tornado's AsyncHttpTestCase is not available outside self.fetch - testing

Question

I have an AsyncHttpTestCase and I want to access it from methods besides self.fetch. Specifically, I have a SockJS handler that I want a sockjs-client to attach too for my tests.
I've discovered that even though self.get_url('/foo') returns a valid url, that url does not respond to anything except for self.fetch(). What gives?
Is this just not possible with AsyncHttpTestCase? What is the best pattern for doing this?
Here's tests.py
import urllib2
from tornado.httpclient import AsyncHTTPClient
import tornado.testing
from tornado.testing import AsyncTestCase, AsyncHTTPTestCase
from app import DebugApp
class TestDebug(AsyncHTTPTestCase):
def get_app(self):
return DebugApp()
def test_foo(self):
response = self.fetch('/foo')
print response.body
assert response.body == 'derp'
def test_foo_from_urllib(self):
response = urllib2.urlopen(self.get_url('/foo'), None, 2)
print response
assert response.body == 'derp'
def runTest(self):
pass
and app.py
import tornado.httpserver
import tornado.ioloop
import tornado.web
from tornado.options import options
class FooHandler(tornado.web.RequestHandler):
def get(self):
self.write("derp")
url_patterns = [
(r"/foo", FooHandler),
]
class DebugApp(tornado.web.Application):
def __init__(self):
tornado.web.Application.__init__(self, url_patterns, debug=True, xsrf_cookies=False)
def main():
app = DebugApp()
http_server = tornado.httpserver.HTTPServer(app)
http_server.listen(6006)
tornado.ioloop.IOLoop.instance().start()
if __name__ == "__main__":
main()
and runtest.py
#!/usr/bin/env python
import unittest
from os import path
import sys
import tornado.testing
PROJECT_PATH = path.dirname(path.abspath(__file__))
sys.path.append(PROJECT_PATH)
def all():
suite = unittest.defaultTestLoader.discover('./', 'tests.py', path.dirname(path.abspath(__file__)))
print suite
return suite
if __name__ == '__main__':
# Print a nice message so that we can differentiate between test runs
print ''
print '%s %s' % ('Debug app', '0.1.0')
print '\033[92m' + '-------------- Running Test Suite --------------' + '\033[0m'
print ''
tornado.testing.main()

Answer 1

The problem is that the IOLoop is not running when you call urlopen (and it cannot be, because urlopen is a blocking function). You must run the IOLoop (with either #gen_test, self.wait(), or indirectly via methods like self.fetch()) for the server to respond, and you can only interact with it via non-blocking functions (or if you must use blocking functions like urlopen, run them in a separate thread).