Singleton Comment

The s-gehring/singleton-comment action lets you write comments in pull requests as the github-user-bot. However, instead of creating new comments for every run (ie. pull request update), it finds the older version of the comment and edits it to keep the PR history clean.

It works similar to peter-evans/create-or-update-comment, but manages to find its older comments by appending IDs to the message body.

Usage

Basic Usage

- uses: s-gehring/singleton-comment@v1
  with:
    comment-body: |
      Hi there  
      This is a test with markdown 

      ```java
      class Example {
        public static void main(String[] args) {
          System.out.println("I'm example code.");
        }
      }
      ```

      And I'm **bold**.
      However, this comment will be overwritten/edited 
      once this workflow is triggered again.

Github will add a comment with the given body and update it in every subsequent run instead of creating new ones each time.

However, it will also overwrite other comments created by this action in the same workflow.

This means that the following steps lead to only one comment:

- uses: s-gehring/singleton-comment@v1
  with:
    comment-body: |
      Pineapple on pizza is great.
- uses: s-gehring/singleton-comment@v1
  with:
    comment-body: |
      Pineapple on pizza is horrible.

There would be a comment claiming that pineapple on pizza is great for a brief moment until it is overwritten by the next step. To define multiple comments, add an ID.

Usage with ID

To manage multiple comments simultaneously, you have to provide the corresponding step with an identifier. This identifier should be a string and ideally not contain any whitespaces.

- uses: s-gehring/singleton-comment@v1
  with:
    comment-body: |
      Pineapple on pizza is great.
    id: some-insane-guy
- uses: s-gehring/singleton-comment@v1
  with:
    comment-body: |
      Pineapple on pizza is horrible.
    id: some-smart-guy

In this example, two comments will be added to the pull request.

Usage in other pull requests / issues

If you want to post on a different thread (ie. pull request or issue), you can supply the action with issue-number.

- uses: s-gehring/singleton-comment@v1
  with:
    comment-body: |
      I just want to say that there's another pull request by ${{ github.actor }} for this issue.
    issue-number: ${{ env.CORRESPONDING_ISSUE }}

This example assumes you somehow managed to attach a corresponding issue number to the pull request (via a CORRESPONDING_ISSUE environment variable) and will create a comment on how there is a pull request for this issue available. However, each time this workflow is ran it will update the message and therefore the included ${{ github.actor }}.

Parameters

comment-body

Required. The comment body to write. This supports the basic markdown github supports.

id

Optional. Default ${{ github.workflow }}. Used to identify the comment in subsequent action runs.

issue-number

Optional. Default ${{ github.event.pull_request.number }}. Used to identify the pull request or issue you want the commit to be written at.

How it works

This action makes use of peter-evans actions create-or-update-comment and find-comment. It generates (or uses a given) ID and adds it as a suffix to the comment to identify it later.