Merge remote-tracking branch 'anexia-it/draft2020-12'

* anexia-it/draft2020-12:
  Julian/jsonschema#782: Remove ecmascript validation, extend dynamicRef skip description
  Julian/jsonschema#782: Add compatibility to draft7 and older
  Julian/jsonschema#782: Code clenaup, fixes validation messages
  Julian/jsonschema#782: Extend format tests
  Julian/jsonschema#782: Resolve meta schema vocabularies from local cache
  Julian/jsonschema#782: Refactor items behavior with prefixItems
  Julian/jsonschema#782: Update validation message for unevaluatedProperties and unevaluatedItems
  Julian/jsonschema#782: Fixes failing styles
  Julian/jsonschema#782: Adapt validator test for draft2020-12, fixes code styles
  Julian/jsonschema#782: Fixes relative json pointer format validation for leading zero on digit
  Julian/jsonschema#782: Load dependencies from legacy validators
  Julian/jsonschema#782: Implements dynamicRef validations
  Julian/jsonschema#782: Add validation for uuid format
  Julian/jsonschema#782: Implements defs validations
  Julian/jsonschema#782: Extend resolver for anchor
  Julian/jsonschema#782: Fixes ref resolver for folders
  Julian/jsonschema#782: Fixes ref validation priority
  Julian/jsonschema#782: Extend implementation of ref
  Julian/jsonschema#782: Implements unevaluatedProperties validations
  Julian/jsonschema#782: Implements unevaluatedItems validations
  Julian/jsonschema#782: Extend contains with minContains and maxContaints, add contains legacy validator
  Julian/jsonschema#782: Adapt items to work with prefixItems
  Julian/jsonschema#782: Add checks for prefixItems, basic check for unevaluatedItems
  Julian/jsonschema#782: Extend format check for draft2020-12, add duration format check
  Julian/jsonschema#782: Add dependentRequired and dependentSchemas validation
  Julian/jsonschema#782: Split format and regular test cases on draft2020-12
  Julian/jsonschema#782: Enable draft2020-12 test suite

20 files changed, 1095 insertions, 59 deletions

diff --git a/jsonschema/__init__.py b/jsonschema/__init__.py
index 619a7ea..c1cb2e9 100644
--- a/jsonschema/__init__.py
+++ b/jsonschema/__init__.py
@@ -14,6 +14,7 @@ from jsonschema._format import (
     draft4_format_checker,
     draft6_format_checker,
     draft7_format_checker,
+    draft202012_format_checker,
 )
 from jsonschema._types import TypeChecker
 from jsonschema.exceptions import (
@@ -28,6 +29,7 @@ from jsonschema.validators import (
     Draft4Validator,
     Draft6Validator,
     Draft7Validator,
+    Draft202012Validator,
     RefResolver,
     validate,
 )
diff --git a/jsonschema/_format.py b/jsonschema/_format.py
index bdd893d..19f4283 100644
--- a/jsonschema/_format.py
+++ b/jsonschema/_format.py
@@ -1,3 +1,4 @@
+from uuid import UUID
 import datetime
 import ipaddress
 import re
@@ -131,13 +132,14 @@ draft3_format_checker = FormatChecker()
 draft4_format_checker = FormatChecker()
 draft6_format_checker = FormatChecker()
 draft7_format_checker = FormatChecker()
-
+draft202012_format_checker = FormatChecker()
 
 _draft_checkers = dict(
     draft3=draft3_format_checker,
     draft4=draft4_format_checker,
     draft6=draft6_format_checker,
     draft7=draft7_format_checker,
+    draft202012=draft202012_format_checker,
 )
 
 
@@ -147,12 +149,14 @@ def _checks_drafts(
     draft4=None,
     draft6=None,
     draft7=None,
+    draft202012=None,
     raises=(),
 ):
     draft3 = draft3 or name
     draft4 = draft4 or name
     draft6 = draft6 or name
     draft7 = draft7 or name
+    draft202012 = draft202012 or name
 
     def wrap(func):
         if draft3:
@@ -163,13 +167,17 @@ def _checks_drafts(
             func = _draft_checkers["draft6"].checks(draft6, raises)(func)
         if draft7:
             func = _draft_checkers["draft7"].checks(draft7, raises)(func)
+        if draft202012:
+            func = _draft_checkers["draft202012"].checks(
+                draft202012, raises
+            )(func)
 
         # Oy. This is bad global state, but relied upon for now, until
         # deprecation. See https://github.com/Julian/jsonschema/issues/519
         # and test_format_checkers_come_with_defaults
-        FormatChecker.cls_checks(draft7 or draft6 or draft4 or draft3, raises)(
-            func,
-        )
+        FormatChecker.cls_checks(
+            draft202012 or draft7 or draft6 or draft4 or draft3, raises
+        )(func)
         return func
     return wrap
 
@@ -187,6 +195,7 @@ def is_email(instance):
     draft4="ipv4",
     draft6="ipv4",
     draft7="ipv4",
+    draft202012="ipv4",
     raises=ipaddress.AddressValueError,
 )
 def is_ipv4(instance):
@@ -213,6 +222,7 @@ else:
         draft4="hostname",
         draft6="hostname",
         draft7="hostname",
+        draft202012="hostname",
     )
     def is_host_name(instance):
         if not isinstance(instance, str):
@@ -228,6 +238,7 @@ except ImportError:  # pragma: no cover
 else:
     @_checks_drafts(
         draft7="idn-hostname",
+        draft202012="idn-hostname",
         raises=(idna.IDNAError, UnicodeError),
     )
     def is_idn_host_name(instance):
@@ -254,6 +265,7 @@ except ImportError:
         @_checks_drafts(
             draft6="uri-reference",
             draft7="uri-reference",
+            draft202012="uri-reference",
             raises=ValueError,
         )
         def is_uri_reference(instance):
@@ -262,19 +274,30 @@ except ImportError:
             return validate_rfc3986(instance, rule="URI_reference")
 
 else:
-    @_checks_drafts(draft7="iri", raises=ValueError)
+    @_checks_drafts(
+        draft7="iri",
+        draft202012="iri",
+        raises=ValueError,
+    )
     def is_iri(instance):
         if not isinstance(instance, str):
             return True
         return rfc3987.parse(instance, rule="IRI")
 
-    @_checks_drafts(draft7="iri-reference", raises=ValueError)
+    @_checks_drafts(
+        draft7="iri-reference",
+        draft202012="iri-reference",
+        raises=ValueError,
+    )
     def is_iri_reference(instance):
         if not isinstance(instance, str):
             return True
         return rfc3987.parse(instance, rule="IRI_reference")
 
-    @_checks_drafts(name="uri", raises=ValueError)
+    @_checks_drafts(
+        name="uri",
+        raises=ValueError,
+    )
     def is_uri(instance):
         if not isinstance(instance, str):
             return True
@@ -283,6 +306,7 @@ else:
     @_checks_drafts(
         draft6="uri-reference",
         draft7="uri-reference",
+        draft202012="uri-reference",
         raises=ValueError,
     )
     def is_uri_reference(instance):
@@ -306,7 +330,10 @@ if validate_rfc3339:
             return True
         return validate_rfc3339(instance.upper())
 
-    @_checks_drafts(draft7="time")
+    @_checks_drafts(
+        draft7="time",
+        draft202012="time",
+    )
     def is_time(instance):
         if not isinstance(instance, str):
             return True
@@ -327,7 +354,12 @@ else:
         return datetime.datetime.strptime(instance, "%Y-%m-%d")
 
