed the deprecated `CreateAppFeatureLoader` and support for it in other APIs. Switch existing usage to use the newer `createFrontendFeatureLoader` from `@backstage/frontend-plugin-api` instead.

packages/frontend-defaults/report.api.md

@@ -18,14 +18,6 @@ export function createApp(options?: CreateAppOptions): {
   createRoot(): JSX_2.Element;
 };
 
-// @public @deprecated
-export interface CreateAppFeatureLoader {
-  getLoaderName(): string;
-  load(options: { config: ConfigApi }): Promise<{
-    features: FrontendFeature[];
-  }>;
-}
-
 // @public
 export interface CreateAppOptions {
   // (undocumented)
@@ -39,11 +31,7 @@ export interface CreateAppOptions {
     | ExtensionFactoryMiddleware
     | ExtensionFactoryMiddleware[];
   // (undocumented)
-  features?: (
-    | FrontendFeature
-    | FrontendFeatureLoader
-    | CreateAppFeatureLoader
-  )[];
+  features?: (FrontendFeature | FrontendFeatureLoader)[];
   // (undocumented)
   flags?: {
     allowUnknownExtensionConfig?: boolean;
@@ -66,11 +54,7 @@ export function discoverAvailableFeatures(config: Config): {
 // @public (undocumented)
 export function resolveAsyncFeatures(options: {
   config: Config;
-  features?: (
-    | FrontendFeature
-    | FrontendFeatureLoader
-    | CreateAppFeatureLoader
-  )[];
+  features?: (FrontendFeature | FrontendFeatureLoader)[];
 }): Promise<{
   features: FrontendFeature[];
 }>;

packages/frontend-defaults/src/createApp.test.tsx

@@ -21,13 +21,14 @@ import {
   createExtension,
   PageBlueprint,
   createFrontendPlugin,
+  createFrontendFeatureLoader,
   ThemeBlueprint,
   createFrontendModule,
   useAppNode,
   FrontendPluginInfo,
 } from '@backstage/frontend-plugin-api';
 import { screen, waitFor } from '@testing-library/react';
-import { CreateAppFeatureLoader, createApp } from './createApp';
+import { createApp } from './createApp';
 import { mockApis, renderWithEffects } from '@backstage/test-utils';
 import { featureFlagsApiRef, useApi } from '@backstage/core-plugin-api';
 import { default as appPluginOriginal } from '@backstage/plugin-app';
@@ -169,28 +170,21 @@ describe('createApp', () => {
   });
 
   it('should support feature loaders', async () => {
-    const loader: CreateAppFeatureLoader = {
-      getLoaderName() {
-        return 'test-loader';
-      },
-      async load({ config }) {
-        return {
-          features: [
-            createFrontendPlugin({
-              pluginId: 'test',
-              extensions: [
-                PageBlueprint.make({
-                  params: {
-                    defaultPath: '/',
-                    loader: async () => <div>{config.getString('key')}</div>,
-                  },
-                }),
-              ],
+    const loader = createFrontendFeatureLoader({
+      async *loader({ config }) {
+        yield createFrontendPlugin({
+          pluginId: 'test',
+          extensions: [
+            PageBlueprint.make({
+              params: {
+                defaultPath: '/',
+                loader: async () => <div>{config.getString('key')}</div>,
+              },
             }),
           ],
-        };
+        });
       },
-    };
+    });
 
     const app = createApp({
       configLoader: async () => ({
@@ -207,14 +201,11 @@ describe('createApp', () => {
   });
 
   it('should propagate errors thrown by feature loaders', async () => {
-    const loader: CreateAppFeatureLoader = {
-      getLoaderName() {
-        return 'test-loader';
-      },
-      async load() {
+    const loader = createFrontendFeatureLoader({
+      async loader() {
         throw new TypeError('boom');
       },
-    };
+    });
 
     const app = createApp({
       configLoader: async () => ({
@@ -223,10 +214,8 @@ describe('createApp', () => {
       features: [loader],
     });
 
-    await expect(
-      renderWithEffects(app.createRoot()),
-    ).rejects.toThrowErrorMatchingInlineSnapshot(
-      `"Failed to read frontend features from loader 'test-loader', TypeError: boom"`,
+    await expect(renderWithEffects(app.createRoot())).rejects.toThrow(
+      /Failed to read frontend features from loader created at '.*\/createApp\.test\.tsx:\d+:\d+': TypeError: boom/,
     );
   });
 

packages/frontend-defaults/src/createApp.tsx

@@ -36,37 +36,13 @@ import appPlugin from '@backstage/plugin-app';
 import { discoverAvailableFeatures } from './discovery';
 import { resolveAsyncFeatures } from './resolution';
 
