Merge raises_regressions_675327 for Python 2.4 fixes

testtools/compat.py

@@ -65,6 +65,27 @@ else:
 _u.__doc__ = __u_doc
 
 
+if sys.version_info > (2, 5):
+    _error_repr = BaseException.__repr__
+    def isbaseexception(exception):
+        """Return whether exception inherits from BaseException only"""
+        return (isinstance(exception, BaseException)
+            and not isinstance(exception, Exception))
+else:
+    def _error_repr(exception):
+        """Format an exception instance as Python 2.5 and later do"""
+        return exception.__class__.__name__ + repr(exception.args)
+    def isbaseexception(exception):
+        """Return whether exception would inherit from BaseException only
+
+        This approximates the hierarchy in Python 2.5 and later, compare the
+        difference between the diagrams at the bottom of the pages:
+        <http://docs.python.org/release/2.4.4/lib/module-exceptions.html>
+        <http://docs.python.org/release/2.5.4/lib/module-exceptions.html>
+        """
+        return isinstance(exception, (KeyboardInterrupt, SystemExit))
+
+
 def unicode_output_stream(stream):
     """Get wrapper for given stream that writes any unicode without exception
 

testtools/matchers.py

@@ -32,6 +32,8 @@ import operator
 from pprint import pformat
 import sys
 
+from testtools.compat import classtypes, _error_repr, isbaseexception
+
 
 class Matcher(object):
     """A pattern matcher.
@@ -359,25 +361,24 @@ class MatchesException(Matcher):
         """
         Matcher.__init__(self)
         self.expected = exception
-
-    def _expected_type(self):
-        if type(self.expected) is type:
-            return self.expected
-        return type(self.expected)
+        self._is_instance = type(self.expected) not in classtypes()
 
     def match(self, other):
         if type(other) != tuple:
             return Mismatch('%r is not an exc_info tuple' % other)
-        if not issubclass(other[0], self._expected_type()):
-            return Mismatch('%r is not a %r' % (
-                other[0], self._expected_type()))
-        if (type(self.expected) is not type and
-            other[1].args != self.expected.args):
-            return Mismatch('%r has different arguments to %r.' % (
-                other[1], self.expected))
+        expected_class = self.expected
+        if self._is_instance:
+            expected_class = expected_class.__class__
+        if not issubclass(other[0], expected_class):
+            return Mismatch('%r is not a %r' % (other[0], expected_class))
+        if self._is_instance and other[1].args != self.expected.args:
+            return Mismatch('%s has different arguments to %s.' % (
+                _error_repr(other[1]), _error_repr(self.expected)))
 
     def __str__(self):
-        return "MatchesException(%r)" % self.expected
+        if self._is_instance:
+            return "MatchesException(%s)" % _error_repr(self.expected)
+        return "MatchesException(%s)" % repr(self.expected)
 
 
 class StartsWith(Matcher):
@@ -501,7 +502,6 @@ class Raises(Matcher):
         # Catch all exceptions: Raises() should be able to match a
         # KeyboardInterrupt or SystemExit.
         except:
-            exc_info = sys.exc_info()
             if self.exception_matcher:
                 mismatch = self.exception_matcher.match(sys.exc_info())
                 if not mismatch:
@@ -510,9 +510,9 @@ class Raises(Matcher):
                 mismatch = None
             # The exception did not match, or no explicit matching logic was
             # performed. If the exception is a non-user exception (that is, not
-            # a subclass of Exception) then propogate it.
-            if not issubclass(exc_info[0], Exception):
-                raise exc_info[0], exc_info[1], exc_info[2]
+            # a subclass of Exception on Python 2.5+) then propogate it.
+            if isbaseexception(sys.exc_info()[1]):
+                raise
             return mismatch
 
     def __str__(self):

testtools/tests/test_matchers.py

@@ -183,8 +183,7 @@ class TestMatchesExceptionInstanceInterface(TestCase, TestMatchersInterface):
          MatchesException(Exception('foo')))
         ]
     describe_examples = [
-        ("<type 'exceptions.Exception'> is not a "
-         "<type 'exceptions.ValueError'>",
+        ("%r is not a %r" % (Exception, ValueError),
          error_base_foo,
          MatchesException(ValueError("foo"))),
         ("ValueError('bar',) has different arguments to ValueError('foo',).",
@@ -203,12 +202,11 @@ class TestMatchesExceptionTypeInterface(TestCase, TestMatchersInterface):
     matches_mismatches = [error_base_foo]
 
     str_examples = [
-        ("MatchesException(<type 'exceptions.Exception'>)",
+        ("MatchesException(%r)" % Exception,
          MatchesException(Exception))
         ]
     describe_examples = [
-        ("<type 'exceptions.Exception'> is not a "
-         "<type 'exceptions.ValueError'>",
+        ("%r is not a %r" % (Exception, ValueError),
          error_base_foo,
          MatchesException(ValueError)),
         ]
@@ -364,7 +362,12 @@ class TestRaisesBaseTypes(TestCase):
         # Exception, it is propogated.
         match_keyb = Raises(MatchesException(KeyboardInterrupt))
         def raise_keyb_from_match():
-            matcher = Raises(MatchesException(Exception))
+            if sys.version_info > (2, 5):
+                matcher = Raises(MatchesException(Exception))
+            else:
+                # On Python 2.4 KeyboardInterrupt is a StandardError subclass
+                # but should propogate from less generic exception matchers
+                matcher = Raises(MatchesException(EnvironmentError))
             matcher.match(self.raiser)
         self.assertThat(raise_keyb_from_match, match_keyb)