 
-@_checks_drafts(draft3="date", draft7="date", raises=ValueError)
+@_checks_drafts(
+    draft3="date",
+    draft7="date",
+    draft202012="date",
+    raises=ValueError,
+)
 def is_date(instance):
     if not isinstance(instance, str):
         return True
@@ -377,6 +409,7 @@ else:
     @_checks_drafts(
         draft6="json-pointer",
         draft7="json-pointer",
+        draft202012="json-pointer",
         raises=jsonpointer.JsonPointerException,
     )
     def is_json_pointer(instance):
@@ -390,6 +423,7 @@ else:
     #       into a new external library.
     @_checks_drafts(
         draft7="relative-json-pointer",
+        draft202012="relative-json-pointer",
         raises=jsonpointer.JsonPointerException,
     )
     def is_relative_json_pointer(instance):
@@ -400,6 +434,10 @@ else:
         non_negative_integer, rest = [], ""
         for i, character in enumerate(instance):
             if character.isdigit():
+                # digits with a leading "0" are not allowed
+                if i > 0 and int(instance[i-1]) == 0:
+                    return False
+
                 non_negative_integer.append(character)
                 continue
 
@@ -419,8 +457,36 @@ else:
     @_checks_drafts(
         draft6="uri-template",
         draft7="uri-template",
+        draft202012="uri-template",
     )
     def is_uri_template(instance):
         if not isinstance(instance, str):
             return True
         return uri_template.validate(instance)
+
+
+try:
+    import isoduration
+except ImportError:  # pragma: no cover
+    pass
+else:
+    @_checks_drafts(
+        draft202012="duration",
+        raises=isoduration.DurationParsingException,
+    )
+    def is_duration(instance):
+        if not isinstance(instance, str):
+            return True
+        return isoduration.parse_duration(instance)
+
+
+@_checks_drafts(
+    draft202012="uuid",
+    raises=ValueError,
+)
+def is_uuid(instance):
+    if not isinstance(instance, str):
+        return True
+    if "-" not in instance:
+        raise ValueError("Invalid UUID format")
+    return UUID(instance)
diff --git a/jsonschema/_legacy_validators.py b/jsonschema/_legacy_validators.py
index 80f798b..194c68f 100644
--- a/jsonschema/_legacy_validators.py
+++ b/jsonschema/_legacy_validators.py
@@ -2,6 +2,18 @@ from jsonschema import _utils
 from jsonschema.exceptions import ValidationError
 
 
+def ignore_ref_siblings(schema):
+    """
+    Returns a list of validators that should apply for the given schema
+    Used for draft7 and earlier
+    """
+    ref = schema.get(u"$ref")
+    if ref is not None:
+        return [(u"$ref", ref)]
+    else:
+        return schema.items()
+
+
 def dependencies_draft3(validator, dependencies, instance, schema):
     if not validator.is_type(instance, "object"):
         return
@@ -27,6 +39,37 @@ def dependencies_draft3(validator, dependencies, instance, schema):
                     yield ValidationError(message % (each, property))
 
 
+def dependencies_draft4_draft6_draft7(
+    validator,
+    dependencies,
+    instance,
+    schema,
+):
+    """
+    Support for the ``dependencies`` validator from pre-draft 2019-09.
+
+    In later drafts, the validator was split into separate
+    ``dependentRequired`` and ``dependentSchemas`` validators.
+    """
+    if not validator.is_type(instance, "object"):
+        return
+
+    for property, dependency in dependencies.items():
+        if property not in instance:
+            continue
+
+        if validator.is_type(dependency, "array"):
+            for each in dependency:
+                if each not in instance:
+                    message = "%r is a dependency of %r"
+                    yield ValidationError(message % (each, property))
+        else:
+            for error in validator.descend(
+                    instance, dependency, schema_path=property,
+            ):
+                yield error
+
+
 def disallow_draft3(validator, disallow, instance, schema):
     for disallowed in _utils.ensure_list(disallow):
         if validator.is_valid(instance, {"type": [disallowed]}):
@@ -61,6 +104,22 @@ def items_draft3_draft4(validator, items, instance, schema):
                 yield error
 
 
+def items_draft6_draft7(validator, items, instance, schema):
+    if not validator.is_type(instance, "array"):
+        return
+
+    if validator.is_type(items, "array"):
+        for (index, item), subschema in zip(enumerate(instance), items):
+            for error in validator.descend(
+                item, subschema, path=index, schema_path=index,
+            ):
+                yield error
+    else:
+        for index, item in enumerate(instance):
+            for error in validator.descend(item, items, path=index):
+                yield error
+
+
 def minimum_draft3_draft4(validator, minimum, instance, schema):
     if not validator.is_type(instance, "number"):
         return
@@ -138,3 +197,13 @@ def type_draft3(validator, types, instance, schema):
         yield ValidationError(
             _utils.types_msg(instance, types), context=all_errors,
         )
+
+
+def contains_draft6_draft7(validator, contains, instance, schema):
+    if not validator.is_type(instance, "array"):
+        return
+
+    if not any(validator.is_valid(element, contains) for element in instance):
+        yield ValidationError(
+            "None of %r are valid under the given schema" % (instance,)
+        )
diff --git a/jsonschema/_types.py b/jsonschema/_types.py
index 50bcf99..3eab7b0 100644
--- a/jsonschema/_types.py
+++ b/jsonschema/_types.py
@@ -185,3 +185,4 @@ draft6_type_checker = draft4_type_checker.redefine(
     ),
 )
 draft7_type_checker = draft6_type_checker
+draft202012_type_checker = draft7_type_checker
diff --git a/jsonschema/_utils.py b/jsonschema/_utils.py
index 97b7f8f..1b81a09 100644
--- a/jsonschema/_utils.py
+++ b/jsonschema/_utils.py
@@ -1,9 +1,12 @@
 from collections.abc import Mapping, MutableMapping, Sequence
+from pathlib import Path
 from urllib.parse import urlsplit
 import itertools
 import json
+import os
 import pkgutil
 import re
+import sys
 
 
 class URIDict(MutableMapping):
@@ -55,6 +58,19 @@ def load_schema(name):
     return json.loads(data.decode("utf-8"))
 
 
+def load_vocabulary(name):
+    """
+    Load all schema files from ./schemas/``name`` and return them as a list.
+    """
+    vocabulary = []
+    base_path = os.path.dirname(sys.modules["jsonschema"].__file__)
+    pathlist = Path(os.path.join(base_path, 'schemas', name)).glob('*.json')
+    for path in pathlist:
+        with open(path) as data:
+            vocabulary.append(json.load(data))
+    return vocabulary
+
+
 def format_as_index(indices):
     """
     Construct a single string containing indexing operations for the indices.
@@ -232,3 +248,145 @@ def uniq(container):
 
