17. Running Tests

17.1. Overview

You can test your applications by invoking manage.py test --target or manage.py test without any options. manage.py script sets up an environment for testing, so you can write your test code easily. We will take a quick look on werkzeug’s library for testing.

17.2. Your first test

manage.py test automatically collects subclasses of TestCase from tests module under your APP_DIR. So let’s put our test code into myapp/tests/__init.py here.

myapp/tests/__init__.py:

import unittest

from google.appengine.ext import db

from myapp.models import Comment

class ModelTest(unittest.TestCase):
  def tearDown(self):
    db.delete(Comment.all().fetch(10))

  def test_model(self):
    c = Comment(body=u'Hello Test!')
    c.put()
    comments = Comment.all().fetch(100)
    self.assertEquals(len(comments), 1)
    self.assertEquals(comments[0].body, 'Hello Test!')

In this TestCase, we can test a behavior of myapp.models.Comment. You don’t need to care about setting up stubs like DatastoreFileStub. Isn’t it very simple?

17.3. Using werkzeug.Client for testing views

Next, let’s test our views. To do so, we can use werkzeug.Client.

myapp/tests/__init__.py:

import unittest

from werkzeug import BaseResponse, Client, Request
from kay.app import get_application
from google.appengine.ext import db

from myapp.models import Comment

class MyappTestCase(unittest.TestCase):
  def setUp(self):
    app = get_application()
    self.client = Client(app, BaseResponse)

  def tearDown(self):
    db.delete(Comment.all().fetch(10))

  def test_post(self):
    response = self.client.get('/')
    import re
    m = re.search(r'name="_csrf_token" value="([^"]+)"', response.data)
    response = self.client.post('/', data={'comment': 'Hello',
                                           '_csrf_token': m.group(1)},
                                follow_redirects=True)
    comments = Comment.all().fetch(100)
    self.assertEquals(len(comments), 1)

You can test your views by werkzeug.Client. Currently, there is no handy way for parsing Response (in above example, I use re module for this), so you need to do this manually.

See also

Werkzeug test utitilies

Here is an output of these tests. In this example, we can see the test names by using -v2 option.

$ python manage.py test -v2
Running on Kay-0.3.0
test_model (myapp.tests.ModelTest) ... ok
test_post (myapp.tests.MyappTestCase) ... ok

----------------------------------------------------------------------
Ran 2 tests in 0.093s

OK