Julian/jsonschema#782: Load dependencies from legacy validators

1 files changed, 26 insertions, 0 deletions

diff --git a/jsonschema/_legacy_validators.py b/jsonschema/_legacy_validators.py
index b337151..8e46190 100644
--- a/jsonschema/_legacy_validators.py
+++ b/jsonschema/_legacy_validators.py
@@ -27,6 +27,32 @@ 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]}):