             seen.append(e)
     return True
+
+
+def find_evaluated_item_indexes_by_schema(validator, instance, schema):
+    """
+    Get all indexes of items that get evaluated under the current schema
+
+    Covers all keywords related to unevaluatedItems: items, prefixItems, if,
+    then, else, contains, unevaluatedItems, allOf, oneOf, anyOf
+    """
+    if validator.is_type(schema, "boolean"):
+        return []
+    evaluated_indexes = []
+
+    if "items" in schema:
+        return list(range(0, len(instance)))
+
+    if "$ref" in schema:
+        scope, resolved = validator.resolver.resolve(schema["$ref"])
+        validator.resolver.push_scope(scope)
+
+        try:
+            evaluated_indexes += find_evaluated_item_indexes_by_schema(
+                validator, instance, resolved)
+        finally:
+            validator.resolver.pop_scope()
+
+    if "prefixItems" in schema:
+        evaluated_indexes += list(range(0, len(schema["prefixItems"])))
+
+    if "if" in schema:
+        if validator.is_valid(instance, schema["if"]):
+            evaluated_indexes += find_evaluated_item_indexes_by_schema(
+                validator, instance, schema["if"]
+            )
+            if "then" in schema:
+                evaluated_indexes += find_evaluated_item_indexes_by_schema(
+                    validator, instance, schema["then"]
+                )
+        else:
+            if "else" in schema:
+                evaluated_indexes += find_evaluated_item_indexes_by_schema(
+                    validator, instance, schema["else"]
+                )
+
+    for keyword in ["contains", "unevaluatedItems"]:
+        if keyword in schema:
+            for k, v in enumerate(instance):
+                if validator.is_valid(v, schema[keyword]):
+                    evaluated_indexes.append(k)
+
+    for keyword in ["allOf", "oneOf", "anyOf"]:
+        if keyword in schema:
+            for subschema in schema[keyword]:
+                errs = list(validator.descend(instance, subschema))
+                if not errs:
+                    evaluated_indexes += find_evaluated_item_indexes_by_schema(
+                        validator, instance, subschema
+                    )
+
+    return evaluated_indexes
+
+
+def find_evaluated_property_keys_by_schema(validator, instance, schema):
+    """
+    Get all keys of items that get evaluated under the current schema
+
+    Covers all keywords related to unevaluatedProperties: properties,
+    additionalProperties, unevaluatedProperties, patternProperties,
+    dependentSchemas, allOf, oneOf, anyOf, if, then, else
+    """
+    if validator.is_type(schema, "boolean"):
+        return []
+    evaluated_keys = []
+
+    if "$ref" in schema:
+        scope, resolved = validator.resolver.resolve(schema["$ref"])
+        validator.resolver.push_scope(scope)
+
+        try:
+            evaluated_keys += find_evaluated_property_keys_by_schema(
+                validator, instance, resolved
+            )
+        finally:
+            validator.resolver.pop_scope()
+
+    for keyword in [
+        "properties", "additionalProperties", "unevaluatedProperties"
+    ]:
+        if keyword in schema:
+            if validator.is_type(schema[keyword], "boolean"):
+                for property, value in instance.items():
+                    if validator.is_valid({property: value}, schema[keyword]):
+                        evaluated_keys.append(property)
+
+            if validator.is_type(schema[keyword], "object"):
+                for property, subschema in schema[keyword].items():
+                    if property in instance and validator.is_valid(
+                            instance[property], subschema
+                    ):
+                        evaluated_keys.append(property)
+
+    if "patternProperties" in schema:
+        for property, value in instance.items():
+            for pattern, subschema in schema["patternProperties"].items():
+                if re.search(pattern, property) and validator.is_valid(
+                        {property: value}, schema["patternProperties"]
+                ):
+                    evaluated_keys.append(property)
+
+    if "dependentSchemas" in schema:
+        for property, subschema in schema["dependentSchemas"].items():
+            if property not in instance:
+                continue
+            evaluated_keys += find_evaluated_property_keys_by_schema(
+                validator, instance, subschema
+            )
+
+    for keyword in ["allOf", "oneOf", "anyOf"]:
+        if keyword in schema:
+            for subschema in schema[keyword]:
+                errs = list(validator.descend(instance, subschema))
+                if not errs:
+                    evaluated_keys += find_evaluated_property_keys_by_schema(
+                        validator, instance, subschema
+                    )
+
+    if "if" in schema:
+        if validator.is_valid(instance, schema["if"]):
+            evaluated_keys += find_evaluated_property_keys_by_schema(
+                validator, instance, schema["if"]
+            )
+            if "then" in schema:
+                evaluated_keys += find_evaluated_property_keys_by_schema(
+                    validator, instance, schema["then"]
+                )
+        else:
+            if "else" in schema:
+                evaluated_keys += find_evaluated_property_keys_by_schema(
+                    validator, instance, schema["else"]
+                )
+
+    return evaluated_keys
diff --git a/jsonschema/_validators.py b/jsonschema/_validators.py
index 0f7b6fb..b6a2f9c 100644
--- a/jsonschema/_validators.py
+++ b/jsonschema/_validators.py
@@ -1,4 +1,5 @@
 from fractions import Fraction
+from urllib.parse import urldefrag, urljoin
 import re
 
 from jsonschema._utils import (
@@ -6,6 +7,8 @@ from jsonschema._utils import (
     equal,
     extras_msg,
     find_additional_properties,
+    find_evaluated_item_indexes_by_schema,
+    find_evaluated_property_keys_by_schema,
     types_msg,
     unbool,
     uniq,
@@ -70,14 +73,17 @@ def items(validator, items, instance, schema):
     if not validator.is_type(instance, "array"):
         return
 
-    if validator.is_type(items, "array"):
-        for (index, item), subschema in zip(enumerate(instance), items):
-            for error in validator.descend(
-                item, subschema, path=index, schema_path=index,
-            ):
-                yield error
+    if validator.is_type(items, "boolean") and 'prefixItems' in schema:
+        if not items:
+            if len(instance) > len(schema['prefixItems']):
+                yield ValidationError(
+                    "%r has more items than defined in prefixItems" % instance
+                )
     else:
-        for index, item in enumerate(instance):
+        non_prefixed_items = instance[len(schema['prefixItems']):] \
+            if 'prefixItems' in schema else instance
+
+        for index, item in enumerate(non_prefixed_items):
             for error in validator.descend(item, items, path=index):
                 yield error
 
@@ -111,10 +117,56 @@ def contains(validator, contains, instance, schema):
     if not validator.is_type(instance, "array"):
         return
 
-    if not any(validator.is_valid(element, contains) for element in instance):
+    min_contains = max_contains = None
+
+    if 'minContains' in schema:
+        min_contains = schema['minContains']
+
+    if 'maxContains' in schema:
+        max_contains = schema['maxContains']
+
+    # minContains set to 0 will ignore contains
+    if min_contains == 0:
+        return
+
+    matches = sum(1 for each in instance if validator.is_valid(each, contains))
+
+    # default contains behavior
+    if not matches:
         yield ValidationError(
             "None of %r are valid under the given schema" % (instance,)
         )
+        return
+
+    if min_contains and max_contains is None:
+        if matches < min_contains:
+            yield ValidationError(
+                "Too few matches under the given schema. "
+                "Expected %d but there were only %d." % (
+                    min_contains, matches
+                )
+            )
+        return
+
+    if min_contains is None and max_contains:
+        if matches > max_contains:
+            yield ValidationError(
+                "Too many matches under the given schema. "
+                "Expected %d but there were only %d." % (
+                    max_contains, matches
+                )
+            )
+        return
+
+    if min_contains and max_contains:
+        if matches < min_contains or matches > max_contains:
+            yield ValidationError(
+                "Invalid number or matches under the given schema, "
+                "expected between %d and %d, got %d" % (
+                    min_contains, max_contains, matches
+                )
+            )
+        return
 
 
 def exclusiveMinimum(validator, minimum, instance, schema):
@@ -233,24 +285,29 @@ def maxLength(validator, mL, instance, schema):
         yield ValidationError("%r is too long" % (instance,))
 
 
-def dependencies(validator, dependencies, instance, schema):
+def dependentRequired(validator, dependentRequired, instance, schema):
     if not validator.is_type(instance, "object"):
         return
 
-    for property, dependency in dependencies.items():
+    for property, dependency in dependentRequired.items():
         if property not in instance:
             continue
 
-        if validator.is_type(dependency, "array"):
-            for each in dependency:
-                if each not in instance:
-                    message = "%r is a dependency of %r"
-                    yield ValidationError(message % (each, property))
-        else:
-            for error in validator.descend(
+        for each in dependency:
+            if each not in instance:
+                message = "%r is a dependency of %r"
+                yield ValidationError(message % (each, property))
+
+
+def dependentSchemas(validator, dependentSchemas, instance, schema):
+    for property, dependency in dependentSchemas.items():
+        if property not in instance:
+            continue
+
+        for error in validator.descend(
                 instance, dependency, schema_path=property,
-            ):
-                yield error
+        ):
+            yield error
 
 
 def enum(validator, enums, instance, schema):
@@ -279,6 +336,41 @@ def ref(validator, ref, instance, schema):
             validator.resolver.pop_scope()
 
