Checklist: GitHub interface

checklist/src/github.ts

@@ -0,0 +1,158 @@
+/**
+ * Copyright 2020 The AMP HTML 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 {Octokit} from '@octokit/rest';
+
+import {ILogger} from './types';
+
+const trailingSlashRegExp = /\/$/;
+const noTrailingSlash = (path: string) => path.replace(trailingSlashRegExp, '');
+
+/** Interface for working with the GitHub API. */
+export class GitHub {
+  private pathContents: {[path: string]: Set<string>} = {};
+  private pullFiles: {[pullNumber: number]: string[]} = {};
+
+  constructor(
+    private client: Octokit,
+    private owner: string,
+    private repo: string,
+    private logger: ILogger = console
+  ) {
+    // Prevent throwing errors to handle status more easily.
+    this.client.hook.error('request', async error => {
+      const {status} = error;
+      if (status === 404) {
+        return {status};
+      }
+      throw error;
+    });
+  }
+
+  /**
+   * Finds a new directory added in a pull request, matching a regular
+   * expression.
+   * The regex result's first group should match the subdirectory at the level
+   * where it wants to be found, so ^a/b/(foo)/x/y/z will look for foo/ in a/b/.
+   * @return undefined or [filename, path, subdir]
+   */
+  async findNewDirectory(pullNumber: number, pathRegExp: RegExp) {
+    for (const filename of await this.listPullFiles(pullNumber)) {
+      const match = filename.match(pathRegExp);
+      if (!match) {
+        continue;
+      }
+
+      const [full, subdirTrailingSlash] = match;
+
+      if (typeof subdirTrailingSlash !== 'string') {
+        this.logger.error(
+          'findNewDirectory: no group matched',
+          pathRegExp,
+          full
+        );
+        continue;
+      }
+      if (!filename.startsWith(full)) {
+        this.logger.error(
+          'findNewDirectory: match not at start (regex should start with ^)',
+          pathRegExp,
+          full
+        );
+        continue;
+      }
+
+      const subdir = noTrailingSlash(subdirTrailingSlash);
+      const path = noTrailingSlash(full.substr(0, full.indexOf(`/${subdir}/`)));
+
+      const contents = await this.getContents(path);
+      if (contents && !contents.has(subdir)) {
+        return [filename, path, subdir];
+      }
+    }
+  }
+
+  /**
+   * Gets contents in path.
+   * This is cached for looped lookups.
+   */
+  private async getContents(path: string): Promise<Set<string> | undefined> {
+    if (path in this.pathContents) {
+      return this.pathContents[path];
+    }
+
+    const {owner, repo} = this;
+    const {status, data} = await this.client.repos.getContents({
+      owner,
+      repo,
+      path,
+    });
+
+    if (status === 404) {
+      return (this.pathContents[path] = new Set());
+    }
+
+    if (!Array.isArray(data)) {
+      this.logger.error(path, 'is not a directory');
+      return;
+    }
+
+    return (this.pathContents[path] = new Set(data.map(({name}) => name)));
+  }
+
+  /**
+   * List files in a pull request.
+   * This is cached for looped lookups.
+   */
+  private async listPullFiles(pullNumber: number): Promise<string[]> {
+    if (pullNumber in this.pullFiles) {
+      return this.pullFiles[pullNumber];
+    }
+
+    const {owner, repo} = this;
+    const {data} = await this.client.pulls.listFiles({
+      owner,
+      repo,
+      pull_number: pullNumber,
+    });
+
+    return (this.pullFiles[pullNumber] = data.map(({filename}) => filename));
+  }
+
+  /** Adds a comment. */
+  async addComment(issueOrPullNumber: number, body: string) {
+    const {owner, repo} = this;
+    return this.client.issues.createComment({
+      owner,
+      repo,
+      issue_number: issueOrPullNumber,
+      body,
+    });
+  }
+
+  /** Updates a pull request's description. */
+  async updatePullBody(pullNumber: number, body: string) {
+    const {owner, repo} = this;
+    return this.client.pulls.update({
+      owner,
+      repo,
+      pull_number: pullNumber,
+      body,
+    });
+  }
+}
+
+module.exports = {GitHub};

