get-pr-info.yml

description: |
  Gets and sets the following environment variables:
      * `GITHUB_PR_BASE_BRANCH` - The base branch for the PR.
      * `GITHUB_PR_NUMBER` - The number of the PR.
      * `GITHUB_PR_TITLE` - The title of the PR.
      * `GITHUB_PR_COMMIT_MESSAGE` - The current commit's message. (Optional)
      * `GITHUB_PR_AUTHOR_USERNAME` - The PR author's username.
      * `GITHUB_PR_AUTHOR_NAME` - The PR author's name. (Optional)
      * `GITHUB_PR_AUTHOR_EMAIL` - The PR author's email address. (Optional)
  Requires  `GITHUB_TOKEN` to be set as an environment variable.
parameters:
  get_pr_author_email:
    description: |
      If true, also sets GITHUB_PR_AUTHOR_EMAIL. This requires an additional API call.
    type: boolean
    default: false
  get_pr_author_name:
    description: |
      If true, also sets GITHUB_PR_AUTHOR_NAME. This requires an additional API call.
    type: boolean
    default: false
  get_commit_message:
    description: |
      If true, also sets GITHUB_PR_COMMIT_MESSAGE. This requires an additional API call.
    type: boolean
    default: false
steps:
  - run:
      when: always
      name: Get PR information
      command: |
        # Check `jq` dependency
        if ! (command -v jq >/dev/null 2>&1); then
          echo "This command requires jq to be installed"
          exit 1
        fi

        PR_NUMBER=$(echo "$CIRCLE_PULL_REQUEST" | sed "s/.*\/pull\///")
        echo "PR_NUMBER: $PR_NUMBER"
        echo "export GITHUB_PR_NUMBER=$PR_NUMBER" >> $BASH_ENV

        API_GITHUB="https://api.github.com/repos/$CIRCLE_PROJECT_USERNAME/$CIRCLE_PROJECT_REPONAME"
        PR_REQUEST_URL="$API_GITHUB/pulls/$PR_NUMBER"
        PR_RESPONSE=$(curl -H "Authorization: token $GITHUB_TOKEN" "$PR_REQUEST_URL")

        PR_TITLE=$(echo $PR_RESPONSE | jq -e '.title' | tr -d '"')
        echo "PR_TITLE: $PR_TITLE"
        echo "export GITHUB_PR_TITLE='${PR_TITLE/"'"/}'" >> $BASH_ENV

        PR_BASE_BRANCH=$(echo $PR_RESPONSE | jq -e '.base.ref' | tr -d '"')
        echo "PR_BASE_BRANCH: $PR_BASE_BRANCH"
        echo "export GITHUB_PR_BASE_BRANCH='${PR_BASE_BRANCH/"'"/}'" >> $BASH_ENV

        PR_AUTHOR_USERNAME=$(echo $PR_RESPONSE | jq -e '.user.login' | tr -d '"')
        echo "PR_AUTHOR_USERNAME: $PR_AUTHOR_USERNAME"
        echo "export GITHUB_PR_AUTHOR_USERNAME='${PR_AUTHOR_USERNAME/"'"/}'" >> $BASH_ENV

        if [[ << parameters.get_pr_author_email >> == true || << parameters.get_pr_author_name >> ]]; then
          # We need to use the email address associated with the merge_commit_sha since
          # CIRCLE_SHA1 may have been authored by someone who is not the PR author.
          # Sadly, PR_RESPONSE doesn't include the email associated with the merge_commit_sha.
          # So we have to get that from the commit information.

          PR_MERGE_COMMIT_SHA=$(echo $PR_RESPONSE | jq -e '.merge_commit_sha' | tr -d '"')
          COMMIT_REQUEST_URL="$API_GITHUB/commits/$PR_MERGE_COMMIT_SHA"
          COMMIT_RESPONSE=$(curl -H "Authorization: token $GITHUB_TOKEN" "$COMMIT_REQUEST_URL")
        fi

        <<# parameters.get_pr_author_email >>
        PR_AUTHOR_EMAIL=$(echo $COMMIT_RESPONSE | jq -e '.commit.author.email' | tr -d '"')
        echo "PR_AUTHOR_EMAIL: $PR_AUTHOR_EMAIL"
        echo "export GITHUB_PR_AUTHOR_EMAIL='${PR_AUTHOR_EMAIL/"'"/}'" >> $BASH_ENV
        <</ parameters.get_pr_author_email >>

        <<# parameters.get_pr_author_name >>
        PR_AUTHOR_NAME=$(echo $COMMIT_RESPONSE | jq -e '.commit.author.name' | tr -d '"')
        echo "PR_AUTHOR_NAME: $PR_AUTHOR_NAME"
        echo "export GITHUB_PR_AUTHOR_NAME='${PR_AUTHOR_NAME/"'"/}'" >> $BASH_ENV
        <</ parameters.get_pr_author_name >>

        <<# parameters.get_commit_message >>
        COMMIT_REQUEST_URL="$API_GITHUB/commits/$CIRCLE_SHA1"
        COMMIT_RESPONSE=$(curl -H "Authorization: token $GITHUB_TOKEN" "$COMMIT_REQUEST_URL")
        PR_COMMIT_MESSAGE=$(echo $COMMIT_RESPONSE | jq -e '.commit.message' | tr -d '"')
        echo "PR_COMMIT_MESSAGE: $PR_COMMIT_MESSAGE"
        echo "export GITHUB_PR_COMMIT_MESSAGE='${PR_COMMIT_MESSAGE//\'/}'" >> $BASH_ENV
        <</ parameters.get_commit_message >>