 
+def dynamicRef(validator, dynamicRef, instance, schema):
+    _, fragment = urldefrag(dynamicRef)
+    scope_stack = validator.resolver.scopes_stack_copy
+
+    for url in scope_stack:
+        lookup_url = urljoin(url, dynamicRef)
+        with validator.resolver.resolving(lookup_url) as lookup_schema:
+            if ("$dynamicAnchor" in lookup_schema
+                    and fragment == lookup_schema["$dynamicAnchor"]):
+                subschema = lookup_schema
+                for error in validator.descend(instance, subschema):
+                    yield error
+                break
+    else:
+        with validator.resolver.resolving(dynamicRef) as lookup_schema:
+            subschema = lookup_schema
+            for error in validator.descend(instance, subschema):
+                yield error
+
+
+def defs(validator, defs, instance, schema):
+    if not validator.is_type(instance, "object"):
+        return
+
+    if '$defs' in instance:
+        for definition, subschema in instance['$defs'].items():
+            for error in validator.descend(
+                subschema,
+                schema,
+                path=definition,
+                schema_path=definition,
+            ):
+                yield error
+
+
 def type(validator, types, instance, schema):
     types = ensure_list(types)
 
@@ -384,3 +476,51 @@ def if_(validator, if_schema, instance, schema):
         else_ = schema[u"else"]
         for error in validator.descend(instance, else_, schema_path="else"):
             yield error
+
+
+def unevaluatedItems(validator, unevaluatedItems, instance, schema):
+    evaluated_item_indexes = find_evaluated_item_indexes_by_schema(
+        validator, instance, schema
+    )
+    unevaluated_items = []
+    for k, v in enumerate(instance):
+        if k not in evaluated_item_indexes:
+            for error in validator.descend(
+                v, unevaluatedItems, schema_path="unevaluatedItems"
+            ):
+                unevaluated_items.append(v)
+
+    if len(unevaluated_items):
+        error = "Unevaluated items are not allowed (%s %s unexpected)"
+        yield ValidationError(error % extras_msg(unevaluated_items))
+
+
+def unevaluatedProperties(validator, unevaluatedProperties, instance, schema):
+    evaluated_property_keys = find_evaluated_property_keys_by_schema(
+        validator, instance, schema
+    )
+    unevaluated_property_keys = []
+    for property, subschema in instance.items():
+        if property not in evaluated_property_keys:
+            for error in validator.descend(
+                instance[property],
+                unevaluatedProperties,
+                path=property,
+                schema_path=property,
+            ):
+                unevaluated_property_keys.append(property)
+
+    if len(unevaluated_property_keys):
+        error = "Unevaluated properties are not allowed (%s %s unexpected)"
+        yield ValidationError(error % extras_msg(unevaluated_property_keys))
+
+
+def prefixItems(validator, prefixItems, instance, schema):
+    if not validator.is_type(instance, "array"):
+        return
+
+    for k, v in enumerate(instance[:min(len(prefixItems), len(instance))]):
+        for error in validator.descend(
+            v, prefixItems[k], schema_path="prefixItems"
+        ):
+            yield error
diff --git a/jsonschema/schemas/draft2020-12.json b/jsonschema/schemas/draft2020-12.json
new file mode 100644
index 0000000..d5e2d31
--- /dev/null
+++ b/jsonschema/schemas/draft2020-12.json
@@ -0,0 +1,58 @@
+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "$id": "https://json-schema.org/draft/2020-12/schema",
+    "$vocabulary": {
+        "https://json-schema.org/draft/2020-12/vocab/core": true,
+        "https://json-schema.org/draft/2020-12/vocab/applicator": true,
+        "https://json-schema.org/draft/2020-12/vocab/unevaluated": true,
+        "https://json-schema.org/draft/2020-12/vocab/validation": true,
+        "https://json-schema.org/draft/2020-12/vocab/meta-data": true,
+        "https://json-schema.org/draft/2020-12/vocab/format-annotation": true,
+        "https://json-schema.org/draft/2020-12/vocab/content": true
+    },
+    "$dynamicAnchor": "meta",
+
+    "title": "Core and Validation specifications meta-schema",
+    "allOf": [
+        {"$ref": "meta/core"},
+        {"$ref": "meta/applicator"},
+        {"$ref": "meta/unevaluated"},
+        {"$ref": "meta/validation"},
+        {"$ref": "meta/meta-data"},
+        {"$ref": "meta/format-annotation"},
+        {"$ref": "meta/content"}
+    ],
+    "type": ["object", "boolean"],
+    "$comment": "This meta-schema also defines keywords that have appeared in previous drafts in order to prevent incompatible extensions as they remain in common use.",
+    "properties": {
+        "definitions": {
+            "$comment": "\"definitions\" has been replaced by \"$defs\".",
+            "type": "object",
+            "additionalProperties": { "$dynamicRef": "#meta" },
+            "deprecated": true,
+            "default": {}
+        },
+        "dependencies": {
+            "$comment": "\"dependencies\" has been split and replaced by \"dependentSchemas\" and \"dependentRequired\" in order to serve their differing semantics.",
+            "type": "object",
+            "additionalProperties": {
+                "anyOf": [
+                    { "$dynamicRef": "#meta" },
+                    { "$ref": "meta/validation#/$defs/stringArray" }
+                ]
+            },
+            "deprecated": true,
+            "default": {}
+        },
+        "$recursiveAnchor": {
+            "$comment": "\"$recursiveAnchor\" has been replaced by \"$dynamicAnchor\".",
+            "$ref": "meta/core#/$defs/anchorString",
+            "deprecated": true
+        },
+        "$recursiveRef": {
+            "$comment": "\"$recursiveRef\" has been replaced by \"$dynamicRef\".",
+            "$ref": "meta/core#/$defs/uriReferenceString",
+            "deprecated": true
+        }
+    }
+}
diff --git a/jsonschema/schemas/draft2020-12/applicator.json b/jsonschema/schemas/draft2020-12/applicator.json
new file mode 100644
index 0000000..ca69923
--- /dev/null
+++ b/jsonschema/schemas/draft2020-12/applicator.json
@@ -0,0 +1,48 @@
+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "$id": "https://json-schema.org/draft/2020-12/meta/applicator",
+    "$vocabulary": {
+        "https://json-schema.org/draft/2020-12/vocab/applicator": true
+    },
+    "$dynamicAnchor": "meta",
+
+    "title": "Applicator vocabulary meta-schema",
+    "type": ["object", "boolean"],
+    "properties": {
+        "prefixItems": { "$ref": "#/$defs/schemaArray" },
+        "items": { "$dynamicRef": "#meta" },
+        "contains": { "$dynamicRef": "#meta" },
+        "additionalProperties": { "$dynamicRef": "#meta" },
+        "properties": {
+            "type": "object",
+            "additionalProperties": { "$dynamicRef": "#meta" },
+            "default": {}
+        },
+        "patternProperties": {
+            "type": "object",
+            "additionalProperties": { "$dynamicRef": "#meta" },
+            "propertyNames": { "format": "regex" },
+            "default": {}
+        },
+        "dependentSchemas": {
+            "type": "object",
+            "additionalProperties": { "$dynamicRef": "#meta" },
+            "default": {}
+        },
+        "propertyNames": { "$dynamicRef": "#meta" },
+        "if": { "$dynamicRef": "#meta" },
+        "then": { "$dynamicRef": "#meta" },
+        "else": { "$dynamicRef": "#meta" },
+        "allOf": { "$ref": "#/$defs/schemaArray" },
+        "anyOf": { "$ref": "#/$defs/schemaArray" },
+        "oneOf": { "$ref": "#/$defs/schemaArray" },
+        "not": { "$dynamicRef": "#meta" }
+    },
+    "$defs": {
+        "schemaArray": {
+            "type": "array",
+            "minItems": 1,
+            "items": { "$dynamicRef": "#meta" }
+        }
+    }
+}
diff --git a/jsonschema/schemas/draft2020-12/content.json b/jsonschema/schemas/draft2020-12/content.json
new file mode 100644
index 0000000..2f6e056
--- /dev/null
+++ b/jsonschema/schemas/draft2020-12/content.json
@@ -0,0 +1,17 @@
+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "$id": "https://json-schema.org/draft/2020-12/meta/content",
