Cannot extract release version from branch name #697

Describe the bug

I have a release pipeline that needs to take the version from the branch name, following the pattern release/*, ie release/4.8.4.

As per the documentation, the branch name can be taken from the environment variable GITHUB_REF.

To overcome the lack of substring limitation in GitHub actions I have created a JavaScript action that takes some inputs and returns a slice of the string, for example from release/4.8.4 will return 4.8.4.

The issue comes when passing the $GITHUB_REF to the action:

     - name: Release name
        id: release_name
        uses: web3j/slice-action@v1.3
        with:
          value: $GITHUB_REF
          start: 8 # Remove 'release/' prefix 

The return value in the expression ${{ steps.release_name.outputs.result }} would be expected to contain 4.8.4.

Instead it contains REF as you can verify in this build. That means that the GITHUB_REF env. variable has not been parsed but taken as a string instead.

I have tried passing the input as $GITHUB_REF, ${ GITHUB_REF } and ${{ GITHUB_REF }} and none of them works.

This is blocking a fix release so if there is an alternative way please share it. Thank you.

To Reproduce

Try to extract a version from the branch name. If you find a way to do it, please close this issue but for now this is a major limitation.

Expected behavior

The environment variable GITHUB_REF should be suitable for use as an action input.

Desktop (please complete the following information):

• OS: iOS 11.1
• Browser Chrome
• Version 87