Add Django email testing support

This commit adds support for inspecting emails sent that were sent by the Django server started by lettuce.

docs/recipes/django-lxml.rst

@@ -256,6 +256,32 @@ Notice the ``terrain.py`` file at the project root, there you can
 populate the :ref:`lettuce-world` and organize your features and steps
 with it :)
 
+Checking email
+==============
+
+When you run your Django server under lettuce, emails sent by your server
+do not get transmitted over the Internet. Instead, these emails are
+added to a :class:`multiprocessing.Queue` object at
+``lettuce.django.mail.queue``.
+
+Example:
+
+.. highlight:: python
+
+::
+
+  from lettuce import step
+  from lettuce.django import mail
+  from nose.tools import assert_equals
+
+
+  @step(u'an email is sent to "([^"]*?)" with subject "([^"]*)"')
+  def email_sent(step, to, subject):
+      message = mail.queue.get(True, timeout=5)
+      assert_equals(message.subject, subject)
+      assert_equals(message.recipients(), [to])
+
+
 Running without HTTP server
 ===========================
 

lettuce/django/mail/backends.py

@@ -0,0 +1,13 @@
+"""
+Email backend that sends mails to a multiprocessing queue
+"""
+from lettuce.django import mail
+from django.core.mail.backends.base import BaseEmailBackend
+
+
+class QueueEmailBackend(BaseEmailBackend):
+
+    def send_messages(self, messages):
+        for message in messages:
+            mail.queue.put(message)
+        return len(messages)

lettuce/django/server.py

@@ -46,9 +46,15 @@
 except ImportError:
     pass
 
+from lettuce.django import mail
 from lettuce.registry import call_hook
 
 
+def create_mail_queue():
+    mail.queue = multiprocessing.Queue()
+    return mail.queue
+
+
 class LettuceServerException(WSGIServerException):
     pass
 
@@ -104,10 +110,16 @@ class ThreadedServer(multiprocessing.Process):
     lock = multiprocessing.Lock()
     daemon = True
 
-    def __init__(self, address, port, *args, **kw):
+    def __init__(self, address, port, mail_queue, *args, **kw):
         multiprocessing.Process.__init__(self)
         self.address = address
         self.port = port
+        self.mail_queue = mail_queue
+
+    def configure_mail_queue(self):
+        mail.queue = self.mail_queue
+        settings.EMAIL_BACKEND = \
+            'lettuce.django.mail.backends.QueueEmailBackend'
 
     @staticmethod
     def get_real_address(address):
@@ -162,6 +174,8 @@ def run(self):
 
         open(pidfile, 'w').write(unicode(os.getpid()))
 
+        self.configure_mail_queue()
+
         connector = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
 
         try:
@@ -217,7 +231,8 @@ class Server(object):
     def __init__(self, address='0.0.0.0', port=None):
         self.port = int(port or getattr(settings, 'LETTUCE_SERVER_PORT', 8000))
         self.address = unicode(address)
-        self._actual_server = ThreadedServer(self.address, self.port)
+        queue = create_mail_queue()
+        self._actual_server = ThreadedServer(self.address, self.port, queue)
 
     def start(self):
         """Starts the webserver thread, and waits it to be available"""

lettuce/django/tests/functional/Makefile

@@ -0,0 +1,2 @@
+test:
+	PYTHONPATH=`pwd` DJANGO_SETTINGS_MODULE=djangoapp django-admin.py harvest email.feature

lettuce/django/tests/functional/djangoapp.py

@@ -0,0 +1,25 @@
+"""
+
+A minimal Django app, just one file.
+
+See: http://olifante.blogs.com/covil/2010/04/minimal-django.html
+
+"""
+import os
+from django.conf.urls.defaults import patterns
+from django.core.mail import send_mail
+
+from django.http import HttpResponse
+filepath, extension = os.path.splitext(__file__)
+ROOT_URLCONF = os.path.basename(filepath)
+INSTALLED_APPS = (
+    "lettuce.django"
+    )
+
+
+def mail(request):
+    send_mail('Subject here', 'Here is the message.', 'from@example.com',
+             ['to@example.com'], fail_silently=False)
+    return HttpResponse('Mail has been sent')
+
+urlpatterns = patterns('', (r'^mail/$', mail))

lettuce/django/tests/functional/email.feature

@@ -0,0 +1,7 @@
+Feature: Check email sent by Django server
+
+Scenario: Access a web page which triggers an email
+    Given I visit "/mail/"
+    Then I see "Mail has been sent"
+    and an email is sent to "to@example.com" with subject "Subject here"
+

lettuce/django/tests/functional/steps.py

@@ -0,0 +1,22 @@
+from lettuce import world, step
+from lettuce.django import mail
+from lettuce.django import django_url
+
+from nose.tools import assert_equals
+
+
+@step(u'I visit "([^"]*)"')
+def visit(step, url):
+    world.browser.visit(django_url(url))
+
+
+@step(u'I see "([^"]*)"')
+def see(step, text):
+    assert world.browser.is_text_present(text)
+
+
+@step(u'an email is sent to "([^"]*?)" with subject "([^"]*)"')
+def email_sent(step, to, subject):
+    message = mail.queue.get(True, timeout=5)
+    assert_equals(message.subject, subject)
+    assert_equals(message.recipients(), [to])

lettuce/django/tests/functional/terrain.py

@@ -0,0 +1,12 @@
+from splinter.browser import Browser
+from lettuce import before, after, world
+
+
+@before.harvest
+def setup(server):
+    world.browser = Browser()
+
+
+@after.harvest
+def cleanup(server):
+    world.browser.quit()

lettuce/django/tests/functional/test_email.py

@@ -0,0 +1,25 @@
+import os
+import sys
+import commands
+
+from tests.asserts import assert_not_equals
+from lettuce.fs import FileSystem
+
+current_directory = FileSystem.dirname(__file__)
+
+OLD_PYTHONPATH = os.getenv('PYTHONPATH', ':'.join(sys.path))
+
+
+def teardown():
+    os.environ['PYTHONPATH'] = OLD_PYTHONPATH
+
+
+def test_email():
+    'lettuce should be able to receive emails sent from django server'
+    os.environ['PYTHONPATH'] = current_directory
+    os.environ['DJANGO_SETTINGS_MODULE'] = 'djangoapp'
+
+    status, out = commands.getstatusoutput(
+        "django-admin.py harvest email.feature --verbosity=2")
+
+    assert_not_equals(status, 0)