Brett Cannon | bf36409 | 2006-03-01 04:25:17 +0000 | [diff] [blame] | 1 | import unittest |
| 2 | import __builtin__ |
| 3 | import exceptions |
| 4 | import warnings |
| 5 | from test.test_support import run_unittest |
| 6 | import os |
| 7 | from platform import system as platform_system |
| 8 | |
| 9 | class ExceptionClassTests(unittest.TestCase): |
| 10 | |
| 11 | """Tests for anything relating to exception objects themselves (e.g., |
| 12 | inheritance hierarchy)""" |
| 13 | |
| 14 | def test_builtins_new_style(self): |
| 15 | self.failUnless(issubclass(Exception, object)) |
| 16 | |
| 17 | def verify_instance_interface(self, ins): |
Brett Cannon | 19d76c5 | 2006-09-09 07:18:44 +0000 | [diff] [blame^] | 18 | for attr in ("args", "message", "__str__", "__repr__", "__getitem__"): |
Brett Cannon | bf36409 | 2006-03-01 04:25:17 +0000 | [diff] [blame] | 19 | self.failUnless(hasattr(ins, attr), "%s missing %s attribute" % |
| 20 | (ins.__class__.__name__, attr)) |
| 21 | |
| 22 | def test_inheritance(self): |
| 23 | # Make sure the inheritance hierarchy matches the documentation |
| 24 | exc_set = set(x for x in dir(exceptions) if not x.startswith('_')) |
| 25 | inheritance_tree = open(os.path.join(os.path.split(__file__)[0], |
| 26 | 'exception_hierarchy.txt')) |
| 27 | try: |
| 28 | superclass_name = inheritance_tree.readline().rstrip() |
| 29 | try: |
| 30 | last_exc = getattr(__builtin__, superclass_name) |
| 31 | except AttributeError: |
| 32 | self.fail("base class %s not a built-in" % superclass_name) |
| 33 | self.failUnless(superclass_name in exc_set) |
| 34 | exc_set.discard(superclass_name) |
| 35 | superclasses = [] # Loop will insert base exception |
| 36 | last_depth = 0 |
| 37 | for exc_line in inheritance_tree: |
| 38 | exc_line = exc_line.rstrip() |
| 39 | depth = exc_line.rindex('-') |
| 40 | exc_name = exc_line[depth+2:] # Slice past space |
| 41 | if '(' in exc_name: |
| 42 | paren_index = exc_name.index('(') |
| 43 | platform_name = exc_name[paren_index+1:-1] |
Brett Cannon | 6b4ed74 | 2006-03-01 06:10:48 +0000 | [diff] [blame] | 44 | exc_name = exc_name[:paren_index-1] # Slice off space |
Brett Cannon | bf36409 | 2006-03-01 04:25:17 +0000 | [diff] [blame] | 45 | if platform_system() != platform_name: |
| 46 | exc_set.discard(exc_name) |
| 47 | continue |
| 48 | if '[' in exc_name: |
| 49 | left_bracket = exc_name.index('[') |
| 50 | exc_name = exc_name[:left_bracket-1] # cover space |
| 51 | try: |
| 52 | exc = getattr(__builtin__, exc_name) |
| 53 | except AttributeError: |
| 54 | self.fail("%s not a built-in exception" % exc_name) |
| 55 | if last_depth < depth: |
| 56 | superclasses.append((last_depth, last_exc)) |
| 57 | elif last_depth > depth: |
| 58 | while superclasses[-1][0] >= depth: |
| 59 | superclasses.pop() |
| 60 | self.failUnless(issubclass(exc, superclasses[-1][1]), |
| 61 | "%s is not a subclass of %s" % (exc.__name__, |
| 62 | superclasses[-1][1].__name__)) |
| 63 | try: # Some exceptions require arguments; just skip them |
| 64 | self.verify_instance_interface(exc()) |
| 65 | except TypeError: |
| 66 | pass |
| 67 | self.failUnless(exc_name in exc_set) |
| 68 | exc_set.discard(exc_name) |
| 69 | last_exc = exc |
| 70 | last_depth = depth |
| 71 | finally: |
| 72 | inheritance_tree.close() |
| 73 | self.failUnlessEqual(len(exc_set), 0, "%s not accounted for" % exc_set) |
| 74 | |
| 75 | interface_tests = ("length", "args", "message", "str", "unicode", "repr", |
| 76 | "indexing") |
| 77 | |
| 78 | def interface_test_driver(self, results): |
