[Python-checkins] cpython: Issue #22936: Allow showing local variables in unittest errors.

Fri Mar 6 01:46:58 CET 2015

https://hg.python.org/cpython/rev/b4a26b28f5b3
changeset: 94872:b4a26b28f5b3
user: Robert Collins <rbtcollins at hp.com>
date: Fri Mar 06 13:46:35 2015 +1300
summary:
 Issue #22936: Allow showing local variables in unittest errors.
files:
 Doc/library/unittest.rst | 25 ++++++++--
 Lib/unittest/main.py | 23 +++++++--
 Lib/unittest/result.py | 7 ++-
 Lib/unittest/runner.py | 10 +++-
 Lib/unittest/test/test_break.py | 3 +
 Lib/unittest/test/test_program.py | 26 +++++++++-
 Lib/unittest/test/test_result.py | 43 +++++++++++++++---
 Lib/unittest/test/test_runner.py | 10 +++-
 Misc/NEWS | 3 +-
 9 files changed, 118 insertions(+), 32 deletions(-)

diff --git a/Doc/library/unittest.rst b/Doc/library/unittest.rst
--- a/Doc/library/unittest.rst
+++ b/Doc/library/unittest.rst
@@ -223,9 +223,16 @@
 
 Stop the test run on the first error or failure.
 
+.. cmdoption:: --locals
+
+ Show local variables in tracebacks.
+
 .. versionadded:: 3.2
 The command-line options ``-b``, ``-c`` and ``-f`` were added.
 
+.. versionadded:: 3.5
+ The command-line option ``--locals``.
+
 The command line can also be used for test discovery, for running all of the
 tests in a project or just a subset.
 
@@ -1782,12 +1789,10 @@
 
 Set to ``True`` when the execution of tests should stop by :meth:`stop`.
 
-
 .. attribute:: testsRun
 
 The total number of tests run so far.
 
-
 .. attribute:: buffer
 
 If set to true, ``sys.stdout`` and ``sys.stderr`` will be buffered in between
@@ -1797,7 +1802,6 @@
 
 .. versionadded:: 3.2
 
-
 .. attribute:: failfast
 
 If set to true :meth:`stop` will be called on the first failure or error,
@@ -1805,6 +1809,11 @@
 
 .. versionadded:: 3.2
 
+ .. attribute:: tb_locals
+
+ If set to true then local variables will be shown in tracebacks.
+
+ .. versionadded:: 3.5
 
 .. method:: wasSuccessful()
 
@@ -1815,7 +1824,6 @@
 Returns ``False`` if there were any :attr:`unexpectedSuccesses`
 from tests marked with the :func:`expectedFailure` decorator.
 
-
 .. method:: stop()
 
 This method can be called to signal that the set of tests being run should
@@ -1947,12 +1955,14 @@
 
 
 .. class:: TextTestRunner(stream=None, descriptions=True, verbosity=1, failfast=False, \
- buffer=False, resultclass=None, warnings=None)
+ buffer=False, resultclass=None, warnings=None, *, tb_locals=False)
 
 A basic test runner implementation that outputs results to a stream. If *stream*
 is ``None``, the default, :data:`sys.stderr` is used as the output stream. This class
 has a few configurable parameters, but is essentially very simple. Graphical
- applications which run test suites should provide alternate implementations.
+ applications which run test suites should provide alternate implementations. Such
+ implementations should accept ``**kwargs`` as the interface to construct runners
+ changes when features are added to unittest.
 
 By default this runner shows :exc:`DeprecationWarning`,
 :exc:`PendingDeprecationWarning`, :exc:`ResourceWarning` and
@@ -1971,6 +1981,9 @@
 The default stream is set to :data:`sys.stderr` at instantiation time rather
 than import time.
 
