diff --git a/modules/openapi-generator/src/main/resources/ruby-client/partial_anyof_module.mustache b/modules/openapi-generator/src/main/resources/ruby-client/partial_anyof_module.mustache
index f979fdd3100e..040a52199e00 100644
--- a/modules/openapi-generator/src/main/resources/ruby-client/partial_anyof_module.mustache
+++ b/modules/openapi-generator/src/main/resources/ruby-client/partial_anyof_module.mustache
@@ -29,8 +29,7 @@
         openapi_any_of.each do |klass|
           begin
             next if klass == :AnyType # "nullable: true"
-            typed_data = find_and_cast_into_type(klass, data)
-            return typed_data if typed_data
+            return find_and_cast_into_type(klass, data)
           rescue # rescue all errors so we keep iterating even if the current item lookup raises
           end
         end
diff --git a/modules/openapi-generator/src/main/resources/ruby-client/partial_oneof_module.mustache b/modules/openapi-generator/src/main/resources/ruby-client/partial_oneof_module.mustache
index 8dd7b381d2bd..04fa0d311024 100644
--- a/modules/openapi-generator/src/main/resources/ruby-client/partial_oneof_module.mustache
+++ b/modules/openapi-generator/src/main/resources/ruby-client/partial_oneof_module.mustache
@@ -69,8 +69,7 @@
         openapi_one_of.each do |klass|
           begin
             next if klass == :AnyType # "nullable: true"
-            typed_data = find_and_cast_into_type(klass, data)
-            return typed_data if typed_data
+            return find_and_cast_into_type(klass, data)
           rescue # rescue all errors so we keep iterating even if the current item lookup raises
           end
         end
diff --git a/modules/openapi-generator/src/test/resources/3_0/ruby/petstore-with-fake-endpoints-models-for-testing.yaml b/modules/openapi-generator/src/test/resources/3_0/ruby/petstore-with-fake-endpoints-models-for-testing.yaml
index 9cdb45fcd65d..064862059da5 100644
--- a/modules/openapi-generator/src/test/resources/3_0/ruby/petstore-with-fake-endpoints-models-for-testing.yaml
+++ b/modules/openapi-generator/src/test/resources/3_0/ruby/petstore-with-fake-endpoints-models-for-testing.yaml
@@ -2162,3 +2162,33 @@ components:
           type: string
         type_:
           type: string
+    OneOfPrimitiveTypes:
+      oneOf:
+        - type: string
+        - type: number
+        - type: integer
+        - type: boolean
+        - type: string
+          format: date
+        - type: string
+          format: date-time
+        - type: array
+          items:
+            type: string
+        - type: array
+          items:
+            type: number
+        - type: array
+          items:
+            type: integer
+        - type: array
+          items:
+            type: boolean
+        - type: array
+          items:
+            type: string
+            format: date
+        - type: array
+          items:
+            type: string
+            format: date-time
diff --git a/samples/client/petstore/ruby-httpx/.openapi-generator/FILES b/samples/client/petstore/ruby-httpx/.openapi-generator/FILES
index 7bc5bf3b003e..fa488c13b2d9 100644
--- a/samples/client/petstore/ruby-httpx/.openapi-generator/FILES
+++ b/samples/client/petstore/ruby-httpx/.openapi-generator/FILES
@@ -48,6 +48,7 @@ docs/Name.md
 docs/NullableClass.md
 docs/NumberOnly.md
 docs/ObjectWithDeprecatedFields.md
+docs/OneOfPrimitiveTypes.md
 docs/Order.md
 docs/OuterComposite.md
 docs/OuterEnum.md
@@ -118,6 +119,7 @@ lib/petstore/models/name.rb
 lib/petstore/models/nullable_class.rb
