使用 Github 操作设置工作流时，会针对“pull_request”事件过滤哪个分支？

Question

I am trying to run a build for each pull request (PR) on the branch from which the PR originates, whenever a specific branch is being targeted. How do I set this up using Github Actions?

What confuses me is two branches are involved: the branch from which the PR originates, and the target branch.

From the documentation on pull_request events it is clear that GITHUB_REF is set to the "PR merge branch", meaning that the checkout action will check out the branch from which the pull request originates in case the pull_request event is triggered.

But, it is less clear which branch the 'branches' filter of on filters on. Would the following event trigger when a PR is received on develop, or when it originates from it (or possibly, both)? How do I set up a trigger for PRs to a specific branch?

on:
  pull_request:
    branches: 
      - develop

Answer 1

I tried using the above (on pull_request branches develop) and set it up as a workflow on GitHub.

It worked as I intended to set it up. This makes me conclude that the 'branches' filter thus filters on the target branch .