cli,frontend-app-api: switch experimental discovery to use default export

Co-authored-by: Fredrik Adelöw <freben@gmail.com>
Co-authored-by: Johan Haals <johan.haals@gmail.com>
Co-authored-by: Camila Belo <camilaibs@gmail.com>
Co-authored-by: Philipp Hugenroth <philipph@spotify.com>
Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

packages/app-next-example-plugin/api-report.md

@@ -7,7 +7,8 @@ import { BackstagePlugin } from '@backstage/frontend-plugin-api';
 import { default as React_2 } from 'react';
 
 // @public (undocumented)
-export const examplePlugin: BackstagePlugin;
+const examplePlugin: BackstagePlugin;
+export default examplePlugin;
 
 // @public (undocumented)
 export const ExampleSidebarItem: () => React_2.JSX.Element;

packages/app-next-example-plugin/package.json

@@ -32,6 +32,7 @@
     "postpack": "backstage-cli package postpack",
     "clean": "backstage-cli package clean"
   },
+  "sideEffects": false,
   "dependencies": {
     "@backstage/core-components": "workspace:^",
     "@backstage/frontend-plugin-api": "workspace:^",

packages/app-next-example-plugin/src/index.ts

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-export { examplePlugin } from './plugin';
+export { examplePlugin as default } from './plugin';
 
 // TODO: This should be an extension created & exported in the `plugin.tsx`
 export { ExampleSidebarItem } from './ExampleSidebarItem';

packages/cli/src/lib/bundler/packageDetection.ts

@@ -87,7 +87,7 @@ async function detectPackages(
 
 async function writeDetectedPackagesModule(packageNames: string[]) {
   const requirePackageScript = packageNames
-    ?.map(pkg => `{name: '${pkg}', module: require('${pkg}')}`)
+    ?.map(pkg => `{ name: '${pkg}', default: require('${pkg}').default }`)
     .join(',');
 
   await fs.writeFile(

packages/frontend-app-api/src/wiring/discovery.test.ts

@@ -39,55 +39,26 @@ describe('getAvailablePlugins', () => {
   it('should discover a plugin', () => {
     const testPlugin = createPlugin({ id: 'test' });
     globalSpy.mockReturnValue({
-      modules: [
-        {
-          module: {
-            testPlugin,
-          },
-        },
-      ],
+      modules: [{ default: testPlugin }],
     });
     expect(getAvailablePlugins()).toEqual([testPlugin]);
   });
 
   it('should ignore garbage', () => {
-    const testPlugin = createPlugin({ id: 'test' });
-    globalSpy.mockReturnValue({
-      modules: [
-        {
-          module: {
-            testPlugin,
-            a: 'a',
-            b: null,
-            c: undefined,
-            d: Symbol('wat'),
-            e: () => {},
-            f: [],
-            g: {},
-            h: class {},
-            i: NaN,
-            j: Infinity,
-            k: -Infinity,
-            l: new Date(),
-            m: new RegExp('wat'),
-            n: new Error('wat'),
-            o: new Map(),
-            p: new Set(),
-            q: new WeakMap(),
-            r: new WeakSet(),
-            s: new ArrayBuffer(1),
-            t: new DataView(new ArrayBuffer(1)),
-            u: false,
-            v: true,
-            w: 0,
-            x: 1,
-            y: -1,
-            z: '',
-          },
-        },
-      ],
-    });
-    expect(getAvailablePlugins()).toEqual([testPlugin]);
+    globalSpy.mockReturnValueOnce({ modules: [{ default: null }] });
+    expect(getAvailablePlugins()).toEqual([]);
+    globalSpy.mockReturnValueOnce({ modules: [{ default: undefined }] });
+    expect(getAvailablePlugins()).toEqual([]);
+    globalSpy.mockReturnValueOnce({ modules: [{ default: Symbol() }] });
+    expect(getAvailablePlugins()).toEqual([]);
+    globalSpy.mockReturnValueOnce({ modules: [{ default: () => {} }] });
+    expect(getAvailablePlugins()).toEqual([]);
+    globalSpy.mockReturnValueOnce({ modules: [{ default: 0 }] });
+    expect(getAvailablePlugins()).toEqual([]);
+    globalSpy.mockReturnValueOnce({ modules: [{ default: false }] });
+    expect(getAvailablePlugins()).toEqual([]);
+    globalSpy.mockReturnValueOnce({ modules: [{ default: true }] });
+    expect(getAvailablePlugins()).toEqual([]);
   });
 
   it('should discover multiple plugins', () => {
@@ -96,17 +67,9 @@ describe('getAvailablePlugins', () => {
     const test3Plugin = createPlugin({ id: 'test3' });
     globalSpy.mockReturnValue({
       modules: [
-        {
-          module: {
-            test1Plugin,
-            test2Plugin,
-          },
-        },
-        {
-          module: {
-            test3Plugin,
-          },
-        },
+        { default: test1Plugin },
+        { default: test2Plugin },
+        { default: test3Plugin },
       ],
     });
     expect(getAvailablePlugins()).toEqual([

packages/frontend-app-api/src/wiring/discovery.ts

@@ -17,7 +17,7 @@
 import { BackstagePlugin } from '@backstage/frontend-plugin-api';
 
 interface DiscoveryGlobal {
-  modules: Array<{ name: string; module: object }>;
+  modules: Array<{ name: string; default: unknown }>;
 }
 
 /**
@@ -29,9 +29,7 @@ export function getAvailablePlugins(): BackstagePlugin[] {
   )['__@backstage/discovered__'];
 
   return (
-    discovered?.modules.flatMap(({ module: mod }) =>
-      Object.values(mod).filter(isBackstagePlugin),
-    ) ?? []
+    discovered?.modules.map(m => m.default).filter(isBackstagePlugin) ?? []
   );
 }