cpython/Lib/test/test_exceptions.py

554 lines
19 KiB
Python

# Python test set -- part 5, built-in exceptions
import os
import sys
import unittest
import pickle
import weakref
from test.support import TESTFN, unlink, run_unittest
# XXX This is not really enough, each *operation* should be tested!
class ExceptionTests(unittest.TestCase):
def raise_catch(self, exc, excname):
try:
raise exc("spam")
except exc as err:
buf1 = str(err)
try:
raise exc("spam")
except exc as err:
buf2 = str(err)
self.assertEquals(buf1, buf2)
self.assertEquals(exc.__name__, excname)
def testRaising(self):
self.raise_catch(AttributeError, "AttributeError")
self.assertRaises(AttributeError, getattr, sys, "undefined_attribute")
self.raise_catch(EOFError, "EOFError")
fp = open(TESTFN, 'w')
fp.close()
fp = open(TESTFN, 'r')
savestdin = sys.stdin
try:
try:
import marshal
marshal.loads('')
except EOFError:
pass
finally:
sys.stdin = savestdin
fp.close()
unlink(TESTFN)
self.raise_catch(IOError, "IOError")
self.assertRaises(IOError, open, 'this file does not exist', 'r')
self.raise_catch(ImportError, "ImportError")
self.assertRaises(ImportError, __import__, "undefined_module")
self.raise_catch(IndexError, "IndexError")
x = []
self.assertRaises(IndexError, x.__getitem__, 10)
self.raise_catch(KeyError, "KeyError")
x = {}
self.assertRaises(KeyError, x.__getitem__, 'key')
self.raise_catch(KeyboardInterrupt, "KeyboardInterrupt")
self.raise_catch(MemoryError, "MemoryError")
self.raise_catch(NameError, "NameError")
try: x = undefined_variable
except NameError: pass
self.raise_catch(OverflowError, "OverflowError")
x = 1
for dummy in range(128):
x += x # this simply shouldn't blow up
self.raise_catch(RuntimeError, "RuntimeError")
self.raise_catch(SyntaxError, "SyntaxError")
try: exec('/\n')
except SyntaxError: pass
self.raise_catch(IndentationError, "IndentationError")
self.raise_catch(TabError, "TabError")
try: compile("try:\n\t1/0\n \t1/0\nfinally:\n pass\n",
'<string>', 'exec')
except TabError: pass
else: self.fail("TabError not raised")
self.raise_catch(SystemError, "SystemError")
self.raise_catch(SystemExit, "SystemExit")
self.assertRaises(SystemExit, sys.exit, 0)
self.raise_catch(TypeError, "TypeError")
try: [] + ()
except TypeError: pass
self.raise_catch(ValueError, "ValueError")
self.assertRaises(ValueError, chr, 17<<16)
self.raise_catch(ZeroDivisionError, "ZeroDivisionError")
try: x = 1/0
except ZeroDivisionError: pass
self.raise_catch(Exception, "Exception")
try: x = 1/0
except Exception as e: pass
def testSyntaxErrorMessage(self):
# make sure the right exception message is raised for each of
# these code fragments
def ckmsg(src, msg):
try:
compile(src, '<fragment>', 'exec')
except SyntaxError as e:
if e.msg != msg:
self.fail("expected %s, got %s" % (msg, e.msg))
else:
self.fail("failed to get expected SyntaxError")
s = '''while 1:
try:
pass
finally:
continue'''
if not sys.platform.startswith('java'):
ckmsg(s, "'continue' not supported inside 'finally' clause")
s = '''if 1:
try:
continue
except:
pass'''
ckmsg(s, "'continue' not properly in loop")
ckmsg("continue\n", "'continue' not properly in loop")
def testSettingException(self):
