Fix #320 add __cache__ property into PydanticMixin (#625)

* add __cache__ property into PydanticMixin

* add new test for exclude fields on relations

* fix the return type from __cache__  property

* run pre-commit lints/checks

Co-authored-by: collerek <collerek@gmail.com>

ormar/models/mixins/pydantic_mixin.py

@@ -22,6 +22,9 @@ from ormar.queryset.utils import translate_list_to_dict
 
 
 class PydanticMixin(RelationMixin):
+
+    __cache__: Dict[str, Type[pydantic.BaseModel]] = {}
+
     if TYPE_CHECKING:  # pragma: no cover
         __fields__: Dict[str, ModelField]
         _skip_ellipsis: Callable
@@ -68,6 +71,11 @@ class PydanticMixin(RelationMixin):
         fields_to_process.sort(
             key=lambda x: list(cls.Meta.model_fields.keys()).index(x)
         )
+
+        cache_key = f"{cls.__name__}_{str(include)}_{str(exclude)}"
+        if cache_key in cls.__cache__:
+            return cls.__cache__[cache_key]
+
         for name in fields_to_process:
             field = cls._determine_pydantic_field_type(
                 name=name,
@@ -85,6 +93,7 @@ class PydanticMixin(RelationMixin):
         )
         model = cast(Type[pydantic.BaseModel], model)
         cls._copy_field_validators(model=model)
+        cls.__cache__[cache_key] = model
         return model
 
     @classmethod

tests/test_inheritance_and_pydantic_generation/test_geting_pydantic_models.py

@@ -60,6 +60,7 @@ class MutualB(ormar.Model):
         tablename = "mutual_b"
 
     id: int = ormar.Integer(primary_key=True)
+    name = ormar.String(max_length=100, default="test")
     mutual_a = ormar.ForeignKey(MutualA, related_name="mutuals_b")
 
 
@@ -183,7 +184,26 @@ def test_getting_pydantic_model_self_ref():
     assert len(InnerSelf2.__fields__) == 2
     assert set(InnerSelf2.__fields__.keys()) == {"id", "name"}
 
-    assert InnerSelf2 != InnerSelf
+
+def test_getting_pydantic_model_self_ref_exclude():
+    PydanticSelfRef = SelfRef.get_pydantic(exclude={"children": {"name"}})
+    assert len(PydanticSelfRef.__fields__) == 4
+    assert set(PydanticSelfRef.__fields__.keys()) == {
+        "id",
+        "name",
+        "parent",
+        "children",
+    }
+
+    InnerSelf = PydanticSelfRef.__fields__["parent"].type_
+    assert len(InnerSelf.__fields__) == 2
+    assert set(InnerSelf.__fields__.keys()) == {"id", "name"}
+
+    PydanticSelfRefChildren = PydanticSelfRef.__fields__["children"].type_
+    assert len(PydanticSelfRefChildren.__fields__) == 1
+    assert set(PydanticSelfRefChildren.__fields__.keys()) == {"id"}
+    assert PydanticSelfRef != PydanticSelfRefChildren
+    assert InnerSelf != PydanticSelfRefChildren
 
 
 def test_getting_pydantic_model_mutual_rels():
@@ -193,10 +213,23 @@ def test_getting_pydantic_model_mutual_rels():
 
     MutualB1 = MutualAPydantic.__fields__["mutual_b"].type_
     MutualB2 = MutualAPydantic.__fields__["mutuals_b"].type_
-    assert MutualB1 != MutualB2
+    assert len(MutualB1.__fields__) == 2
+    assert set(MutualB1.__fields__.keys()) == {"id", "name"}
+    assert len(MutualB2.__fields__) == 2
+    assert set(MutualB2.__fields__.keys()) == {"id", "name"}
+    assert MutualB1 == MutualB2
+
+
+def test_getting_pydantic_model_mutual_rels_exclude():
+    MutualAPydantic = MutualA.get_pydantic(exclude={"mutual_b": {"name"}})
+    assert len(MutualAPydantic.__fields__) == 3
+    assert set(MutualAPydantic.__fields__.keys()) == {"id", "mutual_b", "mutuals_b"}
+
+    MutualB1 = MutualAPydantic.__fields__["mutual_b"].type_
+    MutualB2 = MutualAPydantic.__fields__["mutuals_b"].type_
 
     assert len(MutualB1.__fields__) == 1
-    assert "id" in MutualB1.__fields__
+    assert set(MutualB1.__fields__.keys()) == {"id"}
-
+    assert len(MutualB2.__fields__) == 2
-    assert len(MutualB2.__fields__) == 1
+    assert set(MutualB2.__fields__.keys()) == {"id", "name"}
-    assert "id" in MutualB2.__fields__
+    assert MutualB1 != MutualB2