backend-app-api: settle all inits before exiting on error

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

packages/backend-app-api/src/wiring/BackendInitializer.test.ts

@@ -418,6 +418,49 @@ describe('BackendInitializer', () => {
     );
   });
 
+  it('should forward errors when multiple plugins fail to start', async () => {
+    const init = new BackendInitializer([]);
+    init.add(
+      createBackendPlugin({
+        pluginId: 'test-1',
+        register(reg) {
+          reg.registerInit({
+            deps: {},
+            async init() {
+              throw new Error('NOPE A');
+            },
+          });
+        },
+      }),
+    );
+    init.add(
+      createBackendPlugin({
+        pluginId: 'test-2',
+        register(reg) {
+          reg.registerInit({
+            deps: {},
+            async init() {
+              throw new Error('NOPE B');
+            },
+          });
+        },
+      }),
+    );
+    const result = init.start();
+
+    await expect(result).rejects.toThrow('Backend startup failed');
+    await expect(result).rejects.toMatchObject({
+      errors: [
+        expect.objectContaining({
+          message: "Plugin 'test-1' startup failed; caused by Error: NOPE A",
+        }),
+        expect.objectContaining({
+          message: "Plugin 'test-2' startup failed; caused by Error: NOPE B",
+        }),
+      ],
+    });
+  });
+
   it('should forward errors when modules fail to start', async () => {
     const init = new BackendInitializer([]);
     init.add(testPlugin);

packages/backend-app-api/src/wiring/BackendInitializer.ts

@@ -275,7 +275,7 @@ export class BackendInitializer {
     );
 
     // All plugins are initialized in parallel
-    await Promise.all(
+    const results = await Promise.allSettled(
       allPluginIds.map(async pluginId => {
         // Initialize all eager services
         await this.#serviceRegistry.initializeEagerServicesWithScope(
@@ -345,6 +345,16 @@ export class BackendInitializer {
       }),
     );
 
+    const initErrors = results.flatMap(r =>
+      r.status === 'rejected' ? [r.reason] : [],
+    );
+    if (initErrors.length === 1) {
+      throw initErrors[0];
+    } else if (initErrors.length > 1) {
+      // TODO(Rugvip): Seems like there aren't proper types for AggregateError yet
+      throw new (AggregateError as any)(initErrors, 'Backend startup failed');
+    }
+
     // Once all plugins and modules have been initialized, we can signal that the backend has started up successfully
     const lifecycleService = await this.#getRootLifecycleImpl();
     await lifecycleService.startup();