Roundtrip json serialization using dataclasses for all interfaces. Separate JSON schema generation from core_schema generation. More consistent json dumping behavior - always return just the array unless round_trip=True.

docs/api/monkeypatch.md

@@ -1,6 +0,0 @@
-# monkeypatch
-
-```{eval-rst}
-.. automodule:: numpydantic.monkeypatch
-    :members:
-```

docs/index.md

@@ -473,6 +473,7 @@ dumped = instance.model_dump_json(context={'zarr_dump_array': True})
 
 design
 syntax
+serialization
 interfaces
 todo
 changelog
@@ -489,7 +490,6 @@ api/dtype
 api/ndarray
 api/maps
 api/meta
-api/monkeypatch
 api/schema
 api/shape
 api/types

docs/serialization.md

@@ -0,0 +1,2 @@
+# Serialization
+

pyproject.toml

@@ -109,6 +109,12 @@ filterwarnings = [
     # nptyping's alias warnings
     'ignore:.*deprecated alias.*Deprecated NumPy 1\.24.*'
 ]
+markers = [
+    "dtype: mark test related to dtype validation",
+    "shape: mark test related to shape validation",
+    "json_schema: mark test related to json schema generation",
+    "serialization: mark test related to serialization"
+]
 
 [tool.ruff]
 target-version = "py311"

src/numpydantic/interface/__init__.py

@@ -4,12 +4,13 @@ Interfaces between nptyping types and array backends
 
 from numpydantic.interface.dask import DaskInterface
 from numpydantic.interface.hdf5 import H5Interface
-from numpydantic.interface.interface import Interface
+from numpydantic.interface.interface import Interface, JsonDict
 from numpydantic.interface.numpy import NumpyInterface
 from numpydantic.interface.video import VideoInterface
 from numpydantic.interface.zarr import ZarrInterface
 
 __all__ = [
+    "JsonDict",
     "Interface",
     "DaskInterface",
     "H5Interface",

src/numpydantic/interface/dask.py

@@ -2,26 +2,59 @@
 Interface for Dask arrays
 """
 
-from typing import Any, Optional
+from dataclasses import dataclass
+from typing import Any, Iterable, Literal, Optional
 
 import numpy as np
 from pydantic import SerializationInfo
 
-from numpydantic.interface.interface import Interface
+from numpydantic.interface.interface import Interface, JsonDict
 from numpydantic.types import DtypeType, NDArrayType
 
 try:
+    from dask.array import from_array
     from dask.array.core import Array as DaskArray
 except ImportError:  # pragma: no cover
     DaskArray = None
 
 
+def _as_tuple(a_list: list | Any) -> tuple:
+    """Make a list of list into a tuple of tuples"""
+    return tuple(
+        [_as_tuple(item) if isinstance(item, list) else item for item in a_list]
+    )
+
+
+@dataclass(kw_only=True)
+class DaskJsonDict(JsonDict):
+    """
+    Round-trip json serialized form of a dask array
+    """
+
+    type: Literal["dask"]
+    name: str
+    chunks: Iterable[tuple[int, ...]]
+    dtype: str
+    array: list
+
+    def to_array_input(self) -> DaskArray:
+        """Construct a dask array"""
+        np_array = np.array(self.array, dtype=self.dtype)
+        array = from_array(
+            np_array,
+            name=self.name,
+            chunks=_as_tuple(self.chunks),
+        )
+        return array
+
+
 class DaskInterface(Interface):
     """
     Interface for Dask :class:`~dask.array.core.Array`
     """
 
-    input_types = (DaskArray,)
+    name = "dask"
+    input_types = (DaskArray, dict)
     return_type = DaskArray
 
     @classmethod
@@ -29,7 +62,24 @@ class DaskInterface(Interface):
         """
         check if array is a dask array
         """
-        return DaskArray is not None and isinstance(array, DaskArray)
+        if DaskArray is None:
+            return False
+        elif isinstance(array, DaskArray):
+            return True
+        elif isinstance(array, dict):
+            return DaskJsonDict.is_valid(array)
+        else:
+            return False
+
+    def before_validation(self, array: Any) -> DaskArray:
+        """
+        If given a dict (like that from ``model_dump_json(round_trip=True)`` ),
+        re-cast to dask array
+        """
+        if isinstance(array, dict):
+            array = DaskJsonDict(**array).to_array_input()
+
+        return array
 
     def get_object_dtype(self, array: NDArrayType) -> DtypeType:
         """Dask arrays require a compute() call to retrieve a single value"""
@@ -43,7 +93,7 @@ class DaskInterface(Interface):
     @classmethod
     def to_json(
         cls, array: DaskArray, info: Optional[SerializationInfo] = None
-    ) -> list:
+    ) -> list | DaskJsonDict:
         """
         Convert an array to a JSON serializable array by first converting to a numpy
         array and then to a list.
@@ -56,4 +106,14 @@ class DaskInterface(Interface):
             method of serialization here using the python object itself rather than
             its JSON representation.
         """
-        return np.array(array).tolist()
+        np_array = np.array(array)
+        as_json = np_array.tolist()
+        if info.round_trip:
+            as_json = DaskJsonDict(
+                type=cls.name,
+                array=as_json,
+                name=array.name,
+                chunks=array.chunks,
+                dtype=str(np_array.dtype),
+            )
+        return as_json

