Add PR Comment

add-pr-comment

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

This actions also works on issue, issue_comment, deployment_status, push and any other event where an issue can be found directly on the payload or via a commit sha.

Features

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.
Optional message overrides based on job status.
Multiple posts to the same conversation optionally allowable.
Supports a proxy for fork-based PRs. See below.
Supports creating a message from a file path.

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**
            🌏
            !

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
        with:
          message: |
            **Hello MAIN**

Configuration options

Input	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. Supports multi-line input and globs. Multiple messages will be concatenated.	maybe
message-success	with	A message override, printed in case of success.	no
message-failure	with	A message override, printed in case of failure.	no
message-cancelled	with	A message override, printed in case of cancelled.	no
message-skipped	with	A message override, printed in case of skipped.	no
status	with	Required if you want to use message status overrides.	no	{{ job.status }}
repo-owner	with	Owner of the repo.	no	{{ github.repository_owner }}
repo-name	with	Name of the repo.	no	{{ github.event.repository.name }}
repo-token	with	Valid GitHub token, either the temporary token GitHub provides or a personal access token.	no	{{ github.token }}
message-id	with	Message id to use when searching existing comments. If found, updates the existing (sticky comment).	no
refresh-message-position	with	Should the sticky message be the last one in the PR's feed.	no	false
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
issue	with	Optional issue number override.	no
update-only	with	Only update the comment if it already exists.	no	false
GITHUB_TOKEN	env	Valid GitHub token, can alternatively be defined in the env.	no
preformatted	with	Treat message text as pre-formatted and place it in a codeblock	no
find	with	Patterns to find in an existing message and replace with either `replace` text or a resolved `message`. See Find-and-Replace for more detail.	no
replace	with	Strings to replace a found pattern with. Each new line is a new replacement, or if you only have one pattern, you can replace with a multiline string.	no

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

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.

Example

on:
  pull_request:

jobs:
  pr:
    runs-on: ubuntu-latest
    permissions:
      pull-requests: write
    steps:
      - uses: mshick/add-pr-comment@v2
        if: always()
        with:
          message: |
            **Howdie!**
          message-failure: |
            Uh oh!

Multiple Message Files

Instead of directly setting the message you can also load a file with the text of your message using message-path. message-path supports loading multiple files and files on multiple lines, the contents of which will be concatenated.

Example

on:
  pull_request:

jobs:
  pr:
    runs-on: ubuntu-latest
    permissions:
      pull-requests: write
    steps:
      - uses: mshick/add-pr-comment@v2
        if: always()
        with:
          message-path: |
            message-part-*.txt

Find-and-Replace

Patterns can be matched and replaced to update comments. This could be useful for some situations, for instance, updating a checklist comment.

Find is a regular expression passed to the RegExp() constructor. You can also include modifiers to override the default gi.

Example

Original message:

[ ] Hello
[ ] World

Action:

on:
  pull_request:

jobs:
  pr:
    runs-on: ubuntu-latest
    permissions:
      pull-requests: write
    steps:
      - uses: mshick/add-pr-comment@v2
        if: always()
        with:
          find: |
            \n\\[ \\]
          replace: |
            [X]

Final message:

[X] Hello
[X] World

Multiple find and replaces can be used:

Example

Original message:

hello world!

Action:

on:
  pull_request:

jobs:
  pr:
    runs-on: ubuntu-latest
    permissions:
      pull-requests: write
    steps:
      - uses: mshick/add-pr-comment@v2
        if: always()
        with:
          find: |
            hello
            world
          replace: |
            goodnight
            moon

Final message:

goodnight moon!

It defaults to your resolved message (either from message or message-path) to do a replacement:

Example

Original message:

hello

<< FILE_CONTENTS >>

world

Action:

on:
  pull_request:

jobs:
  pr:
    runs-on: ubuntu-latest
    permissions:
      pull-requests: write
    steps:
      - uses: mshick/add-pr-comment@v2
        if: always()
        with:
          message-path: |
            message.txt
          find: |
            << FILE_CONTENTS >>

Final message:

hello

secret message from message.txt

world

Bring your own issues

You can set an issue id explicitly. Helpful for cases where you want to post to an issue but for some reason the event would not allow the id to be determined.

Example

In this case add-pr-comment should have no problem finding the issue number on its own, but for demonstration purposes.

on:
  deployment_status:

jobs:
  pr:
    runs-on: ubuntu-latest
    permissions:
      pull-requests: write
    steps:
      - id: pr
        run: |
          issue=$(gh pr list --search "${{ github.sha }}" --state open --json number --jq ".[0].number")
          echo "issue=$issue" >>$GITHUB_OUTPUT
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

      - uses: mshick/add-pr-comment@v2
        with:
          issue: ${{ steps.pr.outputs.issue }}
          message: |
            **Howdie!**