Passing variable argument to .ps1 script not working from Github Actions

Question

I need to pass branch name as a parameter to .ps1 script using Github Actions. Github Actions part:

    runs-on: windows-latest
    env:
      DOTNET_CLI_TELEMETRY_OPTOUT: 'true'

    steps:
    - name: Extract branch name
      shell: bash
      run: echo "${GITHUB_REF}"
      id: extract_branch

    - uses: actions/checkout@v1
    - name: Run a one-line script
      run: .\Scripts\my_script.ps1 -branch_name ${GITHUB_REF}
      shell: powershell

.ps1 part:

##############################################
#Script Title: Download File PowerShell Tool
#Script File Name: Download-File.ps1 
#Author: Ron Ratzlaff  
#Date Created: 4/21/2016 
##############################################

#Requires -Version 3.0
param($branch_name)


"Current branch"
$branch = git rev-parse --abbrev-ref HEAD
"$branch"
"${branch}"
"${GITHUB_REF}"
"$GITHUB_REF"
"$branch_name"
"{branch_name}"
Write-Host $branch_name

.ps1 part is shown by me in order to display branch name inside of the .ps1 script using different ways of displaying. Because of branch name depends a lot of scripts logic. So, it does not display anything. But:

1. run: echo "${GITHUB_REF}" in Extract branch name part fully displays the branch name
2. If I pass hardcoded argument like this run: .\Scripts\my_script.ps1 -branch_name customtext it will be passed to the script and successfully displayed in different ways.

How to achieve passing value of GITHUB_REF and read/display it inside .ps1?

Answer 1

Accessing environment variables in Powershell is different from bash, you need to prefix it with env:. For your script, you can access the ref using $env:GITHUB_REF.

Alternatively, you can use the templating that GitHub Actions expose by replacing the run property with .\Scripts\my_script.ps1 -branch_name ${{github.ref}} to populate branch_name parameter.