Include location footer in logs for AssertionErrors

[jayeshathila]

Changes:

1. Adding Location footer in AssertionErrors.

Concerns:

1. Didn't add tests for the change as I can't find other tests for the Locations.
2. Approach doesn't seem clean to me, not sure if how we can improve it.

issue #126

[darrenburns]

I wonder if there's a way we could have the location always be the line number that the test failed on, just to keep things consistent throughout? If so, I also think we should print out the surrounding context of where the failure occurred, as per the "Failure" header shown in the image below.

[blueyed]

The location (file + lnum) of the test failure is very useful, since it allows to quickly go there in an editor.
Keep in mind though that it might fail before or after the actual test however (fixture setup/teardown etc). In that case it should be the location of the "crash" probably.

[darrenburns]

Very good point @blueyed.

There's two relevant lines: the location of the failing test definition, and the location the failure/error actually occurs. I wonder what the least confusing way to communicate those to the user is? Any thoughts @jayeshathila? I'd be open to changing the existing output if we can think of something clearer.

[blueyed]

With pytest I am using nodeid::test_file.py:42 by default, but expand it to nodeid::test_file.py:42 (some/other/file.py:123) if the crash happened somewhere else. This provides two locations then: one to easily go to the test's code that triggered it, and another for going to the crash itself (which might be a lib or a non-hidden test helper).

[jayeshathila]

Very good point @blueyed.

There's two relevant lines: the location of the failing test definition, and the location the failure/error actually occurs. I wonder what the least confusing way to communicate those to the user is? Any thoughts @jayeshathila? I'd be open to changing the existing output if we can think of something clearer.

Ya, I am myself aligned with that we should print the line_num where failure actually occur. Will see what can be done to print the line_num. Will update my finding here.

[jayeshathila]

@darrenburns @blueyed I have added line_number explicitly (using traceback) in case of AssertionError while creating TestResult here. Any thoughts on the approach ?

[darrenburns]

My understanding is that sys.exc_info only works in the context of except blocks?

I think you can get the traceback from the exception using exc_traceback = exception.__traceback__.

[jayeshathila]

My understanding is that sys.exc_info only works in the context of except blocks?

I think you can get the traceback from the exception using exc_traceback = exception.__traceback__.

Ah. Agree get_result being public method I shouldn't expect it to be in context of except. Will change this to use exception.__traceback

[jayeshathila]

@darrenburns, Updated with exception.__traceback__.

[darrenburns]

Looks good, thanks @jayeshathila. Will take a closer look asap!

[darrenburns]

This change has been included in Ward 0.39.0b0 - thanks again @jayeshathila :)