Make branch changes testable in development mode

[colincasey]

In development mode (e.g.; using @main) will install the actions binary from this repository's main branch. We may want to extend this to allow for a git-ref to be supplied so that changes can be tested from a feature branch before merging to main.

GUS-W-13955891.

[edmorley]

I think we should be able to use github.job_workflow_sha for this case right? Since we won't be using it in a use: definition (where dynamic values aren't permitted), but instead can use it inside a with: to pass the SHA to the "install languages CLI" action?

[colincasey]

from the documentation you would think that github.job_workflow_sha is the thing to use but according to actions/runner#2417 it is never set. i observed the same behavior when attempting to determine the ref of the shared workflow.

until the issues with github.job_workflow_sha are fixed, i think the only option would be to expose it as an optional input that defaults to main.

[edmorley]

Ah right - that was the second issue you mentioned about it being null.

I've opened a GitHub support ticket to try and nudge things along with getting that acknowledged as a bug:
https://support.github.com/ticket/personal/0/2287074