chromatic-label-helper.yml

# The DCR repo has a required status check on the Chromatic UI Tests
# To save £££, we only run the Chromatic tests once the `run_chromatic`
# label is applied. This workflow reminds people to add the label
# because it isn't always obvious.

name: Chromatic Label Helper

on:
  pull_request:
    types: [opened, ready_for_review]

jobs:
  write_comment:
    runs-on: ubuntu-latest
    permissions:
      pull-requests: write

    # We only comment on pull requests that have been marked as ready for review
    if: ${{ github.event.pull_request.draft == false}}

    steps:
      - uses: actions/github-script@v7
        with:
          script: |
            const labels = await github.rest.issues
              .listLabelsOnIssue({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: context.issue.number,
              })
              .then(({ data }) => data);
            const hasChromaticLabel = labels.some(
              (label) => label.name === 'run_chromatic',
            );

            if (!hasChromaticLabel) {
              const commentLines = [
                "Hello :wave:! When you're ready to run Chromatic, please apply the `run_chromatic` label to this PR.",
                "You will need to reapply the label each time you want to run Chromatic.",
                '[Click here to see the Chromatic project.](https://www.chromatic.com/builds?appId=63e251470cfbe61776b0ef19)',
              ];

              /** Checks if this label helper has already commented on the pull request */
              const hasChromaticCommentAlready = await github.rest.issues.listComments({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: context.issue.number,
              }).then(({ data }) => {
                return data.some((comment) => {
                  return comment.body.includes(commentLines[0]);
                });
              });

              if (!hasChromaticCommentAlready) {
                  github.rest.issues.createComment({
                    issue_number: context.issue.number,
                    owner: context.repo.owner,
                    repo: context.repo.repo,
                    body: commentLines.join('\n\n'),
                });
              }
            }