support pull_request_target event

[KhudaDad414]

Context

We were using this action to update branches and it worked fine for push event. Now we are trying to add the capability for contributors to update their branch from PRs.

Problem

Since we are using forks for contributions and the pull_request event causes the workflow to run on the fork, and forks don't have access to the secrets, hence, this error will show up: https://github.com/asyncapi/glee/runs/5838503289?check_suite_focus=true

Possible solution

adding support for pull_request_target may be the solution here.

Related to #212

[kevinrobayna]

I don’t believe this is possible from what I know from the GH API. In order to do this the action would need to know about the forks and have permission on the fork itself.

After the above it would somehow trigger the update from the fork 😅

[ReenigneArcher]

@KhudaDad414 did you ever find a solution for this?

I'm also trying to update branches of PRs from forks (if a contributor has "allow edits by maintainers" and also checks a box in my PR template).

I'm using pull_request_target along with a personal access token. I gave the PAT just about every permission feasible, but didn't seem to make any difference.

Error: Could not update pull request #34 due to an authorisation error. This is probably because this pull request is from a fork and the current token does not have write access to the forked repository. Error was: Must have admin rights to Repository.

The user who own's the PAT is an owner of my repo...

I can also update the PR from this button, so seems like I do have proper permissions.

Edit:
I would think if "allow edits and access to secrets by maintainers" is checked, it would be enough of a permission... assuming the token is from a user who is a maintainer of the repo.

[ephys]

I think I've finally found the solution to this problem. To bypass github's API limitations, I did the update via git instead of the API: https://github.com/sequelize/pr-auto-update-and-handle-conflicts/blob/74929c430b8843e691e7b83d229d8d13d78d89e3/src/action.ts#L331-L398

Feel free to copy the solution for this project