add-pr-comment

A GitHub Action which adds a comment to a pull request's issue.

Features

Fast, runs in the GitHub Actions node.js runtime.
Modify issues for PRs merged to main.
By default will post "sticky" comments. If on a subsequent run the message text changes the original comment will be updated.
Multiple sticky comments allowed by setting unique message-ids.
Multiple posts of the same comment optionally allowable.
Supports emoji 😂😂😂!
Supports a proxy for fork-based PRs. See below.
Supports creating a message from a file path.
Optional message / status overrides.

Usage

Note that write access needs to be granted for the pull-requests scope.

on:
  pull_request:

jobs:
  test:
    runs-on: ubuntu-latest
    permissions:
      pull-requests: write
    steps:
      - uses: mshick/add-pr-comment@v2
        with:
          message: |
            **Hello**
            🌏
            !
          repo-token: ${{ secrets.GITHUB_TOKEN }}
          allow-repeats: false # This is the default
          message-id: 'add-pr-comment' # This is the default

You can even use it on PR Issues that are related to PRs that were merged into main, for example:

on:
  push:
    branches:
      - main

jobs:
  test:
    runs-on: ubuntu-latest
    permissions:
      pull-requests: write
    steps:
      - uses: mshick/add-pr-comment@v2
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        with:
          message: |
            **Hello MAIN**

Configuration options

Variable or Argument	Location	Description	Required	Default
message	with	The message you'd like displayed, supports Markdown and all valid Unicode characters.	maybe
message-path	with	Path to a message you'd like displayed. Will be read and displayed just like a normal message.	maybe
message-success	with	A message override, printed in case of success.	maybe
message-failure	with	A message override, printed in case of failure.	maybe
message-cancelled	with	A message override, printed in case of cancelled.	maybe
status	with	Required if you want to use message status overrides.	maybe
repo-token	with	Valid GitHub token, either the temporary token GitHub provides or a personal access token.	maybe
message-id	with	Message id to use when searching existing comments. If found, updates the existing (sticky comment).	no
allow-repeats	with	Boolean flag to allow identical messages to be posted each time this action is run.	no	false
proxy-url	with	String for your proxy service URL if you'd like this to work with fork-based PRs.	no
GITHUB_TOKEN	env	Valid GitHub token, can alternatively be defined in the env.	maybe

Advanced Uses

Proxy for Fork-based PRs

GitHub limits GITHUB_TOKEN and other API access token permissions when creating a PR from a fork. This precludes adding comments when your PRs are coming from forks, which is the norm for open source projects. To work around this situation I've created a simple companion app you can deploy to Cloud Run or another host to proxy the create comment requests with a personal access token you provide.

See this issue: https://github.community/t/github-actions-are-severely-limited-on-prs/18179/4 for more details.

Check out the proxy service here: https://github.com/mshick/add-pr-comment-proxy

Example

on:
  pull_request:

jobs:
  pr:
    runs-on: ubuntu-latest
    permissions:
      pull-requests: write
    steps:
      - uses: mshick/add-pr-comment@v2
        with:
          message: |
            **Howdie!**
          proxy-url: https://add-pr-comment-proxy-94idvmwyie-uc.a.run.app
          repo-token: ${{ secrets.GITHUB_TOKEN }}

Status Message Overrides

You can override your messages based on your job status. This can be helpful if you don't anticipate having the data required to create a helpful message in case of failure, but you still want a message to be sent to the PR comment.