Add pydantic 2 compatibility layer (#321)

allow to use with pydantic 2

napari/napari#6350

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

.github/workflows/ci.yml

@@ -23,13 +23,14 @@ jobs:
         run: pipx run check-manifest
 
   test:
-    name: ${{ matrix.platform }} (${{ matrix.python-version }})
+    name: ${{ matrix.platform }} (${{ matrix.python-version }}) ${{ matrix.pydantic }}
     runs-on: ${{ matrix.platform }}
     strategy:
       fail-fast: false
       matrix:
         python-version: [3.8, 3.9, "3.10", "3.11"]
         platform: [ubuntu-latest, macos-latest, windows-latest]
+        pydantic: ["pydantic<2", "pydantic>2"]
 
     steps:
       - uses: actions/checkout@v4
@@ -42,6 +43,7 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
+          pip install "${{ matrix.pydantic }}"
           pip install -e .[json,docs,testing]
 
       - name: Test Main docs build

pyproject.toml

@@ -35,7 +35,7 @@ dependencies = [
     "appdirs",
     "build>=1",
     "psygnal>=0.3.0",
-    "pydantic<2",
+    "pydantic",
     "tomli-w",
     "tomli; python_version < '3.11'",
     "rich",

src/npe2/_dynamic_plugin.py

@@ -14,7 +14,7 @@
     overload,
 )
 
-from pydantic import BaseModel, ValidationError
+from npe2._pydantic_compat import BaseModel, ValidationError
 
 from ._plugin_manager import PluginManager
 from .manifest.contributions import (

src/npe2/_pydantic_compat.py

@@ -0,0 +1,54 @@
+try:
+    # pydantic v2
+    from pydantic.v1 import (
+        BaseModel,
+        Extra,
+        Field,
+        PrivateAttr,
+        ValidationError,
+        color,
+        conlist,
+        constr,
+        root_validator,
+        validator,
+    )
+    from pydantic.v1.error_wrappers import ErrorWrapper
+    from pydantic.v1.fields import SHAPE_LIST
+    from pydantic.v1.generics import GenericModel
+    from pydantic.v1.main import ModelMetaclass
+except ImportError:
+    # pydantic v2
+    from pydantic import (
+        BaseModel,
+        Extra,
+        Field,
+        PrivateAttr,
+        ValidationError,
+        color,
+        conlist,
+        constr,
+        root_validator,
+        validator,
+    )
+    from pydantic.error_wrappers import ErrorWrapper
+    from pydantic.fields import SHAPE_LIST
+    from pydantic.generics import GenericModel
+    from pydantic.main import ModelMetaclass
+
+
+__all__ = (
+    "BaseModel",
+    "Extra",
+    "Field",
+    "ValidationError",
+    "root_validator",
+    "validator",
+    "PrivateAttr",
+    "color",
+    "conlist",
+    "constr",
+    "ModelMetaclass",
+    "ErrorWrapper",
+    "GenericModel",
+    "SHAPE_LIST",
+)

src/npe2/implements.py

@@ -2,7 +2,7 @@
 from inspect import Parameter, Signature
 from typing import Any, Callable, List, Sequence, Type, TypeVar
 
-from pydantic import BaseModel
+from npe2._pydantic_compat import BaseModel
 
 from .manifest import contributions
 

src/npe2/implements.pyi

@@ -1,6 +1,6 @@
 from typing import Any, Callable, TypeVar
 
-from pydantic import BaseModel as BaseModel
+from npe2._pydantic_compat import BaseModel as BaseModel
 
 from .manifest import PluginManifest as PluginManifest
 from .manifest import contributions as contributions

src/npe2/manifest/_bases.py

@@ -4,7 +4,8 @@
 from typing import Callable, Dict, Optional, Union
 
 import yaml
-from pydantic import BaseModel, PrivateAttr
+
+from npe2._pydantic_compat import BaseModel, PrivateAttr
 
 
 class ImportExportModel(BaseModel):

src/npe2/manifest/_package_metadata.py

@@ -1,8 +1,14 @@
 from importlib import metadata
 from typing import Dict, List, Literal, Optional, Union
 
-from pydantic import BaseModel, Extra, Field, constr, root_validator
-from pydantic.fields import SHAPE_LIST
+from npe2._pydantic_compat import (
+    SHAPE_LIST,
+    BaseModel,
+    Extra,
+    Field,
+    constr,
+    root_validator,
+)
 
 # https://packaging.python.org/specifications/core-metadata/
 

src/npe2/manifest/contributions/_commands.py

@@ -1,7 +1,6 @@
 from typing import TYPE_CHECKING, Any, Optional, Union
 
-from pydantic import BaseModel, Extra, Field, validator
-
+from npe2._pydantic_compat import BaseModel, Extra, Field, validator
 from npe2.manifest import _validators
 from npe2.types import PythonName
 

src/npe2/manifest/contributions/_configuration.py

@@ -1,6 +1,6 @@
 from typing import Any, Dict, List, Literal, Optional, Union
 
-from pydantic import BaseModel, Field, conlist, root_validator, validator
+from npe2._pydantic_compat import BaseModel, Field, conlist, root_validator, validator
 
 from ._json_schema import (
     Draft07JsonSchema,

src/npe2/manifest/contributions/_contributions.py

@@ -1,6 +1,6 @@
 from typing import Dict, List, Optional
 
-from pydantic import BaseModel, Field, validator
+from npe2._pydantic_compat import BaseModel, Field, validator
 
 from ._commands import CommandContribution
 from ._configuration import ConfigurationContribution

src/npe2/manifest/contributions/_icon.py

@@ -1,6 +1,6 @@
 from typing import Optional
 
-from pydantic import BaseModel
+from npe2._pydantic_compat import BaseModel
 
 
 class Icon(BaseModel):

src/npe2/manifest/contributions/_json_schema.py

@@ -2,7 +2,14 @@
 
 from typing import TYPE_CHECKING, Any, Dict, List, Literal, Optional, Type, Union
 
