chore: add script to pull commits to cherrypick (#16637)

* chore: add script to pull commits to cherrypick

* lint

package.json

@@ -32,7 +32,8 @@
     "preinstall": "node ./tools/npm/check-npm.js",
     "format:ts": "git-clang-format HEAD $(git diff HEAD --name-only | grep -v \"\\.d\\.ts\")",
     "format:bazel": "yarn -s bazel:buildifier --lint=fix --mode=fix",
-    "format": "yarn -s format:ts && yarn -s format:bazel"
+    "format": "yarn -s format:ts && yarn -s format:bazel",
+    "cherry-pick-patch": "ts-node --project tools/cherry-pick-patch/ tools/cherry-pick-patch/cherry-pick-patch.ts"
   },
   "version": "8.1.2",
   "requiredAngularVersion": "^8.0.0 || ^9.0.0-0",
@@ -72,7 +73,7 @@
     "@bazel/karma": "0.32.2",
     "@bazel/typescript": "0.32.2",
     "@firebase/app-types": "^0.3.2",
-    "@octokit/rest": "^15.9.4",
+    "@octokit/rest": "^16.28.7",
     "@schematics/angular": "^8.0.3",
     "@types/browser-sync": "^0.0.42",
     "@types/chalk": "^0.4.31",

tools/cherry-pick-patch/cherry-pick-patch.ts

@@ -0,0 +1,53 @@
+import {GitHub} from './github';
+import {outputResults} from './output-results';
+import {
+  requestLatestCherryPickedCommitSha,
+  requestPatchBranch,
+  verifyLatestCherryPickedCommit
+} from './prompt';
+
+
+/**
+ * Task to run the script that attempts to produce cherry-pick commands for the patch branch.
+ */
+class CherryPickPatchTask {
+  github = new GitHub();
+
+  async run() {
+    const patchBranchSuggestion = await this.github.getPatchBranchSuggestion();
+    const branch = await requestPatchBranch(patchBranchSuggestion);
+    const sha = await this.getLatestCherryPickedCommitSha(branch);
+
+    const commit = await this.github.getCommit(sha);
+    const pullRequests = await this.github.getPatchPullRequestsSince(commit.commit.author.date);
+
+    outputResults(pullRequests);
+  }
+
+  /** Returns the commit SHA of the last cherry-picked commit on master. */
+  async getLatestCherryPickedCommitSha(branch: any): Promise<string> {
+    const commits = await this.github.listCommits(branch);
+
+    /** Gets the SHA from the string: "(cherry picked from commit 4c6eeb9aba73d3)" */
+    const regexp = new RegExp('cherry picked from commit (.*[^)])');
+    const latestShas = commits
+                           .map(d => {
+                             const result = d.commit.message.match(regexp);
+                             return result ? result[1] : null;
+                           })
+                           .filter(d => !!d);
+
+    const latestSha = latestShas[0];
+    if (!latestSha) {
+      return await requestLatestCherryPickedCommitSha();
+    } else {
+      const commit = await this.github.getCommit(latestSha);
+      return await verifyLatestCherryPickedCommit(commit);
+    }
+  }
+}
+
+/** Entry-point for the script. */
+if (require.main === module) {
+  new CherryPickPatchTask().run();
+}

