How to get commit message on pull_request workflow?

[gabrielbahniuk]

Hi there,

i have some jobs running when people open pull request, so it starts like this:

name: PR checks

on: pull_request

jobs:
  cleanup:
   [...]
  eslint:
   [...]
  unit_tests:
   [...]
  e2e_tests_A:
   [...]
  e2e_tests_B:
   [...]

In e2e_tests_A or B I want to have a conditional that: if commit message contains something I define e.g. git commit -m [skip e2e_tests_A] && git push then the job e2e_tests_A should NOT run.

I ended up adding the following to e2e_tests_A:

if: "!contains(github.event.head_commit.message, '[skip e2e_tests_A]')"

According to the following urls, it won't work because I can only have github.event.head_commit.message if I had on: push and I currently have on: pull_request:

https://docs.github.com/en/developers/webhooks-and-events/webhooks/webhook-events-and-payloads#pull_request
https://docs.github.com/en/developers/webhooks-and-events/webhooks/webhook-events-and-payloads#push

I know Github has already some keywords like [skip ci] and similar but I want to define my own keywords to the commit message.

Also, according to my searches, github.event.head_commit.message was working in the past. Was it replaced by something else or just removed?

So I would be thankful if anyone knows how I can solve this.

Thanks in advance!!

[airtower-luna]

So I would be thankful if anyone knows how I can solve this.

The first question to answer here is: Which commit(s) do you want to look at? Only the head commit of the pull request branch? All commits on the branch (which could be many)?

github.event.pull_request.head.sha should give you the ID of the head commit, github.event.pull_request.base.sha that of the base (target) branch (in case you want to look at all commits).

Note that you'll have to tell actions/checkout to download more than the latest commit if you want to inspect those, or fetch the relevant part of history in your workflow. The triggering commit for pull_request events is a temporary merge commit, so it's none of your commits. 😉

[gabrielbahniuk]

@airtower-luna thanks for the response!

The first question to answer here is: Which commit(s) do you want to look at? Only the head commit of the pull request branch? All commits on the branch (which could be many)?

I want only the head commit message.

If I understand your suggestion correctly, I could use actions/checkout with ref: ${{ github.event.pull_request.head.sha }} and then I would be able to get the commit message.

So the end result would look similar to this:

jobs:
  check_skip_flags:
    name: Check skip flags
    runs-on: ubuntu-latest
    steps:
      - name: Get repo
        uses: actions/checkout@v3
        with:
          ref: ${{ github.event.pull_request.head.sha }}
      - name: Print head git commit message
        run: |
          echo "$(git show -s --format=%s)" 
          
   e2e_tests_A:
    name: E2E tests
    runs-on: self-hosted
    needs: check_skip_flags
    # if: // i don't really know how to get the git show result here
    timeout-minutes: 120
    steps:
      - name: Setup node
        uses: actions/setup-node@v3
        with:
          node-version: 14

I came up with different solutions but let's use the above one to exemplify. How would I be able to save git show command into some env variable and use it in my if condition in e2e_tests_A?

One of my failed attempts was adding outputs to check_skip_flags job and id to the second step, looking similar to:

[...]
  check_skip_flags:
    name: Check skip flags
    runs-on: ubuntu-latest
    outputs:
      head-commit-message: ${{ steps.get_head_commit_message.outputs }}
    steps:
      - name: Get repo
        uses: actions/checkout@v3
        with:
          ref: ${{ github.event.pull_request.head.sha }}
      - name: Print head git commit message
        id: get_head_commit_message
        run: echo "::set-output name=headCommitMsg::$(git show -s --format=%s)"

  e2e_tests_A:
    name: E2E tests
    runs-on: self-hosted
    needs: check_skip_flags
    if: ${{ !contains(steps.get_head_commit_message.outputs.data, '[skip e2e_tests_A]') }}
[...]

but this didn't work as well.

[airtower-luna]

In principle the output approach is correct, at least as long as you stick to the single line format. For multiple lines you'd have to URL encode the newlines so they don't get cut off while setting the output.

The issues I see above are:

• The outputs setting in check_skip_flags doesn't reference the actual output, just the outputs object of the relevant step (might work with toJSON() if you really wanted to).
• The steps context doesn't carry across jobs. You need to use the needs context to access outputs from previous jobs.

Something like this should work:

  check_skip_flags:
    name: Check skip flags
    runs-on: ubuntu-latest
    outputs:
      head-commit-message: ${{ steps.get_head_commit_message.outputs.headCommitMsg }}
    steps:
      - name: Get repo
        uses: actions/checkout@v3
        with:
          ref: ${{ github.event.pull_request.head.sha }}
      - name: Print head git commit message
        id: get_head_commit_message
        run: echo "::set-output name=headCommitMsg::$(git show -s --format=%s)"

  e2e_tests_A:
    name: E2E tests
    runs-on: self-hosted
    needs: check_skip_flags
    if: ${{ !contains(needs.check_skip_flags.outputs.head-commit-message, '[skip e2e_tests_A]') }}

[gabrielbahniuk]

@airtower-luna oh i missed that on the if i had to use needs, not steps, thank you, it worked nicely!! =D

[airtower-luna]

Excellent, I'm glad to hear it worked! Marking the answer would be appreciated. 😸

[ILikePlayingGames]

@airtower-luna thank you! I had the same issue with the workflow_dispatch event and your solution worked.
For anyone else who recently found this via Google, the set-output command has been deprecated. The new steps use the GITHUB_SHA variable and the $GITHUB_OUTPUT environment file.

    - name: Checkout Commit
      uses: actions/checkout@v3
      with:
        ref: ${{ env.GITHUB_SHA }}
    - name: Get Head Commit Message
      id: get_head_commit_message
      run: echo "HEAD_COMMIT_MESSAGE=$(git show -s --format=%s)" >> "$GITHUB_OUTPUT"

[mustafabahaa]

Sorry but I'm confused, in the solution purposed we checkout the last commit on the branch to get the commit message, we are not checking the merge commit, testing the last commit on the pull request branch and testing on merge commit is different, and it may introduce other issue after merging because we didn't test the merge commit, am i missing something ?

[airtower-luna]

The question was about how to get the commit message of a specific commit (the HEAD commit of the branch to be merged). For running test using the temporary merge commit is almost certainly what you want.

[mustafabahaa]

Okay, maybe probably you will have to checkout again with the merge commit later, or try to checkout the merge commit by any other means , i didn't want to handle this I've chosen another path

without checking out the branch using ref, you can curl the path ${{ github.event.pull_request.commits_url }} this will give you a response with all commits on the branch you can just filter to the last one then access the message using commit.message