Merge pull request #6013 from tudi2d/4782-forward-unhandled-errors

Catch unhandled promise rejections & forward them to the ErrorApi

.changeset/fair-knives-relax.md

@@ -0,0 +1,5 @@
+---
+'@backstage/core-app-api': patch
+---
+
+Introducing new UnhandledErrorForwarder installed by default. For catching unhandled promise rejections, you can override the API to align with general error handling.

docs/api/utility-apis.md

@@ -71,8 +71,11 @@ For example, this is the default `ApiFactory` for the `ErrorApi`:
 createApiFactory({
   api: errorApiRef,
   deps: { alertApi: alertApiRef },
-  factory: ({ alertApi }) =>
-    new ErrorAlerter(alertApi, new ErrorApiForwarder()),
+  factory: ({ alertApi }) => {
+    const errorApi = new ErrorAlerter(alertApi, new ErrorApiForwarder());
+    UnhandledErrorForwarder.forward(errorApi, { hidden: false });
+    return errorApi;
+  },
 });
 ```
 

packages/core-app-api/api-report.md

@@ -394,6 +394,11 @@ export type SignInResult = {
     signOut?: () => Promise<void>;
 };
 
+// @public (undocumented)
+export class UnhandledErrorForwarder {
+    static forward(errorApi: ErrorApi, errorContext: ErrorContext): void;
+}
+
 // @public
 export class UrlPatternDiscovery implements DiscoveryApi {
     static compile(pattern: string): UrlPatternDiscovery;

packages/core-app-api/src/apis/implementations/ErrorApi/UnhandledErrorForwarder.ts

@@ -0,0 +1,31 @@
+import { ErrorApi, ErrorContext } from '@backstage/core-plugin-api';
+
+/*
+ * Copyright 2020 Spotify AB
+ *
+ * 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.
+ */
+
+export class UnhandledErrorForwarder {
+  /**
+   * Add event listener, such that unhandled errors can be forwarded using an given `ErrorApi` instance
+   */
+  static forward(errorApi: ErrorApi, errorContext: ErrorContext) {
+    window.addEventListener(
+      'unhandledrejection',
+      (e: PromiseRejectionEvent) => {
+        errorApi.post(e.reason as Error, errorContext);
+      },
+    );
+  }
+}

packages/core-app-api/src/apis/implementations/ErrorApi/index.ts

@@ -16,3 +16,4 @@
 
 export { ErrorAlerter } from './ErrorAlerter';
 export { ErrorApiForwarder } from './ErrorApiForwarder';
+export { UnhandledErrorForwarder } from './UnhandledErrorForwarder';

packages/core-app-api/src/app/defaultApis.ts

@@ -30,6 +30,7 @@ import {
   UrlPatternDiscovery,
   SamlAuth,
   OneLoginAuth,
+  UnhandledErrorForwarder,
 } from '../apis';
 
 import {
@@ -67,8 +68,11 @@ export const defaultApis = [
   createApiFactory({
     api: errorApiRef,
     deps: { alertApi: alertApiRef },
-    factory: ({ alertApi }) =>
-      new ErrorAlerter(alertApi, new ErrorApiForwarder()),
+    factory: ({ alertApi }) => {
+      const errorApi = new ErrorAlerter(alertApi, new ErrorApiForwarder());
+      UnhandledErrorForwarder.forward(errorApi, { hidden: false });
+      return errorApi;
+    },
   }),
   createApiFactory({
     api: storageApiRef,

packages/core-app-api/src/index.test.ts

@@ -37,6 +37,7 @@ describe('index', () => {
       ConfigReader: expect.any(Function),
       ErrorAlerter: expect.any(Function),
       ErrorApiForwarder: expect.any(Function),
+      UnhandledErrorForwarder: expect.any(Function),
       FeatureFlagged: expect.any(Function),
       GithubAuth: expect.any(Function),
       GitlabAuth: expect.any(Function),