"""Test cases for traceback module""" from StringIO import StringIO import sys import unittest from imp import reload from test.test_support import run_unittest, is_jython, Error, cpython_only 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 syntax_error_bad_indentation2(self): compile(" 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) err = self.get_exception_format(self.syntax_error_bad_indentation2, IndentationError) self.assertEqual(len(err), 4) self.assertEqual(err[1].strip(), "print(2)") self.assertIn("^", err[2]) self.assertEqual(err[1].find("p"), err[2].find("^")) 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 = '' % 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): @cpython_only def test_traceback_format(self): from _testcapi import traceback_print 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()