+    "$vocabulary": {
+        "https://json-schema.org/draft/2020-12/vocab/content": true
+    },
+    "$dynamicAnchor": "meta",
+
+    "title": "Content vocabulary meta-schema",
+
+    "type": ["object", "boolean"],
+    "properties": {
+        "contentEncoding": { "type": "string" },
+        "contentMediaType": { "type": "string" },
+        "contentSchema": { "$dynamicRef": "#meta" }
+    }
+}
diff --git a/jsonschema/schemas/draft2020-12/core.json b/jsonschema/schemas/draft2020-12/core.json
new file mode 100644
index 0000000..dfc092d
--- /dev/null
+++ b/jsonschema/schemas/draft2020-12/core.json
@@ -0,0 +1,51 @@
+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "$id": "https://json-schema.org/draft/2020-12/meta/core",
+    "$vocabulary": {
+        "https://json-schema.org/draft/2020-12/vocab/core": true
+    },
+    "$dynamicAnchor": "meta",
+
+    "title": "Core vocabulary meta-schema",
+    "type": ["object", "boolean"],
+    "properties": {
+        "$id": {
+            "$ref": "#/$defs/uriReferenceString",
+            "$comment": "Non-empty fragments not allowed.",
+            "pattern": "^[^#]*#?$"
+        },
+        "$schema": { "$ref": "#/$defs/uriString" },
+        "$ref": { "$ref": "#/$defs/uriReferenceString" },
+        "$anchor": { "$ref": "#/$defs/anchorString" },
+        "$dynamicRef": { "$ref": "#/$defs/uriReferenceString" },
+        "$dynamicAnchor": { "$ref": "#/$defs/anchorString" },
+        "$vocabulary": {
+            "type": "object",
+            "propertyNames": { "$ref": "#/$defs/uriString" },
+            "additionalProperties": {
+                "type": "boolean"
+            }
+        },
+        "$comment": {
+            "type": "string"
+        },
+        "$defs": {
+            "type": "object",
+            "additionalProperties": { "$dynamicRef": "#meta" }
+        }
+    },
+    "$defs": {
+        "anchorString": {
+            "type": "string",
+            "pattern": "^[A-Za-z_][-A-Za-z0-9._]*$"
+        },
+        "uriString": {
+            "type": "string",
+            "format": "uri"
+        },
+        "uriReferenceString": {
+            "type": "string",
+            "format": "uri-reference"
+        }
+    }
+}
diff --git a/jsonschema/schemas/draft2020-12/format-annotation.json b/jsonschema/schemas/draft2020-12/format-annotation.json
new file mode 100644
index 0000000..51ef7ea
--- /dev/null
+++ b/jsonschema/schemas/draft2020-12/format-annotation.json
@@ -0,0 +1,14 @@
+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "$id": "https://json-schema.org/draft/2020-12/meta/format-annotation",
+    "$vocabulary": {
+        "https://json-schema.org/draft/2020-12/vocab/format-annotation": true
+    },
+    "$dynamicAnchor": "meta",
+
+    "title": "Format vocabulary meta-schema for annotation results",
+    "type": ["object", "boolean"],
+    "properties": {
+        "format": { "type": "string" }
+    }
+}
diff --git a/jsonschema/schemas/draft2020-12/meta-data.json b/jsonschema/schemas/draft2020-12/meta-data.json
new file mode 100644
index 0000000..05cbc22
--- /dev/null
+++ b/jsonschema/schemas/draft2020-12/meta-data.json
@@ -0,0 +1,37 @@
+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "$id": "https://json-schema.org/draft/2020-12/meta/meta-data",
+    "$vocabulary": {
+        "https://json-schema.org/draft/2020-12/vocab/meta-data": true
+    },
+    "$dynamicAnchor": "meta",
+
+    "title": "Meta-data vocabulary meta-schema",
+
+    "type": ["object", "boolean"],
+    "properties": {
+        "title": {
+            "type": "string"
+        },
+        "description": {
+            "type": "string"
+        },
+        "default": true,
+        "deprecated": {
+            "type": "boolean",
+            "default": false
+        },
+        "readOnly": {
+            "type": "boolean",
+            "default": false
+        },
+        "writeOnly": {
+            "type": "boolean",
+            "default": false
+        },
+        "examples": {
+            "type": "array",
+            "items": true
+        }
+    }
+}
diff --git a/jsonschema/schemas/draft2020-12/unevaluated.json b/jsonschema/schemas/draft2020-12/unevaluated.json
new file mode 100644
index 0000000..5f62a3f
--- /dev/null
+++ b/jsonschema/schemas/draft2020-12/unevaluated.json
@@ -0,0 +1,15 @@
+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "$id": "https://json-schema.org/draft/2020-12/meta/unevaluated",
+    "$vocabulary": {
+        "https://json-schema.org/draft/2020-12/vocab/unevaluated": true
+    },
+    "$dynamicAnchor": "meta",
+
+    "title": "Unevaluated applicator vocabulary meta-schema",
+    "type": ["object", "boolean"],
+    "properties": {
+        "unevaluatedItems": { "$dynamicRef": "#meta" },
+        "unevaluatedProperties": { "$dynamicRef": "#meta" }
+    }
+}
diff --git a/jsonschema/schemas/draft2020-12/validation.json b/jsonschema/schemas/draft2020-12/validation.json
new file mode 100644
index 0000000..606b87b
--- /dev/null
+++ b/jsonschema/schemas/draft2020-12/validation.json
@@ -0,0 +1,98 @@
+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "$id": "https://json-schema.org/draft/2020-12/meta/validation",
+    "$vocabulary": {
+        "https://json-schema.org/draft/2020-12/vocab/validation": true
+    },
+    "$dynamicAnchor": "meta",
+
+    "title": "Validation vocabulary meta-schema",
+    "type": ["object", "boolean"],
+    "properties": {
+        "type": {
+            "anyOf": [
+                { "$ref": "#/$defs/simpleTypes" },
+                {
+                    "type": "array",
+                    "items": { "$ref": "#/$defs/simpleTypes" },
+                    "minItems": 1,
+                    "uniqueItems": true
+                }
+            ]
+        },
+        "const": true,
+        "enum": {
+            "type": "array",
+            "items": true
+        },
+        "multipleOf": {
+            "type": "number",
+            "exclusiveMinimum": 0
+        },
+        "maximum": {
+            "type": "number"
+        },
+        "exclusiveMaximum": {
+            "type": "number"
+        },
+        "minimum": {
+            "type": "number"
+        },
+        "exclusiveMinimum": {
+            "type": "number"
+        },
+        "maxLength": { "$ref": "#/$defs/nonNegativeInteger" },
+        "minLength": { "$ref": "#/$defs/nonNegativeIntegerDefault0" },
+        "pattern": {
+            "type": "string",
+            "format": "regex"
+        },
+        "maxItems": { "$ref": "#/$defs/nonNegativeInteger" },
+        "minItems": { "$ref": "#/$defs/nonNegativeIntegerDefault0" },
+        "uniqueItems": {
+            "type": "boolean",
+            "default": false
+        },
+        "maxContains": { "$ref": "#/$defs/nonNegativeInteger" },
+        "minContains": {
+            "$ref": "#/$defs/nonNegativeInteger",
+            "default": 1
+        },
+        "maxProperties": { "$ref": "#/$defs/nonNegativeInteger" },
+        "minProperties": { "$ref": "#/$defs/nonNegativeIntegerDefault0" },
+        "required": { "$ref": "#/$defs/stringArray" },
+        "dependentRequired": {
+            "type": "object",
+            "additionalProperties": {
+                "$ref": "#/$defs/stringArray"
+            }
+        }
+    },
+    "$defs": {
+        "nonNegativeInteger": {
+            "type": "integer",
+            "minimum": 0
+        },
+        "nonNegativeIntegerDefault0": {
+            "$ref": "#/$defs/nonNegativeInteger",
+            "default": 0
+        },
+        "simpleTypes": {
+            "enum": [
+                "array",
+                "boolean",
+                "integer",
+                "null",
+                "number",
+                "object",
+                "string"
+            ]
+        },
+        "stringArray": {
+            "type": "array",
+            "items": { "type": "string" },
+            "uniqueItems": true,
+            "default": []
+        }
+    }
+}
diff --git a/jsonschema/tests/test_cli.py b/jsonschema/tests/test_cli.py
index 884a037..ae4f13d 100644
--- a/jsonschema/tests/test_cli.py
+++ b/jsonschema/tests/test_cli.py
@@ -10,7 +10,7 @@ import subprocess
 import sys
 import tempfile
 
