[3239] Update exception messages returned when types mismatch

We include the type of the received value so that the user can see the
type mismatch more clearly from the returned exception message.

src/lib/python/isc/config/config_data.py

@@ -53,6 +53,22 @@ def spec_part_is_any(spec_part):
     return (type(spec_part) == dict and 'item_type' in spec_part and
             spec_part['item_type'] == "any")
 
+def _type_as_string(value):
+    if type(value) == int:
+        return 'integer'
+    elif type(value) == float:
+        return 'real'
+    elif type(value) == bool:
+        return 'boolean'
+    elif type(value) == str:
+        return 'string'
+    elif type(value) == list:
+        return 'list'
+    elif type(value) == dict:
+        return 'map'
+    else:
+        return '<unknown>'
+
 def check_type(spec_part, value):
     """Does nothing if the value is of the correct type given the
        specification part relevant for the value. Raises an
@@ -65,27 +81,35 @@ def check_type(spec_part, value):
 
     if data_type == "integer":
         if type(value) != int:
-            raise isc.cc.data.DataTypeError(str(value) + " is not an integer")
+            raise isc.cc.data.DataTypeError('%s is not an integer (%s was passed)' % \
+                                            (str(value), _type_as_string(value)))
         if value > sys.maxsize:
-            raise isc.cc.data.DataTypeError(str(value) + " is too large an integer")
+            raise isc.cc.data.DataTypeError('%s is too large an integer' % \
+                                            (str(value)))
     elif data_type == "real":
         if type(value) != float:
-            raise isc.cc.data.DataTypeError(str(value) + " is not a real")
+            raise isc.cc.data.DataTypeError('%s is not a real (%s was passed)' % \
+                                            (str(value), _type_as_string(value)))
         if float(value) > sys.float_info.max:
-            raise isc.cc.data.DataTypeError(str(value) + " is too large a float")
+            raise isc.cc.data.DataTypeError('%s is too large for a float' % \
+                                            (str(value)))
     elif data_type == "boolean" and type(value) != bool:
-        raise isc.cc.data.DataTypeError(str(value) + " is not a boolean")
+        raise isc.cc.data.DataTypeError('%s is not a boolean (%s was passed)' % \
+                                        (str(value), _type_as_string(value)))
     elif data_type == "string" and type(value) != str:
-        raise isc.cc.data.DataTypeError(str(value) + " is not a string")
+        raise isc.cc.data.DataTypeError('%s is not a string (%s was passed)' % \
+                                        (str(value), _type_as_string(value)))
     elif data_type == "list":
         if type(value) != list:
-            raise isc.cc.data.DataTypeError(str(value) + " is not a list")
+            raise isc.cc.data.DataTypeError('%s is not a list (%s was passed)' % \
+                                            (str(value), _type_as_string(value)))
         else:
             for element in value:
                 check_type(spec_part['list_item_spec'], element)
     elif data_type == "map" and type(value) != dict:
         # todo: check types of map contents too
-        raise isc.cc.data.DataTypeError(str(value) + " is not a map")
+        raise isc.cc.data.DataTypeError('%s is not a map (%s was passed)' % \
+                                        (str(value), _type_as_string(value)))
 
 def convert_type(spec_part, value):
     """Convert the given value(type is string) according specification