todo-backend: add tests for TodoScmReader and make constructor public

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

plugins/todo-backend/src/lib/TodoReader/TodoScmReader.test.ts

@@ -0,0 +1,186 @@
+/*
+ * Copyright 2021 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 {
+  getVoidLogger,
+  ReadTreeResponse,
+  UrlReader,
+} from '@backstage/backend-common';
+import { ConfigReader } from '@backstage/config';
+import { NotFoundError, NotModifiedError } from '@backstage/errors';
+import { ScmIntegrations } from '@backstage/integration';
+import { createTodoParser } from './createTodoParser';
+import { TodoScmReader } from './TodoScmReader';
+
+function mockReader(): jest.Mocked<UrlReader> {
+  return {
+    read: jest.fn(),
+    readTree: jest.fn(),
+    search: jest.fn(),
+  } as jest.Mocked<UrlReader>;
+}
+
+describe('TodoScmReader', () => {
+  it('should be created from config', () => {
+    const todoReader = TodoScmReader.fromConfig(new ConfigReader({}), {
+      logger: getVoidLogger(),
+      reader: mockReader(),
+    });
+    expect(todoReader).toEqual(expect.any(TodoScmReader));
+  });
+
+  it('should read TODOs', async () => {
+    const reader = mockReader();
+    const todoReader = new TodoScmReader({
+      logger: getVoidLogger(),
+      reader,
+      integrations: ScmIntegrations.fromConfig(new ConfigReader({})),
+    });
+
+    reader.readTree.mockResolvedValueOnce({
+      etag: 'my-etag',
+      files: async () => [
+        {
+          content: async () => Buffer.from('// TODO: my-todo', 'utf8'),
+          path: 'my-folder/my-file.js',
+        },
+      ],
+    } as ReadTreeResponse);
+
+    const url = 'https://github.com/backstage/backstage/catalog-info.yaml';
+    const expected = {
+      items: [
+        {
+          text: 'my-todo',
+          tag: 'TODO',
+          lineNumber: 1,
+          repoFilePath: 'my-folder/my-file.js',
+          viewUrl:
+            'https://github.com/backstage/backstage/my-folder/my-file.js#L1',
+        },
+      ],
+    };
+
+    await expect(todoReader.readTodos({ url })).resolves.toEqual(expected);
+
+    expect(reader.readTree).toHaveBeenCalledTimes(1);
+    expect(reader.readTree).toHaveBeenCalledWith(
+      'https://github.com/backstage/backstage/catalog-info.yaml',
+      {
+        etag: undefined,
+        filter: expect.any(Function),
+      },
+    );
+
+    // Filter function should filter out dotfiles
+    const filterFunc = reader.readTree.mock.calls[0][1]!.filter!;
+    expect(filterFunc('my-file.js')).toBe(true);
+    expect(filterFunc('my-folder/my-file.js')).toBe(true);
+    expect(filterFunc('.my-file.js')).toBe(false);
+    expect(filterFunc('.my-folder/my-file.js')).toBe(false);
+    expect(filterFunc('my-folder/.my-file.js')).toBe(false);
+
+    // A NotModifiedError should return a cached result
+    reader.readTree.mockRejectedValueOnce(new NotModifiedError('nope'));
+    await expect(todoReader.readTodos({ url })).resolves.toEqual(expected);
+
+    expect(reader.readTree).toHaveBeenCalledTimes(2);
+    expect(reader.readTree).toHaveBeenLastCalledWith(
+      'https://github.com/backstage/backstage/catalog-info.yaml',
+      {
+        etag: 'my-etag',
+        filter: expect.any(Function),
+      },
+    );
+
+    // Other errors should re-throw
+    reader.readTree.mockRejectedValueOnce(new NotFoundError('not found'));
+    await expect(todoReader.readTodos({ url })).rejects.toThrow('not found');
+  });
+
+  it('should use custom parser', async () => {
+    const parser = jest.fn(createTodoParser({ additionalTags: ['XXX'] }));
+    const reader = mockReader();
+    const todoReader = new TodoScmReader({
+      logger: getVoidLogger(),
+      reader,
+      parser,
+      integrations: ScmIntegrations.fromConfig(new ConfigReader({})),
+    });
+
+    reader.readTree.mockResolvedValueOnce({
+      files: async () => [
+        {
+          content: async () => Buffer.from('-- XXX: my-todo', 'utf8'),
+          path: 'my-file.lua',
+        },
+      ],
+    } as ReadTreeResponse);
+
+    await expect(
+      todoReader.readTodos({
+        url: 'https://github.com/backstage/backstage/catalog-info.yaml',
+      }),
+    ).resolves.toEqual({
+      items: [
+        {
+          text: 'my-todo',
+          tag: 'XXX',
+          lineNumber: 1,
+          repoFilePath: 'my-file.lua',
+          viewUrl: 'https://github.com/backstage/backstage/my-file.lua#L1',
+        },
+      ],
+    });
+    expect(parser).toHaveBeenCalledTimes(1);
+    expect(parser).toHaveBeenCalledWith({
+      content: '-- XXX: my-todo',
+      path: 'my-file.lua',
+    });
+  });
+
+  it('should log and ignore parser errors', async () => {
+    const logger = getVoidLogger();
+    const errorSpy = jest.spyOn(logger, 'error');
+    const reader = mockReader();
+    const todoReader = new TodoScmReader({
+      logger,
+      reader,
+      parser() {
+        throw new Error('failed to parse');
+      },
+      integrations: ScmIntegrations.fromConfig(new ConfigReader({})),
+    });
+
+    reader.readTree.mockResolvedValueOnce({
+      files: async () => [
+        {
+          content: async () => Buffer.from('# XXX: my-todo', 'utf8'),
+          path: 'my-file.sh',
+        },
+      ],
+    } as ReadTreeResponse);
+
+    await expect(
+      todoReader.readTodos({
+        url: 'https://github.com/o/r/catalog-info.yaml',
+      }),
+    ).resolves.toEqual({ items: [] });
+    expect(errorSpy).toHaveBeenCalledWith(
+      'Failed to parse TODO in https://github.com/o/r/catalog-info.yaml at my-file.sh, Error: failed to parse',
+    );
+  });
+});

plugins/todo-backend/src/lib/TodoReader/TodoScmReader.ts

@@ -31,6 +31,7 @@ import { createTodoParser } from './createTodoParser';
 type Options = {
   logger: Logger;
   reader: UrlReader;
+  integrations: ScmIntegrations;
   parser?: TodoParser;
 };
 
@@ -47,15 +48,18 @@ export class TodoScmReader implements TodoReader {
 
   private readonly cache = new Map<string, CacheItem>();
 
-  static fromConfig(config: Config, options: Options) {
-    return new TodoScmReader(options, ScmIntegrations.fromConfig(config));
+  static fromConfig(config: Config, options: Omit<Options, 'integrations'>) {
+    return new TodoScmReader({
+      ...options,
+      integrations: ScmIntegrations.fromConfig(config),
+    });
   }
 
-  private constructor(options: Options, integrations: ScmIntegrations) {
+  constructor(options: Options) {
     this.logger = options.logger;
     this.reader = options.reader;
     this.parser = options.parser ?? createTodoParser();
-    this.integrations = integrations;
+    this.integrations = options.integrations;
   }
 
   async readTodos({ url }: ReadTodosOptions): Promise<ReadTodosResult> {