#782: Implements dynamicRef validations

Author: nezhar

jsonschema/_validators.py

@@ -1,4 +1,5 @@
 from fractions import Fraction
+from urllib.parse import urldefrag, urljoin
 import re
 
 from jsonschema._utils import (
@@ -384,6 +385,24 @@ 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:
+        with validator.resolver.resolving(urljoin(url, dynamicRef)) 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

jsonschema/tests/test_jsonschema_test_suite.py

@@ -713,5 +713,18 @@ def ecmascript_regex_validation(test):
         or complex_email_validation(test)
         or format_validation_annotation(test)
         or ecmascript_regex_validation(test)
+        or skip(
+            message="ToDo: Extend validation",
+            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="ToDo: Extend validation",
+            subject="dynamicRef",
+            case_description="multiple dynamic paths to the $dynamicRef keyword",
+            description='recurse to integerNode - floats are not allowed',
+        )(test)
     ),
 )

jsonschema/validators.py

@@ -437,6 +437,7 @@ def extend(validator, validators=(), version=None, type_checker=None):
     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,
@@ -609,6 +610,13 @@ def resolution_scope(self):
         """
         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):
         """
@@ -677,6 +685,7 @@ def resolve_local(self, url, schema):
                     self.store[url] = subschema
                 return subschema
 
+
     def resolve(self, ref):
         """
         Resolve the given reference.
@@ -720,10 +729,12 @@ def resolve_fragment(self, document, fragment):
 
         fragment = fragment.lstrip(u"/")
 
-        # Resolve via anchor
-        for subschema in self._finditem(document, "$anchor"):
-            if fragment == subschema['$anchor']:
-                return subschema
+        # 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 []