Check for the "deprecated" keyword

jsonschema/_keywords.py

@@ -447,3 +447,8 @@ def prefixItems(validator, prefixItems, instance, schema):
             schema_path=index,
             path=index,
         )
+
+
+def deprecated(validator, deprecated, instance, schema):
+    if validator.check_deprecated and deprecated is True:
+        yield ValidationError(f"{instance!r} is deprecated")

jsonschema/protocols.py

@@ -81,6 +81,12 @@ class Validator(Protocol):
             its `extra (optional) dependencies <index:extras>` when
             invoking ``pip``.
 
+        check_deprecated:
+
+            if ``True``, raise validation errors when the :kw:`deprecated`
+            keyword is ``true`` for an instance value, indicating it should not
+            be used and may be removed in the future.
+
     .. deprecated:: v4.12.0
 
         Subclassing validator classes now explicitly warns this is not part of
@@ -216,7 +222,7 @@ def evolve(self, **kwargs) -> Validator:
 
         >>> validator = Draft202012Validator({})
         >>> validator.evolve(schema={"type": "number"})
-        Draft202012Validator(schema={'type': 'number'}, format_checker=None)
+        Draft202012Validator(schema={'type': 'number'}, format_checker=None, check_deprecated=False)
 
         The returned object satisfies the validator protocol, but may not
         be of the same concrete class! In particular this occurs
@@ -226,5 +232,5 @@ def evolve(self, **kwargs) -> Validator:
         >>> validator.evolve(
         ...     schema={"$schema": Draft7Validator.META_SCHEMA["$id"]}
         ... )
-        Draft7Validator(schema=..., format_checker=None)
-        """
+        Draft7Validator(schema=..., format_checker=None, check_deprecated=False)
+        """  # noqa: E501

jsonschema/tests/test_validators.py

@@ -127,7 +127,8 @@ def test_repr(self):
         self.addCleanup(validators._VALIDATORS.pop, "my version")
         self.assertEqual(
             repr(Validator({})),
-            "MyVersionValidator(schema={}, format_checker=None)",
+            "MyVersionValidator(schema={}, format_checker=None, "
+            "check_deprecated=False)",
         )
 
     def test_long_repr(self):
@@ -140,15 +141,16 @@ def test_long_repr(self):
         self.assertEqual(
             repr(Validator({"a": list(range(1000))})), (
                 "MyVersionValidator(schema={'a': [0, 1, 2, 3, 4, 5, ...]}, "
-                "format_checker=None)"
+                "format_checker=None, check_deprecated=False)"
             ),
         )
 
     def test_repr_no_version(self):
         Validator = validators.create(meta_schema={})
         self.assertEqual(
             repr(Validator({})),
-            "Validator(schema={}, format_checker=None)",
+            "Validator(schema={}, format_checker=None, "
+            "check_deprecated=False)",
         )
 
     def test_dashes_are_stripped_from_validator_names(self):
@@ -530,6 +532,32 @@ def test_maxLength(self):
         )
         self.assertEqual(message, "'abc' is too long")
 
+    def test_deprecated(self):
+        message = self.message_for(
+            instance={"id": 1, "name": "abc"},
+            schema={
+                "properties": {
+                    "id": {"type": "integer"},
+                    "name": {"type": "string", "deprecated": True},
+                },
+            },
+            check_deprecated=True,
+        )
+        self.assertEqual(message, "'abc' is deprecated")
+
+    def test_deprecated_disabled(self):
+        schema = {
+            "properties": {
+                "id": {"type": "integer"},
+                "name": {"type": "string", "deprecated": True},
+            },
+        }
+        instance={"id": 1, "name": "abc"}
+
+        validator = validators.Draft202012Validator(schema)
+        errors = list(validator.iter_errors(instance))
+        self.assertListEqual(errors, [])
+
     def test_pattern(self):
         message = self.message_for(
             instance="bbb",

jsonschema/validators.py

@@ -229,6 +229,7 @@ class Validator:
         schema: referencing.jsonschema.Schema = field(repr=reprlib.repr)
         _ref_resolver = field(default=None, repr=False, alias="resolver")
         format_checker: _format.FormatChecker | None = field(default=None)
+        check_deprecated: bool = field(default=False)
         # TODO: include new meta-schemas added at runtime
         _registry: referencing.jsonschema.SchemaRegistry = field(
             default=_REMOTE_WARNING_REGISTRY,
@@ -758,6 +759,7 @@ def extend(
         "contains": _keywords.contains,
         "dependentRequired": _keywords.dependentRequired,
         "dependentSchemas": _keywords.dependentSchemas,
+        "deprecated": _keywords.deprecated,
         "enum": _keywords.enum,
         "exclusiveMaximum": _keywords.exclusiveMaximum,
         "exclusiveMinimum": _keywords.exclusiveMinimum,
@@ -805,6 +807,7 @@ def extend(
         "contains": _keywords.contains,
         "dependentRequired": _keywords.dependentRequired,
         "dependentSchemas": _keywords.dependentSchemas,
+        "deprecated": _keywords.deprecated,
         "enum": _keywords.enum,
         "exclusiveMaximum": _keywords.exclusiveMaximum,
         "exclusiveMinimum": _keywords.exclusiveMinimum,