src/numpydantic/interface/hdf5.py

@@ -40,6 +40,7 @@ as ``S32`` isoformatted byte strings (timezones optional) like:
 """
 
 import sys
+from dataclasses import dataclass
 from datetime import datetime
 from pathlib import Path
 from typing import Any, Iterable, List, NamedTuple, Optional, Tuple, TypeVar, Union
@@ -47,7 +48,7 @@ from typing import Any, Iterable, List, NamedTuple, Optional, Tuple, TypeVar, Un
 import numpy as np
 from pydantic import SerializationInfo
 
-from numpydantic.interface.interface import Interface
+from numpydantic.interface.interface import Interface, JsonDict
 from numpydantic.types import DtypeType, NDArrayType
 
 try:
@@ -76,6 +77,21 @@ class H5ArrayPath(NamedTuple):
     """Refer to a specific field within a compound dtype"""
 
 
+@dataclass
+class H5JsonDict(JsonDict):
+    """Round-trip Json-able version of an HDF5 dataset"""
+
+    file: str
+    path: str
+    field: Optional[str] = None
+
+    def to_array_input(self) -> H5ArrayPath:
+        """Construct an :class:`.H5ArrayPath`"""
+        return H5ArrayPath(
+            **{k: v for k, v in self.to_dict().items() if k in H5ArrayPath._fields}
+        )
+
+
 class H5Proxy:
     """
     Proxy class to mimic numpy-like array behavior with an HDF5 array
@@ -110,6 +126,7 @@ class H5Proxy:
         self.path = path
         self.field = field
         self._annotation_dtype = annotation_dtype
+        self._h5arraypath = H5ArrayPath(self.file, self.path, self.field)
 
     def array_exists(self) -> bool:
         """Check that there is in fact an array at :attr:`.path` within :attr:`.file`"""
@@ -212,6 +229,15 @@ class H5Proxy:
         """self.shape[0]"""
         return self.shape[0]
 
+    def __eq__(self, other: "H5Proxy") -> bool:
+        """
+        Check that we are referring to the same hdf5 array
+        """
+        if isinstance(other, H5Proxy):
+            return self._h5arraypath == other._h5arraypath
+        else:
+            raise ValueError("Can only compare equality of two H5Proxies")
+
     def open(self, mode: str = "r") -> "h5py.Dataset":
         """
         Return the opened :class:`h5py.Dataset` object
@@ -251,6 +277,7 @@ class H5Interface(Interface):
     passthrough numpy-like interface to the dataset.
     """
 
+    name = "hdf5"
     input_types = (H5ArrayPath, H5Arraylike, H5Proxy)
     return_type = H5Proxy
 
@@ -268,6 +295,13 @@ class H5Interface(Interface):
         if isinstance(array, (H5ArrayPath, H5Proxy)):
             return True
 
+        if isinstance(array, dict):
+            if array.get("type", False) == cls.name:
+                return True
+            # continue checking if dict contains an hdf5 file
+            file = array.get("file", "")
+            array = (file, "")
+
         if isinstance(array, (tuple, list)) and len(array) in (2, 3):
             # check that the first arg is an hdf5 file
             try:
@@ -294,6 +328,9 @@ class H5Interface(Interface):
 
     def before_validation(self, array: Any) -> NDArrayType:
         """Create an :class:`.H5Proxy` to use throughout validation"""
+        if isinstance(array, dict):
+            array = H5JsonDict(**array).to_array_input()
+
         if isinstance(array, H5ArrayPath):
             array = H5Proxy.from_h5array(h5array=array)
         elif isinstance(array, H5Proxy):
@@ -349,21 +386,27 @@ class H5Interface(Interface):
     @classmethod
     def to_json(cls, array: H5Proxy, info: Optional[SerializationInfo] = None) -> dict:
         """
-        Dump to a dictionary containing
+        Render HDF5 array as JSON
+
+        If ``round_trip == True``, we dump just the proxy info, a dictionary like:
 
         * ``file``: :attr:`.file`
         * ``path``: :attr:`.path`
         * ``attrs``: Any HDF5 attributes on the dataset
         * ``array``: The array as a list of lists
+
+        Otherwise, we dump the array as a list of lists
         """
+        if info.round_trip:
+            as_json = {
+                "type": cls.name,
+            }
+            as_json.update(array._h5arraypath._asdict())
+        else:
             try:
                 dset = array.open()
-            meta = {
+                as_json = dset[:].tolist()
-                "file": array.file,
-                "path": array.path,
-                "attrs": dict(dset.attrs),
-                "array": dset[:].tolist(),
-            }
-            return meta
             finally:
                 array.close()
+
+        return as_json

src/numpydantic/interface/interface.py

@@ -2,12 +2,15 @@
 Base Interface metaclass
 """
 