 lib/petstore/models/number_only.rb
 lib/petstore/models/object_with_deprecated_fields.rb
+lib/petstore/models/one_of_primitive_types.rb
 lib/petstore/models/order.rb
 lib/petstore/models/outer_composite.rb
 lib/petstore/models/outer_enum.rb
diff --git a/samples/client/petstore/ruby-httpx/README.md b/samples/client/petstore/ruby-httpx/README.md
index 3805aba77108..587ccdfcb967 100644
--- a/samples/client/petstore/ruby-httpx/README.md
+++ b/samples/client/petstore/ruby-httpx/README.md
@@ -164,6 +164,7 @@ Class | Method | HTTP request | Description
  - [Petstore::NullableClass](docs/NullableClass.md)
  - [Petstore::NumberOnly](docs/NumberOnly.md)
  - [Petstore::ObjectWithDeprecatedFields](docs/ObjectWithDeprecatedFields.md)
+ - [Petstore::OneOfPrimitiveTypes](docs/OneOfPrimitiveTypes.md)
  - [Petstore::Order](docs/Order.md)
  - [Petstore::OuterComposite](docs/OuterComposite.md)
  - [Petstore::OuterEnum](docs/OuterEnum.md)
diff --git a/samples/client/petstore/ruby-httpx/docs/OneOfPrimitiveTypes.md b/samples/client/petstore/ruby-httpx/docs/OneOfPrimitiveTypes.md
new file mode 100644
index 000000000000..9023811f8f1c
--- /dev/null
+++ b/samples/client/petstore/ruby-httpx/docs/OneOfPrimitiveTypes.md
@@ -0,0 +1,69 @@
+# Petstore::OneOfPrimitiveTypes
+
+## Class instance methods
+
+### `openapi_one_of`
+
+Returns the list of classes defined in oneOf.
+
+#### Example
+
+```ruby
+require 'petstore'
+
+Petstore::OneOfPrimitiveTypes.openapi_one_of
+# =>
+# [
+#   :'Array<Boolean>',
+#   :'Array<Date>',
+#   :'Array<Float>',
+#   :'Array<Integer>',
+#   :'Array<String>',
+#   :'Array<Time>',
+#   :'Boolean',
+#   :'Date',
+#   :'Float',
+#   :'Integer',
+#   :'String',
+#   :'Time'
+# ]
+```
+
+### build
+
+Find the appropriate object from the `openapi_one_of` list and casts the data into it.
+
+#### Example
+
+```ruby
+require 'petstore'
+
+Petstore::OneOfPrimitiveTypes.build(data)
+# => #<Array<Boolean>:0x00007fdd4aab02a0>
+
+Petstore::OneOfPrimitiveTypes.build(data_that_doesnt_match)
+# => nil
+```
+
+#### Parameters
+
+| Name | Type | Description |
+| ---- | ---- | ----------- |
+| **data** | **Mixed** | data to be matched against the list of oneOf items |
+
+#### Return type
+
+- `Array<Boolean>`
+- `Array<Date>`
+- `Array<Float>`
+- `Array<Integer>`
+- `Array<String>`
+- `Array<Time>`
+- `Boolean`
+- `Date`
+- `Float`
+- `Integer`
+- `String`
+- `Time`
+- `nil` (if no type matches)
+
diff --git a/samples/client/petstore/ruby-httpx/lib/petstore.rb b/samples/client/petstore/ruby-httpx/lib/petstore.rb
index 261b537134af..9984140c1e41 100644
--- a/samples/client/petstore/ruby-httpx/lib/petstore.rb
+++ b/samples/client/petstore/ruby-httpx/lib/petstore.rb
@@ -53,6 +53,7 @@
 require 'petstore/models/nullable_class'
 require 'petstore/models/number_only'
 require 'petstore/models/object_with_deprecated_fields'
+require 'petstore/models/one_of_primitive_types'
 require 'petstore/models/order'
 require 'petstore/models/outer_composite'
 require 'petstore/models/outer_enum'
diff --git a/samples/client/petstore/ruby-httpx/lib/petstore/models/mammal_anyof.rb b/samples/client/petstore/ruby-httpx/lib/petstore/models/mammal_anyof.rb
index d9983576863c..5db21348bee0 100644
--- a/samples/client/petstore/ruby-httpx/lib/petstore/models/mammal_anyof.rb
+++ b/samples/client/petstore/ruby-httpx/lib/petstore/models/mammal_anyof.rb
@@ -37,8 +37,7 @@ def build(data)
         openapi_any_of.each do |klass|
           begin
             next if klass == :AnyType # "nullable: true"
-            typed_data = find_and_cast_into_type(klass, data)
