unittest -h shows a flag -s but it doesn't work

[FarisChugthai]

BPO	41253
Nosy	@ericvsmith, @serhiy-storchaka, @tirkarthi

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

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GitHub fields:

assignee = None
closed_at = <Date 2020-07-10.21:13:26.680>
created_at = <Date 2020-07-09.04:37:30.659>
labels = ['3.8', 'type-bug', 'tests', 'invalid']
title = "unittest -h shows a flag -s but it doesn't work"
updated_at = <Date 2020-07-10.21:13:26.677>
user = 'https://bugs.python.org/FarisChugthai'

bugs.python.org fields:

activity = <Date 2020-07-10.21:13:26.677>
actor = 'eric.smith'
assignee = 'none'
closed = True
closed_date = <Date 2020-07-10.21:13:26.680>
closer = 'eric.smith'
components = ['Tests']
creation = <Date 2020-07-09.04:37:30.659>
creator = 'Faris Chugthai'
dependencies = []
files = []
hgrepos = []
issue_num = 41253
keywords = []
message_count = 4.0
messages = ['373372', '373373', '373376', '373484']
nosy_count = 4.0
nosy_names = ['eric.smith', 'serhiy.storchaka', 'xtreak', 'Faris Chugthai']
pr_nums = []
priority = 'normal'
resolution = 'not a bug'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue41253'
versions = ['Python 3.8']

[FarisChugthai]

I'm not 100% sure what's happening here but running:

python -m unittest -h

shows a flag -s as does

python -m unittest discover -h.

When run as:

python -m unittest discover -s test

the command runs correctly but when run as

python -m unittest -s test

the command fails.

$ python -m unittest -s test  
                      
usage: python -m unittest [-h] [-v] [-q] [--locals] [-f]                                [-c] [-b] [-k TESTNAMEPATTERNS]                               [tests [tests ...]

       
python -m unittest: error: unrecognized arguments: -s

Which I believe to be a bug as the help generated by the discover subcommand indicates that the flag -s should be recognized.

[serhiy-storchaka]

Where do you see option -s?

[tirkarthi]

The -s option shown in python3 -m unittest -h is grouped under help for discover. Options for a discover command don't necessarily apply to the unittest command itself.

$ python3 -m unittest -h
usage: python3 -m unittest [-h] [-v] [-q] [--locals] [-f] [-c] [-b]
                           [-k TESTNAMEPATTERNS]
                           [tests [tests ...]]

positional arguments:
tests a list of any number of test modules, classes and test
methods.

optional arguments:
-h, --help show this help message and exit
-v, --verbose Verbose output
-q, --quiet Quiet output
--locals Show local variables in tracebacks
-f, --failfast Stop on first fail or error
-c, --catch Catch Ctrl-C and display results so far
-b, --buffer Buffer stdout and stderr during tests
-k TESTNAMEPATTERNS Only run tests which match the given substring

Examples:
python3 -m unittest test_module - run tests from test_module
python3 -m unittest module.TestClass - run tests from module.TestClass
python3 -m unittest module.Class.test_method - run specified test method
python3 -m unittest path/to/test_file.py - run tests from test_file.py

usage: python3 -m unittest discover [-h] [-v] [-q] [--locals] [-f] [-c] [-b]
[-k TESTNAMEPATTERNS] [-s START]
[-p PATTERN] [-t TOP]

optional arguments:
-h, --help show this help message and exit
-v, --verbose Verbose output
-q, --quiet Quiet output
--locals Show local variables in tracebacks
-f, --failfast Stop on first fail or error
-c, --catch Catch Ctrl-C and display results so far
-b, --buffer Buffer stdout and stderr during tests
-k TESTNAMEPATTERNS Only run tests which match the given substring
-s START, --start-directory START
Directory to start discovery ('.' default)
-p PATTERN, --pattern PATTERN
Pattern to match tests ('test*.py' default)
-t TOP, --top-level-directory TOP
Top level directory of project (defaults to start
directory)

For test discovery all test modules must be importable from the top level
directory of the project.

[ericvsmith]

This appears to just be a misunderstanding: -s is a flag to "unittest discover", not to "unittest" itself. I think this is clear from the help text, so I'm closing this.

If I'm incorrect, let me know.