+import inspect
 from abc import ABC, abstractmethod
+from dataclasses import asdict, dataclass
+from importlib.metadata import PackageNotFoundError, version
 from operator import attrgetter
-from typing import Any, Generic, Optional, Tuple, Type, TypeVar, Union
+from typing import Any, Generic, Tuple, Type, TypedDict, TypeVar, Union
 
 import numpy as np
-from pydantic import SerializationInfo
+from pydantic import SerializationInfo, TypeAdapter, ValidationError
 
 from numpydantic.exceptions import (
     DtypeError,
@@ -21,6 +24,60 @@ from numpydantic.types import DtypeType, NDArrayType, ShapeType
 T = TypeVar("T", bound=NDArrayType)
 
 
+class InterfaceMark(TypedDict):
+    """JSON-able mark to be able to round-trip json dumps"""
+
+    module: str
+    cls: str
+    version: str
+
+
+@dataclass(kw_only=True)
+class JsonDict:
+    """
+    Representation of array when dumped with round_trip == True.
+
+    Using a dataclass rather than a pydantic model to not tempt
+    us to use more sophisticated types than can be serialized to json.
+    """
+
+    type: str
+
+    @abstractmethod
+    def to_array_input(self) -> Any:
+        """
+        Convert this roundtrip specifier to the relevant input class
+        (one of the ``input_types`` of an interface).
+        """
+
+    def to_dict(self) -> dict:
+        """
+        Convenience method for casting dataclass to dict,
+        removing None-valued items
+        """
+        return {k: v for k, v in asdict(self).items() if v is not None}
+
+    @classmethod
+    def get_adapter(cls) -> TypeAdapter:
+        """Convenience method to get a typeadapter for this class"""
+        return TypeAdapter(cls)
+
+    @classmethod
+    def is_valid(cls, val: dict) -> bool:
+        """
+        Check whether a given dictionary matches this JsonDict specification
+
+        Returns:
+            bool - true if valid, false if not
+        """
+        adapter = cls.get_adapter()
+        try:
+            _ = adapter.validate_python(val)
+            return True
+        except ValidationError:
+            return False
+
+
 class Interface(ABC, Generic[T]):
     """
     Abstract parent class for interfaces to different array formats
@@ -30,7 +87,7 @@ class Interface(ABC, Generic[T]):
     return_type: Type[T]
     priority: int = 0
 
-    def __init__(self, shape: ShapeType, dtype: DtypeType) -> None:
+    def __init__(self, shape: ShapeType = Any, dtype: DtypeType = Any) -> None:
         self.shape = shape
         self.dtype = dtype
 
@@ -86,6 +143,7 @@ class Interface(ABC, Generic[T]):
         self.raise_for_shape(shape_valid, shape)
 
         array = self.after_validation(array)
+
         return array
 
     def before_validation(self, array: Any) -> NDArrayType:
@@ -117,8 +175,6 @@ class Interface(ABC, Generic[T]):
         """
         Validate the dtype of the given array, returning
         ``True`` if valid, ``False`` if not.
-
-
         """
         if self.dtype is Any:
             return True
@@ -196,6 +252,13 @@ class Interface(ABC, Generic[T]):
         """
         return array
 
+    def mark_input(self, array: Any) -> Any:
+        """
+        Preserve metadata about the interface and passed input when dumping with
+        ``round_trip``
+        """
+        return array
+
     @classmethod
     @abstractmethod
     def check(cls, array: Any) -> bool:
@@ -211,17 +274,40 @@ class Interface(ABC, Generic[T]):
         installed, etc.)
         """
 
+    @property
+    @abstractmethod
+    def name(self) -> str:
+        """
+        Short name for this interface
+        """
+
     @classmethod
-    def to_json(
+    @abstractmethod
-        cls, array: Type[T], info: Optional[SerializationInfo] = None
+    def to_json(cls, array: Type[T], info: SerializationInfo) -> Union[list, JsonDict]:
-    ) -> Union[list, dict]:
         """
         Convert an array of :attr:`.return_type` to a JSON-compatible format using
         base python types
         """
-        if not isinstance(array, np.ndarray):  # pragma: no cover
+
-            array = np.array(array)
+    @classmethod
-        return array.tolist()
+    def mark_json(cls, array: Union[list, dict]) -> dict:
+        """
+        When using ``model_dump_json`` with ``mark_interface: True`` in the ``context``,
+        add additional annotations that would allow the serialized array to be
+        roundtripped.
+
+        Default is just to add an :class:`.InterfaceMark`
+
+        Examples:
+
+            >>> from pprint import pprint
+            >>> pprint(Interface.mark_json([1.0, 2.0]))
+            {'interface': {'cls': 'Interface',
+                           'module': 'numpydantic.interface.interface',
+                           'version': '1.2.2'},
+             'value': [1.0, 2.0]}
+        """
+        return {"interface": cls.mark_interface(), "value": array}
 
