Finding SHA or ref of branch for [push] event after a pull-request #26459

ghutchis · 2020-04-26T23:21:57Z

ghutchis
Apr 26, 2020

I’m trying to make an action workflow that operates on the git diff from the branch point.

The current SHA is easy:

github.sha

When I have a pull-request event, I can also use github.head_ref to get the source branch of the pull request.

But when I push to that branch (e.g. fixing something), then github.head_ref is empty.

Is there a way to continue to access github.head_ref on push events already part of a pull request? I’d accept some git methods, something like:

git merge-base --fork-point origin/master

But I see that there’s no .git/refs/heads/master when I check out…

Answered by ghutchis

Apr 27, 2020

I think this is a fairly common use case, judging from some of the searching I did. I think push events made to a pull request should be able to fetch their branch point.

This doesn’t work robustly, but is close enough for now:

# I didn't use ${{ github.repository }} because that points to the fork
git remote set-url origin https://x-access-token:${{ secrets.GITHUB_TOKEN }}@github.com/openchemistry/avogadrolibs
git fetch origin master:master

export MASTER_SHA=cat .git/refs/heads/master

git diff ${MASTER_SHA} --name-only
whatever else you want to do

View full answer

weide-zhou · 2020-04-27T10:36:48Z

weide-zhou
Apr 27, 2020

Hi @ghutchis ,

‘github.head_ref’ is not supported for push event, since it’s not in the push event github context, you can use below command to check all of the context values:

- name: Dump GitHub context
        env:
          GITHUB_CONTEXT: ${{ toJson(github) }}
        run: echo "$GITHUB_CONTEXT"

Hope it helps!

0 replies

ghutchis · 2020-04-27T13:20:49Z

ghutchis
Apr 27, 2020
Author

I think this is a fairly common use case, judging from some of the searching I did. I think push events made to a pull request should be able to fetch their branch point.

This doesn’t work robustly, but is close enough for now:

# I didn't use ${{ github.repository }} because that points to the fork
git remote set-url origin https://x-access-token:${{ secrets.GITHUB_TOKEN }}@github.com/openchemistry/avogadrolibs
git fetch origin master:master

export MASTER_SHA=cat .git/refs/heads/master

git diff ${MASTER_SHA} --name-only
whatever else you want to do

1 reply

kirkath Jan 24, 2024

dont think we need to pull down whole master for this.

git ls-remote https://x-access-token:${{ secrets.GITHUB_TOKEN }}@github.com/openchemistry/avogadrolibs --tags master | sed "s/\tHEAD//" | cut -d $'\t' -f 1

will do the trick

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Finding SHA or ref of branch for [push] event after a pull-request #26459

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Finding SHA or ref of branch for [push] event after a pull-request #26459

ghutchis Apr 26, 2020

whatever else you want to do

Replies: 2 comments · 1 reply

weide-zhou Apr 27, 2020

ghutchis Apr 27, 2020 Author

whatever else you want to do

kirkath Jan 24, 2024

ghutchis
Apr 26, 2020

Replies: 2 comments 1 reply

weide-zhou
Apr 27, 2020

ghutchis
Apr 27, 2020
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