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.CondaPkg/env/lib/python3.11/site-packages/jsons/_validation.py

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+"""
+PRIVATE MODULE: do not import (from) it directly.
+
+This module contains functionality for validating objects.
+"""
+from typing import Union, Sequence, Callable
+
+from jsons._cache import cached
+from jsons._common_impl import StateHolder, get_class_name
+from jsons._lizers_impl import _get_lizer
+from jsons.exceptions import ValidationError
+
+
+def set_validator(
+        func: Callable[[object], bool],
+        cls: Union[type, Sequence[type]],
+        *,
+        fork_inst: type = StateHolder) -> None:
+    """
+    Set a validator function for the given ``cls``. The function should accept
+    an instance of the type it should validate and must return ``False`` or
+    raise any exception in case of a validation failure.
+    :param func: the function that takes an instance of type ``cls`` and
+    returns a bool (``True`` if the validation was successful).
+    :param cls: the type or types that ``func`` is able to validate.
+    :param fork_inst: if given, it uses this fork of ``JsonSerializable``.
+    :return: None.
+    """
+    if isinstance(cls, Sequence):
+        for cls_ in cls:
+            set_validator(func, cls=cls_, fork_inst=fork_inst)
+    else:
+        cls_name = get_class_name(cls, fully_qualified=True)
+        fork_inst._validators[cls_name.lower()] = func
+        fork_inst._classes_validators.append(cls)
+
+
+@cached
+def get_validator(
+        cls: type,
+        fork_inst: type = StateHolder) -> callable:
+    """
+    Return the validator function that would be used for the given ``cls``.
+    :param cls: the type for which a deserializer is to be returned.
+    :param fork_inst: if given, it uses this fork of ``JsonSerializable``.
+    :return: a validator function.
+    """
+    return _get_lizer(cls, fork_inst._validators,
+                      fork_inst._classes_validators, fork_inst)
+
+
+def validate(
+        obj: object,
+        cls: type,
+        fork_inst: type = StateHolder) -> None:
+    """
+    Validate the given ``obj`` with the validator that was registered for
+    ``cls``. Raises a ``ValidationError`` if the validation failed.
+    :param obj: the object that is to be validated.
+    :param cls: the type of which the validator function was registered.
+    :param fork_inst: if given, it uses this fork of ``JsonSerializable``.
+    :return: None.
+    """
+    validator = get_validator(cls, fork_inst)
+    result = True
+    msg = 'Validation failed.'
+    if validator:
+        try:
+            result = validator(obj)
+        except Exception as err:
+            if err.args:
+                msg = err.args[0]
+            result = False
+    if not result:
+        raise ValidationError(msg)