hook_lib.py

#!/usr/bin/env python

"""Library for code shared by hghook.py and githook.py.

This library does the actual linting, after the VCS-specific commands
to get the data that needs linting.
"""

import re
import sys

import runlint


def lint_files(files_to_lint):
    """Given a list of filenames in the commit, lint them all.

    Emits errors it sees to stderr.

    Returns the number of lint errors seen.
    """
    return runlint.main(files_to_lint, blacklist='yes')


def lint_commit_message(commit_message):
    """Given the text of a commit message, lint it for correctness.

    Every non-merge commit must list either a test plan or a review
    that it's part of (the first commit in a review must have a test
    plan, but subsequent ones don't need to restate it).
    TODO(csilvers): should we do anything special with substate-update
    commits?

    Emits errors it sees to stderr.

    Returns the number of lint errors seen in the commit message.
    """
    num_errors = 0

    if not re.search('^(test plan|review):', commit_message, re.I | re.M):
        print >> sys.stderr, ('Missing "Test plan:" or "Review:" section '
                              'in the commit message.')
        num_errors += 1

    elif re.search('^    <see below>$', commit_message, re.M):
        print >> sys.stderr, ('Must enter a "Test plan:" (or "Review:") '
                              'in the commit message.')
        num_errors += 1

    if re.search('^<one-line summary, followed by ', commit_message, re.M):
        print >> sys.stderr, 'Must enter a summary in the commit message.'
        num_errors += 1

    # TODO(csilvers): verify the first-line summary is actually 1 line long?

    return num_errors


def report_errors_and_exit(num_errors, commit_message, save_filename):
    """If num_errors > 0, print a summary message and exit 1.

    In that case, we save the commit message to save_filename.
    """
    if num_errors:
        # save the commit message so we don't need to retype it
        with open(save_filename, 'w') as f:
            f.write(commit_message)
        print >> sys.stderr, ('\n--- %s lint errors ---\n'
                              'Commit message saved to %s'
                              ' (use --template=%s on'
                              ' commit to resume editing)'
                              % (num_errors, save_filename, save_filename))
        sys.exit(1)
    print >> sys.stderr, 'khan-linter: all lint checks passed'
    sys.exit(0)