-            return typed_data if typed_data
+            return find_and_cast_into_type(klass, data)
           rescue # rescue all errors so we keep iterating even if the current item lookup raises
           end
         end
diff --git a/samples/client/petstore/ruby-httpx/lib/petstore/models/mammal_without_discriminator.rb b/samples/client/petstore/ruby-httpx/lib/petstore/models/mammal_without_discriminator.rb
index d60058811f7d..7ec87da986be 100644
--- a/samples/client/petstore/ruby-httpx/lib/petstore/models/mammal_without_discriminator.rb
+++ b/samples/client/petstore/ruby-httpx/lib/petstore/models/mammal_without_discriminator.rb
@@ -38,8 +38,7 @@ def build(data)
         openapi_one_of.each do |klass|
           begin
             next if klass == :AnyType # "nullable: true"
-            typed_data = find_and_cast_into_type(klass, data)
-            return typed_data if typed_data
+            return find_and_cast_into_type(klass, data)
           rescue # rescue all errors so we keep iterating even if the current item lookup raises
           end
         end
diff --git a/samples/client/petstore/ruby-httpx/lib/petstore/models/one_of_primitive_types.rb b/samples/client/petstore/ruby-httpx/lib/petstore/models/one_of_primitive_types.rb
new file mode 100644
index 000000000000..dafa3a0d1817
--- /dev/null
+++ b/samples/client/petstore/ruby-httpx/lib/petstore/models/one_of_primitive_types.rb
@@ -0,0 +1,114 @@
+=begin
+#OpenAPI Petstore
+
+#This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+
+The version of the OpenAPI document: 1.0.0
+
+Generated by: https://openapi-generator.tech
+Generator version: 7.16.0-SNAPSHOT
+
+=end
+
+require 'date'
+require 'time'
+
+module Petstore
+  module OneOfPrimitiveTypes
+    class << self
+      # List of class defined in oneOf (OpenAPI v3)
+      def openapi_one_of
+        [
+          :'Array<Boolean>',
+          :'Array<Date>',
+          :'Array<Float>',
+          :'Array<Integer>',
+          :'Array<String>',
+          :'Array<Time>',
+          :'Boolean',
+          :'Date',
+          :'Float',
+          :'Integer',
+          :'String',
+          :'Time'
+        ]
+      end
+
+      # Builds the object
+      # @param [Mixed] Data to be matched against the list of oneOf items
+      # @return [Object] Returns the model or the data itself
+      def build(data)
+        # Go through the list of oneOf items and attempt to identify the appropriate one.
+        # Note:
+        # - We do not attempt to check whether exactly one item matches.
+        # - No advanced validation of types in some cases (e.g. "x: { type: string }" will happily match { x: 123 })
+        #   due to the way the deserialization is made in the base_object template (it just casts without verifying).
+        # - TODO: scalar values are de facto behaving as if they were nullable.
+        # - TODO: logging when debugging is set.
+        openapi_one_of.each do |klass|
+          begin
+            next if klass == :AnyType # "nullable: true"
+            return find_and_cast_into_type(klass, data)
+          rescue # rescue all errors so we keep iterating even if the current item lookup raises
+          end
+        end
+
+        openapi_one_of.include?(:AnyType) ? data : nil
+      end
+
+      private
+
+      SchemaMismatchError = Class.new(StandardError)
+
+      # Note: 'File' is missing here because in the regular case we get the data _after_ a call to JSON.parse.
+      def find_and_cast_into_type(klass, data)
+        return if data.nil?
