From 1416792f4ed7070131656ad72c7eaf04d6984afd Mon Sep 17 00:00:00 2001
From: Manfred Stienstra <manfred@fngtps.com>
Date: Mon, 23 Feb 2026 19:56:06 +0100
Subject: [PATCH 1/4] Add an example with allOf, anyOf, and oneOf to fixtures.

---
 test/files/openapi/polymorphic.yml       | 105 +++++++++++++++++++++++
 test/reynard/schema/model_naming_test.rb |   3 +-
 2 files changed, 107 insertions(+), 1 deletion(-)
 create mode 100644 test/files/openapi/polymorphic.yml

diff --git a/test/files/openapi/polymorphic.yml b/test/files/openapi/polymorphic.yml
new file mode 100644
index 0000000..e2727c6
--- /dev/null
+++ b/test/files/openapi/polymorphic.yml
@@ -0,0 +1,105 @@
+openapi: "3.1.0"
+info:
+  title: Pets
+  version: 1.0.0
+  contact: {}
+  description: Find out about my pet.
+servers:
+  - url: http://example.com
+tags:
+  - name: pets
+    description: Animals in custody of a person.
+paths:
+  /pets:
+    get:
+      summary: List all pets
+      description: A list of all my pets.
+      operationId: getPets
+      tags:
+        - pets
+      responses:
+        "200":
+          description: Array of pets
+          content:
+            application/json:
+              schema:
+                type: array
+                items:
+                  oneOf:
+                  - $ref: '#/components/schemas/Cat'
+                  - $ref: '#/components/schemas/Dog'
+  /pets/{id}:
+    get:
+      summary: Get pet
+      description: A description of the pet
+      operationId: getPet
+      tags:
+        - pets
+      parameters:
+        - in: path
+          name: id
+          required: true
+          schema:
+            type: string
+      responses:
+        "200":
+          description: A pet
+          content:
+            application/json:
+              schema:
+                oneOf:
+                  - $ref: '#/components/schemas/Cat'
+                  - $ref: '#/components/schemas/Dog'
+                discriminator:
+                  propertyName: pet_type
+  /status:
+    get:
+      summary: Get status of the service
+      description: A status object for the service
+      operationId: getStatus
+      tags:
+        - pets
+      responses:
+        "200":
+          description: A status
+          content:
+            application/json:
+              schema:
+                anyOf:
+                  - type: object
+                    properties:
+                      status:
+                        type: string
+                  - type: object
+                    properties:
+                      description:
+                        type: string
+                  - type: object
+                    properties:
+                      status:
+                        type: integer
+components:
+  schemas:
+    Pet:
+      type: object
+      required:
+        - pet_type
+      properties:
+        pet_type:
+          type: string
+      discriminator:
+        propertyName: pet_type
+    Cat:
+      allOf:
+        - $ref: "#/components/schemas/Pet"
+        - type: object
+          properties:
+            red:
+              type: boolean
+    Dog:
+      allOf:
+        - $ref: "#/components/schemas/Pet"
+        - type: object
+          properties:
+            tial:
+              type: boolean
diff --git a/test/reynard/schema/model_naming_test.rb b/test/reynard/schema/model_naming_test.rb
index 44119c8..fb4d20f 100644
--- a/test/reynard/schema/model_naming_test.rb
+++ b/test/reynard/schema/model_naming_test.rb
@@ -70,7 +70,8 @@ class RegressionModelNamingTest < Reynard::Test
         'weird' => %w[
           HowdyPardner AFRootWithInThe Fugol Bird Duckbill Duckbill HowdyPardner
           FugolCollection BirdsCollection DuckbillCollection
-        ]
+        ],
+        'polymorphic' => %w[Pet PetCollection]
       }.freeze
 
       test 'produces a model name for every schema node in every specification' do

From ebc014e2a352da6ee040f20e8cdbb3f60035eaf4 Mon Sep 17 00:00:00 2001
From: Manfred Stienstra <manfred@fngtps.com>
Date: Mon, 23 Feb 2026 20:08:03 +0100
Subject: [PATCH 2/4] Add method to determine the schema type.

---
 lib/reynard/schema.rb       |  8 ++++++++
 test/reynard/schema_test.rb | 23 +++++++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/lib/reynard/schema.rb b/lib/reynard/schema.rb
index 8a6f6d3..c111e7a 100644
--- a/lib/reynard/schema.rb
+++ b/lib/reynard/schema.rb
@@ -46,6 +46,14 @@ def property_schema(name)
       )
     end
 
+    def self.determine_schema_type(schema)
+      if schema.key?('type')
+        schema['type']
+      elsif schema.keys.intersect?(%w[allOf anyOf oneOf])
+        'object'
+      end
+    end
+
     private
 
     def model_naming
diff --git a/test/reynard/schema_test.rb b/test/reynard/schema_test.rb
index 7605929..733605c 100644
--- a/test/reynard/schema_test.rb
+++ b/test/reynard/schema_test.rb
@@ -4,6 +4,29 @@
 
 class Reynard
   class SchemaTest < Reynard::Test
+    test 'uses object schema type for object schemas' do
+      assert_equal('object', Schema.determine_schema_type({ 'type' => 'object' }))
+    end
+
+    test 'uses array schema type for array schemas' do
+      assert_equal('array', Schema.determine_schema_type({ 'type' => 'array' }))
+    end
+
+    test 'uses object schema type for allOf' do
+      assert_equal('object', Schema.determine_schema_type({ 'allOf' => {} }))
+    end
+
+    test 'uses object schema type for anyOf' do
+      assert_equal('object', Schema.determine_schema_type({ 'anyOf' => {} }))
+    end
+
+    test 'uses object schema type for oneOf' do
+      assert_equal('object', Schema.determine_schema_type({ 'oneOf' => {} }))
+    end
+
+    test 'does not return a schema type for unsupported schemas' do
+      assert_nil Schema.determine_schema_type({})
+    end
   end
 
   class SingularTopLevelSchemaTest < Reynard::Test

From 789e03d7d607329bd2d33e002de86878f0331175 Mon Sep 17 00:00:00 2001
From: Manfred Stienstra <manfred@fngtps.com>
Date: Mon, 23 Feb 2026 20:10:03 +0100
Subject: [PATCH 3/4] Initialize model for polymorphic schemas.

