How do I run a github action only on the head commit of a branch for a pull request?

Question

Is there a way to run a check during a pull request only on the head commit of a feature branch?

For example, if my branch looks like this:

• TICKET-123: Doing some work
• fix
• fix
• unit test

I want this GitHub action to only run on TICKET-123: Doing some work

Currently, I have

name: 'Pull Request Commit Linter'
on: 
- pull_request

jobs:
  commitlint:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
        with:
          fetch-depth: 0
      - uses: wagoid/commitlint-github-action@v4

I tried playing with fetch-depth, using 1 and 2, but that did not work. Any advice?

Answer 1

You should remove fetch-depth: 0 definition because I looked up the https://github.com/wagoid/commitlint-github-action repo and I found below sentence:

It's necessary that you specify the fetch-depth argument to actions/checkout@v2 step. By default they fetch only latest commit of the branch, but we need more commits since we validate a range of commit messages.

If you fetch the latest commit only, your problem will be solved.