Django PEP8 Test Generator Example

pep8_tests.py

import os
import re
import subprocess

from django.conf import settings
from django import test


class PEP8Tests(test.TestCase):
    def _generate_pep8_tests(class_namespace):
        function_name_scrubber_regex = re.compile(r'\W|^(?=\d)')

        # Generate a PEP8 test method for a python file in a closure
        def generate_pep8_test(python_filename):
            def test_method(self):
                # Run pep8 command on this file, if there's output fail with it
                pep8_process = subprocess.Popen(
                    ['pep8', '--ignore=E501', python_filename],
                    stdout=subprocess.PIPE,
                )
                pep8_process.wait()
                pep8_output = pep8_process.stdout.read().strip()

                if pep8_output:
                    self.fail("PEP8 failed on file: %s\n\n%s" % (
                        python_filename, pep8_output,
                    ))

            # Cleanly name this method based on the filename
            test_method.__name__ = 'test_pep8_on_%s' % (
                function_name_scrubber_regex.sub('_', python_filename),
            )
            return test_method

        # Go through all Python files in PROJECT_ROOT
        for root, dirs, files in os.walk(settings.PROJECT_ROOT):
            for filename in files:
                filename = os.path.join(root, filename)
                if filename.endswith('.py') and os.path.exists(filename):
                    test_method = generate_pep8_test(filename)
                    # Bind method into TestCase's namespace
                    class_namespace[test_method.__name__] = test_method

    _generate_pep8_tests(locals())
    del _generate_pep8_tests