[Python-checkins] [2.7] bpo-24746: Avoid stripping trailing whitespace in doctest fancy diff (#11482)

Wed Jan 9 14:03:12 EST 2019

https://github.com/python/cpython/commit/02e33d9567aa4bd612f9f08053acbfd5e68480d0
commit: 02e33d9567aa4bd612f9f08053acbfd5e68480d0
branch: 2.7
author: Sanyam Khurana <8039608+CuriousLearner at users.noreply.github.com>
committer: Senthil Kumaran <skumaran at gatech.edu>
date: 2019年01月09日T11:03:03-08:00
summary:
[2.7] bpo-24746: Avoid stripping trailing whitespace in doctest fancy diff (#11482)
* bpo-24746: Avoid stripping trailing whitespace in doctest fancy diff
* [2.7] bpo-24746: Avoid stripping trailing whitespace in doctest fancy diff (GH-10639).
(cherry picked from commit cbb16459934eaf29c7c7d362939cd05550b2f21f)
Co-authored-by: Sanyam Khurana <8039608+CuriousLearner at users.noreply.github.com>
files:
A Misc/NEWS.d/next/Library/2018-11-22-15-22-56.bpo-24746.eSLKBE.rst
M Lib/doctest.py
M Lib/test/test_doctest.py

diff --git a/Lib/doctest.py b/Lib/doctest.py
index fedf67011d92..1d822b576bb3 100644
--- a/Lib/doctest.py
+++ b/Lib/doctest.py
@@ -1651,8 +1651,6 @@ def output_difference(self, example, got, optionflags):
 kind = 'ndiff with -expected +actual'
 else:
 assert 0, 'Bad diff option'
- # Remove trailing whitespace on diff output.
- diff = [line.rstrip() + '\n' for line in diff]
 return 'Differences (%s):\n' % kind + _indent(''.join(diff))
 
 # If we're not using diff, then simply list the expected
diff --git a/Lib/test/test_doctest.py b/Lib/test/test_doctest.py
index 354c33baa988..88f4b6127938 100644
--- a/Lib/test/test_doctest.py
+++ b/Lib/test/test_doctest.py
@@ -2355,7 +2355,12 @@ def test_unittest_reportflags():
 Then the default eporting options are ignored:
 
 >>> result = suite.run(unittest.TestResult())
- >>> print result.failures[0][1] # doctest: +ELLIPSIS
+ """
+ """
+ *NOTE*: These doctest are intentionally not placed in raw string to depict
+ the trailing whitespace using `\x20` in the diff below.
+
+ >>> print(result.failures[0][1]) # doctest: +ELLIPSIS
 Traceback ...
 Failed example:
 favorite_color
@@ -2368,7 +2373,7 @@ def test_unittest_reportflags():
 Differences (ndiff with -expected +actual):
 a
 - <BLANKLINE>
- +
+ +\x20
 b
 <BLANKLINE>
 <BLANKLINE>
@@ -2717,6 +2722,47 @@ def old_test4(): """
 TestResults(failed=0, attempted=4)
 """
 
+def test_no_trailing_whitespace_stripping():
+ r"""
+ The fancy reports had a bug for a long time where any trailing whitespace on
+ the reported diff lines was stripped, making it impossible to see the
+ differences in line reported as different that differed only in the amount of
+ trailing whitespace. The whitespace still isn't particularly visible unless
+ you use NDIFF, but at least it is now there to be found.
+
+ *NOTE*: This snippet was intentionally put inside a raw string to get rid of
+ leading whitespace error in executing the example below
+
+ >>> def f(x):
+ ... r'''
+ ... >>> print('\n'.join(['a ', 'b']))
+ ... a
+ ... b
+ ... '''
+ """
+ """
+ *NOTE*: These doctest are not placed in raw string to depict the trailing whitespace
+ using `\x20`
+
+ >>> test = doctest.DocTestFinder().find(f)[0]
+ >>> flags = doctest.REPORT_NDIFF
+ >>> doctest.DocTestRunner(verbose=False, optionflags=flags).run(test)
+ ... # doctest: +ELLIPSIS
+ **********************************************************************
+ File ..., line 3, in f
+ Failed example:
+ print('\n'.join(['a ', 'b']))
+ Differences (ndiff with -expected +actual):
+ - a
+ + a
+ b
+ TestResults(failed=1, attempted=1)
+
+ *NOTE*: `\x20` is for checking the trailing whitespace on the +a line above.
+ We cannot use actual spaces there, as a commit hook prevents from committing
+ patches that contain trailing whitespace. More info on Issue 24746.
+ """
+
 ######################################################################
 ## Main
 ######################################################################
diff --git a/Misc/NEWS.d/next/Library/2018-11-22-15-22-56.bpo-24746.eSLKBE.rst b/Misc/NEWS.d/next/Library/2018-11-22-15-22-56.bpo-24746.eSLKBE.rst
new file mode 100644
index 000000000000..c592516d1466
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2018-11-22-15-22-56.bpo-24746.eSLKBE.rst
@@ -0,0 +1,2 @@
+Avoid stripping trailing whitespace in doctest fancy diff. Orignial patch by
+R. David Murray & Jairo Trad. Enhanced by Sanyam Khurana.
