PowerShell Script - To Automate Clean up of Stale Branches From Remote Repository

delete-stale-branches.ps1

################################################################
## Note: This script should be executed 
## from the machine where the remote repository is cloned.
################################################################

## Parameter is_dry_run, defaulted to true to avoid deletion by mistake
## Invoke Command - "$ delete-stale-branches.ps1 -is_dry_run $true"
param([Boolean]$is_dry_run = $true) 

##---------------------------------------------------------------
## List of Main Branches (Which Should Not Be Deleted)
##---------------------------------------------------------------

## Exclusion List - Add general default branch names
$excludedBranchNames = @('main', 'master', 'develop')

## Just in case if there is any other name of default branch, add that too in exclusion list 
$defaultBranch = git symbolic-ref refs/remotes/origin/HEAD --short
write-host "Default Branch In Repo: $defaultBranch" 
if ($excludedBranchNames -inotcontains $defaultBranch) 
{
    $excludedBranchNames += $defaultBranch
}

##---------------------------------------------------------------
## Prune Local References Of Remote Branches
##---------------------------------------------------------------

## Just to avoid error due to non-existing remote branch
## prune local list
git fetch --prune 

##---------------------------------------------------------------
## Cleanup of Stale Branches - No Commits since 3 Months 
##---------------------------------------------------------------

## List all remote branches
$remoteBranches = git branch -r


## Explicitly Exclude HEAD
$remoteBranchesFiltered = $remoteBranches | Where { $_ -notlike '*HEAD*'};

## Loop through each branch
foreach ($branch in $remoteBranchesFiltered) 
{
    ## Remove the origin/ prefix
    $branchName = $branch.Trim().Substring(7)

    ## Continue deletion only if Branch name is not present in exclusion list
    if ( $excludedBranchNames -inotcontains $branchName) 
    {
        ## Try to find at least 1 commit in last 3 months
        $lastCommitDate = git log -1 --since="3 months ago" --format="%cd" origin/$branchName

        ## If not found, delete the branch
        if (!$lastCommitDate) 
        {
            
            Write-Host "Deleting branch $branchName"
            
            if ($is_dry_run -eq $false ) 
            {
                ## --porcelain is used so that git command writes script friendly output
                git push origin -d $branchName --porcelain
            }
        }
    }
}

##---------------------------------------------------------------
## Prune Local References Again
##---------------------------------------------------------------
git fetch --prune