Added NDIFF_DIFF option.
diff --git a/Doc/lib/libdoctest.tex b/Doc/lib/libdoctest.tex
index c0bdf6d..0741aa0 100644
--- a/Doc/lib/libdoctest.tex
+++ b/Doc/lib/libdoctest.tex
@@ -356,6 +356,15 @@
actual outputs will be displayed using a context diff.
\end{datadesc}
+\begin{datadesc}{NDIFF_DIFF}
+ When specified, differences are computed by \code{difflib.Differ},
+ using the same algorithm as the popular \file{ndiff.py} utility.
+ This is the only method that marks differences within lines as
+ well as across lines. For example, if a line of expected output
+ contains digit \code{1} where actual output contains letter \code{l},
+ a line is inserted with a caret marking the mismatching column
+ positions.
+\end{datadesc}
A "doctest directive" is a trailing Python comment on a line of a doctest
example:
@@ -414,7 +423,8 @@
\versionchanged[Constants \constant{DONT_ACCEPT_BLANKLINE},
\constant{NORMALIZE_WHITESPACE}, \constant{ELLIPSIS},
- \constant{UNIFIED_DIFF}, and \constant{CONTEXT_DIFF}
+ \constant{UNIFIED_DIFF}, \constant{CONTEXT_DIFF}, and
+ \constant{NDIFF_DIFF}
were added; by default \code{<BLANKLINE>} in expected output
matches an empty line in actual output; and doctest directives
were added]{2.4}
diff --git a/Lib/doctest.py b/Lib/doctest.py
index 74714c5..0cafac6 100644
--- a/Lib/doctest.py
+++ b/Lib/doctest.py
@@ -178,6 +178,7 @@
'ELLIPSIS',
'UNIFIED_DIFF',
'CONTEXT_DIFF',
+ 'NDIFF_DIFF',
# 1. Utility Functions
'is_private',
# 2. Example & DocTest
@@ -253,6 +254,7 @@
ELLIPSIS = register_optionflag('ELLIPSIS')
UNIFIED_DIFF = register_optionflag('UNIFIED_DIFF')
CONTEXT_DIFF = register_optionflag('CONTEXT_DIFF')
+NDIFF_DIFF = register_optionflag('NDIFF_DIFF')
# Special string markers for use in `want` strings:
BLANKLINE_MARKER = '<BLANKLINE>'
@@ -1569,6 +1571,24 @@
# We didn't find any match; return false.
return False
+ # Should we do a fancy diff?
+ def _do_a_fancy_diff(self, want, got, optionflags):
+ # Not unless they asked for a fancy diff.
+ if not optionflags & (UNIFIED_DIFF |
+ CONTEXT_DIFF |
+ NDIFF_DIFF):
+ return False
+ # If expected output uses ellipsis, a meaningful fancy diff is
+ # too hard.
+ if optionflags & ELLIPSIS and ELLIPSIS_MARKER in want:
+ return False
+ # ndiff does intraline difference marking, so can be useful even
+ # for 1-line inputs.
+ if optionflags & NDIFF_DIFF:
+ return True
+ # The other diff types need at least a few lines to be helpful.
+ return want.count('\n') > 2 and got.count('\n') > 2
+
def output_difference(self, want, got, optionflags):
"""
Return a string describing the differences between the
@@ -1586,9 +1606,7 @@
# Check if we should use diff. Don't use diff if the actual
# or expected outputs are too short, or if the expected output
# contains an ellipsis marker.
- if ((optionflags & (UNIFIED_DIFF | CONTEXT_DIFF)) and
- want.count('\n') > 2 and got.count('\n') > 2 and
- not (optionflags & ELLIPSIS and '...' in want)):
+ if self._do_a_fancy_diff(want, got, optionflags):
# Split want & got into lines.
want_lines = [l+'\n' for l in want.split('\n')]
got_lines = [l+'\n' for l in got.split('\n')]
@@ -1596,16 +1614,20 @@
if optionflags & UNIFIED_DIFF:
diff = difflib.unified_diff(want_lines, got_lines, n=2,
fromfile='Expected', tofile='Got')
- kind = 'unified'
+ kind = 'unified diff'
elif optionflags & CONTEXT_DIFF:
diff = difflib.context_diff(want_lines, got_lines, n=2,
fromfile='Expected', tofile='Got')
- kind = 'context'
+ kind = 'context diff'
+ elif optionflags & NDIFF_DIFF:
+ engine = difflib.Differ(charjunk=difflib.IS_CHARACTER_JUNK)
+ diff = list(engine.compare(want_lines, got_lines))
+ 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 _tag_msg("Differences (" + kind + " diff)",
+ return _tag_msg("Differences (" + kind + ")",
''.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 6d9d745..969ee17 100644
--- a/Lib/test/test_doctest.py
+++ b/Lib/test/test_doctest.py
@@ -283,7 +283,7 @@
'test_doctest.py'
>>> test.test_doctest.__file__ = old
-
+
>>> e = tests[0].examples[0]
>>> (e.source, e.want, e.lineno)
@@ -931,7 +931,33 @@
g
<BLANKLINE>
(1, 1)
-"""
+
+
+The NDIFF_DIFF flag causes failures to use the difflib.Differ algorithm
+used by the popular ndiff.py utility. This does intraline difference
+marking, as well as interline differences.
+
+ >>> def f(x):
+ ... r'''
+ ... >>> print "a b c d e f g h i j k l m"
+ ... a b c d e f g h i j k 1 m
+ ... '''
+ >>> test = doctest.DocTestFinder().find(f)[0]
+ >>> flags = doctest.NDIFF_DIFF
+ >>> doctest.DocTestRunner(verbose=False, optionflags=flags).run(test)
+ **********************************************************************
+ Line 2, in f
+ Failed example:
+ print "a b c d e f g h i j k l m"
+ Differences (ndiff with -expected +actual):
+ - a b c d e f g h i j k 1 m
+ ? ^
+ + a b c d e f g h i j k l m
+ ? + ++ ^
+ <BLANKLINE>
+ (1, 1)
+ """
+
def option_directives(): r"""
Tests of `DocTestRunner`'s option directive mechanism.
@@ -1468,7 +1494,7 @@
def test_trailing_space_in_test():
"""
Trailing spaces in expcted output are significant:
-
+
>>> x, y = 'foo', ''
>>> print x, y
foo \n