"""Test cases for traceback module"""

import unittest

from test.test_support import run_unittest, is_jython

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_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.assert_(len(err) == 4)

        self.assert_(err[1].strip() == "return x!")

        self.assert_("^" in err[2]) # third line has caret

        self.assert_(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.assert_(len(err) == 3)

        self.assert_(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.assert_(len(err) == 4)

        self.assert_(err[1].strip() == "print 2")

        self.assert_("^" in err[2])

        self.assert_(err[1].find("2") == err[2].find("^"))

    def test_bug737473(self):

        import sys, 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.failUnlessEqual(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_members(self):

        # Covers Python/structmember.c::listmembers()

        try:

            1/0

        except:

            import sys

            sys.exc_traceback.__members__

    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_main():

    run_unittest(TracebackCases)

if __name__ == "__main__":

    test_main()