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Clean git branches and stale references
#!/usr/bin/env python
import sys
import argparse
import subprocess
REMOTE = 'origin'
class CmdError(RuntimeError):
pass
def run_cmd(cmd, dry_run=False, log=True, print_stderr=True, on_error=''):
# runs command, captures stdout, and return output lines
# if command exits with non-zero status raises a CmdError
if log or dry_run:
print(('(dry-run) ' if dry_run else '-> ') + ' '.join(cmd))
if dry_run:
return []
proc = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=None if print_stderr else subprocess.PIPE)
out, _ = proc.communicate()
if proc.returncode == 0:
out = out.decode('utf-8').strip()
return out.split('\n') if out else []
else:
raise CmdError(on_error or ' '.join(cmd))
def get_git_commit_for(commitish):
# returns the commit for a commitish: branch, tag, etc.
cmd = ['git', 'rev-parse', commitish]
return run_cmd(cmd, log=False, on_error='unrecognized commitish ' + commitish)[0]
def get_remote_tracking_branch_for(branch):
# returns the remote tracking branch or None if none.
cmd = ['git', 'rev-parse', '--abbrev-ref', branch + '@{upstream}']
try:
for line in run_cmd(cmd, log=False, print_stderr=False):
return line
except CmdError:
pass
def verify_master_status():
# asserts that master and origin/master are at the same commit
# assumes git fetch has already been called
local = get_git_commit_for('master')
remote = get_git_commit_for('origin/master')
if local != remote:
raise CmdError('master and origin/master are not in the same place: %s vs %s' %
(local[:8], remote[:8]))
def git_fetch():
run_cmd(['git', 'fetch'])
def get_current_branch():
return run_cmd(['git', 'rev-parse', '--abbrev-ref', 'HEAD'], log=False)[0]
def branch_is_protected(branch):
return 'HEAD' in branch or 'master' in branch or 'release' in branch
def get_merged_local_branches():
# yields git branches, excluding current and protected branches, that have
# been merged into <remote>/master.
# NOTE assumes git fetch has already been called.
current_branch = get_current_branch()
cmd = [
'git', 'branch',
'--format', '%(refname:short)', # drop formatting, including the asterisk
'--merged', 'origin/master' # only include merged branches
]
for line in run_cmd(cmd, log=False):
branch = line.strip()
if branch != current_branch and not branch_is_protected(branch):
yield branch
def get_pushed_local_branches():
# yields git branches, excluding current and protected branches, that are
# up to date with remote.
# NOTE assumes git fetch has been called.
current_branch = get_current_branch()
cmd = [
'git', 'branch',
'--format', '%(refname:short)', # drop formatting, including the asterisk
]
for line in run_cmd(cmd, log=False):
branch = line.strip()
if branch == current_branch or branch_is_protected(branch):
continue
rt_branch = get_remote_tracking_branch_for(branch)
if rt_branch is None:
continue
local = get_git_commit_for(branch)
remote = get_git_commit_for(rt_branch)
if local == remote:
yield branch
def delete_local_branch(branch, dry_run=False):
cmd = ['git', 'branch', '-d', branch]
err = 'Failed to delete branch ' + branch
run_cmd(cmd, dry_run=dry_run, on_error=err)
def delete_merged_local_branches(dry_run=False):
for branch in get_merged_local_branches():
delete_local_branch(branch, dry_run=dry_run)
def delete_stale_remote_tracking_branches(dry_run=False):
# removes local tracking branches for branches that have been removed from
# remote (regardless of merge status)
for line in run_cmd(['git', 'remote', 'prune', 'origin'], dry_run=dry_run):
print(line)
def delete_pushed_local_branches(dry_run=False):
for branch in get_pushed_local_branches():
delete_local_branch(branch, dry_run=dry_run)
def clean_branches(dry_run):
git_fetch()
verify_master_status()
delete_merged_local_branches(dry_run=dry_run)
delete_stale_remote_tracking_branches(dry_run=dry_run)
delete_pushed_local_branches(dry_run=dry_run)
if __name__ == '__main__':
parser = argparse.ArgumentParser(description="""
Clean git branches and stale references.
- remove all local branches that are merged in {remote}/master
- remove stale remote tracking branches: those that are no longer on
{remote}.
- remove all local branches that are up to date with their upstream in
remote.
Notes:
- Nothing is pushed to / modified in remote.
- Nothing is every done to protected branches (master and releases)
- Nothing is done to the current checked out branch.
""".format(remote=REMOTE))
parser.add_argument('--dry-run', action='store_true',
help='print git commands instead of running them')
args = parser.parse_args()
try:
clean_branches(dry_run=args.dry_run)
except CmdError as e:
print('ERROR: ' + str(e))
sys.exit(1)
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