feat(stackoverflow): migrate to new frontend system

Signed-off-by: Camila Belo <camilaibs@gmail.com>

plugins/stack-overflow/alpha-api-report.md

@@ -0,0 +1,13 @@
+## API Report File for "@backstage/plugin-stack-overflow"
+
+> Do not edit this file. It is a report generated by [API Extractor](https://api-extractor.com/).
+
+```ts
+import { BackstagePlugin } from '@backstage/frontend-plugin-api';
+
+// @alpha (undocumented)
+const _default: BackstagePlugin;
+export default _default;
+
+// (No @packageDocumentation comment for this package)
+```

plugins/stack-overflow/package.json

@@ -5,9 +5,22 @@
   "types": "src/index.ts",
   "license": "Apache-2.0",
   "publishConfig": {
-    "access": "public",
-    "main": "dist/index.esm.js",
-    "types": "dist/index.d.ts"
+    "access": "public"
+  },
+  "exports": {
+    ".": "./src/index.ts",
+    "./alpha": "./src/alpha.tsx",
+    "./package.json": "./package.json"
+  },
+  "typesVersions": {
+    "*": {
+      "alpha": [
+        "src/alpha.tsx"
+      ],
+      "package.json": [
+        "package.json"
+      ]
+    }
   },
   "backstage": {
     "role": "frontend-plugin"
@@ -32,6 +45,7 @@
     "@backstage/config": "workspace:^",
     "@backstage/core-components": "workspace:^",
     "@backstage/core-plugin-api": "workspace:^",
+    "@backstage/frontend-plugin-api": "workspace:^",
     "@backstage/plugin-home-react": "workspace:^",
     "@backstage/plugin-search-common": "workspace:^",
     "@backstage/plugin-search-react": "workspace:^",

plugins/stack-overflow/src/alpha.tsx

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2023 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 { configApiRef, createApiFactory } from '@backstage/core-plugin-api';
+import {
+  createApiExtension,
+  createPlugin,
+} from '@backstage/frontend-plugin-api';
+import { createSearchResultListItemExtension } from '@backstage/plugin-search-react/alpha';
+import { StackOverflowClient, stackOverflowApiRef } from './api';
+
+/** @alpha */
+const StackOverflowApi = createApiExtension({
+  factory: createApiFactory({
+    api: stackOverflowApiRef,
+    deps: { configApi: configApiRef },
+    factory: ({ configApi }) => StackOverflowClient.fromConfig(configApi),
+  }),
+});
+
+/** @alpha */
+const StackOverflowSearchResultListItem = createSearchResultListItemExtension({
+  id: 'stack-overflow',
+  predicate: result => result.type === 'stack-overflow',
+  component: () =>
+    import('./search/StackOverflowSearchResultListItem').then(
+      m => m.StackOverflowSearchResultListItem,
+    ),
+});
+
+/** @alpha */
+export default createPlugin({
+  id: 'stack-overflow',
+  extensions: [StackOverflowApi, StackOverflowSearchResultListItem],
+});