register techdocs storage api to dev app (#2139)

plugins/techdocs/dev/api.ts

@@ -0,0 +1,52 @@
+/*
+ * 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.
+ */
+
+import { ParsedEntityId } from '../src/types';
+
+import { TechDocsStorage } from '../src/api';
+
+export class TechDocsDevStorageApi implements TechDocsStorage {
+  public apiOrigin: string;
+
+  constructor({ apiOrigin }: { apiOrigin: string }) {
+    this.apiOrigin = apiOrigin;
+  }
+
+  async getEntityDocs(entityId: ParsedEntityId, path: string) {
+    const { name } = entityId;
+
+    const url = `${this.apiOrigin}/${name}/${path}`;
+
+    const request = await fetch(
+      `${url.endsWith('/') ? url : `${url}/`}index.html`,
+    );
+
+    if (request.status === 404) {
+      throw new Error('Page not found');
+    }
+
+    return request.text();
+  }
+
+  getBaseUrl(
+    oldBaseUrl: string,
+    entityId: ParsedEntityId,
+    path: string,
+  ): string {
+    const { name } = entityId;
+    return new URL(oldBaseUrl, `${this.apiOrigin}/${name}/${path}`).toString();
+  }
+}

plugins/techdocs/dev/index.tsx

@@ -16,5 +16,17 @@
 
 import { createDevApp } from '@backstage/dev-utils';
 import { plugin } from '../src/plugin';
+import { TechDocsDevStorageApi } from './api';
+import { techdocsStorageApiRef } from '../src';
 
-createDevApp().registerPlugin(plugin).render();
+createDevApp()
+  .registerApiFactory({
+    deps: {},
+    factory: () =>
+      new TechDocsDevStorageApi({
+        apiOrigin: 'http://localhost:3000/api',
+      }),
+    implements: techdocsStorageApiRef,
+  })
+  .registerPlugin(plugin)
+  .render();