diff --git a/pyproject.toml b/pyproject.toml
index 3f46a80..0f34c91 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -127,8 +127,7 @@ markers = [
 
 [tool.ruff]
 target-version = "py39"
-include = ["src/numpydantic/**/*.py", "pyproject.toml"]
-exclude = ["tests"]
+include = ["src/numpydantic/**/*.py", "tests/**/*.py", "pyproject.toml"]
 
 [tool.ruff.lint]
 select = [
@@ -177,6 +176,10 @@ ignore = [
 
 fixable = ["ALL"]
 
+[tool.ruff.lint.per-file-ignores]
+"src/numpydantic/testing/*" = ["D", "F722"]
+"tests/*" = ["D", "F403", "F722", "ANN", ]
+
 [tool.mypy]
 plugins = [
     "pydantic.mypy"
diff --git a/src/numpydantic/testing/cases.py b/src/numpydantic/testing/cases.py
index dd9274d..26f1227 100644
--- a/src/numpydantic/testing/cases.py
+++ b/src/numpydantic/testing/cases.py
@@ -18,7 +18,6 @@ else:
     YES_PIPE = False
 
 
-
 class BasicModel(BaseModel):
     x: int
 
@@ -129,4 +128,3 @@ if YES_PIPE:
             "union-pipe-str",
         ]
     )
-
diff --git a/src/numpydantic/testing/helpers.py b/src/numpydantic/testing/helpers.py
index 4b196d0..3d0ae56 100644
--- a/src/numpydantic/testing/helpers.py
+++ b/src/numpydantic/testing/helpers.py
@@ -1,5 +1,6 @@
 from typing import Any, Tuple, Type, Union
 
+import numpy as np
 from pydantic import BaseModel, ConfigDict, computed_field
 
 from numpydantic import NDArray, Shape
diff --git a/tests/conftest.py b/tests/conftest.py
index cea8ea6..9e6a39a 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -1,7 +1,10 @@
-import sys
-
-from numpydantic.testing.cases import YES_PIPE, RGB_UNION, UNION_PIPE, DTYPE_CASES, DTYPE_IDS
+import pytest
 
+from numpydantic.testing.cases import (
+    DTYPE_CASES,
+    DTYPE_IDS,
+    RGB_UNION,
+)
 from numpydantic.testing.helpers import ValidationCase
 from tests.fixtures import *
 
@@ -14,9 +17,6 @@ def pytest_addoption(parser):
     )
 
 
-
-
-
 @pytest.fixture(
     scope="module",
     params=[
diff --git a/tests/fixtures/__init__.py b/tests/fixtures/__init__.py
index d7efce2..f080c4f 100644
--- a/tests/fixtures/__init__.py
+++ b/tests/fixtures/__init__.py
@@ -1,3 +1,3 @@
-from .paths import *
 from .generation import *
-from .models import *
\ No newline at end of file
+from .models import *
+from .paths import *
diff --git a/tests/fixtures/generation.py b/tests/fixtures/generation.py
index a6dd6f6..05f68b0 100644
--- a/tests/fixtures/generation.py
+++ b/tests/fixtures/generation.py
@@ -24,15 +24,16 @@ def hdf5_array(
         compound: bool = False,
     ) -> H5ArrayPath:
         array_path = "/" + "_".join([str(s) for s in shape]) + "__" + dtype.__name__
-
+        generator = np.random.default_rng()
+        
         if not compound:
             if dtype is str:
-                data = np.random.random(shape).astype(bytes)
+                data = generator.random(shape).astype(bytes)
             elif dtype is datetime:
                 data = np.empty(shape, dtype="S32")
                 data.fill(datetime.now(timezone.utc).isoformat().encode("utf-8"))
             else:
-                data = np.random.random(shape).astype(dtype)
+                data = generator.random(shape).astype(dtype)
 
             h5path = H5ArrayPath(hdf5_file, array_path)
         else:
@@ -64,7 +65,7 @@ def zarr_nested_array(tmp_output_dir_func) -> ZarrArrayPath:
     file = tmp_output_dir_func / "nested.zarr"
     path = "a/b/c"
     root = zarr.open(str(file), mode="w")
-    array = root.zeros(path, shape=(100, 100), chunks=(10, 10))
+    _ = root.zeros(path, shape=(100, 100), chunks=(10, 10))
     return ZarrArrayPath(file=file, path=path)
 