+
+        case klass.to_s
+        when 'Boolean'
+          return data if data.instance_of?(TrueClass) || data.instance_of?(FalseClass)
+        when 'Float'
+          return data if data.instance_of?(Float)
+        when 'Integer'
+          return data if data.instance_of?(Integer)
+        when 'Time'
+          return Time.parse(data)
+        when 'Date'
+          return Date.iso8601(data)
+        when 'String'
+          return data if data.instance_of?(String)
+        when 'Object' # "type: object"
+          return data if data.instance_of?(Hash)
+        when /\AArray<(?<sub_type>.+)>\z/ # "type: array"
+          if data.instance_of?(Array)
+            sub_type = Regexp.last_match[:sub_type]
+            return data.map { |item| find_and_cast_into_type(sub_type, item) }
+          end
+        when /\AHash<String, (?<sub_type>.+)>\z/ # "type: object" with "additionalProperties: { ... }"
+          if data.instance_of?(Hash) && data.keys.all? { |k| k.instance_of?(Symbol) || k.instance_of?(String) }
+            sub_type = Regexp.last_match[:sub_type]
+            return data.each_with_object({}) { |(k, v), hsh| hsh[k] = find_and_cast_into_type(sub_type, v) }
+          end
+        else # model
+          const = Petstore.const_get(klass)
+          if const
+            if const.respond_to?(:openapi_one_of) # nested oneOf model
+              model = const.build(data)
+              return model if model
+            else
+              # raise if data contains keys that are not known to the model
+              raise if const.respond_to?(:acceptable_attributes) && !(data.keys - const.acceptable_attributes).empty?
+              model = const.build_from_hash(data)
+              return model if model
+            end
+          end
+        end
+
+        raise # if no match by now, raise
+      rescue
+        raise SchemaMismatchError, "#{data} doesn't match the #{klass} type"
+      end
+    end
+  end
+
+end
diff --git a/samples/client/petstore/ruby-httpx/spec/models/one_of_primitive_types_spec.rb b/samples/client/petstore/ruby-httpx/spec/models/one_of_primitive_types_spec.rb
new file mode 100644
index 000000000000..8ab4c1cd193b
--- /dev/null
+++ b/samples/client/petstore/ruby-httpx/spec/models/one_of_primitive_types_spec.rb
@@ -0,0 +1,32 @@
+=begin
+#OpenAPI Petstore
+
+#This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+
+The version of the OpenAPI document: 1.0.0
+
+Generated by: https://openapi-generator.tech
+Generator version: 7.16.0-SNAPSHOT
+
+=end
+
+require 'spec_helper'
+require 'json'
+require 'date'
+
+# Unit tests for Petstore::OneOfPrimitiveTypes
+# Automatically generated by openapi-generator (https://openapi-generator.tech)
+# Please update as you see appropriate
+describe Petstore::OneOfPrimitiveTypes do
+  describe '.openapi_one_of' do
+    it 'lists the items referenced in the oneOf array' do
+      expect(described_class.openapi_one_of).to_not be_empty
+    end
+  end
+
+  describe '.build' do
+    it 'returns the correct model' do
+      # assertion here. ref: https://rspec.info/features/3-12/rspec-expectations/built-in-matchers/
+    end
+  end
+end
diff --git a/samples/client/petstore/ruby/.openapi-generator/FILES b/samples/client/petstore/ruby/.openapi-generator/FILES
index 7bc5bf3b003e..fa488c13b2d9 100644
--- a/samples/client/petstore/ruby/.openapi-generator/FILES
+++ b/samples/client/petstore/ruby/.openapi-generator/FILES
@@ -48,6 +48,7 @@ docs/Name.md
 docs/NullableClass.md
 docs/NumberOnly.md
 docs/ObjectWithDeprecatedFields.md
+docs/OneOfPrimitiveTypes.md
