Extend dynamicRef keyword

Author: nezhar

jsonschema/_utils.py

@@ -1,3 +1,4 @@
+from collections import deque
 from collections.abc import Mapping, MutableMapping, Sequence
 from urllib.parse import urlsplit
 import itertools
@@ -346,3 +347,84 @@ def find_evaluated_property_keys_by_schema(validator, instance, schema):
                 )
 
     return evaluated_keys
+
+
+def _schema_is_referenced(schema, parent_schema):
+    """
+    Checks if a schema is referenced by another schema
+    """
+    return ("$id" in schema and "$ref" in parent_schema
+            and parent_schema["$ref"] == schema["$id"])
+
+
+def _find_dynamic_anchor_extender(validator, scopes, fragment, schema):
+    """
+    Find a schema that extends the dynamic anchor
+    """
+    for url in scopes:
+        with validator.resolver.resolving(url) as parent_schema:
+            if _schema_is_referenced(schema, parent_schema):
+                return validator.resolver.resolve_fragment(
+                    parent_schema,
+                    fragment,
+                )
+
+
+def _find_dynamic_anchor_intermediate(validator, scopes, fragment):
+    """
+    Find a schema that extends the dynamic anchor by an intermediate schema
+    """
+    for url in scopes:
+        with validator.resolver.resolving(url) as schema:
+            if "$id" in schema:
+                for intermediate_url in scopes:
+                    with validator.resolver.resolving(
+                            intermediate_url) as intermediate_schema:
+                        for subschema in search_schema(
+                                intermediate_schema, match_keyword("$ref")):
+                            if _schema_is_referenced(subschema, schema):
+                                return _find_dynamic_anchor_extender(
+                                    validator,
+                                    scopes,
+                                    fragment,
+                                    subschema,
+                                )
+
+
+def dynamic_anchor_extender(validator, scopes, fragment, schema, subschema):
+    extender_schema = _find_dynamic_anchor_extender(
+        validator, scopes, fragment, schema,
+    )
+    if not extender_schema:
+        extender_schema = _find_dynamic_anchor_extender(
+            validator, scopes, fragment, subschema,
+        )
+    if not extender_schema:
+        extender_schema = _find_dynamic_anchor_intermediate(
+            validator, scopes, fragment,
+        )
+
+    return extender_schema
+
+
+def match_keyword(keyword):
+
+    def matcher(value):
+        if keyword in value:
+            yield value
+
+    return matcher
+
+
+def search_schema(schema, matcher):
+    """Breadth-first search routine."""
+    values = deque([schema])
+    while values:
+        value = values.pop()
+        if isinstance(value, list):
+            values.extendleft(value)
+            continue
+        if not isinstance(value, dict):
+            continue
+        yield from matcher(value)
+        values.extendleft(value.values())

jsonschema/_validators.py

@@ -3,6 +3,7 @@
 import re
 
 from jsonschema._utils import (
+    dynamic_anchor_extender,
     ensure_list,
     equal,
     extras_msg,
@@ -302,14 +303,21 @@ def ref(validator, ref, instance, schema):
 
 def dynamicRef(validator, dynamicRef, instance, schema):
     _, fragment = urldefrag(dynamicRef)
-
     for url in validator.resolver._scopes_stack:
         lookup_url = urljoin(url, dynamicRef)
         with validator.resolver.resolving(lookup_url) as subschema:
             if ("$dynamicAnchor" in subschema
                     and fragment == subschema["$dynamicAnchor"]):
+                scope_stack = list(validator.resolver._scopes_stack)
+                scope_stack.reverse()
+                extended_schema = dynamic_anchor_extender(
+                    validator, scope_stack, fragment, schema, subschema,
+                )
+                if extended_schema:
+                    yield from validator.descend(instance, extended_schema)
+                    break
+
                 yield from validator.descend(instance, subschema)
-                break
     else:
         with validator.resolver.resolving(dynamicRef) as subschema:
             yield from validator.descend(instance, subschema)

jsonschema/tests/test_jsonschema_test_suite.py

@@ -401,15 +401,7 @@ def leap_second(test):
     skip=lambda test: (
         narrow_unicode_build(test)
         or skip(
-            message="dynamicRef support isn't working yet.",
-            subject="dynamicRef",
-        )(test)
-        or skip(
-            message="These tests depends on dynamicRef working.",
-            subject="defs",
-        )(test)
-        or skip(
-            message="These tests depends on dynamicRef working.",
+            message="These tests require an extension or the url resolver.",
             subject="anchor",
             case_description="same $anchor with different base uri",
         )(test)

jsonschema/validators.py

@@ -1,7 +1,6 @@
 """
 Creation and extension of validators, with implementations for existing drafts.
 """
-from collections import deque
 from collections.abc import Sequence
 from functools import lru_cache
 from urllib.parse import unquote, urldefrag, urljoin, urlsplit
@@ -761,7 +760,7 @@ def _find_in_referrer(self, key):
     @lru_cache()
     def _get_subschemas_cache(self):
         cache = {key: [] for key in _SUBSCHEMAS_KEYWORDS}
-        for keyword, subschema in _search_schema(
+        for keyword, subschema in _utils.search_schema(
             self.referrer, _match_subschema_keywords,
         ):
             cache[keyword].append(subschema)
@@ -835,7 +834,7 @@ def resolve_fragment(self, document, fragment):
         else:
 
             def find(key):
-                yield from _search_schema(document, _match_keyword(key))
+                yield from _utils.search_schema(document, _utils.match_keyword(key))
 
         for keyword in ["$anchor", "$dynamicAnchor"]:
             for subschema in find(keyword):
@@ -921,32 +920,12 @@ def resolve_remote(self, uri):
 _SUBSCHEMAS_KEYWORDS = ("$id", "id", "$anchor", "$dynamicAnchor")
 
 
-def _match_keyword(keyword):
-
-    def matcher(value):
-        if keyword in value:
-            yield value
-
-    return matcher
-
-
 def _match_subschema_keywords(value):
     for keyword in _SUBSCHEMAS_KEYWORDS:
         if keyword in value:
             yield keyword, value
 
 
-def _search_schema(schema, matcher):
-    """Breadth-first search routine."""
-    values = deque([schema])
-    while values:
-        value = values.pop()
-        if not isinstance(value, dict):
-            continue
-        yield from matcher(value)
-        values.extendleft(value.values())
-
-
 def validate(instance, schema, cls=None, *args, **kwargs):
     """
     Validate an instance under the given schema.