tools/cherry-pick-patch/github.ts

@@ -0,0 +1,88 @@
+import * as OctokitApi from '@octokit/rest';
+
+// TODO: Consider using local git information for the data to avoid worrying about rate limits. */
+/** Class to act as an interface to the GitHub API. */
+export class GitHub {
+  // TODO: Use an authentication token to increase rate limits.
+  /** Octokit API instance that can be used to make Github API calls. */
+  private _api = new OctokitApi();
+
+  /** Owner of the repository to query. */
+  private _owner = 'angular';
+
+  /** Name of the repository to query. */
+  private _name = 'components';
+
+  /**
+   * Retrieves merged patch-eligible pull requests that have been merged since the date.
+   * Results are sorted by merge date.
+   */
+  async getPatchPullRequestsSince(dateSince: string): Promise<OctokitApi.PullsGetResponse[]> {
+    const query = 'base:master is:pr -label:"target: minor" -label:"target: major" is:merged' +
+        ` merged:>${dateSince}`;
+    const result = await this._search(query);
+
+    // Load information for each pull request. Waits for each pull request response until loading
+    // the next pull request to avoid GitHub's abuse detection (too many calls in a short amount
+    // of time).
+    const pullRequests: OctokitApi.PullsGetResponse[] = [];
+    for (let i = 0; i < result.items.length; i++) {
+      pullRequests.push(await this.loadPullRequest(result.items[i].number));
+    }
+
+    // Sort by merge date.
+    pullRequests.sort((a, b) => (a.merged_at < b.merged_at) ? -1 : 1);
+    return pullRequests;
+  }
+
+  /** Loads the information for the provided pull request number. */
+  async loadPullRequest(prNumber: number): Promise<OctokitApi.PullsGetResponse> {
+    const response = await this._api.pulls.get({
+      owner: this._owner,
+      repo: this._name,
+      pull_number: prNumber,
+    });
+    return response.data;
+  }
+
+  /** Gets the commit information for the given SHA. */
+  async getCommit(sha: string): Promise<OctokitApi.ReposGetCommitResponse> {
+    const response = await this._api.repos.getCommit({
+      owner: this._owner,
+      repo: this._name,
+      ref: sha,
+    });
+
+    return response.data;
+  }
+
+  /** Retrieves the list of latest commits from the branch. */
+  async listCommits(branch: string): Promise<OctokitApi.ReposListCommitsResponse> {
+    const response = await this._api.repos.listCommits({
+      owner: this._owner,
+      repo: this._name,
+      sha: branch,
+    });
+
+    return response.data;
+  }
+
+  // TODO: Handle pagination in case there are more than 100 results.
+  /** Gets a suggestion for the latest patch branch. */
+  async getPatchBranchSuggestion(): Promise<string> {
+    const response = await this._api.repos.listBranches({owner: this._owner, repo: this._name});
+
+    // Matches branch names that have two digits separated by period and ends with an x
+    const patchBranches =
+        response.data.map(branch => branch.name).filter(name => !!/^\d+\.\d+\.x$/g.exec(name));
+    return patchBranches.pop() || '';
+  }
+
+  // TODO: Handle pagination in case there are more than 100 results.
+  /** Searches the repository using the provided query. */
+  private async _search(query: string): Promise<{items: any[]}> {
+    const scopedQuery = `repo:${this._owner}/${this._name} ${query}`;
+    const result = await this._api.search.issuesAndPullRequests({per_page: 100, q: scopedQuery});
+    return result.data;
+  }
+}

tools/cherry-pick-patch/output-results.ts

@@ -0,0 +1,34 @@
+import {PullsGetResponse} from '@octokit/rest';
+import {cyan} from 'chalk';
+
+/** Outputs the information of the pull requests to be cherry-picked and the commands to run. */
+export function outputResults(pullRequests: PullsGetResponse[]) {
+  if (!pullRequests.length) {
+    console.log('No pull requests need to be cherry-picked');
+    return;
+  }
+
+  console.log();
+  console.log(cyan('------------------------'));
+  console.log(cyan('  Results '));
+  console.log(cyan('------------------------'));
+  console.log();
+
+  pullRequests.forEach(p => {
+    const data = [p.number, p.merged_at, p.merge_commit_sha, p.html_url, p.title];
+    console.log(data.join('\t'));
+  });
+
+  console.log();
+  console.log(cyan('------------------------'));
+  console.log(cyan('  Cherry Pick Commands'));
+  console.log(cyan('------------------------'));
+
+  pullRequests.forEach((pr, index) => {
+    if (index % 5 === 0) {
+      console.log();
+    }
+
+    console.log(`git cherry-pick -x ${pr.merge_commit_sha};`);
+  });
+}

tools/cherry-pick-patch/prompt.ts

@@ -0,0 +1,43 @@
+import {prompt} from 'inquirer';
+import * as OctokitApi from '@octokit/rest';
+
+/** Requests the user to provide the name of the patch branch. */
+export async function requestPatchBranch(suggestion: string): Promise<string> {
+  const result = await prompt<{branch: string}>([{
+    type: 'input',
+    name: 'branch',
+    message: `What is the name of the current patch branch?`,
+    default: suggestion || null,
+  }]);
+
+  return result.branch;
+}
+
+/** Confirms the latest cherry-picked commit on master; requests one if not confirmed. */
+export async function verifyLatestCherryPickedCommit(commit: OctokitApi.ReposGetCommitResponse) {
+  console.log(`\nThe last cherry-picked commit on master is "${commit.commit.message}"`);
+
+  const result = await prompt<{confirm: boolean}>([{
+    type: 'confirm',
+    name: 'confirm',
+    message: `Is this correct?`,
+    default: true,
+  }]);
+
+  if (!result.confirm) {
+    return await requestLatestCherryPickedCommitSha();
+  } else {
+    return commit.sha;
+  }
+}
+
+/** Requests the SHA of the latest cherry picked commit on master. */
+export async function requestLatestCherryPickedCommitSha(): Promise<string> {
+  const result = await prompt<{sha: string}>([{
+    type: 'input',
+    name: 'sha',
+    message: `What is the SHA of the latest cherry-picked commit on master?`,
+  }]);
+
+  return result.sha;
+}

tools/cherry-pick-patch/tsconfig.json

@@ -0,0 +1,7 @@
+{
+  "compilerOptions": {
+    "lib": ["es2016"],
+    "types": ["node"],
+    "strictNullChecks": true
+  }
+}