 docs/Order.md
 docs/OuterComposite.md
 docs/OuterEnum.md
@@ -118,6 +119,7 @@ lib/petstore/models/name.rb
 lib/petstore/models/nullable_class.rb
 lib/petstore/models/number_only.rb
 lib/petstore/models/object_with_deprecated_fields.rb
+lib/petstore/models/one_of_primitive_types.rb
 lib/petstore/models/order.rb
 lib/petstore/models/outer_composite.rb
 lib/petstore/models/outer_enum.rb
diff --git a/samples/client/petstore/ruby/README.md b/samples/client/petstore/ruby/README.md
index 3805aba77108..587ccdfcb967 100644
--- a/samples/client/petstore/ruby/README.md
+++ b/samples/client/petstore/ruby/README.md
@@ -164,6 +164,7 @@ Class | Method | HTTP request | Description
  - [Petstore::NullableClass](docs/NullableClass.md)
  - [Petstore::NumberOnly](docs/NumberOnly.md)
  - [Petstore::ObjectWithDeprecatedFields](docs/ObjectWithDeprecatedFields.md)
+ - [Petstore::OneOfPrimitiveTypes](docs/OneOfPrimitiveTypes.md)
  - [Petstore::Order](docs/Order.md)
  - [Petstore::OuterComposite](docs/OuterComposite.md)
  - [Petstore::OuterEnum](docs/OuterEnum.md)
diff --git a/samples/client/petstore/ruby/docs/OneOfPrimitiveTypes.md b/samples/client/petstore/ruby/docs/OneOfPrimitiveTypes.md
new file mode 100644
index 000000000000..9023811f8f1c
--- /dev/null
+++ b/samples/client/petstore/ruby/docs/OneOfPrimitiveTypes.md
@@ -0,0 +1,69 @@
+# Petstore::OneOfPrimitiveTypes
+
+## Class instance methods
+
+### `openapi_one_of`
+
+Returns the list of classes defined in oneOf.
+
+#### Example
+
+```ruby
+require 'petstore'
+
+Petstore::OneOfPrimitiveTypes.openapi_one_of
+# =>
+# [
+#   :'Array<Boolean>',
+#   :'Array<Date>',
+#   :'Array<Float>',
+#   :'Array<Integer>',
+#   :'Array<String>',
+#   :'Array<Time>',
+#   :'Boolean',
+#   :'Date',
+#   :'Float',
+#   :'Integer',
+#   :'String',
+#   :'Time'
+# ]
+```
+
+### build
+
+Find the appropriate object from the `openapi_one_of` list and casts the data into it.
+
+#### Example
+
+```ruby
+require 'petstore'
+
+Petstore::OneOfPrimitiveTypes.build(data)
+# => #<Array<Boolean>:0x00007fdd4aab02a0>
+
+Petstore::OneOfPrimitiveTypes.build(data_that_doesnt_match)
+# => nil
+```
+
+#### Parameters
+
+| Name | Type | Description |
+| ---- | ---- | ----------- |
+| **data** | **Mixed** | data to be matched against the list of oneOf items |
+
+#### Return type
+
+- `Array<Boolean>`
+- `Array<Date>`
+- `Array<Float>`
+- `Array<Integer>`
+- `Array<String>`
+- `Array<Time>`
+- `Boolean`
+- `Date`
+- `Float`
+- `Integer`
+- `String`
+- `Time`
+- `nil` (if no type matches)
+
diff --git a/samples/client/petstore/ruby/lib/petstore.rb b/samples/client/petstore/ruby/lib/petstore.rb
index 261b537134af..9984140c1e41 100644
--- a/samples/client/petstore/ruby/lib/petstore.rb
+++ b/samples/client/petstore/ruby/lib/petstore.rb
@@ -53,6 +53,7 @@
 require 'petstore/models/nullable_class'
 require 'petstore/models/number_only'
 require 'petstore/models/object_with_deprecated_fields'
+require 'petstore/models/one_of_primitive_types'
 require 'petstore/models/order'
 require 'petstore/models/outer_composite'
 require 'petstore/models/outer_enum'
diff --git a/samples/client/petstore/ruby/lib/petstore/models/mammal_anyof.rb b/samples/client/petstore/ruby/lib/petstore/models/mammal_anyof.rb
index d9983576863c..5db21348bee0 100644
--- a/samples/client/petstore/ruby/lib/petstore/models/mammal_anyof.rb
+++ b/samples/client/petstore/ruby/lib/petstore/models/mammal_anyof.rb
@@ -37,8 +37,7 @@ def build(data)
         openapi_any_of.each do |klass|
           begin
             next if klass == :AnyType # "nullable: true"
