add test for select_related with limit

ormar/models/metaclass.py

@@ -1,6 +1,17 @@
 import logging
 import warnings
-from typing import Any, Dict, List, Optional, Set, TYPE_CHECKING, Tuple, Type, Union, cast
+from typing import (
+    Any,
+    Dict,
+    List,
+    Optional,
+    Set,
+    TYPE_CHECKING,
+    Tuple,
+    Type,
+    Union,
+    cast,
+)
 
 import databases
 import pydantic
@@ -540,9 +551,7 @@ def update_attrs_and_fields(
     model_fields.update(new_model_fields)
 
 
-def update_attrs_from_base_meta(
-        base_class: "Model",
-        attrs: Dict, ) -> None:
+def update_attrs_from_base_meta(base_class: "Model", attrs: Dict,) -> None:
     """
     Updates Meta parameters in child from parent if needed.
 
@@ -564,7 +573,9 @@ def update_attrs_from_base_meta(
                     curr_value.union(getattr(base_class.Meta, param))
                 else:
                     # overwrite with child value if both set and its param / object
-                    setattr(attrs["Meta"], param, getattr(base_class.Meta, param)) # pragma: no cover
+                    setattr(
+                        attrs["Meta"], param, getattr(base_class.Meta, param)
+                    )  # pragma: no cover
             else:
                 setattr(attrs["Meta"], param, getattr(base_class.Meta, param))
 
@@ -603,7 +614,9 @@ def extract_mixin_fields_from_dict(
     if hasattr(base_class, "Meta"):
         if attrs.get("Meta"):
             new_fields = set(base_class.Meta.model_fields.keys())  # type: ignore
-            previous_fields = set({k for k, v in attrs.items() if isinstance(v, FieldInfo)})
+            previous_fields = set(
+                {k for k, v in attrs.items() if isinstance(v, FieldInfo)}
+            )
             check_conflicting_fields(
                 new_fields=new_fields,
                 attrs=attrs,

tests/test_select_related_with_limit.py

@@ -0,0 +1,107 @@
+from typing import List, Optional
+
+import databases
+import sqlalchemy
+from sqlalchemy import create_engine
+
+import ormar
+import pytest
+
+from tests.settings import DATABASE_URL
+
+db = databases.Database(DATABASE_URL, force_rollback=True)
+metadata = sqlalchemy.MetaData()
+
+
+class Keyword(ormar.Model):
+    class Meta:
+        metadata = metadata
+        database = db
+        tablename = "keywords"
+
+    id: int = ormar.Integer(primary_key=True)
+    name: str = ormar.String(max_length=50)
+
+
+class KeywordPrimaryModel(ormar.Model):
+    class Meta:
+        metadata = metadata
+        database = db
+        tablename = "primary_models_keywords"
+
+    id: int = ormar.Integer(primary_key=True)
+
+
+class PrimaryModel(ormar.Model):
+    class Meta:
+        metadata = metadata
+        database = db
+        tablename = "primary_models"
+
+    id: int = ormar.Integer(primary_key=True)
+    name: str = ormar.String(max_length=255, index=True)
+    some_text: str = ormar.Text()
+    some_other_text: Optional[str] = ormar.Text(nullable=True)
+    keywords: Optional[List[Keyword]] = ormar.ManyToMany(
+        Keyword, through=KeywordPrimaryModel
+    )
+
+
+class SecondaryModel(ormar.Model):
+    class Meta:
+        metadata = metadata
+        database = db
+        tablename = "secondary_models"
+
+    id: int = ormar.Integer(primary_key=True)
+    name: str = ormar.String(max_length=100)
+    primary_model: PrimaryModel = ormar.ForeignKey(
+        PrimaryModel,
+        related_name="secondary_models",
+    )
+
+
+@pytest.mark.asyncio
+async def test_create_primary_models():
+    async with db:
+        for name, some_text, some_other_text in [
+            ("Primary 1", "Some text 1", "Some other text 1"),
+            ("Primary 2", "Some text 2", "Some other text 2"),
+            ("Primary 3", "Some text 3", "Some other text 3"),
+            ("Primary 4", "Some text 4", "Some other text 4"),
+            ("Primary 5", "Some text 5", "Some other text 5"),
+            ("Primary 6", "Some text 6", "Some other text 6"),
+            ("Primary 7", "Some text 7", "Some other text 7"),
+            ("Primary 8", "Some text 8", "Some other text 8"),
+            ("Primary 9", "Some text 9", "Some other text 9"),
+            ("Primary 10", "Some text 10", "Some other text 10")]:
+            await PrimaryModel(
+                name=name, some_text=some_text, some_other_text=some_other_text
+            ).save()
+
+        for tag_id in [1, 2, 3, 4, 5]:
+            await Keyword.objects.create(name=f"Tag {tag_id}")
+
+        p1 = await PrimaryModel.objects.get(pk=1)
+        p2 = await PrimaryModel.objects.get(pk=2)
+        for i in range(1, 6):
+            keyword = await Keyword.objects.get(pk=i)
+            if i % 2 == 0:
+                await p1.keywords.add(keyword)
+            else:
+                await p2.keywords.add(keyword)
+        models = await PrimaryModel.objects.prefetch_related("keywords").limit(5).all()
+
+        # This test fails, because of the keywords relation.
+        assert len(models) == 5
+        assert len(models[0].keywords) == 2
+        assert len(models[1].keywords) == 3
+        assert len(models[2].keywords) == 0
+
+
+@pytest.fixture(autouse=True, scope="module")
+def create_test_database():
+    engine = create_engine(DATABASE_URL)
+    metadata.create_all(engine)
+    yield
+    metadata.drop_all(engine)