rename main branch to master

master_is_okay.sh

#!/bin/bash

# Exit on any error
set -e

# Script to rename the main branch to master and update the default branch on GitHub via API

# TODO, it'd be nice to have this script use `readonly` for variables that should not be changed

# Configuration
# Load environment variables if .env exists
if [ -f .env ]; then
  export "$(grep -v '^#' .env | xargs)"
fi

# Get repository owner and name from git remote if not set
if [ -z "$REPO_OWNER" ] || [ -z "$REPO_NAME" ]; then
  # Get the remote URL and extract owner/repo
  GIT_REMOTE_URL=$(git config --get remote.origin.url)
  if [[ $GIT_REMOTE_URL =~ ^https?:// ]]; then
    # For HTTPS URLs: https://github.com/owner/repo.git
    REPO_PATH=${GIT_REMOTE_URL#*github.com/}
  else
    # For SSH URLs: [email protected]:owner/repo.git
    REPO_PATH=${GIT_REMOTE_URL#*:}
  fi
  REPO_PATH=${REPO_PATH%.git}  # Remove .git suffix if present
  
  # Only extract the values we need
  IFS='/' read -r GIT_OWNER GIT_REPO <<< "$REPO_PATH"
  [ -z "$REPO_OWNER" ] && REPO_OWNER="$GIT_OWNER"
  [ -z "$REPO_NAME" ] && REPO_NAME="$GIT_REPO"
fi

# Set defaults if not provided
GITHUB_TOKEN=${GITHUB_TOKEN:-"your_personal_access_token"}
REPO_OWNER=${REPO_OWNER:-"your_username"}
REPO_NAME=${REPO_NAME:-"your_repo_name"}

# Check if current branch is main
CURRENT_BRANCH=$(git rev-parse --abbrev-ref HEAD)
if [ "$CURRENT_BRANCH" != "main" ]; then
  echo "Error: Current branch is not 'main'. Please switch to the 'main' branch first."
  exit 1
fi

# Rename main to master locally
echo "Renaming branch 'main' to 'master'..."
git branch -m main master

# Push the master branch to remote
echo "Pushing 'master' branch to remote..."
git push origin master

# Check if using default token
if [ "$GITHUB_TOKEN" = "your_personal_access_token" ]; then
  # Instructions for manual GitHub default branch update
  echo "!!! The next time you run this script you can run it with a valid GITHUB_TOKEN to automate this step."
  echo "Branch renamed and pushed. Now, update the default branch on GitHub:"
  echo "1. Go to your repository on GitHub."
  echo "2. Navigate to the 'Settings' tab."
  echo "3. Scroll to 'Default Branch'."
  echo "4. Click 'Switch to another branch', select 'master', and update."
else
  # Update the default branch to master via GitHub API
  echo "Setting 'master' as the default branch via GitHub API..."

  # Store the response and status code
  RESPONSE=$(curl -s -w "\n%{http_code}" -X PATCH \
    -H "Accept: application/vnd.github+json" \
    -H "Authorization: Bearer $GITHUB_TOKEN" \
    -H "X-GitHub-Api-Version: 2022-11-28" \
    "https://api.github.com/repos/$REPO_OWNER/$REPO_NAME" \
    -d "{\"default_branch\": \"master\"}" 2>&1)

  # Extract HTTP status code and response body
  HTTP_STATUS=$(echo "$RESPONSE" | tail -n1)
  RESPONSE_BODY=$(echo "$RESPONSE" | sed '$d')

  # Handle different HTTP status codes
  case $HTTP_STATUS in
    200|201|204)
      echo "Success: Default branch updated to 'master' on GitHub."
      ;;
    401)
      echo "Error: Authentication failed. Please check your GitHub token."
      echo "Details: $RESPONSE_BODY"
      exit 1
      ;;
    403)
      echo "Error: Permission denied. The token may not have the required scopes."
      echo "Details: $RESPONSE_BODY"
      exit 1
      ;;
    404)
      echo "Error: Repository not found. Please check REPO_OWNER and REPO_NAME."
      echo "Details: $RESPONSE_BODY"
      exit 1
      ;;
    *)
      echo "Error: Failed to update default branch. HTTP Status: $HTTP_STATUS"
      echo "Response: $RESPONSE_BODY"
      exit 1
      ;;
  esac
fi

# Optional: Delete the old main branch
read -p "Do you want to delete the old 'main' branch from the remote? (y/n): " DELETE_CONFIRM
if [ "$DELETE_CONFIRM" = "y" ]; then
  echo "Deleting remote 'main' branch..."
  git push origin --delete main
  echo "Remote 'main' branch deleted."
else
  echo "Skipping deletion of remote 'main' branch."
fi

echo "Done! Inform collaborators to update their local repositories with:"
echo "git fetch origin"
echo "git checkout master"