[Pytest-commit] Issue #626: Add custom message to default assert repr (hpk42/pytest)

[John Dennison]

New issue 626: Add custom message to default assert repr
https://bitbucket.org/hpk42/pytest/issue/626/add-custom-message-to-default-assert-repr

John Dennison:

I asked a question on stackoverflow and was asked to add an issue for my use case so here i go: http://stackoverflow.com/questions/26620740/appending-to-default-py-test-assertion-output/26642915#26642915

I would like to add additional output to the default assertion failure output. 

I am able to over ride the output entirely with pytest_assertrepr_compare but i can't seem to get the default output and add my custom message to it. I have tried:

from _pytest.assertion.util import assertrepr_compare
def pytest_assertrepr_compare(config, op, left, right):
    pytest_output = assertrepr_compare(config, op, left, right)
    # append log output to normal compare, but the pytest_output is always None
    return pytest_output + ['THIS IS MY CUSTOM MESSAGE']

My actual use case is printing logs from remote servers when an assertion fails. If any of my tests fail. display the regular assertion failure and then my custom message.