-/**
- * A source of dynamically loaded frontend features.
- *
- * @public
- * @deprecated Use the {@link @backstage/frontend-plugin-api#createFrontendFeatureLoader} function instead.
- */
-export interface CreateAppFeatureLoader {
-  /**
-   * Returns name of this loader. suitable for showing to users.
-   */
-  getLoaderName(): string;
-
-  /**
-   * Loads a number of features dynamically.
-   */
-  load(options: { config: ConfigApi }): Promise<{
-    features: FrontendFeature[];
-  }>;
-}
-
 /**
  * Options for {@link createApp}.
  *
  * @public
  */
 export interface CreateAppOptions {
-  features?: (
-    | FrontendFeature
-    | FrontendFeatureLoader
-    | CreateAppFeatureLoader
-  )[];
+  features?: (FrontendFeature | FrontendFeatureLoader)[];
   configLoader?: () => Promise<{ config: ConfigApi }>;
   bindRoutes?(context: { bind: CreateAppRouteBinder }): void;
   /**

packages/frontend-defaults/src/index.ts

@@ -20,11 +20,7 @@
  * @packageDocumentation
  */
 
-export {
-  createApp,
-  type CreateAppOptions,
-  type CreateAppFeatureLoader,
-} from './createApp';
+export { createApp, type CreateAppOptions } from './createApp';
 export { createPublicSignInApp } from './createPublicSignInApp';
 export { discoverAvailableFeatures } from './discovery';
 export { resolveAsyncFeatures } from './resolution';

packages/frontend-defaults/src/resolution.test.ts

@@ -20,7 +20,6 @@ import {
   FrontendFeatureLoader,
   PageBlueprint,
 } from '@backstage/frontend-plugin-api';
-import { CreateAppFeatureLoader } from './createApp';
 import { resolveAsyncFeatures } from './resolution';
 import { mockApis } from '@backstage/test-utils';
 
@@ -71,75 +70,6 @@ describe('resolveAsyncFeatures', () => {
     ]);
   });
 
-  it('supports deprecated feature loaders', async () => {
-    const loader: CreateAppFeatureLoader = {
-      getLoaderName() {
-        return 'test-loader';
-      },
-      async load() {
-        return {
-          features: [
-            createFrontendPlugin({
-              pluginId: 'test',
-              extensions: [
-                PageBlueprint.make({
-                  params: {
-                    defaultPath: '/',
-                    loader: () => new Promise(() => {}),
-                  },
-                }),
-              ],
-            }),
-          ],
-        };
-      },
-    };
-
-    const { features } = await resolveAsyncFeatures({
-      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 deprecated feature loaders', async () => {
-    const loader: CreateAppFeatureLoader = {
-      getLoaderName() {
-        return 'test-loader';
-      },
-      async load() {
-        throw new TypeError('boom');
-      },
-    };
-
-    await expect(() =>
-      resolveAsyncFeatures({
-        config: mockApis.config(),
-        features: [loader],
-      }),
-    ).rejects.toThrowErrorMatchingInlineSnapshot(
-      `"Failed to read frontend features from loader 'test-loader', TypeError: boom"`,
-    );
-  });
-
   it('supports feature loaders', async () => {
     const loader: FrontendFeatureLoader = createFrontendFeatureLoader({
       async loader({ config: _ }) {

packages/frontend-defaults/src/resolution.ts

@@ -20,40 +20,14 @@ import {
   FrontendFeature,
   FrontendFeatureLoader,
 } from '@backstage/frontend-plugin-api';
-import { CreateAppFeatureLoader } from './createApp';
 // eslint-disable-next-line @backstage/no-relative-monorepo-imports
 import { isInternalFrontendFeatureLoader } from '../../frontend-plugin-api/src/wiring/createFrontendFeatureLoader';
 
 /** @public */
 export async function resolveAsyncFeatures(options: {
   config: Config;
-  features?: (
-    | FrontendFeature
-    | FrontendFeatureLoader
-    | CreateAppFeatureLoader
-  )[];
+  features?: (FrontendFeature | FrontendFeatureLoader)[];
 }): Promise<{ features: FrontendFeature[] }> {
-  const features: (FrontendFeature | FrontendFeatureLoader)[] = [];
-
-  // Separate deprecated CreateAppFeatureLoader elements from the frontend features,
-  // and manage the deprecated elements first.
-  for (const item of options?.features ?? []) {
-    if ('load' in item) {
-      try {
-        const result = await item.load({ config: options.config });
-        features.push(...result.features);
-      } catch (e) {
-        throw new Error(
-          `Failed to read frontend features from loader '${item.getLoaderName()}', ${stringifyError(
-            e,
-          )}`,
-        );
-      }
-    } else {
-      features.push(item);
-    }
-  }
-
   const loadedFeatures: FrontendFeature[] = [];
   const alreadyMetFeatureLoaders: FrontendFeatureLoader[] = [];
   const maxRecursionDepth = 5;
@@ -96,7 +70,7 @@ export async function resolveAsyncFeatures(options: {
     }
   }
 
-  await applyFeatureLoaders(features, 1);
+  await applyFeatureLoaders(options.features ?? [], 1);
 
   return { features: loadedFeatures };
 }