测试龙卷风应用为4xx状态代码

Question

考虑以下龙卷风（V 4.0.2）的应用程序，这是官方hello world例如一点点修改的版本：

import tornado.ioloop 
import tornado.web 

class MainHandler(tornado.web.RequestHandler): 
    def get(self): 
     self.set_status(400) 
     self.write("Hello, world") 

application = tornado.web.Application([ 
    (r"/", MainHandler), 
]) 

if __name__ == "__main__": 
    application.listen(8888) 
    tornado.ioloop.IOLoop.instance().start() 

正如你所看到的，这里唯一的区别set_status致电MainHandler。现在，我将这段代码保存为app.py，然后我打开tests.py，我把有这种简单的单元测试：

import tornado.ioloop 
from tornado.httpclient import HTTPRequest 
from tornado.testing import AsyncHTTPTestCase, gen_test 

from app import application 

class SimpleTest(AsyncHTTPTestCase): 
    def get_app(self): 
     return application 

    def get_new_ioloop(self): 
     return tornado.ioloop.IOLoop.instance() 

    @gen_test 
    def test_bad_request(self): 
     request = HTTPRequest(url=self.get_url('/')) 
     response = yield self.http_client.fetch(request) 
     self.assertEqual(response.code, 400) 

当我运行这个测试与python -m tornado.test.runtests tests我得到以下结果：

E 
====================================================================== 
ERROR: test_bad_request (tests.SimpleTest) 
---------------------------------------------------------------------- 
Traceback (most recent call last): 
    File "/usr/local/lib/python2.7/dist-packages/tornado/testing.py", line 118, in __call__ 
    result = self.orig_method(*args, **kwargs) 
    File "/usr/local/lib/python2.7/dist-packages/tornado/testing.py", line 494, in post_coroutine 
    timeout=timeout) 
    File "/usr/local/lib/python2.7/dist-packages/tornado/ioloop.py", line 418, in run_sync 
    return future_cell[0].result() 
    File "/usr/local/lib/python2.7/dist-packages/tornado/concurrent.py", line 109, in result 
    raise_exc_info(self._exc_info) 
    File "/usr/local/lib/python2.7/dist-packages/tornado/gen.py", line 631, in run 
    yielded = self.gen.throw(*sys.exc_info()) 
    File "tests.py", line 18, in test_bad_request 
    response = yield self.http_client.fetch(request) 
    File "/usr/local/lib/python2.7/dist-packages/tornado/gen.py", line 628, in run 
    value = future.result() 
    File "/usr/local/lib/python2.7/dist-packages/tornado/concurrent.py", line 111, in result 
    raise self._exception 
HTTPError: HTTP 400: Bad Request 

---------------------------------------------------------------------- 
Ran 1 test in 0.022s 

FAILED (errors=1) 
[E 140929 12:55:59 testing:687] FAIL 

显然这是正确的，因为处理程序设置了400个状态码。 但是，如何测试我的应用程序的这种情况？我认为4xx代码很有用，所以我不想放弃它们。不过，我对Tornado并不陌生，因此我无法找到测试它们的方法。有没有？

Answer 1

试试这个：

@gen_test 
    def test_bad_request(self): 
     request = HTTPRequest(url=self.get_url('/')) 
     with self.assertRaises(tornado.httpclient.HTTPError) as context: 
      yield self.http_client.fetch(request) 

     self.assertEqual(context.exception.code, 400) 

查看文档assertRaises。