Delete all branches X number of commits behind master

Azure DevOps - Delete Stale Branches.ps1

# Define variables
$organization = ""
$project = ""
$repositoryName = ""
$masterBranch = "master"
$devBranch = "develop"
$maxCommitsBehind = 500
$apiKey = $env:AZURE_DEVOPS_API_KEY

# Validate API Key
if (-not $apiKey) {
    Write-Error "Azure DevOps API Key is not set in the environment variable 'AZURE_DEVOPS_API_KEY'."
    exit 1
}

# Azure DevOps API base URL
$repositoryApiUrl = "https://dev.azure.com/$organization/$project/_apis/git/repositories?api-version=6.0"

# Set API headers
$headers = @{
    "Authorization" = "Basic " + [Convert]::ToBase64String([Text.Encoding]::ASCII.GetBytes(":$apiKey"))
    "Content-Type"  = "application/json"
}

# Fetch repositories and validate existence
Write-Host "Validating repository existence..." -ForegroundColor Yellow
$repositoriesResponse = Invoke-RestMethod -Uri $repositoryApiUrl -Headers $headers -Method Get

# Match the repository by name
$repository = $repositoriesResponse.value | Where-Object { $_.name -ieq $repositoryName }

if (-not $repository) {
    Write-Error "Repository with name '$repositoryName' does not exist in the project '$project'."
    exit 1
}

Write-Host "Repository '$repositoryName' found." -ForegroundColor Green

# Extract repository ID (GUID) for subsequent API calls
$repositoryId = $repository.id
Write-Host "Using Repository ID: $repositoryId" -ForegroundColor Cyan

# Azure DevOps repository-specific API base URL
$baseApiUrl = "https://dev.azure.com/$organization/$project/_apis/git/repositories/$repositoryId"

# Fetch all branches
Write-Host "Fetching all branches in repository '$repositoryName'..." -ForegroundColor Yellow
$branchesUrl = "$baseApiUrl/refs?filter=heads/&api-version=6.0"
$branchesResponse = Invoke-RestMethod -Uri $branchesUrl -Headers $headers -Method Get
$branches = $branchesResponse.value

if (-not $branches) {
    Write-Error "No branches found in the repository '$repositoryName'."
    exit 1
}

# Process each branch
foreach ($branch in $branches) {
    $branchName = $branch.name -replace "^refs/heads/", ""  # Remove refs/heads/ prefix
    if ($branchName -eq $masterBranch -or $branchName -eq $devBranch) {
        Write-Host "Skipping $branchName branch..." -ForegroundColor Yellow
        continue
    }

    # Compare commits between the branch and master using diffs/commits API
    $compareUrl = "$baseApiUrl/diffs/commits?baseVersionType=branch&baseVersion=$masterBranch&targetVersionType=branch&targetVersion=$branchName&api-version=6.0"

    try {
        $compareResponse = Invoke-RestMethod -Uri $compareUrl -Headers $headers -Method Get
    } catch {
        Write-Warning "Unable to compare commits for branch: $branchName. Skipping..."
        continue
    }

    if (-not $compareResponse.behindCount) {
        Write-Warning "No commit comparison data for branch: $branchName. Skipping..."
        continue
    }

    $commitsBehind = $compareResponse.behindCount

    if ($commitsBehind -gt $maxCommitsBehind) {
        # Prepare the delete request
        $deleteBranchUrl = "$baseApiUrl/refs/?api-version=6.0"

        # Get the current commit ID of the branch (oldObjectId)
        $oldObjectId = $branch.objectId

        # Prepare the request body as a JSON array
        $body = ConvertTo-Json @(
            @{
                name        = "refs/heads/$branchName";
                oldObjectId = $oldObjectId;
                newObjectId = "0000000000000000000000000000000000000000";
            }
        ) -Depth 10

        # Debug the request body
        # Write-Host "Request Body JSON: $body" -ForegroundColor Yellow

        try {
            # Send the POST request to delete the branch
            $deleteResponse = Invoke-RestMethod -Uri $deleteBranchUrl -Headers $headers -Method Post -Body $body -ContentType "application/json" -UseBasicParsing
            Write-Host "Branch $branchName is $commitsBehind commits behind master. Deleted successfully." -ForegroundColor Red
        } catch {
            Write-Warning "Failed to delete branch: $branchName."
            Write-Warning "Error details: $($_.Exception.Message)"
            if ($_.Exception.Response -and $_.Exception.Response.Content) {
                $reader = [System.IO.StreamReader]::new($_.Exception.Response.GetResponseStream())
                $responseContent = $reader.ReadToEnd()
                Write-Warning "Response content: $responseContent"
            }
        }
    } else {
        Write-Host "Branch $branchName is only $commitsBehind commits behind master. Skipping..." -ForegroundColor Green
    }
}

Write-Host "Branch cleanup complete." -ForegroundColor Green