-from jsonschema import Draft4Validator, Draft7Validator, __version__, cli
+from jsonschema import Draft4Validator, Draft202012Validator, __version__, cli
 from jsonschema.exceptions import (
     RefResolutionError,
     SchemaError,
@@ -336,7 +336,7 @@ class TestCLI(TestCase):
 
             exit_code=1,
             stderr="""\
-                57: 57 is not valid under any of the given schemas
+                57: 57 is not of type 'object', 'boolean'
             """,
         )
 
@@ -776,7 +776,7 @@ class TestCLI(TestCase):
         # is hidden inside the CLI, so guard that that's the case, and
         # this test will have to be updated when versions change until
         # we can think of a better way to ensure this behavior.
-        self.assertIs(Draft7Validator, _LATEST_VERSION)
+        self.assertIs(Draft202012Validator, _LATEST_VERSION)
 
         self.assertOutputs(
             files=dict(some_schema='{"const": "check"}', some_instance='"a"'),
diff --git a/jsonschema/tests/test_format.py b/jsonschema/tests/test_format.py
index 6dba484..06f841c 100644
--- a/jsonschema/tests/test_format.py
+++ b/jsonschema/tests/test_format.py
@@ -79,10 +79,29 @@ class TestFormatChecker(TestCase):
 
     def test_repr(self):
         checker = FormatChecker(formats=())
-        checker.checks("foo")(lambda thing: True)
-        checker.checks("bar")(lambda thing: True)
-        checker.checks("baz")(lambda thing: True)
+        checker.checks("foo")(lambda thing: True)  # pragma: no cover
+        checker.checks("bar")(lambda thing: True)  # pragma: no cover
+        checker.checks("baz")(lambda thing: True)  # pragma: no cover
         self.assertEqual(
             repr(checker),
             "<FormatChecker checkers=['bar', 'baz', 'foo']>",
         )
+
+    def test_duration_format(self):
+        try:
+            from jsonschema._format import is_duration  # noqa: F401
+        except ImportError:  # pragma: no cover
+            pass
+        else:
+            checker = FormatChecker()
+            self.assertTrue(checker.conforms(1, "duration"))
+            self.assertTrue(checker.conforms("P4Y", "duration"))
+            self.assertFalse(checker.conforms("test", "duration"))
+
+    def test_uuid_format(self):
+        checker = FormatChecker()
+        self.assertTrue(checker.conforms(1, "uuid"))
+        self.assertTrue(
+            checker.conforms("6e6659ec-4503-4428-9f03-2e2ea4d6c278", "uuid")
+        )
+        self.assertFalse(checker.conforms("test", "uuid"))
diff --git a/jsonschema/tests/test_jsonschema_test_suite.py b/jsonschema/tests/test_jsonschema_test_suite.py
index 40e3d85..b1e0723 100644
--- a/jsonschema/tests/test_jsonschema_test_suite.py
+++ b/jsonschema/tests/test_jsonschema_test_suite.py
@@ -13,10 +13,12 @@ from jsonschema import (
     Draft4Validator,
     Draft6Validator,
     Draft7Validator,
+    Draft202012Validator,
     draft3_format_checker,
     draft4_format_checker,
     draft6_format_checker,
     draft7_format_checker,
+    draft202012_format_checker,
 )
 from jsonschema.tests._helpers import bug
 from jsonschema.tests._suite import Suite
@@ -26,6 +28,7 @@ DRAFT3 = SUITE.version(name="draft3")
 DRAFT4 = SUITE.version(name="draft4")
 DRAFT6 = SUITE.version(name="draft6")
 DRAFT7 = SUITE.version(name="draft7")
+DRAFT202012 = SUITE.version(name="draft2020-12")
 
 
 def skip(message, **kwargs):
@@ -398,3 +401,63 @@ TestDraft7 = DRAFT7.to_unittest_testcase(
         )(test)
     ),
 )
+
+
+TestDraft202012 = DRAFT202012.to_unittest_testcase(
+    DRAFT202012.tests(),
+    DRAFT202012.optional_tests_of(name="bignum"),
+    DRAFT202012.optional_tests_of(name="float-overflow"),
+    DRAFT202012.optional_tests_of(name="non-bmp-regex"),
+    DRAFT202012.optional_tests_of(name="refOfUnknownKeyword"),
+    Validator=Draft202012Validator,
+    skip=lambda test: (
+        narrow_unicode_build(test)
+        or skip(
+            message="Issue: Resolving of dynamicRef based on dynamic scope",
+            subject="dynamicRef",
+            case_description="A $dynamicRef that initially resolves to a "
+                             "schema with a matching $dynamicAnchor should "
+                             "resolve to the first $dynamicAnchor in the "
+                             "dynamic scope",
+            description='The recursive part is not valid against the root',
+        )(test)
+        or skip(
+            message="Issue: Resolving of dynamicRef based on dynamic scope",
+            subject="dynamicRef",
+            case_description="multiple dynamic paths to the $dynamicRef "
+                             "keyword",
+            description="recurse to integerNode - floats are not allowed",
+        )(test)
+        or skip(
+            message="Issue: Resolving of dynamicRef based on dynamic scope",
+            subject="dynamicRef",
+            case_description="after leaving a dynamic scope, it should not be "
+                             "used by a $dynamicRef",
+            description="/then/$defs/thingy is the final stop for the "
+                        "$dynamicRef",
+        )(test)
+        or skip(
+            message="Issue: Resolving of dynamicRef based on dynamic scope",
+            subject="dynamicRef",
+            case_description="after leaving a dynamic scope, it should not be "
+                             'used by a $dynamicRef',
+            description="string matches /$defs/thingy, but the $dynamicRef "
+                        "does not stop here",
+        )(test)
+    ),
+)
+
+
+TestDraft202012Format = DRAFT202012.to_unittest_testcase(
+    DRAFT202012.format_tests(),
+    Validator=Draft202012Validator,
+    format_checker=draft202012_format_checker,
+    skip=lambda test: (
+        complex_email_validation(test)
+        or missing_date_fromisoformat(test)
+        or allowed_leading_zeros(test)
+        or leap_second(test)
+        or missing_format(draft202012_format_checker)(test)
+        or complex_email_validation(test)
+    )
+)
diff --git a/jsonschema/tests/test_validators.py b/jsonschema/tests/test_validators.py
index af5dfeb..bb3fefb 100644
--- a/jsonschema/tests/test_validators.py
+++ b/jsonschema/tests/test_validators.py
@@ -383,6 +383,40 @@ class TestValidationErrorMessages(TestCase):
         )
         self.assertIn("False schema does not allow 'something'", message)
 
