335: If Command.__convert_scalar() is called with None, it now returns None instead of raising TypeError

ipalib/frontend.py

@@ -106,6 +106,8 @@ class Param(plugable.ReadOnly):
         lock(self)
 
     def __dispatch(self, value, scalar):
+        if value is None:
+            return None
         if self.multivalue:
             if type(value) in (tuple, list):
                 if len(value) == 0:
@@ -146,7 +148,7 @@ class Param(plugable.ReadOnly):
 
     def __convert_scalar(self, value, index=None):
         if value is None:
-            raise TypeError('value cannot be None')
+            return None
         converted = self.type(value)
         if converted is None:
             raise errors.ConversionError(
@@ -155,10 +157,13 @@ class Param(plugable.ReadOnly):
         return converted
 
     def convert(self, value):
+        """
+        Convert/coerce ``value`` to Python type for this parameter.
+
+        :param value: A proposed value for this parameter.
+        """
         return self.__dispatch(value, self.__convert_scalar)
 
-
-
     def __validate_scalar(self, value, index=None):
         if type(value) is not self.type.type:
             raise_TypeError(value, self.type.type, 'value')

ipalib/tests/test_frontend.py

@@ -148,8 +148,7 @@ class test_Param(ClassChecker):
 
         # Scenario 1: multivalue=False
         o = self.cls(name, type_)
-        e = raises(TypeError, o.convert, None)
-        assert str(e) == 'value cannot be None'
+        assert o.convert(None) is None
         for value in okay:
             new = o.convert(value)
             assert new == 7
@@ -163,10 +162,8 @@ class test_Param(ClassChecker):
 
         # Scenario 2: multivalue=True
         o = self.cls(name, type_, multivalue=True)
-        assert o.convert([]) is None
-        for none in [None, (7, None)]:
-            e = raises(TypeError, o.convert, none)
-            assert str(e) == 'value cannot be None'
+        for none in (None, tuple(), []):
+            assert o.convert(none) is None
         for value in okay:
             assert o.convert((value,)) == (7,)
             assert o.convert([value]) == (7,)