-            typed_data = find_and_cast_into_type(klass, data)
-            return typed_data if typed_data
+            return find_and_cast_into_type(klass, data)
           rescue # rescue all errors so we keep iterating even if the current item lookup raises
           end
         end
diff --git a/samples/client/petstore/ruby/lib/petstore/models/mammal_without_discriminator.rb b/samples/client/petstore/ruby/lib/petstore/models/mammal_without_discriminator.rb
index d60058811f7d..7ec87da986be 100644
--- a/samples/client/petstore/ruby/lib/petstore/models/mammal_without_discriminator.rb
+++ b/samples/client/petstore/ruby/lib/petstore/models/mammal_without_discriminator.rb
@@ -38,8 +38,7 @@ def build(data)
         openapi_one_of.each do |klass|
           begin
             next if klass == :AnyType # "nullable: true"
-            typed_data = find_and_cast_into_type(klass, data)
-            return typed_data if typed_data
+            return find_and_cast_into_type(klass, data)
           rescue # rescue all errors so we keep iterating even if the current item lookup raises
           end
         end
diff --git a/samples/client/petstore/ruby/lib/petstore/models/one_of_primitive_types.rb b/samples/client/petstore/ruby/lib/petstore/models/one_of_primitive_types.rb
new file mode 100644
index 000000000000..dafa3a0d1817
--- /dev/null
+++ b/samples/client/petstore/ruby/lib/petstore/models/one_of_primitive_types.rb
@@ -0,0 +1,114 @@
+=begin
+#OpenAPI Petstore
+
+#This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+
+The version of the OpenAPI document: 1.0.0
+
+Generated by: https://openapi-generator.tech
+Generator version: 7.16.0-SNAPSHOT
+
+=end
+
+require 'date'
+require 'time'
+
+module Petstore
+  module OneOfPrimitiveTypes
+    class << self
+      # List of class defined in oneOf (OpenAPI v3)
+      def openapi_one_of
+        [
+          :'Array<Boolean>',
+          :'Array<Date>',
+          :'Array<Float>',
+          :'Array<Integer>',
+          :'Array<String>',
+          :'Array<Time>',
+          :'Boolean',
+          :'Date',
+          :'Float',
+          :'Integer',
+          :'String',
+          :'Time'
+        ]
+      end
+
+      # Builds the object
+      # @param [Mixed] Data to be matched against the list of oneOf items
+      # @return [Object] Returns the model or the data itself
+      def build(data)
+        # Go through the list of oneOf items and attempt to identify the appropriate one.
+        # Note:
+        # - We do not attempt to check whether exactly one item matches.
+        # - No advanced validation of types in some cases (e.g. "x: { type: string }" will happily match { x: 123 })
+        #   due to the way the deserialization is made in the base_object template (it just casts without verifying).
+        # - TODO: scalar values are de facto behaving as if they were nullable.
+        # - TODO: logging when debugging is set.
+        openapi_one_of.each do |klass|
+          begin
+            next if klass == :AnyType # "nullable: true"
+            return find_and_cast_into_type(klass, data)
+          rescue # rescue all errors so we keep iterating even if the current item lookup raises
+          end
+        end
+
+        openapi_one_of.include?(:AnyType) ? data : nil
+      end
+
+      private
+
+      SchemaMismatchError = Class.new(StandardError)
+
+      # Note: 'File' is missing here because in the regular case we get the data _after_ a call to JSON.parse.
+      def find_and_cast_into_type(klass, data)
+        return if data.nil?
