Recipe 573452 revision 2

Diff to Previous Revision

--- revision 1 2008-06-14 05:56:53
+++ revision 2 2010-07-20 13:15:49
@@ -1,13 +1,17 @@
+#!/usr/bin/env python
+#-*- coding: iso-8859-1 -*-
+
+###############################################################################
+
 class expected:
 
     def __init__(self, e):
         if isinstance(e, Exception):
             self._t, self._v = e.__class__, str(e)
-        elif isinstance(e, type):
-            self._t, self._v = e, ""
+        elif isinstance(e, type) and issubclass(e, Exception):
+            self._t, self._v = e, None
         else:
-            raise Exception("usage: with expected(Exception): ... or "
-                            "with expected(Exception(\"text\")): ...")
+            raise Exception("usage: with expected(Exception): or with expected(Exception(\"text\"))")
 
     def __enter__(self):
         try:
@@ -17,24 +21,60 @@
 
     def __exit__(self, t, v, tb):
         assert t is not None, "expected {0:s} to have been thrown".format(self._t.__name__)
-        return t is self._t and str(v).startswith(self._v)
+        return issubclass(t, self._t) and (self._v is None or str(v).startswith(self._v))
+
+###############################################################################
 
 if __name__ == "__main__": # some examples
+
+    try:
+        with expected("foo"):
+            pass
+    except Exception as e:
+        assert str(e) == "usage: with expected(Exception): or with expected(Exception(\"text\"))", str(e)
+    else:
+        assert False
 
     with expected(ZeroDivisionError):
         1 / 0
 
-    with expected(AssertionError("expected ZeroDivisionError to have been thrown")):
+    with expected(ZeroDivisionError("int division or modulo by zero")):
+        1 / 0
+
+    with expected(ZeroDivisionError("int division")):
+        1 / 0
+
+    try:
         with expected(ZeroDivisionError):
             1 / 2
+    except AssertionError as e:
+        assert str(e) == "expected ZeroDivisionError to have been thrown", str(e)
+    else:
+        assert False
 
-    with expected(Exception("foo")):
-        raise Exception("foo")
+    try:
+        with expected(ZeroDivisionError("failure !!!")):
+            1 / 0
+    except ZeroDivisionError as e:
+        assert str(e) == "int division or modulo by zero", str(e)
+    else:
+        assert False
 
-    with expected(Exception("bar")):
-        with expected(Exception("foo")): # this won't catch it
-            raise Exception("bar")
-        assert False, "should not see me"
+    try:
+        with expected(ZeroDivisionError):
+            {}["foo"]
+    except KeyError as e:
+        assert str(e) == "'foo'", str(e)
+    else:
+        assert False
 
-    with expected(Exception("can specify")):
-        raise Exception("can specify prefixes")
+    with expected(KeyError):
+        with expected(ZeroDivisionError):
+            with expected(RuntimeError):
+                {}["foo"]
+
+    with expected(Exception("int division or modulo by zero")):
+        1 / 0
+
+    with expected(Exception):
+        1 / 0