+ .. versionchanged:: 3.5
+ Added the tb_locals parameter.
+
 .. method:: _makeResult()
 
 This method returns the instance of ``TestResult`` used by :meth:`run`.
diff --git a/Lib/unittest/main.py b/Lib/unittest/main.py
--- a/Lib/unittest/main.py
+++ b/Lib/unittest/main.py
@@ -58,7 +58,7 @@
 def __init__(self, module='__main__', defaultTest=None, argv=None,
 testRunner=None, testLoader=loader.defaultTestLoader,
 exit=True, verbosity=1, failfast=None, catchbreak=None,
- buffer=None, warnings=None):
+ buffer=None, warnings=None, *, tb_locals=False):
 if isinstance(module, str):
 self.module = __import__(module)
 for part in module.split('.')[1:]:
@@ -73,6 +73,7 @@
 self.catchbreak = catchbreak
 self.verbosity = verbosity
 self.buffer = buffer
+ self.tb_locals = tb_locals
 if warnings is None and not sys.warnoptions:
 # even if DeprecationWarnings are ignored by default
 # print them anyway unless other warnings settings are
@@ -159,7 +160,9 @@
 parser.add_argument('-q', '--quiet', dest='verbosity',
 action='store_const', const=0,
 help='Quiet output')
-
+ parser.add_argument('--locals', dest='tb_locals',
+ action='store_true',
+ help='Show local variables in tracebacks')
 if self.failfast is None:
 parser.add_argument('-f', '--failfast', dest='failfast',
 action='store_true',
@@ -231,10 +234,18 @@
 self.testRunner = runner.TextTestRunner
 if isinstance(self.testRunner, type):
 try:
- testRunner = self.testRunner(verbosity=self.verbosity,
- failfast=self.failfast,
- buffer=self.buffer,
- warnings=self.warnings)
+ try:
+ testRunner = self.testRunner(verbosity=self.verbosity,
+ failfast=self.failfast,
+ buffer=self.buffer,
+ warnings=self.warnings,
+ tb_locals=self.tb_locals)
+ except TypeError:
+ # didn't accept the tb_locals argument
+ testRunner = self.testRunner(verbosity=self.verbosity,
+ failfast=self.failfast,
+ buffer=self.buffer,
+ warnings=self.warnings)
 except TypeError:
 # didn't accept the verbosity, buffer or failfast arguments
 testRunner = self.testRunner()
diff --git a/Lib/unittest/result.py b/Lib/unittest/result.py
--- a/Lib/unittest/result.py
+++ b/Lib/unittest/result.py
@@ -45,6 +45,7 @@
 self.unexpectedSuccesses = []
 self.shouldStop = False
 self.buffer = False
+ self.tb_locals = False
 self._stdout_buffer = None
 self._stderr_buffer = None
 self._original_stdout = sys.stdout
@@ -179,9 +180,11 @@
 if exctype is test.failureException:
 # Skip assert*() traceback levels
 length = self._count_relevant_tb_levels(tb)
- msgLines = traceback.format_exception(exctype, value, tb, length)
 else:
- msgLines = traceback.format_exception(exctype, value, tb)
+ length = None
+ tb_e = traceback.TracebackException(
+ exctype, value, tb, limit=length, capture_locals=self.tb_locals)
+ msgLines = list(tb_e.format())
 
 if self.buffer:
 output = sys.stdout.getvalue()
diff --git a/Lib/unittest/runner.py b/Lib/unittest/runner.py
--- a/Lib/unittest/runner.py
+++ b/Lib/unittest/runner.py
@@ -126,7 +126,13 @@
 resultclass = TextTestResult
 
