Add Github App for the devrel reviews and approvals workflow

approvals/app.js

@@ -0,0 +1,212 @@
+/*
+ * Copyright 2022 Google LLC
+ *
+ * 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
+ *
+ *     https://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.
+ */
+
+const micromatch = require('micromatch');
+const axios = require('axios');
+
+const CONFIG_FILE = '.github/chrome-devrel-bot.json';
+
+const CHECK_RESULTS = {
+  success: {
+    conclusion: 'success',
+    title: 'Approvals complete',
+    summary: 'All required approvals are granted'
+  },
+  approval_missing: {
+    conclusion: 'failure',
+    title: 'Approvals missing',
+    summary: 'At least one approving review is required'
+  },
+  no_config: {
+    conclusion: 'cancelled',
+    title: 'Missing config file',
+    summary: 'The config file does not exist'
+  },
+  no_files: {
+    conclusion: 'cancelled',
+    title: 'Missing PR files',
+    summary: 'No changed files found'
+  }
+}
+
+/**
+ * Main entrypoint to the Probot app
+ * @param {import('probot').Probot} app
+ */
+module.exports = (app) => {
+
+  app.on([
+    'pull_request.opened',
+    'pull_request.reopened',
+    'pull_request.ready_for_review',
+    'pull_request.edited',
+  ], checkPR);
+
+  /**
+   * @param {import('probot').ProbotOctokit} octokit Github's lib instance.
+   * @param {Object} checkOptions Values to be set on the createCheck call.
+   * @param {Object} checkOptions.headers Key-value pairs to be set as headers for the HTTP call.
+   * @param {string} checkOptions.name Name of the check.
+   * @param {Date} checkOptions.started_at Date when the check started.
+   * @param {string} checkOptions.head_sha HeadSha property of the target PR.
+   * @param {string} checkOptions.owner ID of the owner of the Github's repo
+   * @param {string} checkOptions.repo ID of the Github's repo.
+   * @param {Object} result Result of the check.
+   * @param {string} conclusion Outcome of teh check, e.g. 'success' or 'failure'.
+   * @param {string} title Title to be displayed on the check in Github.
+   * @param {string} summary Summary to be displayed on the check in Github.
+   */
+  async function createCheck(octokit, checkOptions, result) {
+    return await octokit.checks.create({
+      ...checkOptions,
+      ...result,
+    });
+  }
+
+  function createCompletedResult({conclusion, title, summary}) {
+    return {
+      status: 'completed',
+      conclusion,
+      output: {
+        title,
+        summary
+      }
+    };
+  }
+
+  /**
+   * @param {import('probot').ProbotOctokit} octokit Github's lib instance.
+   * @param {Object} checkOptions Values to be set on the createCheck call.
+   * @param {Object} checkOptions.headers Key-value pairs to be set as headers for the HTTP call.
+   * @param {string} checkOptions.name Name of the check.
+   * @param {Date} checkOptions.started_at Date when the check started.
+   * @param {string} checkOptions.head_sha HeadSha property of the target PR.
+   * @param {string} checkOptions.owner ID of the owner of the Github's repo
+   * @param {string} checkOptions.repo ID of the Github's repo.
+   * @param {Number} pullNumber Number of the target pull request
+   */
+  async function getFiles(octokit, checkOptions, pullNumber) {
+    const filesRequest = await octokit.rest.pulls.listFiles({
+      owner: checkOptions.owner,
+      repo: checkOptions.repo,
+      pull_number: pullNumber,
+    });
+    if (filesRequest.status !== 200) {
+      result = createCompletedResult(CHECK_RESULTS.no_files);
+      await createCheck(octokit, checkOptions, result);
+      return null;
+    }
+    return filesRequest.data;
+  }
+
+  /**
+   * @param {import('probot').ProbotOctokit} octokit Github's lib instance.
+   * @param {Object} checkOptions Values to be set on the createCheck call.
+   * @param {Object} checkOptions.headers Key-value pairs to be set as headers for the HTTP call.
+   * @param {string} checkOptions.name Name of the check.
+   * @param {Date} checkOptions.started_at Date when the check started.
+   * @param {string} checkOptions.head_sha HeadSha property of the target PR.
+   * @param {string} checkOptions.owner ID of the owner of the Github's repo
+   * @param {string} checkOptions.repo ID of the Github's repo.
+   * @param {Number} pullNumber Number of the target pull request
+   */
+  async function getReviews(octokit, checkOptions, pullNumber) {
+    const reviewsRequest = await octokit.rest.pulls.listReviews({
+      owner: checkOptions.owner,
+      repo: checkOptions.repo,
+      pull_number: pullNumber,
+    });
+    if (reviewsRequest.status !== 200) {
+      result = createCompletedResult(CHECK_RESULTS.approval_missing);
+      await createCheck(octokit, checkOptions, result);
+      return null;
+    }
+    return reviewsRequest.data;
+  }
+
+  async function checkPR(context) {
+    const startTime = new Date();
+    const pullRequest = context.payload.pull_request;
+    if (pullRequest.state !== 'open' || pullRequest.draft) {
+      return;
+    }
+
+    const octokit = context.octokit;
+    const headSha = pullRequest.head.sha;
+    const owner = context.payload.repository.full_name.split('/')[0];
+    const repo = context.payload.repository.name;
+    const pullNumber = pullRequest.number;
+    let result;
+
+    const checkOptions = {
+      headers: {
+        accept: "application/vnd.github.v3+json"
+      },
+      name: "Chrome DevRel PR checks",
+      started_at: startTime,
+      head_sha: headSha,
+      owner,
+      repo
+    };
+
+    // Get Config file
+    const url = `https://raw.githubusercontent.com/${owner}/${repo}/main/${CONFIG_FILE}`;
+    const response = await axios.get(url);
+    if (response.status !== 200) {
+      result = createCompletedResult(CHECK_RESULTS.no_config);
+      return await createCheck(octokit, checkOptions, result);
+    }
+    const config = response.data;
+
+    // Get PR files
+    const files = await getFiles(octokit, checkOptions, pullNumber);
+    if (!files) {
+      return;
+    }
+    const paths = files.map(file => file.filename);
+
+    // Get PR reviews
+    const reviews = await getReviews(octokit, checkOptions, pullNumber);
+    if (!reviews) {
+      return;
+    }
+    const approvers = [];
+    for (const review of reviews) {
+      if (review.state === 'APPROVED') {
+        approvers.push(review.user.login);
+      }
+    }
+    if (!approvers.length) {
+      result = createCompletedResult(CHECK_RESULTS.approval_missing);
+      return await createCheck(octokit, checkOptions, result);
+    }
+
+    for (const check of config.pr_checks.approvals) {
+      const isCheckRequired = micromatch.some(paths, check.paths, {'dot': true});
+      if (isCheckRequired) {
+        const isApproved = approvers.some(login => check.users.includes(login));
+        if (!isApproved) {
+          result = createCompletedResult(CHECK_RESULTS.approval_missing);
+          result.output.summary = `${check.check_name} failed`;
+          return await createCheck(octokit, checkOptions, result);
+        }
+      }
+    }
+
+    result = createCompletedResult(CHECK_RESULTS.success);
+    return await createCheck(octokit, checkOptions, result);
+  }
+};