     @classmethod
     def interfaces(
@@ -335,3 +421,24 @@ class Interface(ABC, Generic[T]):
             raise NoMatchError(f"No matching interfaces found for output {array}")
         else:
             return matches[0]
+
+    @classmethod
+    def mark_interface(cls) -> InterfaceMark:
+        """
+        Create an interface mark indicating this interface for validation after
+        JSON serialization with ``round_trip==True``
+        """
+        interface_module = inspect.getmodule(cls)
+        interface_module = (
+            None if interface_module is None else interface_module.__name__
+        )
+        try:
+            v = (
+                None
+                if interface_module is None
+                else version(interface_module.split(".")[0])
+            )
+        except PackageNotFoundError:
+            v = None
+        interface_name = cls.__name__
+        return InterfaceMark(module=interface_module, cls=interface_name, version=v)

src/numpydantic/interface/numpy.py

@@ -2,9 +2,12 @@
 Interface to numpy arrays
 """
 
-from typing import Any
+from dataclasses import dataclass
+from typing import Any, Literal, Union
 
-from numpydantic.interface.interface import Interface
+from pydantic import SerializationInfo
+
+from numpydantic.interface.interface import Interface, JsonDict
 
 try:
     import numpy as np
@@ -18,11 +21,29 @@ except ImportError:  # pragma: no cover
     np = None
 
 
+@dataclass
+class NumpyJsonDict(JsonDict):
+    """
+    JSON-able roundtrip representation of numpy array
+    """
+
+    type: Literal["numpy"]
+    dtype: str
+    array: list
+
+    def to_array_input(self) -> ndarray:
+        """
+        Construct a numpy array
+        """
+        return np.array(self.array, dtype=self.dtype)
+
+
 class NumpyInterface(Interface):
     """
     Numpy :class:`~numpy.ndarray` s!
     """
 
+    name = "numpy"
     input_types = (ndarray, list)
     return_type = ndarray
     priority = -999
@@ -41,6 +62,8 @@ class NumpyInterface(Interface):
         """
         if isinstance(array, ndarray):
             return True
+        elif isinstance(array, dict):
+            return NumpyJsonDict.is_valid(array)
         else:
             try:
                 _ = np.array(array)
@@ -53,6 +76,9 @@ class NumpyInterface(Interface):
         Coerce to an ndarray. We have already checked if coercion is possible
         in :meth:`.check`
         """
+        if isinstance(array, dict):
+            array = NumpyJsonDict(**array).to_array_input()
+
         if not isinstance(array, ndarray):
             array = np.array(array)
         return array
@@ -61,3 +87,22 @@ class NumpyInterface(Interface):
     def enabled(cls) -> bool:
         """Check that numpy is present in the environment"""
         return ENABLED
+
+    @classmethod
+    def to_json(
+        cls, array: ndarray, info: SerializationInfo = None
+    ) -> Union[list, JsonDict]:
+        """
+        Convert an array of :attr:`.return_type` to a JSON-compatible format using
+        base python types
+        """
+        if not isinstance(array, np.ndarray):  # pragma: no cover
+            array = np.array(array)
+
+        json_array = array.tolist()
+
+        if info.round_trip:
+            json_array = NumpyJsonDict(
+                type=cls.name, dtype=str(array.dtype), array=json_array
+            )
+        return json_array

src/numpydantic/interface/video.py

@@ -2,11 +2,14 @@
 Interface to support treating videos like arrays using OpenCV
 """
 
+from dataclasses import dataclass
 from pathlib import Path
-from typing import Any, Optional, Tuple, Union
+from typing import Any, Literal, Optional, Tuple, Union
 
 import numpy as np
+from pydantic_core.core_schema import SerializationInfo
 
+from numpydantic.interface import JsonDict
 from numpydantic.interface.interface import Interface
 
 try:
@@ -19,6 +22,20 @@ except ImportError:  # pragma: no cover
 VIDEO_EXTENSIONS = (".mp4", ".avi", ".mov", ".mkv")
 
 
+@dataclass(kw_only=True)
+class VideoJsonDict(JsonDict):
+    """Json-able roundtrip representation of a video file"""
+
+    type: Literal["video"]
+    file: str
+
+    def to_array_input(self) -> "VideoProxy":
+        """
+        Construct a :class:`.VideoProxy`
+        """
+        return VideoProxy(path=Path(self.file))
+
+
 class VideoProxy:
     """
     Passthrough proxy class to interact with videos as arrays
@@ -184,6 +201,12 @@ class VideoProxy:
     def __getattr__(self, item: str):
         return getattr(self.video, item)
 
+    def __eq__(self, other: "VideoProxy") -> bool:
+        """Check if this is a proxy to the same video file"""
+        if not isinstance(other, VideoProxy):
+            raise TypeError("Can only compare equality of two VideoProxies")
+        return self.path == other.path
+
     def __len__(self) -> int:
         """Number of frames in the video"""
         return self.shape[0]
@@ -194,6 +217,7 @@ class VideoInterface(Interface):
     OpenCV interface to treat videos as arrays.
     """
 
+    name = "video"
     input_types = (str, Path, VideoCapture, VideoProxy)
     return_type = VideoProxy
 
@@ -213,6 +237,9 @@ class VideoInterface(Interface):
         ):
             return True
 
