Allow using go-version and go-version-file at same time in certain conditions

[ccoVeille]

Description:

go-version already accepts stable and oldstable aliases, they are great.

go-version-file was also a great addition, but these options cannot be used at same time.

As the documentation explains it clearly

If both the go-version and the go-version-file inputs are provided then the go-version input is used.

Justification:

Take a look at this PR

monzo/typhon#178

The version 1.19 had be hardcoded, while it was the one in the go.mod

go-version-file could have been used,
but you cannot use it with go-version

I wish this could have been used

name: Run Tests
on:
  - pull_request
jobs:
  test:
    strategy:
      matrix:
        go-version: ["go-version-file", "1.23.x"]
        os: [ubuntu-latest]
    runs-on: ${{ matrix.os }}
    steps:
    - uses: actions/setup-go@v5
      with:
        go-version: ${{ matrix.go-version }}
        go-version-file: "go.mod"

I didn't check, but maybe it's working by using

name: Run Tests
on:
  - pull_request
jobs:
  test:
    strategy:
      matrix:
        go-version: ["", "1.23.x"]
        os: [ubuntu-latest]
    runs-on: ${{ matrix.os }}
    steps:
    - uses: actions/setup-go@v5
      with:
        go-version: ${{ matrix.go-version }}
        go-version-file: "go.mod"

But adding the alias "go-version-file" in go-version would make things clearer.

Also, maybe if accepted it could help with:

• Make go-version-file: go.mod the default #523

This could also provides a solution for:

• Use version from module and another version in matrix testing #450

EDIT, I found out the #450 after opening my issue, so I'm quoting it here. I can close my issue and comment in #450 if you prefer.

Are you willing to submit a PR?

Not yet, I'm opening the discussion for now.

[mahabaleshwars]

Hi @ccoVeille,
Thank you for creating this feature request. We will investigate it and provide feedback as soon as we have some updates.