Pytest: Show entire repr of fixture values

[dmtucker]

pytest 3.6.3 on Debian 9.5 (though, I'm running in Docker and can repro on CentOS 7)

This example from StackOverflow captures what I'd like to do:

================================================================= FAILURES =================================================================
____________________________________________________ test_check_default_content_for_user ___________________________________________________

test_data = {'amount_of_number_of_days_options': 6, 'available_for_guest': 'True', 'fl_password': 'password', 'fl_user': '[email protected]', ...}

When a test fails/errors, I want the full fixture value to be shown (i.e. no ...).
No combination of --tb long, -v, --full-trace, or --showlocals that I've tried has worked.
Is there a way to do this?

[pytestbot]

GitMate.io thinks possibly related issues are https://github.com/pytest-dev/pytest/issues/1392 (Idea: make FixtureLookupError show prettier fixture list), https://github.com/pytest-dev/pytest/issues/833 (--fixtures only shows fixtures from first file), https://github.com/pytest-dev/pytest/issues/351 (Show repr() of exceptions passed to @parametrize), https://github.com/pytest-dev/pytest/issues/2934 (capsysbinary fixture), and https://github.com/pytest-dev/pytest/issues/3377 (Rescope a fixture).

[RonnyPfannschmidt]

i would suggest to pretty-print it yourself
this code is precisely in place to avoid massive objects destroying all sensible reading of the output (because after a certain size we have no way safely figure if it is still barely ok or not)

what could-be done is increasing the limit with verbosity however

[dmtucker]

what could-be done is increasing the limit with verbosity however

That would be greatly preferred as we have thousands of tests that would need revision otherwise.

[mgeier]

Is the threshold for shortening the repr with ... hard-coded somewhere in the PyTest code?

If yes, could this somehow be provided as option in pytest.ini or something like that?

[dmtucker]

Looks like this is the relevant code:
https://github.com/pytest-dev/pytest/blob/5903f4596a6394be4ffb534451a6af4af459fc34/src/_pytest/_code/code.py#L622-L630

py.io.saferepr is the call that does the shortening:
https://github.com/pytest-dev/py/blob/b9da2ed6178cd37d4ed6b41f9fa8234dce96973f/py/_io/saferepr.py#L53-L57

It takes a maxsize parameter; however, it only seems to allow tightening:

(Pdb) pp type(obj), len(obj)
(<class 'dict'>, 1000)
(Pdb) pp py.io.saferepr(obj)
'{0: 6009, 1: 6010, 2: 6011, 3: 6012, ...}'
(Pdb) pp py.io.saferepr(obj, maxsize=10)
'{0:......}'
(Pdb) pp py.io.saferepr(obj, maxsize=100)
'{0: 6017, 1: 6018, 2: 6019, 3: 6020, ...}'
(Pdb) pp py.io.saferepr(obj, maxsize=1000)
'{0: 6021, 1: 6022, 2: 6023, 3: 6024, ...}'
(Pdb) pp py.io.saferepr(obj, maxsize=10000)
'{0: 6025, 1: 6026, 2: 6027, 3: 6028, ...}'

[dmtucker]

I think py.io.safrepr would need to set other Repr.max* attributes:
https://github.com/pytest-dev/py/blob/b9da2ed6178cd37d4ed6b41f9fa8234dce96973f/py/_io/saferepr.py#L68-L70

[blueyed]

There's an internal "truncate_locals" option that gets used with -vv, and enables skipping of truncation with -l. Via https://github.com/pytest-dev/pytest/pull/3681.

[tucked]

I'm still seeing this issue with Pytest 4.6.6 (looks like #3681 is in 3.7.0, so should be included)... Am I understanding correctly that I should only need to pass -vv -l?

edit: Oh wow, nevermind... The locals appear _below_ the failure.