+        if isinstance(array, dict):
+            array = array.get("file", "")
+
         if isinstance(array, str):
             try:
                 array = Path(array)
@@ -224,10 +251,22 @@ class VideoInterface(Interface):
 
     def before_validation(self, array: Any) -> VideoProxy:
         """Get a :class:`.VideoProxy` object for this video"""
-        if isinstance(array, VideoCapture):
+        if isinstance(array, dict):
+            proxy = VideoJsonDict(**array).to_array_input()
+        elif isinstance(array, VideoCapture):
             proxy = VideoProxy(video=array)
         elif isinstance(array, VideoProxy):
             proxy = array
         else:
             proxy = VideoProxy(path=array)
         return proxy
+
+    @classmethod
+    def to_json(
+        cls, array: VideoProxy, info: SerializationInfo
+    ) -> Union[list, VideoJsonDict]:
+        """Return a json-representation of a video"""
+        if info.round_trip:
+            return VideoJsonDict(type=cls.name, file=str(array.path))
+        else:
+            return np.array(array).tolist()

src/numpydantic/interface/zarr.py

@@ -5,12 +5,12 @@ Interface to zarr arrays
 import contextlib
 from dataclasses import dataclass
 from pathlib import Path
-from typing import Any, Optional, Sequence, Union
+from typing import Any, Literal, Optional, Sequence, Union
 
 import numpy as np
 from pydantic import SerializationInfo
 
-from numpydantic.interface.interface import Interface
+from numpydantic.interface.interface import Interface, JsonDict
 from numpydantic.types import DtypeType
 
 try:
@@ -56,11 +56,34 @@ class ZarrArrayPath:
             raise ValueError("Only len 1-2 iterables can be used for a ZarrArrayPath")
 
 
+@dataclass(kw_only=True)
+class ZarrJsonDict(JsonDict):
+    """Round-trip Json-able version of a Zarr Array"""
+
+    info: dict[str, str]
+    type: Literal["zarr"]
+    file: Optional[str] = None
+    path: Optional[str] = None
+    array: Optional[list] = None
+
+    def to_array_input(self) -> ZarrArray | ZarrArrayPath:
+        """
+        Construct a ZarrArrayPath if file and path are present,
+        otherwise a ZarrArray
+        """
+        if self.file:
+            array = ZarrArrayPath(file=self.file, path=self.path)
+        else:
+            array = zarr.array(self.array)
+        return array
+
+
 class ZarrInterface(Interface):
     """
     Interface to in-memory or on-disk zarr arrays
     """
 
+    name = "zarr"
     input_types = (Path, ZarrArray, ZarrArrayPath)
     return_type = ZarrArray
 
@@ -73,6 +96,9 @@ class ZarrInterface(Interface):
     def _get_array(
         array: Union[ZarrArray, str, Path, ZarrArrayPath, Sequence]
     ) -> ZarrArray:
+        if isinstance(array, dict):
+            array = ZarrJsonDict(**array).to_array_input()
+
         if isinstance(array, ZarrArray):
             return array
 
@@ -92,6 +118,12 @@ class ZarrInterface(Interface):
         if isinstance(array, ZarrArray):
             return True
 
+        if isinstance(array, dict):
+            if array.get("type", False) == cls.name:
+                return True
+            # continue checking if dict contains a zarr file
+            array = array.get("file", "")
+
         # See if can be coerced to ZarrArrayPath
         if isinstance(array, (Path, str)):
             array = ZarrArrayPath(file=array)
@@ -135,26 +167,46 @@ class ZarrInterface(Interface):
         cls,
         array: Union[ZarrArray, str, Path, ZarrArrayPath, Sequence],
         info: Optional[SerializationInfo] = None,
-    ) -> dict:
+    ) -> list | ZarrJsonDict:
         """
-        Dump just the metadata for an array from :meth:`zarr.core.Array.info_items`
+        Dump a Zarr Array to JSON
-        plus the :meth:`zarr.core.Array.hexdigest`.
         
-        The full array can be returned by passing ``'zarr_dump_array': True`` to the
+        If ``info.round_trip == False``, dump the array as a list of lists.
-        serialization ``context`` ::
+        This may be a memory-intensive operation.
+        
+        Otherwise, dump the metadata for an array from :meth:`zarr.core.Array.info_items`
+        plus the :meth:`zarr.core.Array.hexdigest` as a :class:`.ZarrJsonDict`
+        
+        If either the ``zarr_dump_array`` value in the context dictionary is ``True``
+        or the zarr array is an in-memory array, dump the array as well
+        (since without a persistent array it would be impossible to roundtrip and 
+        dumping to JSON would be meaningless) 
+
+        Passing ``'zarr_dump_array': True`` to the serialization ``context`` looks like this::
 
             model.model_dump_json(context={'zarr_dump_array': True})
         """
+        array = cls._get_array(array)
+
+        if info.round_trip:
             dump_array = False
             if info is not None and info.context is not None:
                 dump_array = info.context.get("zarr_dump_array", False)
+            is_file = False
 
