Add feature to give approve automatically for newly created PR

[luboszima]

Add an optional auto-approve parameter to the PR action that automatically approves PRs created by this action.

auto-approve: true  # Optional, defaults to false

Repositories with branch protection rules require manual approval for all PRs, including those from trusted automation like Dependabot or currnet repo GHA. This auto-approve can reduce manual work on PRs created by trusted automations.

I am aware that this functionality will be just for small percentage of people but it will helpful for my workflows in multiple projects.

[ericcornelissen]

This seems like a reasonable request.

I have little experience with this kind of functionality (because I personally don't like it) and I would almost surely want to defer this logic to peter-evans/create-pull-request (used here). However, a quick look at the docs suggests it doesn't support it directly. The closests seems to be the peter-evans/enable-pull-request-automerge action, however this still doesn't do the approving.

For Dependabot, I found this in the docs which I guess we should be able to replicate quite easily (since the GHA environment comes with the gh CLI).

      - name: Approve a PR
        run: gh pr review --approve "$PR_URL"
        env:
          PR_URL: ${{github.event.pull_request.html_url}}
          GH_TOKEN: ${{secrets.GITHUB_TOKEN}}

Do you have any suggestions/experience with this kind of functionality?

[luboszima]

@ericcornelissen
peter-evans/create-pull-request have defined outputs with information about PR.

So maybe we can use the example from above and add there output variable pull-request-url from peter-evans/create-pull-request and add new step under create-pr step (+ add new input bool pr-auto-approve)

      - name: Approve a PR
        if: ${{ inputs.pr-auto-approve == 'true' }}
        run: gh pr review --approve "$PR_URL"
        env:
          PR_URL: ${{steps.create-pr.outputs.pull-request-url}}
          GH_TOKEN: ${{secrets.GITHUB_TOKEN}}

Alternative:
Just add new output:

  pr-url:
    description: |
      The url of the created Pull Request.
    value: ${{ steps.create-pr.outputs.pull-request-url }}

And I can process it in my repositories. ^^

[ericcornelissen]

The pr-number is already an output and we could extend it with pr-url (off-topic: I'm also open to renaming pr-number to pull-request-number for improved readability). Constructing the URL from that for a given repository is straightforward if you want to do it in your own repository today.

Having said that, I think it would make sense to add the option to an auto-approve option as you described. Especially with #373 in mind which would make performing follow-up actions more cumbersome.

Would you want to implement this @luboszima ?

[luboszima]

@ericcornelissen Yes I can do it.

With this new extra step and new input and output, will it be necessary to update some shellspec tests?

edit:
Should I change pr-url output to pull-request-url same output name like from peter-evans/create-pull-request ?

[ericcornelissen]

edit:
Should I change pr-url output to pull-request-url same output name like from peter-evans/create-pull-request ?

Whichever you prefer. If you choose the unshortened one just make sure to add an unshortened version of the new output too (while keeping the shortened one for backwards compatibility).

[luboszima]

Whichever you prefer. If you choose the unshortened one just make sure to add an unshortened version of the new output too (while keeping the shortened one for backwards compatibility).

ok let's keep shortened version. ^^