Make NullContext an alias of ContextBase

Author: github-actions[bot]

ccflow/base.py

@@ -829,6 +829,9 @@ class ContextBase(ResultBase):
 
     @model_validator(mode="wrap")
     def _context_validator(cls, v, handler, info):
+        if v is None:
+            return handler({})
+
         # Add deepcopy for v2 because it doesn't support copy_on_model_validation
         v = copy.deepcopy(v)
 

ccflow/context.py

@@ -90,15 +90,8 @@
 
 _SEPARATOR = ","
 
-
-class NullContext(ContextBase):
-    """A Null Context that is used when no context is provided."""
-
-    @model_validator(mode="wrap")
-    def _validate_none(cls, v, handler, info):
-        v = v or {}
-        return handler(v)
-
+# Starting 0.8.0 Nullcontext is an alias to ContextBase
+NullContext = ContextBase
 
 C = TypeVar("C", bound=Hashable)
 

ccflow/tests/test_callable.py

@@ -11,6 +11,7 @@
     CallableModelGenericType,
     ContextBase,
     ContextType,
+    DateContext,
     Flow,
     GenericResult,
     GraphDepList,
@@ -50,6 +51,12 @@ def __call__(self, context: MyContext) -> MyResult:
         return MyResult(x=self.i, y=context.a)
 
 
+class MyCallableNullContext(CallableModel):
+    @Flow.call
+    def __call__(self, context: NullContext) -> MyResult:
+        return MyResult(x=1, y="default")
+
+
 class MyCallableOptionalContext(CallableModel):
     @Flow.call
     def __call__(self, context: Optional[MyContext] = None) -> MyResult:
@@ -152,7 +159,7 @@ class BadModelMismatchedContextAndCall(CallableModel):
 
     @property
     def context_type(self):
-        return NullContext
+        return DateContext
 
     @property
     def result_type(self):
@@ -163,7 +170,7 @@ def __call__(self, context: MyContext) -> MyResult:
         return context
 
 
-class BadModelGenericMismatchedContextAndCall(CallableModelGenericType[NullContext, MyResult]):
+class BadModelGenericMismatchedContextAndCall(CallableModelGenericType[DateContext, MyResult]):
     """Model with mismatched context_type and __call__ annotation"""
 
     @Flow.call
@@ -405,6 +412,11 @@ def test_signature(self):
         self.assertRaises(TypeError, m, context, a="foo")
         self.assertRaises(TypeError, m, context=context, a="foo")
 
+    def test_nullable_context(self):
+        m = MyCallableNullContext()
+        context = MyContext(a="foo")
+        self.assertEqual(m(context=context), m(None))
+
     def test_signature_optional_context(self):
         m = MyCallableOptionalContext()
         context = MyContext(a="foo")
@@ -460,7 +472,7 @@ def test_types(self):
         error = "__call__ method must take a single argument, named 'context'"
         self.assertRaisesRegex(ValueError, error, BadModelDoubleContextArg)
 
-        error = "The context_type <class 'ccflow.context.NullContext'> must match the type of the context accepted by __call__ <class 'ccflow.tests.test_callable.MyContext'>"
+        error = "The context_type <class 'ccflow.context.DateContext'> must match the type of the context accepted by __call__ <class 'ccflow.tests.test_callable.MyContext'>"
         self.assertRaisesRegex(ValueError, error, BadModelMismatchedContextAndCall)
 
         error = "The result_type <class 'ccflow.result.generic.GenericResult'> must match the return type of __call__ <class 'ccflow.tests.test_callable.MyResult'>"
@@ -642,7 +654,7 @@ def __call__(self, context: NullContext) -> GenericResult[float]:
             MyCallable()
 
     def test_types_generic(self):
-        error = "Context type annotation <class 'ccflow.tests.test_callable.MyContext'> on __call__ does not match context_type <class 'ccflow.context.NullContext'> defined by CallableModelGenericType"
+        error = "Context type annotation <class 'ccflow.tests.test_callable.MyContext'> on __call__ does not match context_type <class 'ccflow.context.DateContext'> defined by CallableModelGenericType"
         self.assertRaisesRegex(TypeError, error, BadModelGenericMismatchedContextAndCall)
 
         error = "Return type annotation <class 'ccflow.tests.test_callable.MyResult'> on __call__ does not match result_type <class 'ccflow.result.generic.GenericResult'> defined by CallableModelGenericType"

ccflow/tests/test_context.py

@@ -228,8 +228,6 @@ def setUp(self):
             for name, obj in inspect.getmembers(ctx, inspect.isclass)
             if obj.__module__ == ctx.__name__ and issubclass(obj, ContextBase) and not getattr(obj, "__deprecated__", False)
         }
-        # TODO - remove NullContext until we fix the inheritance
-        self.classes.pop("NullContext")
 
     def test_field_ordering(self):
         """Test that complex contexts have fields in the same order as the basic contexts they are composed of."""