"""Test cases for traceback module"""
from _testcapi import traceback_print
from StringIO import StringIO
import sys
import unittest
from imp import reload
from test.test_support import run_unittest, is_jython, Error
import traceback
class TracebackCases(unittest.TestCase):
# For now, a very minimal set of tests. I want to be sure that
# formatting of SyntaxErrors works based on changes for 2.1.
def get_exception_format(self, func, exc):
try:
func()
except exc, value:
return traceback.format_exception_only(exc, value)
else:
raise ValueError, "call did not raise exception"
def syntax_error_with_caret(self):
compile("def fact(x):\n\treturn x!\n", "?", "exec")
def syntax_error_with_caret_2(self):
compile("1 +\n", "?", "exec")
def syntax_error_without_caret(self):
# XXX why doesn't compile raise the same traceback?
import test.badsyntax_nocaret
def syntax_error_bad_indentation(self):
compile("def spam():\n print 1\n print 2", "?", "exec")
def test_caret(self):
err = self.get_exception_format(self.syntax_error_with_caret,
SyntaxError)
self.assertTrue(len(err) == 4)
self.assertTrue(err[1].strip() == "return x!")
self.assertIn("^", err[2]) # third line has caret
self.assertTrue(err[1].find("!") == err[2].find("^")) # in the right place
err = self.get_exception_format(self.syntax_error_with_caret_2,
SyntaxError)
self.assertIn("^", err[2]) # third line has caret
self.assertTrue(err[2].count('\n') == 1) # and no additional newline
self.assertTrue(err[1].find("+") == err[2].find("^")) # in the right place
def test_nocaret(self):
if is_jython:
# jython adds a caret in this case (why shouldn't it?)
return
err = self.get_exception_format(self.syntax_error_without_caret,
SyntaxError)
self.assertTrue(len(err) == 3)
self.assertTrue(err[1].strip() == "[x for x in x] = x")
def test_bad_indentation(self):
err = self.get_exception_format(self.syntax_error_bad_indentation,
IndentationError)
self.assertTrue(len(err) == 4)
self.assertTrue(err[1].strip() == "print 2")
self.assertIn("^", err[2])
self.assertTrue(err[1].find("2") == err[2].find("^"))
def test_bug737473(self):
import os, tempfile, time
savedpath = sys.path[:]
testdir = tempfile.mkdtemp()
try:
sys.path.insert(0, testdir)
testfile = os.path.join(testdir, 'test_bug737473.py')
print >> open(testfile, 'w'), """
def test():
raise ValueError"""
if 'test_bug737473' in sys.modules:
del sys.modules['test_bug737473']
import test_bug737473
try:
test_bug737473.test()
except ValueError:
# this loads source code to linecache
traceback.extract_tb(sys.exc_traceback)
# If this test runs too quickly, test_bug737473.py's mtime
# attribute will remain unchanged even if the file is rewritten.
# Consequently, the file would not reload. So, added a sleep()
# delay to assure that a new, distinct timestamp is written.
# Since WinME with FAT32 has multisecond resolution, more than
# three seconds are needed for this test to pass reliably :-(
time.sleep(4)
print >> open(testfile, 'w'), """
def test():
raise NotImplementedError"""
reload(test_bug737473)
try:
test_bug737473.test()
except NotImplementedError:
src = traceback.extract_tb(sys.exc_traceback)[-1][-1]
self.assertEqual(src, 'raise NotImplementedError')
finally:
sys.path[:] = savedpath
for f in os.listdir(testdir):
os.unlink(os.path.join(testdir, f))
os.rmdir(testdir)
def test_base_exception(self):
# Test that exceptions derived from BaseException are formatted right
e = KeyboardInterrupt()
lst = traceback.format_exception_only(e.__class__, e)
self.assertEqual(lst, ['KeyboardInterrupt\n'])
# String exceptions are deprecated, but legal. The quirky form with
# separate "type" and "value" tends to break things, because
# not isinstance(value, type)
# and a string cannot be the first argument to issubclass.
#
# Note that sys.last_type and sys.last_value do not get set if an
# exception is caught, so we sort of cheat and just emulate them.
#
# test_string_exception1 is equivalent to
#
# >>> raise "String Exception"
#
# test_string_exception2 is equivalent to
#
# >>> raise "String Exception", "String Value"
#
def test_string_exception1(self):
str_type = "String Exception"
err = traceback.format_exception_only(str_type, None)
self.assertEqual(len(err), 1)
self.assertEqual(err[0], str_type + '\n')
def test_string_exception2(self):
str_type = "String Exception"
str_value = "String Value"
err = traceback.format_exception_only(str_type, str_value)
self.assertEqual(len(err), 1)
self.assertEqual(err[0], str_type + ': ' + str_value + '\n')
def test_format_exception_only_bad__str__(self):
class X(Exception):
def __str__(self):
1 // 0
err = traceback.format_exception_only(X, X())
self.assertEqual(len(err), 1)
str_value = '<unprintable %s object>' % X.__name__
self.assertEqual(err[0], X.__name__ + ': ' + str_value + '\n')
def test_without_exception(self):
err = traceback.format_exception_only(None, None)
self.assertEqual(err, ['None\n'])
def test_unicode(self):
err = AssertionError('\xff')
lines = traceback.format_exception_only(type(err), err)
self.assertEqual(lines, ['AssertionError: \xff\n'])
err = AssertionError(u'\xe9')
lines = traceback.format_exception_only(type(err), err)
self.assertEqual(lines, ['AssertionError: \\xe9\n'])
class TracebackFormatTests(unittest.TestCase):
def test_traceback_format(self):
try:
raise KeyError('blah')
except KeyError:
type_, value, tb = sys.exc_info()
traceback_fmt = 'Traceback (most recent call last):\n' + \
''.join(traceback.format_tb(tb))
file_ = StringIO()
traceback_print(tb, file_)
python_fmt = file_.getvalue()
else:
raise Error("unable to create test traceback string")
# Make sure that Python and the traceback module format the same thing
self.assertEqual(traceback_fmt, python_fmt)
# Make sure that the traceback is properly indented.
tb_lines = python_fmt.splitlines()
self.assertEqual(len(tb_lines), 3)
banner, location, source_line = tb_lines
self.assertTrue(banner.startswith('Traceback'))
self.assertTrue(location.startswith(' File'))
self.assertTrue(source_line.startswith(' raise'))
def test_main():
run_unittest(TracebackCases, TracebackFormatTests)
if __name__ == "__main__":
test_main()