Add patternProperties to Schema

Based on JSON schema 2021 [1]. Where the value is expected to be a map
where the key is a regex (to match a string property name) and value is
a Schema object.

Like the implementation of pattern in this codebase this doesn't have
validation that pattern is a regex, which could be added.

[1]: https://datatracker.ietf.org/doc/html/draft-bhutton-json-schema-00#section-10.3.1.1

Author: kevindew

json-schema-for-3.1.md

@@ -86,7 +86,7 @@ items: array of schema - in 3.0
 contains: schema - done
 
 properties: object, each value json schema - in 3.0
-patternProperties: object each value JSON schema
+patternProperties: object each value JSON schema key regex - done
 additionalProperties: single json schema
 
 unevaluatedItems - single schema
@@ -110,6 +110,7 @@ Little things:
 - schema integer fields generally are required to be non-negative
 - quite common for arrays to be invalid if not unique (required, type)
 - probably want a quick way to get coverage of the methods on nodes
+- could validate that pattern and patternProperties contain regexs
 
 JSON Schema specs:
 

lib/openapi3_parser/node/schema/v3_1.rb

@@ -89,6 +89,11 @@ def prefix_items
         def contains
           self["contains"]
         end
+
+        # @return [Node::Map<String, Schema>]
+        def pattern_properties
+          self["patternProperties"]
+        end
       end
     end
   end

lib/openapi3_parser/node_factory/schema/v3_1.rb

@@ -36,6 +36,7 @@ class V3_1 < NodeFactory::Object # rubocop:disable Naming/ClassAndModuleCamelCas
         field "else", factory: :referenceable_schema
         field "prefixItems", factory: :prefix_items_factory
         field "contains", factory: :referenceable_schema
+        field "patternProperties", factory: :pattern_properties_factory
 
         def build_node(data, node_context)
           Node::Schema::V3_1.new(data, node_context)
@@ -88,6 +89,13 @@ def prefix_items_factory(context)
             value_factory: NodeFactory::Schema.factory(context)
           )
         end
+
+        def pattern_properties_factory(context)
+          NodeFactory::Map.new(
+            context,
+            value_factory: NodeFactory::Schema.factory(context)
+          )
+        end
       end
     end
   end

spec/support/examples/v3.1/changes.yaml

@@ -107,7 +107,11 @@ components:
         type: string
       unevaluatedItems:
         type: string
-     # Add object
+    Object:
+      type: object
+      patternProperties:
+        /^test/:
+          type: string
      # Add content types
      # Add $ref usage (plain, merged, defs)
      # Add compound things: anyOf, oneOf, not, if, then, else