 
diff --git a/tests/fixtures/models.py b/tests/fixtures/models.py
index 088c661..08f1ac3 100644
--- a/tests/fixtures/models.py
+++ b/tests/fixtures/models.py
@@ -1,4 +1,4 @@
-from typing import Callable, Tuple, Union, Type, Optional, Any
+from typing import Any, Callable, Optional, Tuple, Type, Union
 
 import numpy as np
 import pytest
diff --git a/tests/fixtures/paths.py b/tests/fixtures/paths.py
index c3cab21..2a6b133 100644
--- a/tests/fixtures/paths.py
+++ b/tests/fixtures/paths.py
@@ -20,7 +20,8 @@ def tmp_output_dir(request: pytest.FixtureRequest) -> Path:
         except PermissionError as e:
             # sporadic error on windows machines...
             warn(
-                f"Temporary directory could not be removed due to a permissions error: \n{str(e)}"
+                "Temporary directory could not be removed due to a permissions error: "
+                f"\n{str(e)}"
             )
 
 
diff --git a/tests/test_interface/conftest.py b/tests/test_interface/conftest.py
index 5d36fa5..3917ae9 100644
--- a/tests/test_interface/conftest.py
+++ b/tests/test_interface/conftest.py
@@ -1,12 +1,12 @@
-import pytest
-
 from typing import Callable, Tuple, Type
-import numpy as np
+
 import dask.array as da
+import numpy as np
+import pytest
 import zarr
 from pydantic import BaseModel
 
-from numpydantic import interface, NDArray
+from numpydantic import NDArray, interface
 
 
 @pytest.fixture(
diff --git a/tests/test_interface/test_dask.py b/tests/test_interface/test_dask.py
index 919455f..a7c17d4 100644
--- a/tests/test_interface/test_dask.py
+++ b/tests/test_interface/test_dask.py
@@ -1,12 +1,11 @@
-import pytest
 import json
 
 import dask.array as da
+import pytest
 from pydantic import BaseModel, ValidationError
 
-from numpydantic.interface import DaskInterface
 from numpydantic.exceptions import DtypeError, ShapeError
-
+from numpydantic.interface import DaskInterface
 from numpydantic.testing.helpers import ValidationCase
 
 pytestmark = pytest.mark.dask
diff --git a/tests/test_interface/test_hdf5.py b/tests/test_interface/test_hdf5.py
index 361eb90..9dec0b5 100644
--- a/tests/test_interface/test_hdf5.py
+++ b/tests/test_interface/test_hdf5.py
@@ -1,17 +1,16 @@
 import json
-from datetime import datetime, timezone
+from datetime import datetime
 from typing import Any
 
 import h5py
+import numpy as np
 import pytest
 from pydantic import BaseModel, ValidationError
 
-import numpy as np
 from numpydantic import NDArray, Shape
+from numpydantic.exceptions import DtypeError, ShapeError
 from numpydantic.interface import H5Interface
 from numpydantic.interface.hdf5 import H5ArrayPath, H5Proxy
-from numpydantic.exceptions import DtypeError, ShapeError
-
 from numpydantic.testing.helpers import ValidationCase
 
 pytestmark = pytest.mark.hdf5
@@ -221,10 +220,7 @@ def test_empty_dataset(dtype, tmp_path):
     Empty datasets shouldn't choke us during validation
     """
     array_path = tmp_path / "test.h5"
-    if dtype in (str, datetime):
-        np_dtype = "S32"
-    else:
-        np_dtype = dtype
+    np_dtype = "S32" if dtype in (str, datetime) else dtype
 
     with h5py.File(array_path, "w") as h5f:
         _ = h5f.create_dataset(name="/data", dtype=np_dtype)
diff --git a/tests/test_interface/test_interface_base.py b/tests/test_interface/test_interface_base.py
index 0b99ae6..1aa17e1 100644
--- a/tests/test_interface/test_interface_base.py
+++ b/tests/test_interface/test_interface_base.py
@@ -6,18 +6,17 @@ for tests that should apply to all interfaces, use ``test_interfaces.py``
 import gc
 from typing import Literal
 