-        array = cls._get_array(array)
+            as_json = {"type": cls.name}
-        info = array.info_items()
+            if hasattr(array.store, "dir_path"):
-        info_dict = {i[0]: i[1] for i in info}
+                is_file = True
-        info_dict["hexdigest"] = array.hexdigest()
+                as_json["file"] = array.store.dir_path()
+                as_json["path"] = array.name
+            as_json["info"] = {i[0]: i[1] for i in array.info_items()}
+            as_json["info"]["hexdigest"] = array.hexdigest()
 
-        if dump_array:
+            if dump_array or not is_file:
-            info_dict["array"] = array[:].tolist()
+                as_json["array"] = array[:].tolist()
 
-        return info_dict
+            as_json = ZarrJsonDict(**as_json)
+        else:
+            as_json = array[:].tolist()
+
+        return as_json

src/numpydantic/ndarray.py

@@ -24,7 +24,6 @@ from numpydantic.exceptions import InterfaceError
 from numpydantic.interface import Interface
 from numpydantic.maps import python_to_nptyping
 from numpydantic.schema import (
-    _handler_type,
     _jsonize_array,
     get_validate_interface,
     make_json_schema,
@@ -41,6 +40,9 @@ from numpydantic.vendor.nptyping.typing_ import (
 
 if TYPE_CHECKING:  # pragma: no cover
     from nptyping.base_meta_classes import SubscriptableMeta
+    from pydantic._internal._schema_generation_shared import (
+        CallbackGetCoreSchemaHandler,
+    )
 
     from numpydantic import Shape
 
@@ -164,33 +166,34 @@ class NDArray(NPTypingType, metaclass=NDArrayMeta):
     def __get_pydantic_core_schema__(
         cls,
         _source_type: "NDArray",
-        _handler: _handler_type,
+        _handler: "CallbackGetCoreSchemaHandler",
     ) -> core_schema.CoreSchema:
         shape, dtype = _source_type.__args__
         shape: ShapeType
         dtype: DtypeType
 
-        # get pydantic core schema as a list of lists for JSON schema
+        # make core schema for json schema, store it and any model definitions
-        list_schema = make_json_schema(shape, dtype, _handler)
+        # note that there is a big of fragility in this function,
+        # as we need to access a private method of _handler to
+        # flatten out the json schema. See help(make_json_schema)
+        json_schema = make_json_schema(shape, dtype, _handler)
 
-        return core_schema.json_or_python_schema(
+        return core_schema.with_info_plain_validator_function(
-            json_schema=list_schema,
+            get_validate_interface(shape, dtype),
-            python_schema=core_schema.with_info_plain_validator_function(
-                get_validate_interface(shape, dtype)
-            ),
             serialization=core_schema.plain_serializer_function_ser_schema(
                 _jsonize_array, when_used="json", info_arg=True
             ),
+            metadata=json_schema,
         )
 
     @classmethod
     def __get_pydantic_json_schema__(
         cls, schema: core_schema.CoreSchema, handler: GetJsonSchemaHandler
     ) -> core_schema.JsonSchema:
-        json_schema = handler(schema)
+        shape, dtype = cls.__args__
+        json_schema = handler(schema["metadata"])
         json_schema = handler.resolve_ref_schema(json_schema)
 
-        dtype = cls.__args__[1]
         if not isinstance(dtype, tuple) and dtype.__module__ not in (
             "builtins",
             "typing",

src/numpydantic/schema.py

@@ -13,19 +13,24 @@ from pydantic_core import CoreSchema, core_schema
 from pydantic_core.core_schema import ListSchema, ValidationInfo
 
 from numpydantic import dtype as dt
-from numpydantic.interface import Interface
+from numpydantic.interface import Interface, JsonDict
 from numpydantic.maps import np_to_python
 from numpydantic.types import DtypeType, NDArrayType, ShapeType
 from numpydantic.vendor.nptyping.structure import StructureMeta
 
 if TYPE_CHECKING:  # pragma: no cover
+    from pydantic._internal._schema_generation_shared import (
+        CallbackGetCoreSchemaHandler,
+    )
+
     from numpydantic import Shape
 
-_handler_type = Callable[[Any], core_schema.CoreSchema]
 _UNSUPPORTED_TYPES = (complex,)
 
 
-def _numeric_dtype(dtype: DtypeType, _handler: _handler_type) -> CoreSchema:
+def _numeric_dtype(
+    dtype: DtypeType, _handler: "CallbackGetCoreSchemaHandler"
+) -> CoreSchema:
     """Make a numeric dtype that respects min/max values from extended numpy types"""
     if dtype in (np.number,):
         dtype = float
@@ -36,14 +41,19 @@ def _numeric_dtype(dtype: DtypeType, _handler: _handler_type) -> CoreSchema:
     elif issubclass(dtype, np.integer):
         info = np.iinfo(dtype)
         schema = core_schema.int_schema(le=int(info.max), ge=int(info.min))
-
+    elif dtype is float:
+        schema = core_schema.float_schema()
+    elif dtype is int:
+        schema = core_schema.int_schema()
     else:
         schema = _handler.generate_schema(dtype)
 