checklist/test/github.test.ts

@@ -0,0 +1,173 @@
+/**
+ * Copyright 2020 The AMP HTML 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 {createTokenAuth} from '@octokit/auth';
+import nock from 'nock';
+import {Octokit} from '@octokit/rest';
+
+import {GitHub} from '../src/github';
+
+describe('GitHub interface', () => {
+  const githubClient: Octokit = new Octokit({
+    authStrategy: createTokenAuth,
+    auth: '_TOKEN_',
+  });
+  let github: GitHub;
+
+  beforeAll(() => {
+    nock.disableNetConnect();
+  });
+
+  afterAll(() => {
+    nock.enableNetConnect();
+  });
+
+  beforeEach(() => {
+    nock.cleanAll();
+    github = new GitHub(githubClient, 'test_org', 'test_repo');
+  });
+
+  afterEach(() => {
+    // Fail the test if there were unused nocks.
+    if (!nock.isDone()) {
+      throw new Error('Not all nock interceptors were used!');
+    }
+    nock.cleanAll();
+  });
+
+  describe('addComment', () => {
+    it('POSTs /repos/:owner/:repo/issues/:issue_number/comments', async done => {
+      nock('https://api.github.com')
+        .post('/repos/test_org/test_repo/issues/1337/comments', body => {
+          expect(body).toEqual({body: 'Test comment'});
+          return true;
+        })
+        .reply(200);
+
+      await github.addComment(1337, 'Test comment');
+      done();
+    });
+  });
+
+  describe('updatePullBody', () => {
+    it('PATCHes /repos/:owner/:repo/pulls/:pull_number', async done => {
+      nock('https://api.github.com')
+        .patch('/repos/test_org/test_repo/pulls/1337', ({body}) => {
+          expect(body).toEqual('Test description');
+          return true;
+        })
+        .reply(200);
+
+      await github.updatePullBody(1337, 'Test description');
+      done();
+    });
+  });
+
+  describe('findNewDirectory', () => {
+    describe('without regex match', () => {
+      it('GETs /repos/:owner/:repo/pulls/:pull/files', async done => {
+        nock('https://api.github.com')
+          .get('/repos/test_org/test_repo/pulls/1337/files')
+          .reply(200, [{filename: 'foo/bar'}, {filename: 'tacos/no/1'}]);
+
+        expect(await github.findNewDirectory(1337, /no-match/)).toBeFalsy();
+
+        done();
+      });
+
+      it('GETs (once) /repos/:owner/:repo/pulls/:pull/files', async done => {
+        nock('https://api.github.com')
+          .get('/repos/test_org/test_repo/pulls/1337/files')
+          .once()
+          .reply(200, [{filename: 'foo'}]);
+
+        expect(await github.findNewDirectory(1337, /no-match/)).toBeFalsy();
+        expect(await github.findNewDirectory(1337, /no-match/)).toBeFalsy();
+        expect(await github.findNewDirectory(1337, /no-match/)).toBeFalsy();
+
+        done();
+      });
+    });
+
+    describe('with regex match', () => {
+      const pathA = new RegExp('^a/([^/]+)/c');
+      const pathXY = new RegExp('^x/y/([^/]+)/');
+      const finds = ['x/y/added-1/file', 'x/y', 'added-1'];
+
+      describe.each([
+        {finds, contents: [404]},
+        {finds, contents: [200, []]},
+        {finds, contents: [200, [{name: 'foo'}, {name: 'bar'}]]},
+        {contents: [200, [{name: 'added-1'}]]},
+      ])(
+        'GETs /repos/:owner/:repo/contents/:path',
+        ({
+          contents,
+          finds,
+        }: {
+          finds: string[] | undefined;
+          contents: [number, {name: string}[] | undefined];
+        }) => {
+          it(`does${!finds ? ' not' : ''} find when replying ${JSON.stringify(
+            contents
+          )}`, async done => {
+            nock('https://api.github.com')
+              .get('/repos/test_org/test_repo/pulls/1337/files')
+              .reply(200, [
+                {filename: 'a/b/c'},
+                {filename: 'x/y/added-1/file'},
+              ]);
+
+            nock('https://api.github.com')
+              .get('/repos/test_org/test_repo/contents/x/y')
+              .reply(...contents);
+
+            const result = await github.findNewDirectory(1337, pathXY);
+            expect(result).toEqual(finds);
+
+            done();
+          });
+        }
+      );
+
+      it('GETs (once) /repos/:owner/:repo/contents/:path', async done => {
+        nock('https://api.github.com')
+          .get('/repos/test_org/test_repo/pulls/1337/files')
+          .reply(200, [{filename: 'a/b/c'}, {filename: 'x/y/added-1/file'}]);
+
+        nock('https://api.github.com')
+          .get('/repos/test_org/test_repo/contents/x/y')
+          .once()
+          .reply(200, []);
+
+        expect(await github.findNewDirectory(1337, pathXY)).toEqual(finds);
+        expect(await github.findNewDirectory(1337, pathXY)).toEqual(finds);
+        expect(await github.findNewDirectory(1337, pathXY)).toEqual(finds);
+
+        nock('https://api.github.com')
+          .get('/repos/test_org/test_repo/contents/a')
+          .once()
+          .reply(200, [{name: 'b'}]);
+
+        expect(await github.findNewDirectory(1337, pathA)).toEqual(undefined);
+        expect(await github.findNewDirectory(1337, pathA)).toEqual(undefined);
+        expect(await github.findNewDirectory(1337, pathA)).toEqual(undefined);
+
+        done();
+      });
+    });
+  });
+});