create-cherry-pick-pr.yml

name: Create cherry pick PR

on:
  workflow_dispatch:
    inputs:
      pr:
        description: PR number to cherry-pick
        required: true
        type: number
      target_branch:
        description: Target branch to cherry-pick to
        required: true
        type: string

      # Inputs provided by the bot
      distinct_id:
        description: '(bot) A distinct ID'
        required: false
        default: ''
      source_issue:
        description: '(bot) The issue that triggered this workflow'
        required: false
        default: ''
      requesting_user:
        description: '(bot) The user who requested this workflow'
        required: false
        default: ''
      status_comment:
        description: '(bot) The comment to update with the status of this workflow'
        required: false
        default: ''

run-name: ${{ github.workflow }}${{ inputs.distinct_id && format(' (bot run {0})', inputs.distinct_id) || '' }}

permissions:
  contents: read

# Ensure scripts are run with pipefail. See:
# https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#exit-codes-and-error-action-preference
defaults:
  run:
    shell: bash

jobs:
  open-pr:
    runs-on: ubuntu-latest
    if: github.repository == 'microsoft/TypeScript'

    steps:
      - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
        with:
          filter: blob:none # https://github.blog/2020-12-21-get-up-to-speed-with-partial-clone-and-shallow-clone/
          fetch-depth: 0 # Default is 1; need to set to 0 to get the benefits of blob:none.
          token: ${{ secrets.TS_BOT_GITHUB_TOKEN }}

      - uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
        id: open-pr
        env:
          PR: ${{ inputs.pr }}
          TARGET_BRANCH: ${{ inputs.target_branch }}
          DISTINCT_ID: ${{ inputs.distinct_id }}
          SOURCE_ISSUE: ${{ inputs.source_issue }}
          REQUESTING_USER: ${{ inputs.requesting_user }}
          STATUS_COMMENT: ${{ inputs.status_comment }}
        with:
          retries: 3
          github-token: ${{ secrets.TS_BOT_GITHUB_TOKEN }}
          result-encoding: string
          script: |
            const {
              PR,
              TARGET_BRANCH,
              DISTINCT_ID,
              SOURCE_ISSUE,
              REQUESTING_USER,
              STATUS_COMMENT,
            } = process.env;

            const pr = await github.rest.pulls.get({
              owner: context.repo.owner,
              repo: context.repo.repo,
              pull_number: +PR,
            });

            if (!pr.data.merge_commit_sha) throw new Error("No merge commit sha found");

            const pickBranch = `cherry-pick/${PR}/${TARGET_BRANCH}`;

            const title = `🤖 Pick PR #${PR} (${pr.data.title.substring(0, 35)}${pr.data.title.length > 35 ? "..." : ""}) into ${TARGET_BRANCH}`;

            await exec.exec("git", ["config", "user.email", "typescriptbot@microsoft.com"]);
            await exec.exec("git", ["config", "user.name", "TypeScript Bot"]);
            await exec.exec("git", ["switch", "--detach", `origin/${TARGET_BRANCH}`]);
            await exec.exec("git", ["switch", "-c", pickBranch]);

            let updatedBaselinesMessage = "";
            try {
              await exec.exec("git", ["cherry-pick", "-m", "1", pr.data.merge_commit_sha]);
            } catch (e) {
              console.log(e);

              // The cherry-pick failed. If all of the conflicts are in tests/baselines,
              // try to run the tests and accept the new baselines.

              await exec.exec("git", ["add", "tests/baselines"]);
              // This will fail if any other files were modified.
              await exec.exec("git", ["-c", "core.editor=true", "cherry-pick", "--continue"]);

              await exec.exec("npm", ["ci"]);

              try {
                await exec.exec("npm", ["test", "--", "--no-lint"]);
              } catch {
                // Expected to fail.
              }

              await exec.exec("npx", ["hereby", "baseline-accept"]);
              await exec.exec("git", ["add", "tests/baselines"]);
              await exec.exec("git", ["commit", "-m", "Update baselines"]);

              updatedBaselinesMessage = " This involved updating baselines; please check the diff.";
            }

            await exec.exec("git", ["push", "--force", "--set-upstream", "origin", pickBranch]);

            const existingPulls = await github.rest.pulls.list({
              owner: context.repo.owner,
              repo: context.repo.repo,
              head: `${context.repo.owner}:${pickBranch}`,
            });

            let commentBody;

            if (existingPulls.data.length === 0) {
              console.log(`No existing PRs found for ${pickBranch}`);

              const body = `This cherry-pick was triggered by a request on #${PR}.\n\nPlease review the diff and merge if no changes are unexpected.${updatedBaselinesMessage}`;

              const newPr = await github.rest.pulls.create({
                owner: context.repo.owner,
                repo: context.repo.repo,
                base: TARGET_BRANCH,
                head: pickBranch,
                title,
                body,
              });

              await github.rest.issues.addAssignees({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: newPr.data.number,
                assignees: ["DanielRosenwasser"],
              });

              await github.rest.pulls.requestReviewers({
                owner: context.repo.owner,
                repo: context.repo.repo,
                pull_number: newPr.data.number,
                reviewers: ["DanielRosenwasser", REQUESTING_USER],
              });

              commentBody = `I've created #${newPr.data.number} for you.${updatedBaselinesMessage}`;
            }
            else {
              const existing = existingPulls.data[0];
              console.log(`Found existing PR #${existing.number} for ${pickBranch}`);

              await github.rest.pulls.update({
                owner: context.repo.owner,
                repo: context.repo.repo,
                pull_number: existing.number,
                title,
              });

              commentBody = `I've updated #${existing.number} for you.${updatedBaselinesMessage}`;
            }

            return commentBody;

      - uses: microsoft/typescript-bot-test-triggerer/.github/actions/post-workflow-result@master
        if: ${{ !cancelled() && inputs.distinct_id }}
        with:
          success_comment: ${{ steps.open-pr.outputs.result }}
          failure_comment: 'I was unable to cherry-pick this PR.'
          github_token: ${{ secrets.TS_BOT_GITHUB_TOKEN }}
          distinct_id: ${{ inputs.distinct_id }}
          source_issue: ${{ inputs.source_issue }}
          requesting_user: ${{ inputs.requesting_user }}
          status_comment: ${{ inputs.status_comment }}