| 79 | for test_name, (given, expected) in zip(self.interface_tests, results): |
| 80 | self.failUnlessEqual(given, expected, "%s: %s != %s" % (test_name, |
| 81 | given, expected)) |
| 82 | |
| 83 | def test_interface_single_arg(self): |
| 84 | # Make sure interface works properly when given a single argument |
| 85 | arg = "spam" |
| 86 | exc = Exception(arg) |
| 87 | results = ([len(exc.args), 1], [exc.args[0], arg], [exc.message, arg], |
| 88 | [str(exc), str(arg)], [unicode(exc), unicode(arg)], |
| 89 | [repr(exc), exc.__class__.__name__ + repr(exc.args)], [exc[0], arg]) |
| 90 | self.interface_test_driver(results) |
| 91 | |
| 92 | def test_interface_multi_arg(self): |
| 93 | # Make sure interface correct when multiple arguments given |
| 94 | arg_count = 3 |
| 95 | args = tuple(range(arg_count)) |
| 96 | exc = Exception(*args) |
| 97 | results = ([len(exc.args), arg_count], [exc.args, args], |
| 98 | [exc.message, ''], [str(exc), str(args)], |
| 99 | [unicode(exc), unicode(args)], |
| 100 | [repr(exc), exc.__class__.__name__ + repr(exc.args)], |
| 101 | [exc[-1], args[-1]]) |
| 102 | self.interface_test_driver(results) |
| 103 | |
| 104 | def test_interface_no_arg(self): |
| 105 | # Make sure that with no args that interface is correct |
| 106 | exc = Exception() |
| 107 | results = ([len(exc.args), 0], [exc.args, tuple()], [exc.message, ''], |
| 108 | [str(exc), ''], [unicode(exc), u''], |
| 109 | [repr(exc), exc.__class__.__name__ + '()'], [True, True]) |
| 110 | self.interface_test_driver(results) |
| 111 | |
| 112 | class UsageTests(unittest.TestCase): |
| 113 | |
| 114 | """Test usage of exceptions""" |
| 115 | |
| 116 | def setUp(self): |
| 117 | self._filters = warnings.filters[:] |
| 118 | |
| 119 | def tearDown(self): |
| 120 | warnings.filters = self._filters[:] |
| 121 | |
| 122 | def test_raise_classic(self): |
| 123 | class ClassicClass: |
| 124 | pass |
| 125 | try: |
| 126 | raise ClassicClass |
| 127 | except ClassicClass: |
| 128 | pass |
| 129 | except: |
| 130 | self.fail("unable to raise classic class") |
| 131 | try: |
| 132 | raise ClassicClass() |
| 133 | except ClassicClass: |
| 134 | pass |
| 135 | except: |
| 136 | self.fail("unable to raise class class instance") |
| 137 | |
| 138 | def test_raise_new_style_non_exception(self): |
| 139 | class NewStyleClass(object): |
| 140 | pass |
| 141 | try: |
| 142 | raise NewStyleClass |
| 143 | except TypeError: |
| 144 | pass |
| 145 | except: |
| 146 | self.fail("unable to raise new-style class") |
| 147 | try: |
| 148 | raise NewStyleClass() |
| 149 | except TypeError: |
| 150 | pass |
| 151 | except: |
| 152 | self.fail("unable to raise new-style class instance") |
| 153 | |
| 154 | def test_raise_string(self): |
| 155 | warnings.resetwarnings() |
| 156 | warnings.filterwarnings("error") |
| 157 | try: |
| 158 | raise "spam" |
| 159 | except DeprecationWarning: |
| 160 | pass |
| 161 | except: |
| 162 | self.fail("raising a string did not cause a DeprecationWarning") |
| 163 | |
| 164 | def test_catch_string(self): |
| 165 | # Test will be pertinent when catching exceptions raises a |
| 166 | # DeprecationWarning |
| 167 | warnings.filterwarnings("ignore", "raising") |
| 168 | str_exc = "spam" |
| 169 | try: |
| 170 | raise str_exc |
| 171 | except str_exc: |
| 172 | pass |
| 173 | except: |
| 174 | self.fail("catching a string exception failed") |
| 175 | |
| 176 | def test_main(): |
| 177 | run_unittest(ExceptionClassTests, UsageTests) |
| 178 | |
| 179 | |
| 180 | |
| 181 | if __name__ == '__main__': |
| 182 | test_main() |