A bash helper for switching a local clone and a github fork from master to main.

switch_to_main.sh

#!/usr/bin/env bash

set -euo pipefail

echo ":: Renaming local master to main"
git branch -m master main || true
git fetch origin
git remote set-head origin -a

if git remote show upstream >/dev/null 2>&1; then
  echo ":: Upstream remote detected, setting main to track upstream"
  git fetch upstream
  git branch -u upstream/main main
  git remote set-head upstream -a
else
  echo ":: No upstream remote detected, setting main to track origin"
  git branch -u origin/main main
fi

if command -v gh &> /dev/null; then
  echo ":: gh available, attempting fork rename"
  gh_user=$(gh api /user -q .login)
  gh_repo=$(gh repo view --json nameWithOwner -q .nameWithOwner)
  fork_name=$(gh api "repos/${gh_repo}/forks" -F "owner=${gh_user}" -q ".full_name")

  if [[ -n "${fork_name}" ]]; then
    echo ":: renaming ${fork_name} master to main"
    gh api --silent "repos/${fork_name}/branches/master/rename" --method POST --field 'new_name=main'
  else
    echo ":: no fork detected, skipping rename"
  fi
else
  echo ":: gh not found, skipping fork rename"
fi