chore: migrate to new backend in local development

additionally allow defining custom sidebar item for dev app page.

Signed-off-by: Heikki Hellgren <heikki.hellgren@op.fi>

plugins/notifications-backend/dev/index.ts

@@ -0,0 +1,64 @@
+/*
+ * Copyright 2024 The Backstage Authors
+ *
+ * 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.
+ */
+
+import { createBackend } from '@backstage/backend-defaults';
+import {
+  coreServices,
+  createBackendPlugin,
+} from '@backstage/backend-plugin-api';
+import { notificationService } from '@backstage/plugin-notifications-node';
+
+const notificationsDebug = createBackendPlugin({
+  pluginId: 'notifications-debug',
+  register(env) {
+    env.registerInit({
+      deps: {
+        notifications: notificationService,
+        lifecycle: coreServices.lifecycle,
+      },
+      async init({ notifications, lifecycle }) {
+        let interval: NodeJS.Timeout | undefined;
+        lifecycle.addStartupHook(async () => {
+          interval = setInterval(async () => {
+            await notifications.send({
+              recipients: {
+                type: 'entity',
+                entityRef: 'user:development/guest',
+              },
+              payload: { title: 'Test notification' },
+            });
+          }, 5000);
+        });
+
+        lifecycle.addShutdownHook(async () => {
+          if (interval) {
+            clearInterval(interval);
+          }
+        });
+      },
+    });
+  },
+});
+
+const backend = createBackend();
+backend.add(import('@backstage/plugin-events-backend/alpha'));
+backend.add(import('@backstage/plugin-signals-backend'));
+backend.add(import('@backstage/plugin-auth-backend'));
+backend.add(import('@backstage/plugin-auth-backend-module-guest-provider'));
+backend.add(import('../src'));
+backend.add(notificationsDebug);
+
+backend.start();