[Pytest-commit] Issue #637: Assertion reverse engineering often fails (hpk42/pytest)

[gcc111]

New issue 637: Assertion reverse engineering often fails
https://bitbucket.org/hpk42/pytest/issue/637/assertion-reverse-engineering-often-fails

gcc111:

Consider the following simple program:

```
#!python
var = None
def test_foo():
    assert 'Hello' == var, "whee"
```

I get the following output from py.test:

	======================================================= test session starts ========================================================
	platform linux2 -- Python 2.7.3 -- py-1.4.22 -- pytest-2.6.0
	plugins: django-assets, django
	collected 0 items / 1 errors 

	============================================================== ERRORS ==============================================================
	________________________________________ ERROR collecting ../../../../../../../tmp/test.py _________________________________________
	/tmp/test.py:3: in <module>
	    assert 'Hello' == var, "whee"
	E   AssertionError: whee
	===================================================== 1 error in 0.06 seconds ======================================================

Which is very pretty, but didn't actually tell me what went wrong, by giving me the values of the left and right hand sides of the assertion.

I have to switch back to UnitTest.assertEqual, which does tell me (when I set longMessage = True):

	Traceback (most recent call last):
	  File "test.py", line 9, in test_foo
	    self.assertEqual('Hello', var, "whee")
	AssertionError: 'Hello' != None : whee