Add 'FAIL_FAST' flag to doctest

[bitdancer]

BPO	16522
Nosy	@bitdancer, @durban
Files	doctest_fail_fast.patch doctest_fail_fast_3.patch

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

Show more details

GitHub fields:

assignee = 'https://github.com/bitdancer'
closed_at = <Date 2012-11-21.20:11:08.228>
created_at = <Date 2012-11-21.13:39:39.607>
labels = ['easy', 'type-feature']
title = "Add 'FAIL_FAST' flag to doctest"
updated_at = <Date 2012-11-22.11:23:00.010>
user = 'https://github.com/bitdancer'

bugs.python.org fields:

activity = <Date 2012-11-22.11:23:00.010>
actor = 'python-dev'
assignee = 'r.david.murray'
closed = True
closed_date = <Date 2012-11-21.20:11:08.228>
closer = 'r.david.murray'
components = []
creation = <Date 2012-11-21.13:39:39.607>
creator = 'r.david.murray'
dependencies = []
files = ['28063', '28067']
hgrepos = []
issue_num = 16522
keywords = ['patch', 'easy']
message_count = 6.0
messages = ['176059', '176072', '176073', '176075', '176076', '176105']
nosy_count = 3.0
nosy_names = ['r.david.murray', 'daniel.urban', 'python-dev']
pr_nums = []
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue16522'
versions = ['Python 3.4']

[bitdancer]

When debugging using tests or doing test driven development, I find it very useful to have the test run exit immediately on the first failure. Doctest currently has a feature to suppress all output after the first failure, but not to exit on the first failure. Exiting on the first failure in doctest is even more important than in unit test for me, since a typical way to debug using doctest is to add prints to sys.stderr to the code. If the doctest run continues, other tests that follow the same code path may also dump debugging output, making it harder to find the output related specifically to the test failure.

The attached patch does the easy part: adds a FAIL_FAST flag. I don't have time right at the moment to finish the patch with docs and tests. If someone wants to work on this before I get back to it they should feel free (just post a note here that you are working on it).

[durban]

I've added some tests and documentation. English is not my first language, so the docs almost certainly need some correction.

[durban]

I'm sorry, I forgot the versionadded directive. The fixed patch is attached.

[python-dev]

New changeset 966432a0734c by R David Murray in branch 'default':
bpo-16522: Add FAIL_FAST flag to doctest.
http://hg.python.org/cpython/rev/966432a0734c

[bitdancer]

Looks great, I didn't think any changes were needed. Thanks a bunch, Daniel.

[python-dev]

New changeset e456da396ad9 by R David Murray in branch 'default':
bpo-16522: s/always 1/at most 1/.
http://hg.python.org/cpython/rev/e456da396ad9