Fix Interface mapping (#24)

Fixes a bug where an Interface is not properly registered, resulting in an infinite-loop for mapping Interfaces to polymorphic Models.

Changes:

Properly adds Interfaces to mapped_interfaces
Updates deprecated _type_definition references to __strawberry_definition__

Author: asimov-layton

RELEASE.md

@@ -0,0 +1,3 @@
+Release type: patch
+
+Fixes a bug where an Interface is not properly registered, resulting in an infinite-loop for mapping Interfaces to polymorphic Models.

src/strawberry_sqlalchemy_mapper/mapper.py

@@ -683,11 +683,13 @@ def convert(type_: Any) -> Any:
 
             if make_interface:
                 mapped_type = strawberry.interface(type_)
+                self.mapped_interfaces[type_.__name__] = mapped_type
             elif use_federation:
                 mapped_type = strawberry.federation.type(type_)
+                self.mapped_types[type_.__name__] = mapped_type
             else:
                 mapped_type = strawberry.type(type_)
-            self.mapped_types[type_.__name__] = mapped_type
+                self.mapped_types[type_.__name__] = mapped_type
             setattr(mapped_type, _GENERATED_FIELD_KEYS_KEY, generated_field_keys)
             setattr(mapped_type, _ORIGINAL_TYPE_KEY, type_)
             return mapped_type
@@ -728,7 +730,7 @@ def _fix_annotation_namespaces(self) -> None:
             self.edge_types.values(),
             self.connection_types.values(),
         ):
-            for field in mapped_type._type_definition.fields:
+            for field in mapped_type.__strawberry_definition__.fields:
                 if field.name in getattr(mapped_type, _GENERATED_FIELD_KEYS_KEY):
                     namespace = {}
                     if hasattr(mapped_type, _ORIGINAL_TYPE_KEY):

tests/test_mapper.py

@@ -1,6 +1,7 @@
 import enum
 from typing import List, Optional
 
+import pytest
 from sqlalchemy import Column, Enum, ForeignKey, Integer, String
 from sqlalchemy.dialects.postgresql.array import ARRAY
 from sqlalchemy.ext.declarative import declarative_base
@@ -10,6 +11,34 @@
 from strawberry_sqlalchemy_mapper import StrawberrySQLAlchemyMapper
 
 
+@pytest.fixture
+def mapper():
+    return StrawberrySQLAlchemyMapper()
+
+
+@pytest.fixture
+def polymorphic_employee():
+    Base = declarative_base()
+
+    class Employee(Base):
+        __tablename__ = "employee"
+        id = Column(Integer, autoincrement=True, primary_key=True)
+        type = Column(String(50))
+        name = Column(String(50))
+
+        __mapper_args__ = {"polymorphic_identity": "employee", "polymorphic_on": type}
+
+    return Employee
+
+
+@pytest.fixture
+def polymorphic_lawyer(polymorphic_employee):
+    class Lawyer(polymorphic_employee):
+        __mapper_args__ = {"polymorphic_identity": "lawyer"}
+
+    return Lawyer
+
+
 def _create_employee_table():
     # todo: use pytest fixtures
     Base = declarative_base()
@@ -233,14 +262,41 @@ class Employee:
     assert len(additional_types) == 1
     mapped_employee_type = additional_types[0]
     assert mapped_employee_type.__name__ == "Employee"
-    assert len(mapped_employee_type._type_definition._fields) == 2
-    employee_type_fields = mapped_employee_type._type_definition._fields
+    assert len(mapped_employee_type.__strawberry_definition__._fields) == 2
+    employee_type_fields = mapped_employee_type.__strawberry_definition__._fields
     name = list(filter(lambda f: f.name == "name", employee_type_fields))[0]
     assert name.type == str
     id = list(filter(lambda f: f.name == "id", employee_type_fields))[0]
     assert id.type == int
 
 
+def test_interface_and_type_polymorphic(
+    mapper, polymorphic_employee, polymorphic_lawyer
+):
+    @mapper.interface(polymorphic_employee)
+    class EmployeeInterface:
+        pass
+
+    @mapper.type(polymorphic_employee)
+    class Employee:
+        pass
+
+    @mapper.type(polymorphic_lawyer)
+    class Lawyer:
+        pass
+
+    mapper.finalize()
+
+    additional_interfaces = list(mapper.mapped_interfaces.values())
+    assert len(additional_interfaces) == 1
+    mapped_employee_interface_type = additional_interfaces[0]
+    assert mapped_employee_interface_type.__name__ == "EmployeeInterface"
+
+    additional_types = list(mapper.mapped_types.values())
+    assert len(additional_types) == 2
+    assert {"Employee", "Lawyer"} == {t.__name__ for t in additional_types}
+
+
 def test_type_relationships():
     Employee, _ = _create_employee_and_department_tables()
     strawberry_sqlalchemy_mapper = StrawberrySQLAlchemyMapper()
@@ -254,8 +310,8 @@ class Employee:
     assert len(additional_types) == 2
     mapped_employee_type = additional_types[0]
     assert mapped_employee_type.__name__ == "Employee"
-    assert len(mapped_employee_type._type_definition._fields) == 4
-    employee_type_fields = mapped_employee_type._type_definition._fields
+    assert len(mapped_employee_type.__strawberry_definition__._fields) == 4
+    employee_type_fields = mapped_employee_type.__strawberry_definition__._fields
     name = list(filter(lambda f: f.name == "department_id", employee_type_fields))[0]
     assert type(name.type) == StrawberryOptional
     id = list(filter(lambda f: f.name == "department", employee_type_fields))[0]