     return schema
 
 
-def _lol_dtype(dtype: DtypeType, _handler: _handler_type) -> CoreSchema:
+def _lol_dtype(
+    dtype: DtypeType, _handler: "CallbackGetCoreSchemaHandler"
+) -> CoreSchema:
     """Get the innermost dtype schema to use in the generated pydantic schema"""
     if isinstance(dtype, StructureMeta):  # pragma: no cover
         raise NotImplementedError("Structured dtypes are currently unsupported")
@@ -84,6 +94,10 @@ def _lol_dtype(dtype: DtypeType, _handler: _handler_type) -> CoreSchema:
             # TODO: warn and log here
         elif python_type in (float, int):
             array_type = _numeric_dtype(dtype, _handler)
+        elif python_type is bool:
+            array_type = core_schema.bool_schema()
+        elif python_type is Any:
+            array_type = core_schema.any_schema()
         else:
             array_type = _handler.generate_schema(python_type)
 
@@ -208,14 +222,24 @@ def _unbounded_shape(
 
 
 def make_json_schema(
-    shape: ShapeType, dtype: DtypeType, _handler: _handler_type
+    shape: ShapeType, dtype: DtypeType, _handler: "CallbackGetCoreSchemaHandler"
 ) -> ListSchema:
     """
-    Make a list of list JSON schema from a shape and a dtype.
+    Make a list of list pydantic core schema for an array from a shape and a dtype.
+    Used to generate JSON schema in the containing model, but not for validation,
+    which is handled by interfaces.
 
     First resolves the dtype into a pydantic ``CoreSchema`` ,
     and then uses that with :func:`.list_of_lists_schema` .
 
+    .. admonition:: Potentially Fragile
+
+        Uses a private method from the handler to flatten out nested definitions
+        (e.g. when dtype is a pydantic model)
+        so that they are present in the generated schema directly rather than
+        as references. Otherwise, at the time __get_pydantic_json_schema__ is called,
+        the definition references are lost.
+
     Args:
         shape ( ShapeType ): Specification of a shape, as a tuple or
             an nptyping ``Shape``
@@ -234,6 +258,8 @@ def make_json_schema(
     else:
         list_schema = list_of_lists_schema(shape, dtype_schema)
 
+    list_schema = _handler._generate_schema.clean_schema(list_schema)
+
     return list_schema
 
 
@@ -257,4 +283,11 @@ def get_validate_interface(shape: ShapeType, dtype: DtypeType) -> Callable:
 def _jsonize_array(value: Any, info: SerializationInfo) -> Union[list, dict]:
     """Use an interface class to render an array as JSON"""
     interface_cls = Interface.match_output(value)
-    return interface_cls.to_json(value, info)
+    array = interface_cls.to_json(value, info)
+    if isinstance(array, JsonDict):
+        array = array.to_dict()
+
+    if info.context and info.context.get("mark_interface", False):
+        array = interface_cls.mark_json(array)
+
+    return array

tests/test_interface/test_hdf5.py

@@ -101,7 +101,8 @@ def test_assignment(hdf5_array, model_blank):
     assert (model.array[1:3, 2:4] == 10).all()
 
 
-def test_to_json(hdf5_array, array_model):
+@pytest.mark.parametrize("round_trip", (True, False))
+def test_to_json(hdf5_array, array_model, round_trip):
     """
     Test serialization of HDF5 arrays to JSON
     Args:
@@ -115,13 +116,13 @@ def test_to_json(hdf5_array, array_model):
 
     instance = model(array=array)  # type: BaseModel
 
-    json_str = instance.model_dump_json()
+    json_str = instance.model_dump_json(round_trip=round_trip)
-    json_dict = json.loads(json_str)["array"]
+    json_dumped = json.loads(json_str)["array"]
-
+    if round_trip:
-    assert json_dict["file"] == str(array.file)
+        assert json_dumped["file"] == str(array.file)
-    assert json_dict["path"] == str(array.path)
+        assert json_dumped["path"] == str(array.path)
-    assert json_dict["attrs"] == {}
+    else:
-    assert json_dict["array"] == instance.array[:].tolist()
+        assert json_dumped == instance.array[:].tolist()
 
 
 def test_compound_dtype(tmp_path):

tests/test_interface/test_interfaces.py

@@ -2,8 +2,11 @@
 Tests that should be applied to all interfaces
 """
 
+import pytest
 from typing import Callable
 import numpy as np
+import dask.array as da
+from zarr.core import Array as ZarrArray
 from numpydantic.interface import Interface
 
 
@@ -35,8 +38,31 @@ def test_interface_to_numpy_array(all_interfaces):
     _ = np.array(all_interfaces.array)
 