+    def test_unevaluated_properties(self):
+        schema = {
+            "type": "object",
+            "unevaluatedProperties": False
+        }
+        message = self.message_for(
+            instance={
+                "foo": "foo",
+                "bar": "bar",
+            },
+            schema=schema,
+            cls=validators.Draft202012Validator,
+        )
+        self.assertIn(
+            "Unevaluated properties are not allowed "
+            "('foo', 'bar' were unexpected)",
+            message,
+        )
+
+    def test_unevaluated_items(self):
+        schema = {
+            "type": "array",
+            "unevaluatedItems": False
+        }
+        message = self.message_for(
+            instance=["foo", "bar"],
+            schema=schema,
+            cls=validators.Draft202012Validator,
+        )
+        self.assertIn(
+            "Unevaluated items are not allowed ('foo', 'bar' were unexpected)",
+            message,
+        )
+
 
 class TestValidationErrorDetails(TestCase):
     # TODO: These really need unit tests for each individual validator, rather
@@ -1244,6 +1278,12 @@ class TestDraft7Validator(ValidatorTestMixin, TestCase):
     invalid = {"type": "integer"}, "foo"
 
 
+class TestDraft202012Validator(ValidatorTestMixin, TestCase):
+    Validator = validators.Draft202012Validator
+    valid = {}, {}
+    invalid = {"type": "integer"}, "foo"
+
+
 class TestValidatorFor(SynchronousTestCase):
     def test_draft_3(self):
         schema = {"$schema": "http://json-schema.org/draft-03/schema"}
@@ -1297,6 +1337,19 @@ class TestValidatorFor(SynchronousTestCase):
             validators.Draft7Validator,
         )
 
+    def test_draft_202012(self):
+        schema = {"$schema": "https://json-schema.org/draft/2020-12/schema"}
+        self.assertIs(
+            validators.validator_for(schema),
+            validators.Draft202012Validator,
+        )
+
+        schema = {"$schema": "https://json-schema.org/draft/2020-12/schema#"}
+        self.assertIs(
+            validators.validator_for(schema),
+            validators.Draft202012Validator,
+        )
+
     def test_True(self):
         self.assertIs(
             validators.validator_for(True),
@@ -1410,8 +1463,23 @@ class TestValidate(SynchronousTestCase):
             Validator=validators.Draft7Validator,
         )
 
-    def test_draft7_validator_is_the_default(self):
-        self.assertUses(schema={}, Validator=validators.Draft7Validator)
+    def test_draft202012_validator_is_chosen(self):
+        self.assertUses(
+            schema={
+                "$schema": "https://json-schema.org/draft/2020-12/schema#"
+            },
+            Validator=validators.Draft202012Validator,
+        )
+        # Make sure it works without the empty fragment
+        self.assertUses(
+            schema={
+                "$schema": "https://json-schema.org/draft/2020-12/schema"
+            },
+            Validator=validators.Draft202012Validator,
+        )
+
+    def test_draft202012_validator_is_the_default(self):
+        self.assertUses(schema={}, Validator=validators.Draft202012Validator)
 
     def test_validation_error_message(self):
         with self.assertRaises(exceptions.ValidationError) as e:
diff --git a/jsonschema/validators.py b/jsonschema/validators.py
index 70d46c2..a1d4214 100644
--- a/jsonschema/validators.py
+++ b/jsonschema/validators.py
@@ -26,6 +26,7 @@ ErrorTree
 
 validators = {}
 meta_schemas = _utils.URIDict()
+_VOCABULARIES = _utils.URIDict()
 
 
 def validates(version):
@@ -51,8 +52,12 @@ def validates(version):
     def _validates(cls):
         validators[version] = cls
         meta_schema_id = cls.ID_OF(cls.META_SCHEMA)
-        if meta_schema_id:
-            meta_schemas[meta_schema_id] = cls
+        meta_schemas[meta_schema_id] = cls
+
+        for vocabulary in cls.VOCABULARY_SCHEMAS:
+            vocabulary_id = cls.ID_OF(vocabulary)
+            _VOCABULARIES[vocabulary_id] = vocabulary
+
         return cls
     return _validates
 
@@ -63,12 +68,22 @@ def _id_of(schema):
     return schema.get(u"$id", u"")
 
 
+def _store_schema_list():
+    return [
+        (id, validator.META_SCHEMA) for id, validator in meta_schemas.items()
+    ] + [
+        (id, schema) for id, schema in _VOCABULARIES.items()
+    ]
+
+
 def create(
     meta_schema,
+    vocabulary_schemas=(),
     validators=(),
     version=None,
     type_checker=_types.draft7_type_checker,
     id_of=_id_of,
+    applicable_validators=lambda schema: schema.items(),
 ):
     """
     Create a new validator class.
@@ -111,6 +126,11 @@ def create(
 
             A function that given a schema, returns its ID.
 
+        applicable_validators (collections.abc.Callable):
+
+            A function that returns a list of validators that should apply
+            to a given schema
+
     Returns:
 
         a new `jsonschema.IValidator` class
@@ -120,6 +140,7 @@ def create(
 
         VALIDATORS = dict(validators)
         META_SCHEMA = dict(meta_schema)
+        VOCABULARY_SCHEMAS = list(vocabulary_schemas)
         TYPE_CHECKER = type_checker
         ID_OF = staticmethod(id_of)
 
@@ -161,12 +182,7 @@ def create(
             if scope:
                 self.resolver.push_scope(scope)
             try:
-                ref = _schema.get(u"$ref")
-                if ref is not None:
-                    validators = [(u"$ref", ref)]
-                else:
-                    validators = _schema.items()
-
+                validators = applicable_validators(_schema)
                 for k, v in validators:
                     validator = self.VALIDATORS.get(k)
                     if validator is None:
@@ -312,6 +328,7 @@ Draft3Validator = create(
     type_checker=_types.draft3_type_checker,
     version="draft3",
     id_of=lambda schema: schema.get(u"id", ""),
+    applicable_validators=_legacy_validators.ignore_ref_siblings,
 )
 
 Draft4Validator = create(
@@ -322,7 +339,7 @@ Draft4Validator = create(
         u"additionalProperties": _validators.additionalProperties,
         u"allOf": _validators.allOf,
         u"anyOf": _validators.anyOf,
-        u"dependencies": _validators.dependencies,
+        u"dependencies": _legacy_validators.dependencies_draft4_draft6_draft7,
         u"enum": _validators.enum,
         u"format": _validators.format,
         u"items": _legacy_validators.items_draft3_draft4,
@@ -347,6 +364,7 @@ Draft4Validator = create(
     type_checker=_types.draft4_type_checker,
     version="draft4",
     id_of=lambda schema: schema.get(u"id", ""),
+    applicable_validators=_legacy_validators.ignore_ref_siblings,
 )
 
