[New-bugs-announce] [issue17217] Fix test discovery for test_format.py on Windows

[Zachary Ware]

New submission from Zachary Ware:

test_format is an interesting case in the ongoing test discovery conversion.  It already uses unittest.main(), but still has test_main(), and discovery seems to work fine on Linux.  On Windows, however, test_format and test_non_ascii both fail with a UnicodeEncodeError.  Running under regrtest, this doesn't happen because of regrtest's replace_stdout() function.  Thus, running python -m test.test_format with the following patch works:

diff -r 168efd87e051 Lib/test/test_format.py
--- a/Lib/test/test_format.py   Fri Feb 15 23:38:23 2013 +0200
+++ b/Lib/test/test_format.py   Sat Feb 16 15:14:52 2013 -0600
@@ -325,9 +325,7 @@
         self.assertIs("{0:5s}".format(text), text)


-def test_main():
-    support.run_unittest(FormatTest)
-
-
 if __name__ == "__main__":
+    from test.regrtest import replace_stdout
+    replace_stdout()
     unittest.main()


Doing the same in a setUpModule function would work for both running the module and for a unittest discover command, but it would also cause replace_stdout() to be called twice when running under regrtest, which I don't think would be especially good.

The attached patch is one possible solution that I've come up with.  It moves replace_stdout from regrtest to support, and adds a "running_under_regrtest" flag to support that regrtest sets to True.  test_format then checks support.running_under_regrtest in setUpModule to determine whether to run support.replace_stdout.

----------
components: Tests
files: test_format_discovery.diff
keywords: patch
messages: 182248
nosy: brett.cannon, ezio.melotti, zach.ware
priority: normal
severity: normal
status: open
title: Fix test discovery for test_format.py on Windows
type: behavior
versions: Python 3.3, Python 3.4
Added file: http://bugs.python.org/file29093/test_format_discovery.diff

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue17217>
_______________________________________