-import pytest
 import numpy as np
+import pytest
+from pydantic import ValidationError
 
 from numpydantic.interface import (
     Interface,
-    JsonDict,
     InterfaceMark,
-    NumpyInterface,
+    JsonDict,
     MarkedJson,
+    NumpyInterface,
 )
-from pydantic import ValidationError
-
 from numpydantic.interface.interface import V
 
 
@@ -46,9 +45,7 @@ def interfaces():
         @classmethod
         def check(cls, array):
             cls.checked = True
-            if isinstance(array, list):
-                return True
-            return False
+            return isinstance(array, list)
 
         @classmethod
         def enabled(cls) -> bool:
@@ -94,7 +91,8 @@ def interfaces():
 
 def test_interface_match_error(interfaces):
     """
-    Test that `match` and `match_output` raises errors when no or multiple matches are found
+    Test that `match` and `match_output` raises errors when no or multiple matches 
+    are found
     """
     with pytest.raises(ValueError) as e:
         Interface.match([1, 2, 3])
diff --git a/tests/test_interface/test_interfaces.py b/tests/test_interface/test_interfaces.py
index faec0d8..f6efc16 100644
--- a/tests/test_interface/test_interfaces.py
+++ b/tests/test_interface/test_interfaces.py
@@ -2,15 +2,15 @@
 Tests that should be applied to all interfaces
 """
 
-import pytest
-from typing import Callable
-from importlib.metadata import version
 import json
+from importlib.metadata import version
+from typing import Callable
 
-import numpy as np
 import dask.array as da
-from zarr.core import Array as ZarrArray
+import numpy as np
+import pytest
 from pydantic import BaseModel
+from zarr.core import Array as ZarrArray
 
 from numpydantic.interface import Interface, InterfaceMark, MarkedJson
 
diff --git a/tests/test_interface/test_numpy.py b/tests/test_interface/test_numpy.py
index 17bfe9b..e93bffb 100644
--- a/tests/test_interface/test_numpy.py
+++ b/tests/test_interface/test_numpy.py
@@ -1,8 +1,8 @@
 import numpy as np
 import pytest
-from pydantic import ValidationError, BaseModel
-from numpydantic.exceptions import DtypeError, ShapeError
+from pydantic import BaseModel, ValidationError
 
+from numpydantic.exceptions import DtypeError, ShapeError
 from numpydantic.testing.helpers import ValidationCase
 
 pytestmark = pytest.mark.numpy
diff --git a/tests/test_interface/test_video.py b/tests/test_interface/test_video.py
index 5f03a57..a99300c 100644
--- a/tests/test_interface/test_video.py
+++ b/tests/test_interface/test_video.py
@@ -2,12 +2,10 @@
 Needs to be refactored to DRY, but works for now
 """
 
-import numpy as np
-import pytest
-
 from pathlib import Path
-import cv2
 
+import cv2
+import pytest
 from pydantic import BaseModel, ValidationError
 
 from numpydantic import NDArray, Shape
@@ -65,7 +63,7 @@ def test_video_wrong_shape(avi_video):
 
     # should correctly validate :)
     with pytest.raises(ValidationError):
-        instance = MyModel(array=vid)
+        _ = MyModel(array=vid)
 
 
 @pytest.mark.proxy
diff --git a/tests/test_interface/test_zarr.py b/tests/test_interface/test_zarr.py
index 2fa086c..af0d7e9 100644
--- a/tests/test_interface/test_zarr.py
+++ b/tests/test_interface/test_zarr.py
@@ -2,14 +2,11 @@ import json
 
 import pytest
 import zarr
-
 from pydantic import BaseModel, ValidationError
-from numcodecs import Pickle
 
