Set the default branch for all repos for a particular team

githubsetdefaultbranchforteam.ps1

# Set your GitHub API token and team details
$GitHubToken = $env:GH_PAT
$Organization = "orgname"    # Replace with your GitHub Organization name
$TeamSlug = "team-slug"              # Replace with your GitHub Team slug (e.g., "dev-team")
$DefaultBranch = "master"

# GitHub API URL
$GitHubApiBaseUrl = "https://api.github.com"

# Headers for the GitHub API request
$headers = @{
    "Authorization" = "Bearer $GitHubToken"
    "Accept" = "application/vnd.github.v3+json"
}

# Function to get all repositories for a specific GitHub team
function Get-TeamRepositories {
    param (
        [string]$Organization,
        [string]$TeamSlug
    )
    
    # Set initial variables for pagination
    $repos = @()
    $page = 1
    $per_page = 100

    do {
        # Fetch the repositories from the current page
        $url = "$GitHubApiBaseUrl/orgs/$Organization/teams/$TeamSlug/repos?per_page=$per_page&page=$page"
        $response = Invoke-RestMethod -Uri $url -Headers $headers -Method Get
        
        # Append the current page of repos to the list
        $repos += $response

        # Check if the current page has less than $per_page repos, meaning it's the last page
        if ($response.Count -lt $per_page) {
            break
        }

        # Otherwise, move to the next page
        $page++

    } while ($response.Count -eq $per_page)

    return $repos
}

# Function to set default branch to 'master' for a repository
function Set-DefaultBranchToMaster {
    param (
        [string]$Organization,
        [string]$RepoName
    )
    
    $url = "$GitHubApiBaseUrl/repos/$Organization/$RepoName"
    
    # Prepare the body to update the default branch
    $body = @{
        "default_branch" = $DefaultBranch
    } | ConvertTo-Json
    
    # Make the request to set the default branch
    $response = Invoke-RestMethod -Uri $url -Headers $headers -Method Patch -Body $body
    return $response
}

# Main logic: Get repositories and set the default branch
$repos = Get-TeamRepositories -Organization $Organization -TeamSlug $TeamSlug

# Iterate over each repository and update the default branch
foreach ($repo in $repos) {
    $repoName = $repo.name
    Write-Host "Updating default branch for repository: $repoName"
    
    $result = Set-DefaultBranchToMaster -Organization $Organization -RepoName $repoName
    Write-Host "Updated default branch for $repoName to 'master'"
}