assign_reviewers.yml

name: Assign requested reviewers

# This workflow adds requested reviewers as assignees. If you remove a
# requested reviewer, it will not remove them as an assignee.
#
# See https://github.com/google/blockly/issues/5643 for more
# information on why this was added.
#
# N.B.: Runs with a read-write repo token.  Do not check out the
# submitted branch!
on:
  pull_request_target:
    types: [review_requested]

jobs:
  requested-reviewer:
    runs-on: ubuntu-latest
    steps:
      - name: Assign requested reviewer
        uses: actions/github-script@v5
        with:
          script: |
            try {
              if (context.payload.pull_request === undefined) {
              throw new Error("Can't get pull_request payload. " +
                              'Check a request reviewer event was triggered.');
              }
              const reviewers = context.payload.pull_request.requested_reviewers;
              // Assignees takes in a list of logins rather than the
              // reviewer object.
              const reviewerNames = reviewers.map(reviewer => reviewer.login);
              const {number:issue_number} = context.payload.pull_request;
              github.rest.issues.addAssignees({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: issue_number,
                assignees: reviewerNames
              });
            } catch (error) {
              core.setFailed(error.message);
            }