GitHub Action to create, update, or add a reaction to any issue or pull request

• Create a comment
• Update a comment
• Add a reaction to a comment
• Create or update a comment from a markdown file
• Create or update a comment from a markdown file with template variable rendering

The section below will contain a few common examples for how you can use this Action

    - name: Create comment
      uses: GrantBirki/comment@vX.X.X
      with:
        body: |
          This is a multi-line test comment

          - With GitHub **Markdown** ✨
          - Cool!
        reactions: '+1'

This will create a brand new comment on an issue/pr with the comment body seen above. It will also add a 👍 reaction

    - name: Update comment
      uses: GrantBirki/comment@vX.X.X
      with:
        comment-id: 123456789
        body: |
          **Edit:** Some additional info
        reactions: eyes

This will update the comment with the comment body seen above in the default append mode. It will also add a 👀 reaction

    - name: Add reactions
      uses: GrantBirki/comment@vX.X.X
      with:
        comment-id: 123456789
        reactions: heart, hooray, laugh

This will add three reactions to the comment specified by the comment-id

    - name: Create comment from markdown file
      uses: GrantBirki/comment@vX.X.X
      with:
        file: demo/plain-sample.md

This will create a comment and use the markdown file contents as the comment body

    - name: Create comment from markdown file with variables
      uses: GrantBirki/comment@vX.X.X
      with:
        file: demo/render-sample.md
        vars: |
          sha: ${{ github.sha }}
          environment: production
          app: cool-app

This will create a comment and use the markdown file contents as the comment body with the variables specified in the vars section for template rendering

For more information about templating, be sure to check out the templating section below

The ID of the created comment will be output for use in later steps Note that in order to read the step output the action step must have an id.

    - name: Create comment
      uses: GrantBirki/comment@vX.X.X
      id: comment
      with:
        body: hello world

    - name: Check outputs
      run: echo "Comment ID - ${{ steps.comment.outputs.comment-id }}"

Common error: Missing either 'issue-number' or 'comment-id'

The issue-number field can be omitted depending on the type of workflow you are using and it will attempt to find the PR/issue number from the event context automatically

The fallback value is as follows: ${{ github.event.number }}

You can always pass in an exact value for the issue-number field if you wish to override the automatic lookup. The example below obtains the issue number from the event context in a specific way:

  with:
    issue-number: ${{ github.event.issue.number }}

Note: Pull Requests are just Issues under the hood, so when we refer to the issue-number that could also be exchanged for a PR number

There are two ways to leverage templates using this Action:

• Simple Template - Just pass in a file: <path> to the Action
• Template Rendering - Pass in a file: <path> and vars: <values> to the Action

⚠️ Important: Make sure to run the action/checkout Action before this Action if using the file: input so the action can actually read files from your repo

file and vars explained:

• file is the path to a markdown file in your repository to load as a template
• vars are template variables to use when rendering your markdown file template

The vars input is a yaml string that will be parsed and converted to a map of key/value pairs. An example can be seen below

Actions workflow:

  with:
    file: demo/render-sample.md
    vars: |
      sha: ${{ github.sha }}
      environment: production
      app: cool-app

Markdown Template:

# Deployment Status 🚀

**{{ app }}** has been successfully deployed to **{{ environment }}**

- SHA: `{{ sha }}`

This Action uses nunjucks to render template files with the vars variables provided. You can fully leverage all the features nunjucks has to offer to custimize templates to your heart's content.

An example of a markdown template file can be seen here. When this Action runs, it will render the demo/render-sample.md file with the vars provided to dynamically generate the comment body!

You can even pass in GitHub Actions context variables as seen above (ex: ${{ github.sha }})

Checkout a sample workflow file here to see this in action

This example shows how you can iterate over an array of values and populate a template with them:

jobs:
  example:
    runs-on: ubuntu-latest
    steps:
      - id: run
        run:  echo "files=a,b,c" >> "$GITHUB_OUTPUT"

      - uses: GrantBirki/comment@vX.X.X
        with:
          # other config
          vars: |
            files: ${{ steps.run.outputs.files }}
          body: |
            # Files
            {% for file in files.split(",") %}
            - `{{ file }}`
            {% else %}
            - No file
            {% endfor %}

You can also put the iteration logic in the template file itself rather than using the body input in the workflow file:

# Files
{% for file in files.split(",") %}
- `{{ file }}`
{% else %}
- No file
{% endfor %}

Source: #11

How to find the id of a comment will depend a lot on the use case

Here is one example where the id can be found in the github context during an issue_comment event:

on:
  issue_comment:
    types: [created]
jobs:
  commentCreated:
    runs-on: ubuntu-latest
    steps:
      - name: Add reaction
        uses: GrantBirki/comment@vX.X.X
        with:
          comment-id: ${{ github.event.comment.id }}
          reactions: eyes

You can also use the find-comment Action to locate the comment id in many different ways

If you are trying to use this Action with its template features, you will need to checkout the repository first before calling this Action. This ensure the proper files are available to be read by the Action. If your actions/checkout job fails with Repository Not Found, it is likely due to missing permissions. Try adding this at the top of your Actions workflow file:

permissions:
  issues: write # needed for creating comments on issues
  pull-requests: write # needed for creating comments on pull requests
  contents: read # bingo!

Assigning read to the contents permission will allow Actions to checkout your repository

Common causes can be seen below

In public repositories this action does not work in pull_request workflows when triggered by forks

Any attempt will be met with the error, Resource not accessible by integration

This Action needs write access to issue, pull requests, or both depending on how you are using it:

permissions:
  issues: write
  pull-requests: write

You can create and update comments in another repository by using a PAT instead of GITHUB_TOKEN.

The user associated with the PAT must have write access to the repository

This Action was largely inspired by the create-or-update-comment Action by @peter-evans. In fact, it shared the majority of the code with that Action. The reason this Action was created was because a comment Action was needed that supported template rendering and was not available in the create-or-update-comment. It was suggested to use a second Action render-template and pass the outputs of that Action into the create-or-update-comment Action.

This Action solves that problem by using the nunjucks package for full template rendering

MIT