fix: correctly handle collections with constrained items (#436)

polyfactory/factories/pydantic_factory.py

@@ -39,7 +39,7 @@
 
 if TYPE_CHECKING:
     from random import Random
-    from typing import Callable
+    from typing import Callable, Sequence
 
     from typing_extensions import NotRequired, TypeGuard
 
@@ -284,6 +284,19 @@ def from_model_field(  # pragma: no cover
             constraints=cast("PydanticConstraints", {k: v for k, v in constraints.items() if v is not None}) or None,
         )
 
+    if VERSION.startswith("2"):
+
+        @classmethod
+        def get_constraints_metadata(cls, annotation: Any) -> Sequence[Any]:
+            metadata = []
+            for m in super().get_constraints_metadata(annotation):
+                if isinstance(m, FieldInfo):
+                    metadata.extend(m.metadata)
+                else:
+                    metadata.append(m)
+
+            return metadata
+
 
 class ModelFactory(Generic[T], BaseFactory[T]):
     """Base factory for pydantic models"""

polyfactory/field_meta.py

@@ -8,14 +8,21 @@
 from polyfactory.collection_extender import CollectionExtender
 from polyfactory.constants import DEFAULT_RANDOM, TYPE_MAPPING
 from polyfactory.utils.deprecation import check_for_deprecated_parameters
-from polyfactory.utils.helpers import normalize_annotation, unwrap_annotated, unwrap_args, unwrap_new_type
+from polyfactory.utils.helpers import (
+    get_annotation_metadata,
+    normalize_annotation,
+    unwrap_annotated,
+    unwrap_args,
+    unwrap_new_type,
+)
 from polyfactory.utils.predicates import is_annotated, is_any_annotated
 
 if TYPE_CHECKING:
     import datetime
+    from decimal import Decimal
     from random import Random
+    from typing import Sequence
 
-    from _pydecimal import Decimal
     from typing_extensions import NotRequired, Self
 
 
@@ -134,7 +141,7 @@ def from_type(
         field_type = normalize_annotation(annotation, random=random)
 
         if not constraints and is_annotated(annotation):
-            _, metadata = unwrap_annotated(annotation, random=random)
+            metadata = cls.get_constraints_metadata(annotation)
             constraints = cls.parse_constraints(metadata)
 
         if not is_any_annotated(annotation):
@@ -156,7 +163,7 @@ def from_type(
             number_of_args = 1
             extended_type_args = CollectionExtender.extend_type_args(field.annotation, field.type_args, number_of_args)
             field.children = [
-                FieldMeta.from_type(
+                cls.from_type(
                     annotation=unwrap_new_type(arg),
                     random=random,
                 )
@@ -165,7 +172,7 @@ def from_type(
         return field
 
     @classmethod
-    def parse_constraints(cls, metadata: list[Any]) -> "Constraints":
+    def parse_constraints(cls, metadata: Sequence[Any]) -> "Constraints":
         constraints = {}
 
         for value in metadata:
@@ -215,3 +222,15 @@ def parse_constraints(cls, metadata: list[Any]) -> "Constraints":
                     },
                 )
         return cast("Constraints", constraints)
+
+    @classmethod
+    def get_constraints_metadata(cls, annotation: Any) -> Sequence[Any]:
+        """Get the metadatas of the constraints from the given annotation.
+
+        :param annotation: A type annotation.
+        :param random: An instance of random.Random.
+
+        :returns: A list of the metadata in the annotation.
+        """
+
+        return get_annotation_metadata(annotation)

polyfactory/utils/helpers.py

@@ -21,6 +21,7 @@
 
 if TYPE_CHECKING:
     from random import Random
+    from typing import Sequence
 
 
 def unwrap_new_type(annotation: Any) -> Any:
@@ -162,6 +163,17 @@ def normalize_annotation(annotation: Any, random: Random) -> Any:
     return origin
 
 
+def get_annotation_metadata(annotation: Any) -> Sequence[Any]:
+    """Get the metadata in the annotation.
+
+    :param annotation: A type annotation.
+
+    :returns: The metadata.
+    """
+
+    return get_args(annotation)[1:]
+
+
 def get_collection_type(annotation: Any) -> type[list | tuple | set | frozenset | dict]:
     """Get the collection type from the annotation.
 

tests/test_msgspec_factory.py

@@ -7,7 +7,7 @@
 
 import msgspec
 import pytest
-from msgspec import Struct, structs
+from msgspec import Meta, Struct, structs
 from typing_extensions import Annotated
 
 from polyfactory.exceptions import ParameterException
@@ -215,3 +215,37 @@ class BarFactory(MsgspecFactory[Bar]):
 
     validated_bar = msgspec.convert(bar_dict, type=Bar)
     assert validated_bar == bar
+
+
+def test_sequence_with_constrained_item_types() -> None:
+    ConstrainedInt = Annotated[int, Meta(ge=100, le=200)]
+
+    class Foo(Struct):
+        list_field: List[ConstrainedInt]
+        tuple_field: Tuple[ConstrainedInt]
+        variable_tuple_field: Tuple[ConstrainedInt, ...]
+        set_field: Set[ConstrainedInt]
+
+    class FooFactory(MsgspecFactory[Foo]):
+        __model__ = Foo
+
+    foo = FooFactory.build()
+    validated_foo = msgspec.convert(structs.asdict(foo), Foo)
+
+    assert validated_foo == foo
+
+
+def test_mapping_with_constrained_item_types() -> None:
+    ConstrainedInt = Annotated[int, Meta(ge=100, le=200)]
+    ConstrainedStr = Annotated[str, Meta(min_length=1, max_length=3)]
+
+    class Foo(Struct):
+        dict_field = Dict[ConstrainedStr, ConstrainedInt]
+
+    class FooFactory(MsgspecFactory[Foo]):
+        __model__ = Foo
+
+    foo = FooFactory.build()
+    validated_foo = msgspec.convert(structs.asdict(foo), Foo)
+
+    assert validated_foo == foo

tests/test_pydantic_factory.py

@@ -1,8 +1,9 @@
 import sys
-from typing import Optional
+from typing import Dict, List, Optional, Set, Tuple
 
 import pytest
 from pydantic import VERSION, BaseModel, Field, Json
+from typing_extensions import Annotated
 
 from polyfactory.factories.pydantic_factory import ModelFactory
 
@@ -78,3 +79,31 @@ class BFactory(ModelFactory[B]):
         __model__ = B
 
     assert isinstance(BFactory.build(), B)
+
+
+def test_sequence_with_annotated_item_types() -> None:
+    ConstrainedInt = Annotated[int, Field(ge=100, le=200)]
+
+    class Foo(BaseModel):
+        list_field: List[ConstrainedInt]
+        tuple_field: Tuple[ConstrainedInt]
+        variable_tuple_field: Tuple[ConstrainedInt, ...]
+        set_field: Set[ConstrainedInt]
+
+    class FooFactory(ModelFactory[Foo]):
+        __model__ = Foo
+
+    assert FooFactory.build()
+
+
+def test_mapping_with_annotated_item_types() -> None:
+    ConstrainedInt = Annotated[int, Field(ge=100, le=200)]
+    ConstrainedStr = Annotated[str, Field(min_length=1, max_length=3)]
+
+    class Foo(BaseModel):
+        dict_field: Dict[ConstrainedStr, ConstrainedInt]
+
+    class FooFactory(ModelFactory[Foo]):
+        __model__ = Foo
+
+    assert FooFactory.build()