Edit and checkin versions.txt file in GitHub Actions using powershell - github-actions

Question

I see the documentation in github actions to run a powershell script in a step. I need to increment version number and checkin versions.txt file in GitHub Actions using powershell. Can I accomplish this by running a powershell script from my folder and by using git.exe and powershell commands?
How do I set a variable from powershell script to use the version number in subsequent steps?

Answer 1

So there are two questions in your question, I will answer in reverse order.
To have one step (for example shell script) set a value for subsequent steps, you can use the special workflow commands which are just done by outputting specially formatted strings to STDOUT.
In your case, are looking for Setting an Output Parameter:
echo "::set-output name=version::1.2.3"
Which can then be read by subsequent steps, like this (for example):
env:
VERSION: ${{ steps.the-other-step-id.outputs.version }}
As for having GitHub actions modify code and then check it in, I would strongly advise against it as it will a) complicate your workflow, b) might create "workflow loops", where actions-originated checkins trigger this/other workflows.
For version tagging, I suggest you use tags as it is the almost universally accepted way to mark versions in source control. You might want to have a local script that both tags and updates your version.txt, and then your workflow just reads the file or the tag.