# test that setting an exception at the C level works even if the
# exception object can't be constructed.
class BadException(Exception):
def __init__(self_):
raise RuntimeError("can't instantiate BadException")
class InvalidException:
pass
def test_capi1():
import _testcapi
try:
_testcapi.raise_exception(BadException, 1)
except TypeError as err:
exc, err, tb = sys.exc_info()
co = tb.tb_frame.f_code
self.assertEquals(co.co_name, "test_capi1")
self.assert_(co.co_filename.endswith('test_exceptions.py'))
else:
self.fail("Expected exception")
def test_capi2():
import _testcapi
try:
_testcapi.raise_exception(BadException, 0)
except RuntimeError as err:
exc, err, tb = sys.exc_info()
co = tb.tb_frame.f_code
self.assertEquals(co.co_name, "__init__")
self.assert_(co.co_filename.endswith('test_exceptions.py'))
co2 = tb.tb_frame.f_back.f_code
self.assertEquals(co2.co_name, "test_capi2")
else:
self.fail("Expected exception")
def test_capi3():
import _testcapi
self.assertRaises(SystemError, _testcapi.raise_exception,
InvalidException, 1)
if not sys.platform.startswith('java'):
test_capi1()
test_capi2()
test_capi3()
def test_WindowsError(self):
try:
WindowsError
except NameError:
pass
else:
self.failUnlessEqual(str(WindowsError(1001)),
"1001")
self.failUnlessEqual(str(WindowsError(1001, "message")),
"[Error 1001] message")
self.failUnlessEqual(WindowsError(1001, "message").errno, 22)
self.failUnlessEqual(WindowsError(1001, "message").winerror, 1001)
def testAttributes(self):
# test that exception attributes are happy
exceptionList = [
(BaseException, (), {'args' : ()}),
(BaseException, (1, ), {'args' : (1,)}),
(BaseException, ('foo',),
{'args' : ('foo',)}),
(BaseException, ('foo', 1),
{'args' : ('foo', 1)}),
(SystemExit, ('foo',),
{'args' : ('foo',), 'code' : 'foo'}),
(IOError, ('foo',),
{'args' : ('foo',), 'filename' : None,
'errno' : None, 'strerror' : None}),
(IOError, ('foo', 'bar'),
{'args' : ('foo', 'bar'), 'filename' : None,
'errno' : 'foo', 'strerror' : 'bar'}),
(IOError, ('foo', 'bar', 'baz'),
{'args' : ('foo', 'bar'), 'filename' : 'baz',
'errno' : 'foo', 'strerror' : 'bar'}),
(IOError, ('foo', 'bar', 'baz', 'quux'),
{'args' : ('foo', 'bar', 'baz', 'quux')}),
(EnvironmentError, ('errnoStr', 'strErrorStr', 'filenameStr'),
{'args' : ('errnoStr', 'strErrorStr'),
'strerror' : 'strErrorStr', 'errno' : 'errnoStr',
'filename' : 'filenameStr'}),
(EnvironmentError, (1, 'strErrorStr', 'filenameStr'),
{'args' : (1, 'strErrorStr'), 'errno' : 1,
'strerror' : 'strErrorStr', 'filename' : 'filenameStr'}),
(SyntaxError, (), {'msg' : None, 'text' : None,
'filename' : None, 'lineno' : None, 'offset' : None,
'print_file_and_line' : None}),
(SyntaxError, ('msgStr',),
{'args' : ('msgStr',), 'text' : None,
'print_file_and_line' : None, 'msg' : 'msgStr',
'filename' : None, 'lineno' : None, 'offset' : None}),
(SyntaxError, ('msgStr', ('filenameStr', 'linenoStr', 'offsetStr',
'textStr')),
{'offset' : 'offsetStr', 'text' : 'textStr',
'args' : ('msgStr', ('filenameStr', 'linenoStr',
'offsetStr', 'textStr')),
'print_file_and_line' : None, 'msg' : 'msgStr',
'filename' : 'filenameStr', 'lineno' : 'linenoStr'}),
(SyntaxError, ('msgStr', 'filenameStr', 'linenoStr', 'offsetStr',
'textStr', 'print_file_and_lineStr'),
{'text' : None,
'args' : ('msgStr', 'filenameStr', 'linenoStr', 'offsetStr',
'textStr', 'print_file_and_lineStr'),
'print_file_and_line' : None, 'msg' : 'msgStr',
'filename' : None, 'lineno' : None, 'offset' : None}),
(UnicodeError, (), {'args' : (),}),
(UnicodeEncodeError, ('ascii', 'a', 0, 1,
'ordinal not in range'),
