What is a pull_request synchronize event

[simonbyrne]

What precisely causes a synchronize event? The docs don’t define what it is.

[AndreaGriffiths11]

Hi @simonbyrne,

Thank you for being here! A pull_request event it’s only triggered when the pull request’s tracking branch is synchronized with the source branch for the pull request, and that happens when the source branch is updated.

[simonbyrne]

Hi Andrea,

Thanks for your reply. Do you know if it also gets triggered when the base branch (that the PR is merging into) is updated?

Thanks,

Simon

[AndreaGriffiths11]

Hey @simonbyrne,

Thanks for the follow up. What this implies is that if you push a new commit to the HEAD ref of a pull request then this “synchronize” event will be triggered. This is because the system is syncing the pull requests with the latest changes. This will NOT trigger if the base ref is updated.

[carltonbrown]

This will NOT trigger if the base ref is updated.

I wonder if this info has changed in the past few years, since current Github docs appear to say something different:

synchronize: Triggered when a pull request's head branch is updated. For example, when the head branch is updated from the base branch, when new commits are pushed to the head branch, or when the base branch is changed.

[mkuijn-cb]

When the base branch is changed means: when you change the base ref (event "edited" on pull_request)

When there are pushes to the branch the PR's base ref currently points to, the "synchronize" event is not triggered.

[ventsyv]

What this implies is that if you push a new commit to the HEAD ref of a pull request then this “synchronize” event will be triggered.

Wouldn't that also trigger on.push event? For example if I do the following:

git checkout myBranch
git pull origin master
git push

If myBranch has an open pull request against the master branch, should I expect on.push, on.pull_request.synchronize, or both ?