 def __init__(self, stream=None, descriptions=True, verbosity=1,
- failfast=False, buffer=False, resultclass=None, warnings=None):
+ failfast=False, buffer=False, resultclass=None, warnings=None,
+ *, tb_locals=False):
+ """Construct a TextTestRunner.
+
+ Subclasses should accept **kwargs to ensure compatibility as the
+ interface changes.
+ """
 if stream is None:
 stream = sys.stderr
 self.stream = _WritelnDecorator(stream)
@@ -134,6 +140,7 @@
 self.verbosity = verbosity
 self.failfast = failfast
 self.buffer = buffer
+ self.tb_locals = tb_locals
 self.warnings = warnings
 if resultclass is not None:
 self.resultclass = resultclass
@@ -147,6 +154,7 @@
 registerResult(result)
 result.failfast = self.failfast
 result.buffer = self.buffer
+ result.tb_locals = self.tb_locals
 with warnings.catch_warnings():
 if self.warnings:
 # if self.warnings is set, use it to filter all the warnings
diff --git a/Lib/unittest/test/test_break.py b/Lib/unittest/test/test_break.py
--- a/Lib/unittest/test/test_break.py
+++ b/Lib/unittest/test/test_break.py
@@ -211,6 +211,7 @@
 self.verbosity = verbosity
 self.failfast = failfast
 self.catchbreak = catchbreak
+ self.tb_locals = False
 self.testRunner = FakeRunner
 self.test = test
 self.result = None
@@ -221,6 +222,7 @@
 self.assertEqual(FakeRunner.initArgs, [((), {'buffer': None,
 'verbosity': verbosity,
 'failfast': failfast,
+ 'tb_locals': False,
 'warnings': None})])
 self.assertEqual(FakeRunner.runArgs, [test])
 self.assertEqual(p.result, result)
@@ -235,6 +237,7 @@
 self.assertEqual(FakeRunner.initArgs, [((), {'buffer': None,
 'verbosity': verbosity,
 'failfast': failfast,
+ 'tb_locals': False,
 'warnings': None})])
 self.assertEqual(FakeRunner.runArgs, [test])
 self.assertEqual(p.result, result)
diff --git a/Lib/unittest/test/test_program.py b/Lib/unittest/test/test_program.py
--- a/Lib/unittest/test/test_program.py
+++ b/Lib/unittest/test/test_program.py
@@ -134,6 +134,7 @@
 result = None
 verbosity = 1
 defaultTest = None
+ tb_locals = False
 testRunner = None
 testLoader = unittest.defaultTestLoader
 module = '__main__'
@@ -147,18 +148,19 @@
 class FakeRunner(object):
 initArgs = None
 test = None
- raiseError = False
+ raiseError = 0
 
 def __init__(self, **kwargs):
 FakeRunner.initArgs = kwargs
 if FakeRunner.raiseError:
- FakeRunner.raiseError = False
+ FakeRunner.raiseError -= 1
 raise TypeError
 
 def run(self, test):
 FakeRunner.test = test
 return RESULT
 
+
 class TestCommandLineArgs(unittest.TestCase):
 
 def setUp(self):
@@ -166,7 +168,7 @@
 self.program.createTests = lambda: None
 FakeRunner.initArgs = None
 FakeRunner.test = None
- FakeRunner.raiseError = False
+ FakeRunner.raiseError = 0
 
 def testVerbosity(self):
 program = self.program
@@ -256,6 +258,7 @@
 self.assertEqual(FakeRunner.initArgs, {'verbosity': 'verbosity',
 'failfast': 'failfast',
 'buffer': 'buffer',
+ 'tb_locals': False,
 'warnings': 'warnings'})
 self.assertEqual(FakeRunner.test, 'test')
 self.assertIs(program.result, RESULT)
@@ -274,10 +277,25 @@
 self.assertEqual(FakeRunner.test, 'test')
 self.assertIs(program.result, RESULT)
 
+ def test_locals(self):
+ program = self.program
+
+ program.testRunner = FakeRunner
+ program.parseArgs([None, '--locals'])
+ self.assertEqual(True, program.tb_locals)
+ program.runTests()
+ self.assertEqual(FakeRunner.initArgs, {'buffer': False,
+ 'failfast': False,
+ 'tb_locals': True,
+ 'verbosity': 1,
+ 'warnings': None})
+
 def testRunTestsOldRunnerClass(self):
 program = self.program
 
- FakeRunner.raiseError = True
+ # Two TypeErrors are needed to fall all the way back to old-style
+ # runners - one to fail tb_locals, one to fail buffer etc.
+ FakeRunner.raiseError = 2
 program.testRunner = FakeRunner
 program.verbosity = 'verbosity'
 program.failfast = 'failfast'
diff --git a/Lib/unittest/test/test_result.py b/Lib/unittest/test/test_result.py
--- a/Lib/unittest/test/test_result.py
+++ b/Lib/unittest/test/test_result.py
@@ -8,6 +8,20 @@
 import unittest
 