+from numpydantic.exceptions import DtypeError, ShapeError
 from numpydantic.interface import ZarrInterface
 from numpydantic.interface.zarr import ZarrArrayPath
-from numpydantic.exceptions import DtypeError, ShapeError
-
 from numpydantic.testing.helpers import ValidationCase
 
 pytestmark = pytest.mark.zarr
@@ -36,7 +33,7 @@ def nested_dir_array(tmp_output_dir_func) -> zarr.NestedDirectoryStore:
 def _zarr_array(case: ValidationCase, store) -> zarr.core.Array:
     if issubclass(case.dtype, BaseModel):
         pytest.skip(
-            f"Zarr can't handle objects properly at the moment, "
+            "Zarr can't handle objects properly at the moment, "
             "see https://github.com/zarr-developers/zarr-python/issues/2081"
         )
         # return zarr.full(
@@ -103,14 +100,14 @@ def test_zarr_from_tuple(array, model_blank, request):
     """Should be able to do the same validation logic from tuples as an input"""
     array = request.getfixturevalue(array)
     if isinstance(array, ZarrArrayPath):
-        instance = model_blank(array=(array.file, array.path))
+        _ = model_blank(array=(array.file, array.path))
     else:
-        instance = model_blank(array=(array,))
+        _ = model_blank(array=(array,))
 
 
 def test_zarr_from_path(zarr_array, model_blank):
     """Should be able to just pass a path"""
-    instance = model_blank(array=zarr_array)
+    _ = model_blank(array=zarr_array)
 
 
 def test_zarr_array_path_from_iterable(zarr_array):
diff --git a/tests/test_meta.py b/tests/test_meta.py
index c137633..c5d2a51 100644
--- a/tests/test_meta.py
+++ b/tests/test_meta.py
@@ -1,4 +1,5 @@
 import sys
+
 import pytest
 
 from numpydantic import NDArray
@@ -40,4 +41,4 @@ def test_stub_revealed_type():
     """
     Check that the revealed type matches the stub
     """
-    type = reveal_type(NDArray)
+    _ = reveal_type(NDArray)
diff --git a/tests/test_ndarray.py b/tests/test_ndarray.py
index cda092c..4282279 100644
--- a/tests/test_ndarray.py
+++ b/tests/test_ndarray.py
@@ -1,16 +1,13 @@
-import pytest
-
-from typing import Union, Optional, Any
 import json
+from typing import Any, Optional, Union
 
 import numpy as np
-from pydantic import BaseModel, ValidationError, Field
+import pytest
+from pydantic import BaseModel, Field, ValidationError
 
-
-from numpydantic import NDArray, Shape
-from numpydantic.exceptions import ShapeError, DtypeError
-from numpydantic import dtype
+from numpydantic import NDArray, Shape, dtype
 from numpydantic.dtype import Number
+from numpydantic.exceptions import DtypeError
 
 
 @pytest.mark.json_schema
@@ -28,15 +25,15 @@ def test_ndarray_type():
     assert schema["properties"]["array"]["minItems"] == 2
 
     # models should instantiate correctly!
-    instance = Model(array=np.zeros((2, 3)))
+    _ = Model(array=np.zeros((2, 3)))
 
     with pytest.raises(ValidationError):
-        instance = Model(array=np.zeros((4, 6)))
+        _ = Model(array=np.zeros((4, 6)))
 
     with pytest.raises(ValidationError):
-        instance = Model(array=np.ones((2, 3), dtype=bool))
+        _ = Model(array=np.ones((2, 3), dtype=bool))
 
-    instance = Model(array=np.zeros((2, 3)), array_any=np.ones((3, 4, 5)))
+    _ = Model(array=np.zeros((2, 3)), array_any=np.ones((3, 4, 5)))
 
 
 @pytest.mark.dtype
@@ -93,6 +90,7 @@ def test_schema_number():
 
 
 def test_ndarray_union():
+    generator = np.random.default_rng()
     class Model(BaseModel):
         array: Optional[
             Union[
@@ -102,22 +100,22 @@ def test_ndarray_union():
             ]
         ] = Field(None)
 
