From 46361bb84332800bc3632688e6ef3b4dd4a48723 Mon Sep 17 00:00:00 2001 From: Michael Blahay Date: Thu, 4 May 2023 18:37:17 -0400 Subject: [PATCH] gh-68968: Correcting message display issue with assertEqual (#103937) --- Lib/test/test_unittest/test_assertions.py | 6 +- Lib/test/test_unittest/test_case.py | 60 +++++++++++++++++++ Lib/unittest/case.py | 31 +++++++--- ...3-04-27-18-46-31.gh-issue-68968.E3tnhy.rst | 1 + 4 files changed, 87 insertions(+), 11 deletions(-) create mode 100644 Misc/NEWS.d/next/Library/2023-04-27-18-46-31.gh-issue-68968.E3tnhy.rst diff --git a/Lib/test/test_unittest/test_assertions.py b/Lib/test/test_unittest/test_assertions.py index 6557104b81fc0f..5c1a28ecda5b49 100644 --- a/Lib/test/test_unittest/test_assertions.py +++ b/Lib/test/test_unittest/test_assertions.py @@ -273,9 +273,9 @@ def testAssertDictEqual(self): def testAssertMultiLineEqual(self): self.assertMessages('assertMultiLineEqual', ("", "foo"), - [r"\+ foo$", "^oops$", - r"\+ foo$", - r"\+ foo : oops$"]) + [r"\+ foo\n$", "^oops$", + r"\+ foo\n$", + r"\+ foo\n : oops$"]) def testAssertLess(self): self.assertMessages('assertLess', (2, 1), diff --git a/Lib/test/test_unittest/test_case.py b/Lib/test/test_unittest/test_case.py index dd5ff6d553e61d..ed5eb5609a5dd1 100644 --- a/Lib/test/test_unittest/test_case.py +++ b/Lib/test/test_unittest/test_case.py @@ -1149,6 +1149,66 @@ def testAssertEqualSingleLine(self): error = str(e).split('\n', 1)[1] self.assertEqual(sample_text_error, error) + def testAssertEqualwithEmptyString(self): + '''Verify when there is an empty string involved, the diff output + does not treat the empty string as a single empty line. It should + instead be handled as a non-line. + ''' + sample_text = '' + revised_sample_text = 'unladen swallows fly quickly' + sample_text_error = '''\ ++ unladen swallows fly quickly +''' + try: + self.assertEqual(sample_text, revised_sample_text) + except self.failureException as e: + # need to remove the first line of the error message + error = str(e).split('\n', 1)[1] + self.assertEqual(sample_text_error, error) + + def testAssertEqualMultipleLinesMissingNewlineTerminator(self): + '''Verifying format of diff output from assertEqual involving strings + with multiple lines, but missing the terminating newline on both. + ''' + sample_text = 'laden swallows\nfly sloely' + revised_sample_text = 'laden swallows\nfly slowly' + sample_text_error = '''\ + laden swallows +- fly sloely +? ^ ++ fly slowly +? ^ +''' + try: + self.assertEqual(sample_text, revised_sample_text) + except self.failureException as e: + # need to remove the first line of the error message + error = str(e).split('\n', 1)[1] + self.assertEqual(sample_text_error, error) + + def testAssertEqualMultipleLinesMismatchedNewlinesTerminators(self): + '''Verifying format of diff output from assertEqual involving strings + with multiple lines and mismatched newlines. The output should + include a - on it's own line to indicate the newline difference + between the two strings + ''' + sample_text = 'laden swallows\nfly sloely\n' + revised_sample_text = 'laden swallows\nfly slowly' + sample_text_error = '''\ + laden swallows +- fly sloely +? ^ ++ fly slowly +? ^ +-\x20 +''' + try: + self.assertEqual(sample_text, revised_sample_text) + except self.failureException as e: + # need to remove the first line of the error message + error = str(e).split('\n', 1)[1] + self.assertEqual(sample_text_error, error) + def testEqualityBytesWarning(self): if sys.flags.bytes_warning: def bytes_warning(): diff --git a/Lib/unittest/case.py b/Lib/unittest/case.py index 018f22e7ce0c73..001b640dc43ad6 100644 --- a/Lib/unittest/case.py +++ b/Lib/unittest/case.py @@ -1217,19 +1217,34 @@ def assertCountEqual(self, first, second, msg=None): def assertMultiLineEqual(self, first, second, msg=None): """Assert that two multi-line strings are equal.""" - self.assertIsInstance(first, str, 'First argument is not a string') - self.assertIsInstance(second, str, 'Second argument is not a string') + self.assertIsInstance(first, str, "First argument is not a string") + self.assertIsInstance(second, str, "Second argument is not a string") if first != second: - # don't use difflib if the strings are too long + # Don't use difflib if the strings are too long if (len(first) > self._diffThreshold or len(second) > self._diffThreshold): self._baseAssertEqual(first, second, msg) - firstlines = first.splitlines(keepends=True) - secondlines = second.splitlines(keepends=True) - if len(firstlines) == 1 and first.strip('\r\n') == first: - firstlines = [first + '\n'] - secondlines = [second + '\n'] + + # Append \n to both strings if either is missing the \n. + # This allows the final ndiff to show the \n difference. The + # exception here is if the string is empty, in which case no + # \n should be added + first_presplit = first + second_presplit = second + if first and second: + if first[-1] != '\n' or second[-1] != '\n': + first_presplit += '\n' + second_presplit += '\n' + elif second and second[-1] != '\n': + second_presplit += '\n' + elif first and first[-1] != '\n': + first_presplit += '\n' + + firstlines = first_presplit.splitlines(keepends=True) + secondlines = second_presplit.splitlines(keepends=True) + + # Generate the message and diff, then raise the exception standardMsg = '%s != %s' % _common_shorten_repr(first, second) diff = '\n' + ''.join(difflib.ndiff(firstlines, secondlines)) standardMsg = self._truncateMessage(standardMsg, diff) diff --git a/Misc/NEWS.d/next/Library/2023-04-27-18-46-31.gh-issue-68968.E3tnhy.rst b/Misc/NEWS.d/next/Library/2023-04-27-18-46-31.gh-issue-68968.E3tnhy.rst new file mode 100644 index 00000000000000..bf29b64793b933 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2023-04-27-18-46-31.gh-issue-68968.E3tnhy.rst @@ -0,0 +1 @@ +Fixed garbled output of :meth:`~unittest.TestCase.assertEqual` when an input lacks final newline.