Merge pull request #1473 from dmach/nested-models

Support nested models + related fixes

osc/util/models.py

@@ -13,6 +13,7 @@ import types
 from typing import get_type_hints
 
 # supported types
+from enum import Enum
 from typing import Any
 from typing import Dict
 from typing import List
@@ -40,6 +41,7 @@ __all__ = (
     "Field",
     "NotSet",
     "FromParent",
+    "Enum",
     "Dict",
     "List",
     "NewType",
@@ -125,9 +127,26 @@ class Field(property):
         origin_type = get_origin(self.type) or self.type
         if self.is_optional:
             types = [i for i in self.type.__args__ if i != type(None)]
-            return types[0]
+            return get_origin(types[0]) or types[0]
         return origin_type
 
+    @property
+    def inner_type(self):
+        if self.is_optional:
+            types = [i for i in self.type.__args__ if i != type(None)]
+            type_ = types[0]
+        else:
+            type_ = self.type
+
+        if get_origin(type_) != list:
+            return None
+
+        if not hasattr(type_, "__args__"):
+            return None
+
+        inner_type = [i for i in type_.__args__ if i != type(None)][0]
+        return inner_type
+
     @property
     def is_optional(self):
         origin_type = get_origin(self.type) or self.type
@@ -137,6 +156,10 @@ class Field(property):
     def is_model(self):
         return inspect.isclass(self.origin_type) and issubclass(self.origin_type, BaseModel)
 
+    @property
+    def is_model_list(self):
+        return inspect.isclass(self.inner_type) and issubclass(self.inner_type, BaseModel)
+
     def validate_type(self, value, expected_types=None):
         if not expected_types and self.is_optional and value is None:
             return True
@@ -176,6 +199,15 @@ class Field(property):
                 valid_type = True
                 continue
 
+            if (
+                inspect.isclass(expected_type)
+                and issubclass(expected_type, Enum)
+            ):
+                # test if the value is part of the enum
+                expected_type(value)
+                valid_type = True
+                continue
+
             if not isinstance(value, origin_type):
                 msg = f"Field '{self.name}' has type '{self.type}'. Cannot assign a value with type '{type(value).__name__}'."
                 raise TypeError(msg)
@@ -241,9 +273,17 @@ class Field(property):
     def set(self, obj, value):
         # if this is a model field, convert dict to a model instance
         if self.is_model and isinstance(value, dict):
-            new_value = self.origin_type()  # pylint: disable=not-callable
+            # initialize a model instance from a dictionary
-            for k, v in value.items():
+            klass = self.origin_type
-                setattr(new_value, k, v)
+            value = klass(**value)  # pylint: disable=not-callable
+        elif self.is_model_list and isinstance(value, list):
+            new_value = []
+            for i in value:
+                if isinstance(i, dict):
+                    klass = self.inner_type
+                    new_value.append(klass(**i))
+                else:
+                    new_value.append(i)
             value = new_value
 
         self.validate_type(value)
@@ -311,12 +351,12 @@ class BaseModel(metaclass=ModelMeta):
 
         if kwargs:
             unknown_fields_str = ", ".join([f"'{i}'" for i in kwargs])
-            raise TypeError(f"The following kwargs do not match any field: {unknown_fields_str}")
+            raise TypeError(f"The following kwargs of '{self.__class__.__name__}.__init__()' do not match any field: {unknown_fields_str}")
 
         if uninitialized_fields:
             uninitialized_fields_str = ", ".join([f"'{i}'" for i in uninitialized_fields])
             raise TypeError(
-                f"The following fields are not initialized and have no default either: {uninitialized_fields_str}"
+                f"The following fields of '{self.__class__.__name__}' object are not initialized and have no default either: {uninitialized_fields_str}"
             )
 
         for name, field in self.__fields__.items():
@@ -329,8 +369,12 @@ class BaseModel(metaclass=ModelMeta):
         for name, field in self.__fields__.items():
             if field.exclude:
                 continue
-            if field.is_model:
+            value = getattr(self, name)
-                result[name] = getattr(self, name).dict()
+            if value is not None and field.is_model:
+                result[name] = value.dict()
+            if value is not None and field.is_model_list:
+                result[name] = [i.dict() for i in value]
             else:
-                result[name] = getattr(self, name)
+                result[name] = value
+
         return result

tests/test_models.py

@@ -186,14 +186,91 @@ class Test(unittest.TestCase):
         self.assertEqual(field.is_optional, True)
         self.assertEqual(field.origin_type, TestSubmodel)
         self.assertEqual(m.field, None)
+        m.dict()
 
         m = TestModel(field=TestSubmodel())
         self.assertIsInstance(m.field, TestSubmodel)
         self.assertEqual(m.field.text, "default")
+        m.dict()
 
         m = TestModel(field={"text": "text"})
         self.assertNotEqual(m.field, None)
         self.assertEqual(m.field.text, "text")
+        m.dict()
+
+    def test_list_submodels(self):
+        class TestSubmodel(BaseModel):
+            text: str = Field(default="default")
+
+        class TestModel(BaseModel):
+            field: List[TestSubmodel] = Field(default=[])
+
+        m = TestModel()
+
+        field = m.__fields__["field"]
+        self.assertEqual(field.is_model, False)
+        self.assertEqual(field.is_model_list, True)
+        self.assertEqual(field.is_optional, False)
+        self.assertEqual(field.origin_type, list)
+        m.dict()
+
+        m = TestModel(field=[TestSubmodel()])
+        self.assertEqual(m.field[0].text, "default")
+        m.dict()
+
+        m = TestModel(field=[{"text": "text"}])
+        self.assertEqual(m.field[0].text, "text")
+        m.dict()
+
+        self.assertRaises(TypeError, getattr(m, "field"))
+
+    def test_optional_list_submodels(self):
+        class TestSubmodel(BaseModel):
+            text: str = Field(default="default")
+
+        class TestModel(BaseModel):
+            field: Optional[List[TestSubmodel]] = Field(default=[])
+
+        m = TestModel()
+
+        field = m.__fields__["field"]
+        self.assertEqual(field.is_model, False)
+        self.assertEqual(field.is_model_list, True)
+        self.assertEqual(field.is_optional, True)
+        self.assertEqual(field.origin_type, list)
+        m.dict()
+
+        m = TestModel(field=[TestSubmodel()])
+        self.assertEqual(m.field[0].text, "default")
+        m.dict()
+
+        m = TestModel(field=[{"text": "text"}])
+        self.assertEqual(m.field[0].text, "text")
+        m.dict()
+
+        m.field = None
+        self.assertEqual(m.field, None)
+        m.dict()
+
+    def test_enum(self):
+        class Numbers(Enum):
+            one = "one"
+            two = "two"
+
+        class TestModel(BaseModel):
+            field: Optional[Numbers] = Field(default=None)
+
+        m = TestModel()
+        field = m.__fields__["field"]
+        self.assertEqual(field.is_model, False)
+        self.assertEqual(field.is_optional, True)
+        self.assertEqual(field.origin_type, Numbers)
+        self.assertEqual(m.field, None)
+
+        m.field = "one"
+        self.assertEqual(m.field, "one")
+
+        self.assertRaises(ValueError, setattr, m, "field", "does-not-exist")
 
     def test_parent(self):
         class ParentModel(BaseModel):