+
+        case klass.to_s
+        when 'Boolean'
+          return data if data.instance_of?(TrueClass) || data.instance_of?(FalseClass)
+        when 'Float'
+          return data if data.instance_of?(Float)
+        when 'Integer'
+          return data if data.instance_of?(Integer)
+        when 'Time'
+          return Time.parse(data)
+        when 'Date'
+          return Date.iso8601(data)
+        when 'String'
+          return data if data.instance_of?(String)
+        when 'Object' # "type: object"
+          return data if data.instance_of?(Hash)
+        when /\AArray<(?<sub_type>.+)>\z/ # "type: array"
+          if data.instance_of?(Array)
+            sub_type = Regexp.last_match[:sub_type]
+            return data.map { |item| find_and_cast_into_type(sub_type, item) }
+          end
+        when /\AHash<String, (?<sub_type>.+)>\z/ # "type: object" with "additionalProperties: { ... }"
+          if data.instance_of?(Hash) && data.keys.all? { |k| k.instance_of?(Symbol) || k.instance_of?(String) }
+            sub_type = Regexp.last_match[:sub_type]
+            return data.each_with_object({}) { |(k, v), hsh| hsh[k] = find_and_cast_into_type(sub_type, v) }
+          end
+        else # model
+          const = Petstore.const_get(klass)
+          if const
+            if const.respond_to?(:openapi_one_of) # nested oneOf model
+              model = const.build(data)
+              return model if model
+            else
+              # raise if data contains keys that are not known to the model
+              raise if const.respond_to?(:acceptable_attributes) && !(data.keys - const.acceptable_attributes).empty?
+              model = const.build_from_hash(data)
+              return model if model
+            end
+          end
+        end
+
+        raise # if no match by now, raise
+      rescue
+        raise SchemaMismatchError, "#{data} doesn't match the #{klass} type"
+      end
+    end
+  end
+
+end
diff --git a/samples/client/petstore/ruby/spec/custom/model_spec.rb b/samples/client/petstore/ruby/spec/custom/model_spec.rb
index 8e7af2c0db3e..c361ec6e2a66 100644
--- a/samples/client/petstore/ruby/spec/custom/model_spec.rb
+++ b/samples/client/petstore/ruby/spec/custom/model_spec.rb
@@ -25,7 +25,7 @@
       expect(result2).to be_a Petstore::Zebra
 
       # invalid data/hash should result in nil
-      result3 = Petstore::MammalAnyof.build({"something": 123})
+      result3 = Petstore::MammalAnyof.build({ "something": 123 })
       expect(result3).to be_nil
     end
   end
@@ -46,7 +46,7 @@
       expect(result2).to be_a Petstore::Zebra
 
       # invalid data/hash should result in nil
-      result3 = Petstore::Mammal.build({"something": 123})
+      result3 = Petstore::Mammal.build({ "something": 123 })
       expect(result3).to be_nil
     end
 
@@ -65,9 +65,108 @@
       expect(result2).to be_a Petstore::Zebra
 
       # invalid data/hash should result in nil
-      result3 = Petstore::MammalWithoutDiscriminator.build({"something": 123})
+      result3 = Petstore::MammalWithoutDiscriminator.build({ "something": 123 })
       expect(result3).to be_nil
     end
 
   end
 end
+
+describe 'OneOfPrimitiveTypes' do
+  it 'should be able to parse integer' do
+    int_value = Petstore::OneOfPrimitiveTypes.build(
+      123
+    )
+    expect(int_value).to eq 123
+  end
+  it 'should be able to parse float' do
+    float_value = Petstore::OneOfPrimitiveTypes.build(
+      123.45
+    )
+    expect(float_value).to eq 123.45
+  end
+  it 'should be able to parse string' do
+    string_value = Petstore::OneOfPrimitiveTypes.build(
+      'ABC1'
+    )
+    expect(string_value).to eq 'ABC1'
+  end
+  it 'should be able to parse date' do