 
+@pytest.mark.serialization
 def test_interface_dump_json(all_interfaces):
     """
     All interfaces should be able to dump to json
     """
     all_interfaces.model_dump_json()
+
+
+@pytest.mark.serialization
+@pytest.mark.parametrize("round_trip", [True, False])
+def test_interface_roundtrip_json(all_interfaces, round_trip):
+    """
+    All interfaces should be able to roundtrip to and from json
+    """
+    json = all_interfaces.model_dump_json(round_trip=round_trip)
+    model = all_interfaces.model_validate_json(json)
+    if round_trip:
+        assert type(model.array) is type(all_interfaces.array)
+        if isinstance(all_interfaces.array, (np.ndarray, ZarrArray)):
+            assert np.array_equal(model.array, np.array(all_interfaces.array))
+        elif isinstance(all_interfaces.array, da.Array):
+            assert np.all(da.equal(model.array, all_interfaces.array))
+        else:
+            assert model.array == all_interfaces.array
+
+        assert model.array.dtype == all_interfaces.array.dtype
+    else:
+        assert np.array_equal(model.array, np.array(all_interfaces.array))

tests/test_interface/test_zarr.py

@@ -123,7 +123,10 @@ def test_zarr_array_path_from_iterable(zarr_array):
     assert apath.path == inner_path
 
 
-def test_zarr_to_json(store, model_blank):
+@pytest.mark.serialization
+@pytest.mark.parametrize("dump_array", [True, False])
+@pytest.mark.parametrize("roundtrip", [True, False])
+def test_zarr_to_json(store, model_blank, roundtrip, dump_array):
     expected_fields = (
         "Type",
         "Data type",
@@ -137,17 +140,22 @@ def test_zarr_to_json(store, model_blank):
 
     array = zarr.array(lol_array, store=store)
     instance = model_blank(array=array)
-    as_json = json.loads(instance.model_dump_json())["array"]
-    assert "array" not in as_json
-    for field in expected_fields:
-        assert field in as_json
-    assert len(as_json["hexdigest"]) == 40
 
-    # dump the array itself too
+    context = {"zarr_dump_array": dump_array}
-    as_json = json.loads(instance.model_dump_json(context={"zarr_dump_array": True}))[
+    as_json = json.loads(
-        "array"
+        instance.model_dump_json(round_trip=roundtrip, context=context)
-    ]
+    )["array"]
-    for field in expected_fields:
+
-        assert field in as_json
+    if roundtrip:
-    assert len(as_json["hexdigest"]) == 40
+        if dump_array:
             assert as_json["array"] == lol_array
+        else:
+            if as_json.get("file", False):
+                assert "array" not in as_json
+
+        for field in expected_fields:
+            assert field in as_json["info"]
+        assert len(as_json["info"]["hexdigest"]) == 40
+
+    else:
+        assert as_json == lol_array

tests/test_ndarray.py

@@ -15,6 +15,7 @@ from numpydantic import dtype
 from numpydantic.dtype import Number
 
 
+@pytest.mark.json_schema
 def test_ndarray_type():
     class Model(BaseModel):
         array: NDArray[Shape["2 x, * y"], Number]
@@ -40,6 +41,7 @@ def test_ndarray_type():
     instance = Model(array=np.zeros((2, 3)), array_any=np.ones((3, 4, 5)))
 
 
+@pytest.mark.json_schema
 def test_schema_unsupported_type():
     """
     Complex numbers should just be made with an `any` schema
@@ -55,6 +57,7 @@ def test_schema_unsupported_type():
     }
 
 
+@pytest.mark.json_schema
 def test_schema_tuple():
     """
     Types specified as tupled should have their schemas as a union
@@ -72,6 +75,7 @@ def test_schema_tuple():
     assert all([i["minimum"] == 0 for i in conditions])
 
 
+@pytest.mark.json_schema
 def test_schema_number():
     """
     np.numeric should just be the float schema
@@ -164,6 +168,7 @@ def test_ndarray_coercion():
         amod = Model(array=["a", "b", "c"])
 
 
+@pytest.mark.serialization
 def test_ndarray_serialize():
     """
     Arrays should be dumped to a list when using json, but kept as ndarray otherwise
@@ -188,6 +193,7 @@ _json_schema_types = [
 ]
 
 
+@pytest.mark.json_schema
 def test_json_schema_basic(array_model):
     """
     NDArray types should correctly generate a list of lists JSON schema
@@ -210,6 +216,8 @@ def test_json_schema_basic(array_model):
     assert inner["items"]["type"] == "number"
 
 
+@pytest.mark.dtype
+@pytest.mark.json_schema
 @pytest.mark.parametrize("dtype", [*dtype.Integer, *dtype.Float])
 def test_json_schema_dtype_single(dtype, array_model):
     """
@@ -240,6 +248,7 @@ def test_json_schema_dtype_single(dtype, array_model):
     )
 
 
+@pytest.mark.dtype
 @pytest.mark.parametrize(
     "dtype,expected",
     [
@@ -266,6 +275,8 @@ def test_json_schema_dtype_builtin(dtype, expected, array_model):
         assert inner_type["type"] == expected
 
 
+@pytest.mark.dtype
+@pytest.mark.json_schema
 def test_json_schema_dtype_model():
     """
     Pydantic models can be used in arrays as dtypes
@@ -314,6 +325,8 @@ def _recursive_array(schema):
     assert any_of[1]["minimum"] == 0
 
 
+@pytest.mark.shape
+@pytest.mark.json_schema
 def test_json_schema_ellipsis():
     """
     NDArray types should create a recursive JSON schema for any-shaped arrays