[Pytest-commit] Issue #514: Error constructing message for unhooked assertion failure based on private variable (hpk42/pytest)

[Jurko Gospodnetić]

New issue 514: Error constructing message for unhooked assertion failure based on private variable
https://bitbucket.org/hpk42/pytest/issue/514/error-constructing-message-for-unhooked

Jurko Gospodnetić:

In the following scenario:

File: ```test_me.py```

```
#!python
from outsider import Outsider

class Insider:
    def __init__(self):
        self.__private = 5
        assert self.__private == 6

def test_insider():
    Insider()

def test_outsider():
    Outsider()
```

File: ``outsider.py``

```
#!python
class Outsider:
    def __init__(self):
        self.__private = 5
        assert self.__private == 6
```

when running the tests using ``pytest --tb=short`` you get the following output:

```
#!text
================================== FAILURES ===================================
________________________________ test_insider _________________________________
test_me.py:9: in test_insider
>       Insider()
test_me.py:6: in __init__
>       assert self.__private == 6
E       assert 5 == 6
E        +  where 5 = <test_me.Insider object at 0x00000000034460B8>.__private
________________________________ test_outsider ________________________________
test_me.py:12: in test_outsider
>       Outsider()
outsider.py:4: in __init__
>       assert self.__private == 6
E       AssertionError: AttributeError: <outsider.Outsider object at 0x0000000003446AC8>.__private  << 'Outsider' object has no attribute '__private'
========================== 2 failed in 0.08 seconds ===========================
```

As you can see, ``pytest`` attempts to construct the assertion failure description message for the failed ``test_outsider`` test but does not access the private ``__private`` attribute correctly which should have been accessed as ``_Outsider__private``.

Hope this helps.

Best regards,
  Jurko Gospodnetić