---
 lib/reynard/schema.rb               |  3 +-
 test/reynard/object_builder_test.rb | 50 +++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/lib/reynard/schema.rb b/lib/reynard/schema.rb
index c111e7a..149085a 100644
--- a/lib/reynard/schema.rb
+++ b/lib/reynard/schema.rb
@@ -16,7 +16,8 @@ def initialize(specification:, node:, namespace: nil)
     def type
       return @type if defined?(@type)
 
-      @type = @specification.dig(*node, 'type')
+      schema = @specification.dig(*node)
+      @type = schema ? self.class.determine_schema_type(schema) : nil
     end
 
     def model_name
diff --git a/test/reynard/object_builder_test.rb b/test/reynard/object_builder_test.rb
index 3626d94..e79a6d6 100644
--- a/test/reynard/object_builder_test.rb
+++ b/test/reynard/object_builder_test.rb
@@ -305,4 +305,54 @@ def setup
       assert_model_name('NationalIndustry', national_industry)
     end
   end
+
+  class PolymorphicBuilderTest < Reynard::Test
+    Response = Struct.new(:body, keyword_init: true)
+
+    def setup
+      @specification = Specification.new(filename: fixture_file('openapi/polymorphic.yml'))
+      @inflector = Inflector.new
+    end
+
+    test 'handles oneOf and allOf' do
+      operation = @specification.operation('getPets')
+      media_type = @specification.media_type(operation.node, '200', 'application/json')
+      schema = @specification.schema(media_type.node)
+      collection = Reynard::ObjectBuilder.new(
+        schema:,
+        inflector: @inflector,
+        parsed_body: [
+          {
+            'pet_type' => 'Dog',
+            'tail' => true
+          }
+        ]
+      ).call
+
+      assert_equal(1, collection.size)
+      record = collection[0]
+
+      assert_model_name('Pet', record)
+      assert_equal 'Dog', record.pet_type
+      assert record.tail
+    end
+
+    test 'handles anyOf' do
+      operation = @specification.operation('getStatus')
+      media_type = @specification.media_type(operation.node, '200', 'application/json')
+      schema = @specification.schema(media_type.node)
+      record = Reynard::ObjectBuilder.new(
+        schema:,
+        inflector: @inflector,
+        parsed_body: {
+          'status' => 'online',
+          'description' => 'Everything works'
+        }
+      ).call
+
+      assert_model_name('Statu', record)
+      assert_equal 'online', record.status
+      assert_equal 'Everything works', record.description
+    end
+  end
 end

From f78bc253abb6fadeb4dfda98d78c121e2747402a Mon Sep 17 00:00:00 2001
From: Manfred Stienstra <manfred@fngtps.com>
Date: Mon, 23 Feb 2026 20:16:13 +0100
Subject: [PATCH 4/4] Add whitespace for new RuboCop rule.

---
 lib/reynard.rb               | 1 +
 lib/reynard/context.rb       | 1 +
 lib/reynard/http/response.rb | 1 +
 lib/reynard/model.rb         | 1 +
 4 files changed, 4 insertions(+)

diff --git a/lib/reynard.rb b/lib/reynard.rb
index c56695f..c138a5a 100644
--- a/lib/reynard.rb
+++ b/lib/reynard.rb
@@ -11,6 +11,7 @@
 # OpenAPI specification.
 class Reynard
   extend Forwardable
+
   def_delegators :build_context, :logger, :base_url, :operation, :headers, :params
   def_delegators :@specification, :servers
   def_delegators :@inflector, :snake_cases
diff --git a/lib/reynard/context.rb b/lib/reynard/context.rb
index 7e532b5..5e680bb 100644
--- a/lib/reynard/context.rb
+++ b/lib/reynard/context.rb
@@ -4,6 +4,7 @@ class Reynard
   # Exposes a public interface to build a request context.
   class Context
     extend Forwardable
+
     def_delegators :@request_context, :verb, :path, :full_path, :url
 
     def initialize(specification:, inflector:, request_context: nil)
diff --git a/lib/reynard/http/response.rb b/lib/reynard/http/response.rb
index 0e63b4b..8628ff9 100644
--- a/lib/reynard/http/response.rb
+++ b/lib/reynard/http/response.rb
@@ -6,6 +6,7 @@ class Http
     # in the specification.
     class Response
       extend Forwardable
+
       def_delegators :@http_response, :code, :content_type, :[], :body
 
       def initialize(specification:, inflector:, request_context:, http_response:)
diff --git a/lib/reynard/model.rb b/lib/reynard/model.rb
index 5c9f35b..93b3367 100644
--- a/lib/reynard/model.rb
+++ b/lib/reynard/model.rb
@@ -4,6 +4,7 @@ class Reynard
   # Superclass for dynamic classes generated by the object builder.
   class Model < BasicObject
     extend ::Forwardable
+
     def_delegators :@attributes, :[], :empty?
 
     class << self