In a YAML file how do I checkout a specific branch in different repo and fallback if it doesn't exist using Azure DevOps?

Question

I have a project I need to build in ADO that contains code in two different repos. Usually there is a matching release branch in both, but occasionally not. I would like to get the matching value and automatically fallback to main if there's no matching.

I was told instead to make the other repo a nuget package, or just compile to a dll, but those both seem like poor solutions when VS2022 now supports multi-repo solutions pretty cleanly.

Answer 1

steps:
- powershell: |
    $releaseBranch = "$(ReleaseBranchVariable)"  # Replace with the name of the release branch variable
    $mainBranch = "main"  # Specify the name of the main branch

    # Check if the release branch exists in the repository
    if (git branch --list --remote origin/$releaseBranch) {
        $branchToUse = $releaseBranch
    } else {
        Write-Host "Release branch not found, falling back to main branch."
        $branchToUse = $mainBranch
    }

    Write-Host "Using branch: $branchToUse"

    # Check out the selected branch
    git checkout $branchToUse
  displayName: 'Select Branch'

This script checks if the release branch exists in the repository. If it does, it uses the release branch; otherwise, it falls back to the main branch.