git-start

#!/usr/bin/env python
#
# git-start
#
# Creates a new feature branch off your local main branch, rather than the
# current active branch. If an error occurs you will be reverted back to the
# original branch you were on before running the script. The branch name is
# automatically prefixed with your GitHub username.
#
# Usage:
#     git start bananas
#
# Is equivalent to calling:
#     git checkout main
#     git pull origin main
#     git checkout -b dpup/bananas
#
# TODO: Can we get any status updates while waiting for 'git pull'
# TODO: Error cases need informative error messages.

import sys
import os
import git
import util

if len(sys.argv) < 2:
    util.fatal('Incorrect usage, missing branch name. Use: git start [feature]')

try:
    repo = git.Repo(os.getcwd(), search_parent_directories=True)
except git.exc.InvalidGitRepositoryError:
    util.fatal('git start must be run from within a valid git repository.')

new_branch_name = util.get_branch_name(sys.argv[1])
initial_branch = repo.active_branch

util.fatal_if_dirty(repo)

if new_branch_name in repo.heads:
    util.fatal('A branch called "%s" already exists.' % new_branch_name)

util.update_main(repo, initial_branch)

util.info('Creating new head')
new_branch = repo.create_head(new_branch_name)
new_branch.checkout()

util.success('New feature branch created for "%s".' % new_branch_name)