frontend-test-utils: refactor to use createSpecializedApp + API report

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

packages/frontend-test-utils/api-report.md

@@ -0,0 +1,32 @@
+## API Report File for "@backstage/frontend-test-utils"
+
+> Do not edit this file. It is a report generated by [API Extractor](https://api-extractor.com/).
+
+```ts
+import { Extension } from '@backstage/frontend-plugin-api';
+import { JsonObject } from '@backstage/types';
+import { RenderResult } from '@testing-library/react';
+
+// @public (undocumented)
+export function createExtensionTester<TConfig>(
+  subject: Extension<TConfig>,
+  options?: {
+    config?: TConfig;
+  },
+): ExtensionTester;
+
+// @public (undocumented)
+export class ExtensionTester {
+  // (undocumented)
+  add<TConfig>(
+    extension: Extension<TConfig>,
+    options?: {
+      config?: TConfig;
+    },
+  ): ExtensionTester;
+  // (undocumented)
+  render(options?: { config?: JsonObject }): Promise<RenderResult>;
+}
+
+// (No @packageDocumentation comment for this package)
+```

packages/frontend-test-utils/package.json

@@ -35,5 +35,8 @@
     "@backstage/test-utils": "workspace:^",
     "@backstage/types": "workspace:^",
     "@testing-library/react": "^14.0.0"
+  },
+  "peerDependencies": {
+    "react": "^16.13.1 || ^17.0.0 || ^18.0.0"
   }
 }

packages/frontend-test-utils/src/app/createExtensionTester.ts

@@ -14,13 +14,14 @@
  * limitations under the License.
  */
 
-import { createApp } from '@backstage/frontend-app-api';
+import { createSpecializedApp } from '@backstage/frontend-app-api';
 import { Extension, createPlugin } from '@backstage/frontend-plugin-api';
 import { MockConfigApi } from '@backstage/test-utils';
 import { JsonArray, JsonObject, JsonValue } from '@backstage/types';
-import { RenderResult, render, waitFor } from '@testing-library/react';
+import { RenderResult, render } from '@testing-library/react';
 
-class ExtensionTester {
+/** @public */
+export class ExtensionTester {
   /** @internal */
   static forSubject<TConfig>(
     subject: Extension<TConfig>,
@@ -90,25 +91,21 @@ class ExtensionTester {
       },
     };
 
-    const app = createApp({
+    const app = createSpecializedApp({
       features: [
         createPlugin({
           id: 'test',
           extensions: this.#extensions.map(entry => entry.extension),
         }),
       ],
-      configLoader: async () => new MockConfigApi(finalConfig),
+      config: new MockConfigApi(finalConfig),
     });
 
-    const result = render(app.createRoot());
-    await waitFor(() =>
-      // eslint-disable-next-line jest/no-standalone-expect
-      expect(result.queryByText('Loading...')).not.toBeInTheDocument(),
-    );
-    return result;
+    return render(app.createRoot());
   }
 }
 
+/** @public */
 export function createExtensionTester<TConfig>(
   subject: Extension<TConfig>,
   options?: { config?: TConfig },

packages/frontend-test-utils/src/app/index.ts

@@ -14,4 +14,7 @@
  * limitations under the License.
  */
 
-export { createExtensionTester } from './createExtensionTester';
+export {
+  createExtensionTester,
+  type ExtensionTester,
+} from './createExtensionTester';

yarn.lock

@@ -4345,7 +4345,7 @@ __metadata:
   languageName: unknown
   linkType: soft
 
-"@backstage/frontend-test-utils@workspace:packages/frontend-test-utils":
+"@backstage/frontend-test-utils@workspace:^, @backstage/frontend-test-utils@workspace:packages/frontend-test-utils":
   version: 0.0.0-use.local
   resolution: "@backstage/frontend-test-utils@workspace:packages/frontend-test-utils"
   dependencies:
@@ -4356,6 +4356,8 @@ __metadata:
     "@backstage/types": "workspace:^"
     "@testing-library/jest-dom": ^6.0.0
     "@testing-library/react": ^14.0.0
+  peerDependencies:
+    react: ^16.13.1 || ^17.0.0 || ^18.0.0
   languageName: unknown
   linkType: soft