By default a workflow is run when a PR is opened, synchronized or reopened to better optimize for CI workflows.  If you want to run when the PR is merged you can specify that as follows.

on:
  pull_request:
    types: [merged]

Since events are not really individual events but are a set of events that could occur on a givne resources (at lest mostly).  Using the types: field you can filter against the action element in the payload.

Thanks for your reply. I adjusted my .github/workflows/pull_request.yml file as you suggested, but it still didn’t run upon merging a PR. Any further suggestion or insight?

on:
  pull_request:
    types: [merged]
name: on pull request merge, delete the branch
jobs:
  branchCleanup:
    name: branch cleanup
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@master
    - name: branch cleanup
      uses: jessfraz/branch-cleanup-action@master
      env:
        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        NO_BRANCH_DELETED_EXIT_CODE: 0

Should that be ‘closed’? e.g.:

on:
  pull_request:
    types: [closed]

According to the docs there isn’t a ‘merged’ type for a pull_request action:
https://help.github.com/en/articles/events-that-trigger-workflows

@jrobison-sb  - @talldan was exactly right, it should be closed, not merged.

However, even that’s not going to work right now as you’ve uncovered a bug in the system where actions aren’t triggering on a closed PR even when they should be (using this exact setup). I’ve been able to recreate it and I have a fix in the works. I’ll report back here when I have something deployed and working!

(btw, I’m an engineer on the Actions team, not sure if my profile says that)

Thanks @cdb, that fix and the types option would make us very happy :slight_smile:

@ cbd Thanks for identifying this, and thanks for the super quick turn around time on the fix.

It’s working again as expected. 

@cdb wrote:

@jrobison-sb  - @talldan was exactly right, it should be closed, not merged.

Would it be possible to create a merged type? I’m building a pipeline that automatically creates a release when a release/* branch is merged into master. But closed (canceled) pull requests will also trigger this build.

And what about checkout? Is there any workaround if I need to get the code from the merged branch for the pipeline? 

are there any updates?

I’m just trying excute workflow when PR merged.

But it doesn’t kicked from platform…

https://github.com/vvakame/til/blob/master/.github/workflows/pr-to-blog.yml

If I’m reading the documentation correctly, closed will trigger on any reason for closing a PR, so my action could be triggered when a PR is closed without merging which is not what I need. 

Am I missing something? Is there a way to trigger the action on a closed PR that has been merged?