{'args' : ('ascii', 'a', 0, 1,
'ordinal not in range'),
'encoding' : 'ascii', 'object' : 'a',
'start' : 0, 'reason' : 'ordinal not in range'}),
(UnicodeDecodeError, ('ascii', bytearray(b'\xff'), 0, 1,
'ordinal not in range'),
{'args' : ('ascii', bytearray(b'\xff'), 0, 1,
'ordinal not in range'),
'encoding' : 'ascii', 'object' : b'\xff',
'start' : 0, 'reason' : 'ordinal not in range'}),
(UnicodeDecodeError, ('ascii', b'\xff', 0, 1,
'ordinal not in range'),
{'args' : ('ascii', b'\xff', 0, 1,
'ordinal not in range'),
'encoding' : 'ascii', 'object' : b'\xff',
'start' : 0, 'reason' : 'ordinal not in range'}),
(UnicodeTranslateError, ("\u3042", 0, 1, "ouch"),
{'args' : ('\u3042', 0, 1, 'ouch'),
'object' : '\u3042', 'reason' : 'ouch',
'start' : 0, 'end' : 1}),
]
try:
exceptionList.append(
(WindowsError, (1, 'strErrorStr', 'filenameStr'),
{'args' : (1, 'strErrorStr'),
'strerror' : 'strErrorStr', 'winerror' : 1,
'errno' : 22, 'filename' : 'filenameStr'})
)
except NameError:
pass
for exc, args, expected in exceptionList:
try:
e = exc(*args)
except:
print("\nexc=%r, args=%r" % (exc, args), file=sys.stderr)
raise
else:
# Verify module name
self.assertEquals(type(e).__module__, 'builtins')
# Verify no ref leaks in Exc_str()
s = str(e)
for checkArgName in expected:
value = getattr(e, checkArgName)
self.assertEquals(repr(value),
repr(expected[checkArgName]),
'%r.%s == %r, expected %r' % (
e, checkArgName,
value, expected[checkArgName]))
# test for pickling support
for p in [pickle]:
for protocol in range(p.HIGHEST_PROTOCOL + 1):
s = p.dumps(e, protocol)
new = p.loads(s)
for checkArgName in expected:
got = repr(getattr(new, checkArgName))
want = repr(expected[checkArgName])
self.assertEquals(got, want,
'pickled "%r", attribute "%s' %
(e, checkArgName))
def testWithTraceback(self):
try:
raise IndexError(4)
except:
tb = sys.exc_info()[2]
e = BaseException().with_traceback(tb)
self.failUnless(isinstance(e, BaseException))
self.assertEqual(e.__traceback__, tb)
e = IndexError(5).with_traceback(tb)
self.failUnless(isinstance(e, IndexError))
self.assertEqual(e.__traceback__, tb)
class MyException(Exception):
pass
e = MyException().with_traceback(tb)
self.failUnless(isinstance(e, MyException))
self.assertEqual(e.__traceback__, tb)
def testInvalidTraceback(self):
try:
Exception().__traceback__ = 5
except TypeError as e:
self.failUnless("__traceback__ must be a traceback" in str(e))
else:
self.fail("No exception raised")
def testNoneClearsTracebackAttr(self):
try:
raise IndexError(4)
except:
tb = sys.exc_info()[2]
e = Exception()
e.__traceback__ = tb
e.__traceback__ = None
self.assertEqual(e.__traceback__, None)
def testChainingAttrs(self):
e = Exception()
self.assertEqual(e.__context__, None)
self.assertEqual(e.__cause__, None)
e = TypeError()
self.assertEqual(e.__context__, None)
self.assertEqual(e.__cause__, None)
class MyException(EnvironmentError):
pass
e = MyException()
self.assertEqual(e.__context__, None)
self.assertEqual(e.__cause__, None)
def testKeywordArgs(self):
# test that builtin exception don't take keyword args,
# but user-defined subclasses can if they want
self.assertRaises(TypeError, BaseException, a=1)
class DerivedException(BaseException):
def __init__(self, fancy_arg):
BaseException.__init__(self)
self.fancy_arg = fancy_arg
x = DerivedException(fancy_arg=42)
self.assertEquals(x.fancy_arg, 42)
def testInfiniteRecursion(self):
def f():
return f()
self.assertRaises(RuntimeError, f)
def g():
try:
return g()
except ValueError:
return -1
self.assertRaises(RuntimeError, g)
def testUnicodeStrUsage(self):