-    instance = Model()
-    instance = Model(array=np.random.random((5, 10)))
-    instance = Model(array=np.random.random((5, 10, 3)))
-    instance = Model(array=np.random.random((5, 10, 3, 4)))
+    _ = Model()
+    _ = Model(array=generator.random((5, 10)))
+    _ = Model(array=generator.random((5, 10, 3)))
+    _ = Model(array=generator.random((5, 10, 3, 4)))
 
     with pytest.raises(ValidationError):
-        instance = Model(array=np.random.random((5,)))
+        _ = Model(array=generator.random((5,)))
 
     with pytest.raises(ValidationError):
-        instance = Model(array=np.random.random((5, 10, 4)))
+        _ = Model(array=generator.random((5, 10, 4)))
 
     with pytest.raises(ValidationError):
-        instance = Model(array=np.random.random((5, 10, 3, 6)))
+        _ = Model(array=generator.random((5, 10, 3, 6)))
 
     with pytest.raises(ValidationError):
-        instance = Model(array=np.random.random((5, 10, 4, 6)))
+        _ = Model(array=generator.random((5, 10, 4, 6)))
 
 
 @pytest.mark.shape
@@ -127,15 +125,16 @@ def test_ndarray_unparameterized(dtype):
     """
     NDArray without any parameters is any shape, any type
     """
+    generator = np.random.default_rng()
 
     class Model(BaseModel):
         array: NDArray
 
     # not very sophisticated fuzzing of "any shape"
     test_cases = 10
-    for i in range(test_cases):
-        n_dimensions = np.random.randint(1, 8)
-        dim_sizes = np.random.randint(1, 7, size=n_dimensions)
+    for _ in range(test_cases):
+        n_dimensions = generator.integers(1, 8)
+        dim_sizes = generator.integers(1, 7, size=n_dimensions)
         _ = Model(array=np.zeros(dim_sizes, dtype=dtype))
 
 
@@ -144,15 +143,16 @@ def test_ndarray_any():
     """
     using :class:`typing.Any` in for the shape means any shape
     """
+    generator = np.random.default_rng()
 
     class Model(BaseModel):
         array: NDArray[Any, np.uint8]
 
     # not very sophisticated fuzzing of "any shape"
     test_cases = 100
-    for i in range(test_cases):
-        n_dimensions = np.random.randint(1, 8)
-        dim_sizes = np.random.randint(1, 16, size=n_dimensions)
+    for _ in range(test_cases):
+        n_dimensions = generator.integers(1, 8)
+        dim_sizes = generator.integers(1, 16, size=n_dimensions)
         _ = Model(array=np.zeros(dim_sizes, dtype=np.uint8))
 
 
@@ -191,7 +191,7 @@ def test_ndarray_serialize():
     class Model(BaseModel):
         array: NDArray[Any, Number]
 
-    mod = Model(array=np.random.random((3, 3)))
+    mod = Model(array=np.random.default_rng().random((3, 3)))
     mod_str = mod.model_dump_json()
     mod_json = json.loads(mod_str)
     assert isinstance(mod_json["array"], list)
diff --git a/tests/test_serialization.py b/tests/test_serialization.py
index a42ee7c..4042e08 100644
--- a/tests/test_serialization.py
+++ b/tests/test_serialization.py
@@ -3,14 +3,15 @@ Test serialization-specific functionality that doesn't need to be
 applied across every interface (use test_interface/test_interfaces for that
 """
 
-import h5py
-import pytest
+import json
 from pathlib import Path
 from typing import Callable
-import numpy as np
-import json
 
-from numpydantic.serialization import _walk_and_apply, _relativize_paths, relative_path
+import h5py
+import numpy as np
+import pytest
+
+from numpydantic.serialization import _relativize_paths, _walk_and_apply, relative_path
 
 pytestmark = pytest.mark.serialization
 
@@ -115,7 +116,8 @@ def test_absolute_path(hdf5_at_path, tmp_output_dir, model_blank):
 
 def test_walk_and_apply():
     """
-    Walk and apply should recursively apply a function to everything in a nesty structure
+    Walk and apply should recursively apply a function to everything in a 
+    nesty structure
     """
     test = {
         "a": 1,
diff --git a/tests/test_shape.py b/tests/test_shape.py
index b521054..c2ce279 100644
--- a/tests/test_shape.py
+++ b/tests/test_shape.py
@@ -1,9 +1,8 @@
-import pytest
-
 from typing import Any
 
-from pydantic import BaseModel, ValidationError
 import numpy as np
+import pytest
+from pydantic import BaseModel, ValidationError
 
 from numpydantic import NDArray, Shape