 
+class MockTraceback(object):
+ class TracebackException:
+ def __init__(self, *args, **kwargs):
+ self.capture_locals = kwargs.get('capture_locals', False)
+ def format(self):
+ result = ['A traceback']
+ if self.capture_locals:
+ result.append('locals')
+ return result
+
+def restore_traceback():
+ unittest.result.traceback = traceback
+
+
 class Test_TestResult(unittest.TestCase):
 # Note: there are not separate tests for TestResult.wasSuccessful(),
 # TestResult.errors, TestResult.failures, TestResult.testsRun or
@@ -227,6 +241,25 @@
 self.assertIs(test_case, test)
 self.assertIsInstance(formatted_exc, str)
 
+ def test_addError_locals(self):
+ class Foo(unittest.TestCase):
+ def test_1(self):
+ 1/0
+
+ test = Foo('test_1')
+ result = unittest.TestResult()
+ result.tb_locals = True
+
+ unittest.result.traceback = MockTraceback
+ self.addCleanup(restore_traceback)
+ result.startTestRun()
+ test.run(result)
+ result.stopTestRun()
+
+ self.assertEqual(len(result.errors), 1)
+ test_case, formatted_exc = result.errors[0]
+ self.assertEqual('A tracebacklocals', formatted_exc)
+
 def test_addSubTest(self):
 class Foo(unittest.TestCase):
 def test_1(self):
@@ -398,6 +431,7 @@
 self.testsRun = 0
 self.shouldStop = False
 self.buffer = False
+ self.tb_locals = False
 
 classDict['__init__'] = __init__
 OldResult = type('OldResult', (object,), classDict)
@@ -454,15 +488,6 @@
 runner.run(Test('testFoo'))
 
 
-class MockTraceback(object):
- @staticmethod
- def format_exception(*_):
- return ['A traceback']
-
-def restore_traceback():
- unittest.result.traceback = traceback
-
-
 class TestOutputBuffering(unittest.TestCase):
 
 def setUp(self):
diff --git a/Lib/unittest/test/test_runner.py b/Lib/unittest/test/test_runner.py
--- a/Lib/unittest/test/test_runner.py
+++ b/Lib/unittest/test/test_runner.py
@@ -158,7 +158,7 @@
 self.assertEqual(runner.warnings, None)
 self.assertTrue(runner.descriptions)
 self.assertEqual(runner.resultclass, unittest.TextTestResult)
-
+ self.assertFalse(runner.tb_locals)
 
 def test_multiple_inheritance(self):
 class AResult(unittest.TestResult):
@@ -172,14 +172,13 @@
 # on arguments in its __init__ super call
 ATextResult(None, None, 1)
 
-
 def testBufferAndFailfast(self):
 class Test(unittest.TestCase):
 def testFoo(self):
 pass
 result = unittest.TestResult()
 runner = unittest.TextTestRunner(stream=io.StringIO(), failfast=True,
- buffer=True)
+ buffer=True)
 # Use our result object
 runner._makeResult = lambda: result
 runner.run(Test('testFoo'))
@@ -187,6 +186,11 @@
 self.assertTrue(result.failfast)
 self.assertTrue(result.buffer)
 
+ def test_locals(self):
+ runner = unittest.TextTestRunner(stream=io.StringIO(), tb_locals=True)
+ result = runner.run(unittest.TestSuite())
+ self.assertEqual(True, result.tb_locals)
+
 def testRunnerRegistersResult(self):
 class Test(unittest.TestCase):
 def testFoo(self):
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -39,7 +39,8 @@
 - Issue #21619: Popen objects no longer leave a zombie after exit in the with
 statement if the pipe was broken. Patch by Martin Panter.
 
-- Issue #22936: Make it possible to show local variables in tracebacks.
+- Issue #22936: Make it possible to show local variables in tracebacks for
+ both the traceback module and unittest.
 
 - Issue #15955: Add an option to limit the output size in bz2.decompress().
 Patch by Nikolaus Rath.
-- 
Repository URL: https://hg.python.org/cpython