# Make sure both instances and classes have a str and unicode
# representation.
self.failUnless(str(Exception))
self.failUnless(str(Exception))
self.failUnless(str(Exception('a')))
self.failUnless(str(Exception('a')))
def testExceptionCleanupNames(self):
# Make sure the local variable bound to the exception instance by
# an "except" statement is only visible inside the except block.
try:
raise Exception()
except Exception as e:
self.failUnless(e)
del e
self.failIf('e' in locals())
def testExceptionCleanupState(self):
# Make sure exception state is cleaned up as soon as the except
# block is left. See #2507
class MyException(Exception):
def __init__(self, obj):
self.obj = obj
class MyObj:
pass
def inner_raising_func():
# Create some references in exception value and traceback
local_ref = obj
raise MyException(obj)
# Qualified "except" with "as"
obj = MyObj()
wr = weakref.ref(obj)
try:
inner_raising_func()
except MyException as e:
pass
obj = None
obj = wr()
self.failUnless(obj is None, "%s" % obj)
# Qualified "except" without "as"
obj = MyObj()
wr = weakref.ref(obj)
try:
inner_raising_func()
except MyException:
pass
obj = None
obj = wr()
self.failUnless(obj is None, "%s" % obj)
# Bare "except"
obj = MyObj()
wr = weakref.ref(obj)
try:
inner_raising_func()
except:
pass
obj = None
obj = wr()
self.failUnless(obj is None, "%s" % obj)
# "except" with premature block leave
obj = MyObj()
wr = weakref.ref(obj)
for i in [0]:
try:
inner_raising_func()
except:
break
obj = None
obj = wr()
self.failUnless(obj is None, "%s" % obj)
# "except" block raising another exception
obj = MyObj()
wr = weakref.ref(obj)
try:
try:
inner_raising_func()
except:
raise KeyError
except KeyError:
obj = None
obj = wr()
self.failUnless(obj is None, "%s" % obj)
# Some complicated construct
obj = MyObj()
wr = weakref.ref(obj)
try:
inner_raising_func()
except MyException:
try:
try:
raise
finally:
raise
except MyException:
pass
obj = None
obj = wr()
self.failUnless(obj is None, "%s" % obj)
# Inside an exception-silencing "with" block
class Context:
def __enter__(self):
return self
def __exit__ (self, exc_type, exc_value, exc_tb):
return True
obj = MyObj()
wr = weakref.ref(obj)
with Context():
inner_raising_func()
obj = None
obj = wr()
self.failUnless(obj is None, "%s" % obj)
def test_generator_leaking(self):
# Test that generator exception state doesn't leak into the calling
# frame
def yield_raise():
try:
raise KeyError("caught")
except KeyError:
yield sys.exc_info()[0]
yield sys.exc_info()[0]
yield sys.exc_info()[0]
g = yield_raise()
self.assertEquals(next(g), KeyError)
self.assertEquals(sys.exc_info()[0], None)
self.assertEquals(next(g), KeyError)
self.assertEquals(sys.exc_info()[0], None)
self.assertEquals(next(g), None)
# Same test, but inside an exception handler
try:
raise TypeError("foo")
except TypeError:
g = yield_raise()
self.assertEquals(next(g), KeyError)
self.assertEquals(sys.exc_info()[0], TypeError)
self.assertEquals(next(g), KeyError)
self.assertEquals(sys.exc_info()[0], TypeError)
self.assertEquals(next(g), TypeError)
del g
self.assertEquals(sys.exc_info()[0], TypeError)
def test_main():
run_unittest(ExceptionTests)
if __name__ == '__main__':
unittest.main()