Move inlineCallbacks test from twisted.test.test_failure to somewhere better (test_defer?)

[Itamar Turner-Trauring]

Importing twisted.internet in a twisted.python test module is not ideal. The tests involving inlineCallbacks in test_failure should probably be moved somewhere else, e.g. the relevant test_defer.

[Thijs Triemstra]

(In [37306]) Branching to 'move-inlinecbtest-5955'

[Thijs Triemstra]

(In [37307]) move test, add news file. refs #5955

[Thijs Triemstra]

Forced a ​build.

1. moved test to test_defer
2. the test uses getDivisionFailure from test.test_failure. it's being imported now but it seems better to expose this elsewhere (or maybe duplicate)?
3. moved the py3 todo statement and added notes about #6008 being a unittest todo support ticket, found it confusing with the #5949 right above it..

Up for review.

[Tom Prince]

1. Rather than importing getDivisionFailure, you can probably just duplicate it as a local function.
2. The test should use failureResultOf to extract the failure from the deferred.
3. The assertion could be made much stronger (and match the docstring) if the entire extracted traceback was compared to the original traceback.

Please resubmit for review after addressing the above points.

[Thijs Triemstra]

Replying to tom.prince:

1. Rather than importing getDivisionFailure, you can probably just duplicate it as a local function.

Done.

2. The test should use failureResultOf to extract the failure from the deferred.

Fixed.

3. The assertion could be made much stronger (and match the docstring) if the entire extracted traceback was compared to the original traceback.

The assertion has been expanded, and while it's an improvement, i couldn't figure out how to get the original traceback to compare to, but it also feels this is more out of scope for this ticket.

Forced a new ​build.

[Tom Prince]

This looks good. Please merge.

3. The assertion could be made much stronger (and match the docstring) if the entire extracted traceback was compared to the original traceback.

The assertion has been expanded, and while it's an improvement, i couldn't figure out how to get the original traceback to compare to, but it also feels this is more out of scope for this ticket.

I like the new assertions. It would be nice if there was some helpers for doing this, so that the reader doesn't need know how tracebacks look.

[Thijs Triemstra]

(In [37859]) Merge move-inlinecbtest-5955: Move test_inlineCallbacksTracebacks from test_failure to test_defer.

Author: thijs Reviewer: tom.prince Fixes: #5955