-from pydantic import BaseModel, Field, PrivateAttr, conlist, root_validator, validator
+from npe2._pydantic_compat import (
+    BaseModel,
+    Field,
+    PrivateAttr,
+    conlist,
+    root_validator,
+    validator,
+)
 
 if TYPE_CHECKING:
     from jsonschema.exceptions import ValidationError

src/npe2/manifest/contributions/_keybindings.py

@@ -1,7 +1,6 @@
 from typing import Optional
 
-from pydantic.fields import Field
-
+from npe2._pydantic_compat import Field
 from npe2.manifest.utils import Executable
 
 

src/npe2/manifest/contributions/_menus.py

@@ -1,7 +1,6 @@
 from typing import Optional, Union
 
-from pydantic import BaseModel, Field
-
+from npe2._pydantic_compat import BaseModel, Field
 from npe2.manifest.utils import Executable
 
 

src/npe2/manifest/contributions/_readers.py

@@ -1,8 +1,7 @@
 from functools import wraps
 from typing import List, Optional
 
-from pydantic import Extra, Field
-
+from npe2._pydantic_compat import Extra, Field
 from npe2.manifest.utils import Executable, v2_to_v1
 from npe2.types import ReaderFunction
 

src/npe2/manifest/contributions/_sample_data.py

@@ -1,9 +1,7 @@
 from abc import ABC, abstractmethod
 from typing import TYPE_CHECKING, List, Optional, Union
 
-from pydantic.fields import Field
-from pydantic.generics import GenericModel
-
+from npe2._pydantic_compat import Field, GenericModel
 from npe2.manifest.utils import Executable
 from npe2.types import LayerData
 

src/npe2/manifest/contributions/_submenu.py

@@ -1,7 +1,6 @@
 from typing import Optional, Union
 
-from pydantic import BaseModel
-from pydantic.fields import Field
+from npe2._pydantic_compat import BaseModel, Field
 
 from ._icon import Icon
 

src/npe2/manifest/contributions/_themes.py

@@ -1,8 +1,7 @@
 import sys
 from typing import Literal, Optional, Union
 
-from pydantic import BaseModel, color
-from pydantic.fields import Field
+from npe2._pydantic_compat import BaseModel, Field, color
 
 
 # pydantic doesn't implement color equality?

src/npe2/manifest/contributions/_widgets.py

@@ -2,8 +2,7 @@
 
 from typing import TYPE_CHECKING, Callable, Optional
 
-from pydantic import Extra, Field
-
+from npe2._pydantic_compat import Extra, Field
 from npe2.manifest.utils import Executable
 from npe2.types import Widget
 

src/npe2/manifest/contributions/_writers.py

@@ -1,8 +1,7 @@
 from enum import Enum
 from typing import List, Tuple
 
-from pydantic import BaseModel, Extra, Field, validator
-
+from npe2._pydantic_compat import BaseModel, Extra, Field, validator
 from npe2.manifest.utils import Executable
 
 

src/npe2/manifest/schema.py

@@ -8,10 +8,16 @@
 from pathlib import Path
 from typing import Iterator, List, Literal, NamedTuple, Optional, Sequence, Union
 
-from pydantic import Extra, Field, ValidationError, root_validator, validator
-from pydantic.error_wrappers import ErrorWrapper
-from pydantic.main import BaseModel, ModelMetaclass
-
+from npe2._pydantic_compat import (
+    BaseModel,
+    ErrorWrapper,
+    Extra,
+    Field,
+    ModelMetaclass,
+    ValidationError,
+    root_validator,
+    validator,
+)
 from npe2.types import PythonName
 
 from . import _validators
@@ -438,9 +444,8 @@ def _from_package_or_name(
             If the name does not resolve to either a distribution name or a filename.
 
         """
-        from pydantic import ValidationError
-
         from npe2 import PluginManifest
+        from npe2._pydantic_compat import ValidationError
 
         try:
             return PluginManifest.from_file(package_or_filename)

src/npe2/manifest/utils.py

@@ -18,9 +18,7 @@
     Union,
 )
 
-from pydantic import PrivateAttr
-from pydantic.generics import GenericModel
-
+from npe2._pydantic_compat import GenericModel, PrivateAttr
 from npe2.types import PythonName
 
 if TYPE_CHECKING:

tests/test_manifest.py

@@ -3,9 +3,9 @@
 from unittest.mock import patch
 
 import pytest
-from pydantic import ValidationError
 
 from npe2 import PluginManifest
+from npe2._pydantic_compat import ValidationError
 from npe2.manifest import PackageMetadata
 from npe2.manifest.schema import ENTRY_POINT
 

tests/test_validations.py

@@ -1,9 +1,9 @@
 import json
 
 import pytest
-from pydantic import ValidationError
 
 from npe2 import PluginManifest
+from npe2._pydantic_compat import ValidationError
 from npe2.manifest import _validators
 
 # the docstrings here are used to assert the validation error that is printed.