Mark as "Ready for review" and assign reviewers on GitHub pull requests after test suite passes

mark_as_ready_for_review.sh

#!/bin/bash
set -eou pipefail

# This script was partially inspired by https://arturdryomov.dev/posts/auto-github-pull-requests/
# Few notes about some of the decisions that led to the code below:
# - The GitHub REST API does not support the marking PRs as ready for review.
#   Instead, this has to be done through the GraphQL API, **and** requires a
#   personal access token since the Github Action default token cannot have
#   the required permission
# - It would have been cleaner to split up all the queries in this file as
#   different "steps" in the workflow file. However, I found that to be
#   massively more painful to test and debug, as you cannot run the whole
#   flow locally easily. Having it all in this single bash script makes it
#   really easy to test. Simply generate a personal access token in your
#   GitHub account settings!
# - The only dependency is currently `jq`, to help with parsing the JSON
#   output of GitHub API queries. Note that we could consider also using
#   `gh` (the GitHub cli) in the future as it could simplify this code
#   quite a bit

TOKEN="${1}"
PR_NUMBERS="${2}"
LABEL="autoready"
REPO="your-repository"
ORGANIZATION="potloc"

# Split the numbers string (comma-delimited)
for pr_number in $(echo $PR_NUMBERS | tr "," "\n"); do
  # Get the node_id (and labels) from the PR number
  # - https://docs.github.com/en/graphql/guides/using-global-node-ids
  # - https://docs.github.com/en/rest/reference/pulls#get-a-pull-request
  out=$(curl \
          --fail \
          --silent \
          --show-error \
          --header "Accept: application/vnd.github.v3+json" \
          --header "Authorization: token ${TOKEN}" \
          --request "GET" \
          --url "https://api.github.com/repos/${ORGANIZATION}/${REPO}/pulls/${pr_number}"
        )
  node_id=$(jq -r '.node_id' <<< $out)
  contains_label=$(jq "any(.labels[].name == \"${LABEL}\"; .)" <<< $out)
  comments_url=$(jq -r ".comments_url" <<< $out)

  # Check if the PR contains the label we want
  if [ "$contains_label" == "true" ]; then
    # Mark the PR as ready for review
    curl \
      --fail \
      --silent \
      --show-error \
      --header "Content-Type: application/json" \
      --header "Authorization: token ${TOKEN}" \
      --request "POST" \
      --data "{ \"query\": \"mutation { markPullRequestReadyForReview(input: { pullRequestId: \\\"${node_id}\\\" }) { pullRequest { id } } }\" }" \
      --url https://api.github.com/graphql

    # Remove the label
    curl \
      --request "DELETE" \
      --header "Accept: application/vnd.github.v3+json" \
      --header "Authorization: token ${TOKEN}" \
      --url "https://api.github.com/repos/${ORGANIZATION}/${REPO}/issues/${pr_number}/labels/${LABEL}"

    # Get the comments on the PR
    comments_out=$(curl \
                    --fail \
                    --silent \
                    --show-error \
                    --header "Content-Type: application/vnd.github.v3+json" \
                    --header "Authorization: token ${TOKEN}" \
                    --request "GET" \
                    --url $comments_url)

    # Look for a comment matching the 'autoready-reviewers: ' pattern
    # If found, assign the mentionned reviewers to review this PR
    jq -r ".[].body" <<< $comments_out | while IFS='' read comment; do
      if [[ $comment =~ autoready-reviewers:[[:space:]]([a-zA-Z0-9,\-\/]+) ]]; then
        all_reviewers=${BASH_REMATCH[1]}

        # Split the reviewers between teams and individuals
        reviewers_array=()
        team_reviewers_array=()
        for reviewer in $(echo $all_reviewers | tr "," "\n"); do
          if [[ $reviewer =~ [a-zA-Z0-9,\-]+\/[a-zA-Z0-9,\-]+ ]]; then
            # In the case of a team reviewer, only take the part of the username after the '/':
            slug_array=(${reviewer//\// })
            team_slug=${slug_array[1]}
            team_reviewers_array+=("\"$team_slug\"")
          else
            reviewers_array+=("\"$reviewer\"")
          fi
        done

        # Join the array elements into a single comma-separated string:
        reviewers=$(IFS=, ; echo "${reviewers_array[*]}")
        team_reviewers=$(IFS=, ; echo "${team_reviewers_array[*]}")

        # Assign reviewers
        curl \
          --fail \
          --silent \
          --show-error \
          --output /dev/null \
          --header "Accept: application/vnd.github.v3+json" \
          --header "Authorization: token ${TOKEN}" \
          --request "POST" \
          --url "https://api.github.com/repos/${ORGANIZATION}/${REPO}/pulls/${pr_number}/requested_reviewers" \
          --data "{\"reviewers\":[${reviewers}], \"team_reviewers\":[${team_reviewers}]}"

        break
      fi
    done
  fi
done

ready_for_review.yml

name: Ready For Review
on:
  workflow_run:
    workflows: ["Test"] # Change this to the name of your own workflow
    branches-ignore: [main]
    types:
      - completed
jobs:
  mark_as_ready_for_review:
    runs-on: self-hosted
    if: ${{ github.event.workflow_run.conclusion == 'success' }}
    steps:
      - name: Checkout Code
        uses: actions/checkout@v3
      - name: Mark as Ready for Review
        run: bash .github/workflows/mark_as_ready_for_review.sh "${{ secrets.ACCESS_TOKEN }}" "${{ join(github.event.workflow_run.pull_requests.*.number) }}"