+    date_value = Petstore::OneOfPrimitiveTypes.build(
+      '2020-01-02'
+    )
+    expect(date_value).to be_a Date
+    expect(date_value).to eq Date.iso8601('2020-01-02')
+  end
+  it 'should be able to parse date time' do
+    datetime_value = Petstore::OneOfPrimitiveTypes.build(
+      '2020-01-02T12:34:56Z'
+    )
+    expect(datetime_value).to eq Date.iso8601('2020-01-02T12:34:56Z')
+  end
+  it 'should be able to parse boolean' do
+    false_value = Petstore::OneOfPrimitiveTypes.build(
+      false
+    )
+    expect(false_value).to eq false
+
+    true_value = Petstore::OneOfPrimitiveTypes.build(
+      true
+    )
+    expect(true_value).to eq true
+  end
+  it 'should be able to parse array of integer' do
+    array_value = Petstore::OneOfPrimitiveTypes.build(
+      [1, 2, 3]
+    )
+    expect(array_value).to be_a Array
+    expect(array_value).to eq [1, 2, 3]
+  end
+  it 'should be able to parse array of string' do
+    array_value = Petstore::OneOfPrimitiveTypes.build(
+      %w[ABC1 DEF2 GHI3]
+    )
+    expect(array_value).to be_a Array
+    expect(array_value).to eq %w[ABC1 DEF2 GHI3]
+  end
+  it 'should be able to parse array of float' do
+    array_value = Petstore::OneOfPrimitiveTypes.build(
+      [1.1, 2.2, 3.3]
+    )
+    expect(array_value).to be_a Array
+    expect(array_value).to eq [1.1, 2.2, 3.3]
+  end
+  it 'should be able to parse array of date' do
+    array_value = Petstore::OneOfPrimitiveTypes.build(
+      %w[2020-01-02 2020-03-04]
+    )
+    expect(array_value).to be_a Array
+    expect(array_value).to eq [Date.iso8601('2020-01-02'), Date.iso8601('2020-03-04')]
+  end
+  it 'should be able to parse an invalid date' do
+    invalid_date_value = Petstore::OneOfPrimitiveTypes.build(
+      '2020-13-02'
+    )
+    expect(invalid_date_value).to eq '2020-13-02'
+  end
+  it 'should be able to parse array of date time' do
+    array_value = Petstore::OneOfPrimitiveTypes.build(
+      %w[2020-01-02T12:34:56Z 2020-03-04T01:23:45Z]
+    )
+    expect(array_value).to be_a Array
+    expect(array_value).to eq [Date.parse('2020-01-02T12:34:56Z'), Date.parse('2020-03-04T01:23:45Z')]
+  end
+  it 'should be able to parse array of boolean' do
+    array_value = Petstore::OneOfPrimitiveTypes.build(
+      [true, false, true]
+    )
+    expect(array_value).to be_a Array
+    expect(array_value).to eq [true, false, true]
+  end
+  it 'should return nil for unsupported type' do
+    unsupported_value = Petstore::OneOfPrimitiveTypes.build(
+      { foo: 'bar' }
+    )
+    expect(unsupported_value).to be_nil
+  end
+end
diff --git a/samples/client/petstore/ruby/spec/models/one_of_primitive_types_spec.rb b/samples/client/petstore/ruby/spec/models/one_of_primitive_types_spec.rb
new file mode 100644
index 000000000000..8ab4c1cd193b
--- /dev/null
+++ b/samples/client/petstore/ruby/spec/models/one_of_primitive_types_spec.rb
@@ -0,0 +1,32 @@
+=begin
+#OpenAPI Petstore
+
+#This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+
+The version of the OpenAPI document: 1.0.0
+
+Generated by: https://openapi-generator.tech
+Generator version: 7.16.0-SNAPSHOT
+
+=end
+
+require 'spec_helper'
+require 'json'
+require 'date'
+
+# Unit tests for Petstore::OneOfPrimitiveTypes
+# Automatically generated by openapi-generator (https://openapi-generator.tech)
+# Please update as you see appropriate
+describe Petstore::OneOfPrimitiveTypes do
+  describe '.openapi_one_of' do
+    it 'lists the items referenced in the oneOf array' do
+      expect(described_class.openapi_one_of).to_not be_empty
+    end
+  end
+
+  describe '.build' do
+    it 'returns the correct model' do
+      # assertion here. ref: https://rspec.info/features/3-12/rspec-expectations/built-in-matchers/
+    end
+  end
+end