validatingclient.py

import inspect
import tempfile
import codecs
import StringIO
import gzip
import os
import re

import requests
from django.test.client import Client
from django.conf import settings


class ValidatorOperationalError(Exception):
    pass


class ValidationError(AssertionError):
    pass


class ValidatingClient(Client):

    def get(self, *args, **kwargs):
        response = super(ValidatingClient, self).get(*args, **kwargs)
        disabled = getattr(
            settings,
            'VALIDATINGCLIENT_DISABLED',
            True
        )
        if disabled:
            return response

        caller = inspect.stack()[1]
        caller_file = caller[1]
        caller_line = caller[2]
        caller_name = caller[3]

        if (
            response['Content-Type'].startswith('text/html')
            and
            response.status_code == 200
        ):
            try:
                encoding = re.findall(
                    'charset=([\w-]+)',
                    response['Content-Type']
                )[0]
            except IndexError:
                encoding = 'utf-8'  # sensible default

            temp_dir = os.path.join(
                tempfile.gettempdir(), 'outputtestingclient'
            )
            if not os.path.isdir(temp_dir):
                os.mkdir(temp_dir)
            temp_file = os.path.join(
                temp_dir,
                '%s-%s.html' % (caller_name, caller_line)
            )
            with codecs.open(temp_file, 'w', encoding) as f:
                if not response.content:
                    raise ValueError('No response.content', args[0])
                f.write(response.content)
                self._validate(temp_file, encoding, *args, **kwargs)
        return response

    def _validate(self, html_file, encoding, *args, **kwargs):
        buf = StringIO.StringIO()
        gzipper = gzip.GzipFile(fileobj=buf, mode='wb')
        with codecs.open(html_file, 'r', encoding) as f:
            gzipper.write(f.read())
            gzipper.close()
        gzippeddata = buf.getvalue()
        buf.close()

        req = requests.post(
            'http://html5.validator.nu/?out=text',
            headers={
                'Content-Type': 'text/html',
                'Accept-Encoding': 'gzip',
                'Content-Encoding': 'gzip',
                'Content-Length': len(gzippeddata),
            },
            data=gzippeddata
        )

        if req.status_code != 200:
            raise ValidatorOperationalError(req)

        raise_exceptions = getattr(
            settings,
            'VALIDATINGCLIENT_HARDCORE',
            False
        )

        messages = []
        for block in re.split('\n\n+', req.content):
            messages.append(block)

        if req.content:
            print "VALIDATON TROUBLE"
            print "To debug, see:"
            print "\t", html_file
            txt_file = re.sub('\.html$', '.txt', html_file)
            print "\t", txt_file
            with codecs.open(txt_file, 'w', encoding) as f:
                f.write('Arguments to GET:\n')
                for arg in args:
                    f.write('\t%s\n' % arg)
                for k, w in kwargs.items():
                    f.write('\t%s=%s\n' % (k, w))
                f.write('\n')
                f.write(unicode(req.content, encoding))
            if raise_exceptions:
                raise ValidationError(req.content)
            else:
                print "\n\n".join(messages)

Example usage:

import os
import shutil

from django.test import TestCase
from django.conf import settings
from django.contrib.auth.models import User

from .validatingclient import ValidatingClient


class DjangoTestCase(TestCase):

    def shortDescription(self):
        return None

    def setUp(self):
        super(DjangoTestCase, self).setUp()
        self.client = ValidatingClient()

    def tearDown(self):
        super(DjangoTestCase, self).tearDown()
        assert os.path.basename(settings.MEDIA_ROOT).startswith('testmedia')
        if os.path.isdir(settings.MEDIA_ROOT):
            shutil.rmtree(settings.MEDIA_ROOT)

        super(DjangoTestCase, self).tearDown()

    def _login(self, username='mary', email='mary@mozilla.com', pwd='secret'):
        user = User.objects.create_user(
            username, email, pwd
        )
        assert self.client.login(username=username, password=pwd)
        return user

By default, Django's TestCase class creates an instance of django.test.client.Client into the test class instance. This overrides that.

To really enable this you need to edit your settings:

VALIDATINGCLIENT_DISABLED = False

And if you want it to raise an exception if there's any errors:

VALIDATINGCLIENT_HARDCORE = True

Example output can look like this:

$ t -x airmozilla/main/tests/test_views.py:TestPages.test_view_event_with_pin -x -s
VALIDATON TROUBLE
To debug, see:
    /var/folders/l7/9ffkzwg965gf0zl261g34n_m0000gp/T/outputtestingclient/assertRedirects-600.html
    /var/folders/l7/9ffkzwg965gf0zl261g34n_m0000gp/T/outputtestingclient/assertRedirects-600.txt
VALIDATON TROUBLE
To debug, see:
    /var/folders/l7/9ffkzwg965gf0zl261g34n_m0000gp/T/outputtestingclient/test_view_event_with_pin-195.html
    /var/folders/l7/9ffkzwg965gf0zl261g34n_m0000gp/T/outputtestingclient/test_view_event_with_pin-195.txt
VALIDATON TROUBLE
To debug, see:
    /var/folders/l7/9ffkzwg965gf0zl261g34n_m0000gp/T/outputtestingclient/test_view_event_with_pin-207.html
    /var/folders/l7/9ffkzwg965gf0zl261g34n_m0000gp/T/outputtestingclient/test_view_event_with_pin-207.txt
VALIDATON TROUBLE
To debug, see:
    /var/folders/l7/9ffkzwg965gf0zl261g34n_m0000gp/T/outputtestingclient/assertRedirects-600.html
    /var/folders/l7/9ffkzwg965gf0zl261g34n_m0000gp/T/outputtestingclient/assertRedirects-600.txt
VALIDATON TROUBLE
To debug, see:
    /var/folders/l7/9ffkzwg965gf0zl261g34n_m0000gp/T/outputtestingclient/test_view_event_with_pin-223.html
    /var/folders/l7/9ffkzwg965gf0zl261g34n_m0000gp/T/outputtestingclient/test_view_event_with_pin-223.txt
.
----------------------------------------------------------------------
Ran 1 test in 2.710s

And the output something like this:

$ cat /var/folders/l7/9ffkzwg965gf0zl261g34n_m0000gp/T/outputtestingclient/test_view_event_with_pin-223.txt
Arguments to GET:
    /test-event/

Error: Element “div” not allowed as child of element “hgroup” in this context. (Suppressing further errors from this subtree.)
From line 89, column 11; to line 89, column 31

Error: Element “hgroup” is missing a required instance of one or more of the following child elements: “h1”, “h2”, “h3”, “h4”, “h5”, “h6”.
From line 102, column 15; to line 102, column 23

Error: Bad value “navigation” for attribute “role” on element “ul”.
From line 186, column 7; to line 186, column 28

Warning: Consider using the “h1” element as a top-level heading only (all “h1” elements are treated as top-level headings by many screen readers and other tools).
From line 112, column 7; to line 112, column 30

There were errors. (Tried in the text/html mode.)