 Draft6Validator = create(
@@ -358,13 +376,13 @@ Draft6Validator = create(
         u"allOf": _validators.allOf,
         u"anyOf": _validators.anyOf,
         u"const": _validators.const,
-        u"contains": _validators.contains,
-        u"dependencies": _validators.dependencies,
+        u"contains": _legacy_validators.contains_draft6_draft7,
+        u"dependencies": _legacy_validators.dependencies_draft4_draft6_draft7,
         u"enum": _validators.enum,
         u"exclusiveMaximum": _validators.exclusiveMaximum,
         u"exclusiveMinimum": _validators.exclusiveMinimum,
         u"format": _validators.format,
-        u"items": _validators.items,
+        u"items": _legacy_validators.items_draft6_draft7,
         u"maxItems": _validators.maxItems,
         u"maxLength": _validators.maxLength,
         u"maxProperties": _validators.maxProperties,
@@ -386,6 +404,7 @@ Draft6Validator = create(
     },
     type_checker=_types.draft6_type_checker,
     version="draft6",
+    applicable_validators=_legacy_validators.ignore_ref_siblings,
 )
 
 Draft7Validator = create(
@@ -397,14 +416,14 @@ Draft7Validator = create(
         u"allOf": _validators.allOf,
         u"anyOf": _validators.anyOf,
         u"const": _validators.const,
-        u"contains": _validators.contains,
-        u"dependencies": _validators.dependencies,
+        u"contains": _legacy_validators.contains_draft6_draft7,
+        u"dependencies": _legacy_validators.dependencies_draft4_draft6_draft7,
         u"enum": _validators.enum,
         u"exclusiveMaximum": _validators.exclusiveMaximum,
         u"exclusiveMinimum": _validators.exclusiveMinimum,
         u"format": _validators.format,
         u"if": _validators.if_,
-        u"items": _validators.items,
+        u"items": _legacy_validators.items_draft6_draft7,
         u"maxItems": _validators.maxItems,
         u"maxLength": _validators.maxLength,
         u"maxProperties": _validators.maxProperties,
@@ -426,9 +445,57 @@ Draft7Validator = create(
     },
     type_checker=_types.draft7_type_checker,
     version="draft7",
+    applicable_validators=_legacy_validators.ignore_ref_siblings,
 )
 
-_LATEST_VERSION = Draft7Validator
+Draft202012Validator = create(
+    meta_schema=_utils.load_schema("draft2020-12"),
+    vocabulary_schemas=_utils.load_vocabulary("draft2020-12"),
+    validators={
+        u"$ref": _validators.ref,
+        u"$defs": _validators.defs,
+        u"$dynamicRef": _validators.dynamicRef,
+        u"additionalItems": _validators.additionalItems,
+        u"additionalProperties": _validators.additionalProperties,
+        u"allOf": _validators.allOf,
+        u"anyOf": _validators.anyOf,
+        u"const": _validators.const,
+        u"contains": _validators.contains,
+        u"dependentRequired": _validators.dependentRequired,
+        u"dependentSchemas": _validators.dependentSchemas,
+        u"enum": _validators.enum,
+        u"exclusiveMaximum": _validators.exclusiveMaximum,
+        u"exclusiveMinimum": _validators.exclusiveMinimum,
+        u"format": _validators.format,
+        u"if": _validators.if_,
+        u"items": _validators.items,
+        u"maxItems": _validators.maxItems,
+        u"maxLength": _validators.maxLength,
+        u"maxProperties": _validators.maxProperties,
+        u"maximum": _validators.maximum,
+        u"minItems": _validators.minItems,
+        u"minLength": _validators.minLength,
+        u"minProperties": _validators.minProperties,
+        u"minimum": _validators.minimum,
+        u"multipleOf": _validators.multipleOf,
+        u"oneOf": _validators.oneOf,
+        u"not": _validators.not_,
+        u"pattern": _validators.pattern,
+        u"patternProperties": _validators.patternProperties,
+        u"properties": _validators.properties,
+        u"propertyNames": _validators.propertyNames,
+        u"required": _validators.required,
+        u"type": _validators.type,
+        u"uniqueItems": _validators.uniqueItems,
+        u"unevaluatedItems": _validators.unevaluatedItems,
+        u"unevaluatedProperties": _validators.unevaluatedProperties,
+        u"prefixItems": _validators.prefixItems,
+    },
+    type_checker=_types.draft202012_type_checker,
+    version="draft2020-12",
+)
+
+_LATEST_VERSION = Draft202012Validator
 
 
 class RefResolver(object):
@@ -495,10 +562,7 @@ class RefResolver(object):
         self.handlers = dict(handlers)
 
         self._scopes_stack = [base_uri]
-        self.store = _utils.URIDict(
-            (id, validator.META_SCHEMA)
-            for id, validator in meta_schemas.items()
-        )
+        self.store = _utils.URIDict(_store_schema_list())
         self.store.update(store)
         self.store[base_uri] = referrer
 
@@ -561,6 +625,13 @@ class RefResolver(object):
         return self._scopes_stack[-1]
 
     @property
+    def scopes_stack_copy(self):
+        """
+        Retrieve a copy of the stack of resolution scopes.
+        """
+        return self._scopes_stack.copy()
+
+    @property
     def base_uri(self):
         """
         Retrieve the current base URI, not including any fragment.
@@ -600,11 +671,42 @@ class RefResolver(object):
         finally:
             self.pop_scope()
 
+    def _finditem(self, schema, key):
+        results = []
+        if isinstance(schema, dict):
+            if key in schema:
+                results.append(schema)
+
+            for k, v in schema.items():
+                if isinstance(v, dict):
+                    results += self._finditem(v, key)
+
+        return results
+
+    def resolve_local(self, url, schema):
+        """
+        Resolve the given reference within the schema
+        """
+        uri, fragment = urldefrag(url)
+
+        for subschema in self._finditem(schema, "$id"):
+            target_uri = self._urljoin_cache(
+                self.resolution_scope, subschema['$id']
+            )
+            if target_uri.rstrip("/") == uri.rstrip("/"):
+                if fragment:
+                    subschema = self.resolve_fragment(subschema, fragment)
+                return subschema
+
     def resolve(self, ref):
         """
         Resolve the given reference.
         """
-        url = self._urljoin_cache(self.resolution_scope, ref)
+        url = self._urljoin_cache(self.resolution_scope, ref).rstrip("/")
+        local_resolve = self.resolve_local(url, self.referrer)
+
+        if local_resolve:
+            return url, local_resolve
         return url, self._remote_cache(url)
 
     def resolve_from_url(self, url):
@@ -638,8 +740,16 @@ class RefResolver(object):
         """
 
         fragment = fragment.lstrip(u"/")
-        parts = unquote(fragment).split(u"/") if fragment else []
 
+        # Resolve fragment via $anchor or $dynamicAnchor
+        if fragment:
+            for keyword in ["$anchor", "$dynamicAnchor"]:
+                for subschema in self._finditem(document, keyword):
+                    if fragment == subschema[keyword]:
+                        return subschema
+
+        # Resolve via path
+        parts = unquote(fragment).split(u"/") if fragment else []
         for part in parts:
             part = part.replace(u"~1", u"/").replace(u"~0", u"~")
 
diff --git a/setup.cfg b/setup.cfg
index 8806726..d78daaf 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -39,6 +39,7 @@ format =
     strict-rfc3339
     webcolors
     uri_template
+    isoduration;python_version>'3.6'
 format_nongpl =
     fqdn
     idna
@@ -47,13 +48,14 @@ format_nongpl =
     rfc3986-validator>0.1.0
     rfc3339-validator
     uri_template
+    isoduration;python_version>'3.6'
 
 [options.entry_points]
 console_scripts =
     jsonschema = jsonschema.cli:main
 
 [options.package_data]
-jsonschema = schemas/*.json
+jsonschema = schemas/*.json, schemas/*/*.json
 
 [bdist_wheel]
 universal = 1