Test client should re-raise exceptions created while rendering a page

[afternoon@…]

With the current django.test.client.Client class it is not possible to inspect an exception created by the code being tested.

For example, a view may raise an exception due to syntax error, malformed input from the test case or for any number of reasons. The exception is handled by Django and a standard error view (either a 500 page or error debug page) is returned with no other indication about the original exception. It is therefore difficult to track down the actual cause of the error.

A simple patch can handle the got_request_exception signal created by the base handler and capture the actual exception object and it's associated exc_info. The exception can then be reraised, complete with the original frame/location information, after the handler has finished. The exception can then be inspected by the test case. The standard behaviour of the test case is to print a stack trace to stdout, which is very useful when creating or fixing tests. As the exception location information is not modified, the original cause can be found and fixed.

[afternoon@…]

[patch] Reraise exceptions created during request handling so test cases may inspect them

[afternoon@…]

[patch] Reraise exceptions created during request handling so test cases may inspect them, added test and docs

[Chris Beaven]

Certainly seems like a good idea and a good quality patch. Maybe a bit overzealous of me, but I'll fast-track to "ready".

[anonymous]

Hmm, I have another version of this patch with tests and docs ready to go, except that it's causing one of the pre-existing Django tests to fail. I've been meaning to fix it for two weeks. I will get my act together.

[afternoon@…]

The current version of the patch causes the test_view_with_bad_login test from tests/modeltests/test_client/models.py to fail. The auth module throws an exception. Somehow _ becomes bound to an Article object during this test. Adding from django.utils.translation import gettext_lazy as _ to django.contrib.auth.forms fixes the test.

Here is a stack trace of the exception occurring:

Traceback (most recent call last):
  File "/Users/ben/Documents/Code/Python/django_svn/tests/modeltests/test_client/models.py", line 108, in test_view_with_bad_login
    response = self.client.login('/test_client/login_protected_view/', 'otheruser', 'nopassword')
  File "/Users/ben/Documents/Code/Python/django_svn/django/test/client.py", line 236, in login
    response = self.post(login_path, data=form_data, **extra)
  File "/Users/ben/Documents/Code/Python/django_svn/django/test/client.py", line 188, in post
    return self.request(**r)
  File "/Users/ben/Documents/Code/Python/django_svn/django/core/handlers/base.py", line 77, in get_response
    response = callback(request, *callback_args, **callback_kwargs)
  File "/Users/ben/Documents/Code/Python/lib/django/contrib/auth/views.py", line 16, in login
    errors = manipulator.get_validation_errors(request.POST)
  File "/Users/ben/Documents/Code/Python/lib/django/oldforms/__init__.py", line 59, in get_validation_errors
    errors.update(field.get_validation_errors(new_data))
  File "/Users/ben/Documents/Code/Python/lib/django/oldforms/__init__.py", line 357, in get_validation_errors
    self.run_validator(new_data, validator)
  File "/Users/ben/Documents/Code/Python/lib/django/oldforms/__init__.py", line 347, in run_validator
    validator(new_data.get(self.field_name, ''), new_data)
  File "/Users/ben/Documents/Code/Python/django_svn/django/contrib/auth/forms.py", line 59, in isValidUser
    raise validators.ValidationError, _("Please enter a correct username and password. Note that both fields are case-sensitive.")
TypeError: 'Article' object is not callable

[Russell Keith-Magee]

(In [4482]) Fixed #3162 -- Added coded to catch and rethrow exceptions that are thrown by the views visited by the test client. Thanks, Ben <afternoon@…>.