diff --git a/.gitignore b/.gitignore
index c31896c826d..3e0166838b2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -251,6 +251,7 @@ samples/server/petstore/erlang-server/rebar.lock
 # JS
 samples/client/petstore/javascript-es6/package-lock.json
 samples/client/petstore/javascript-promise-es6/package-lock.json
+samples/client/petstore/javascript-apollo/package-lock.json
 
 # elm
 samples/client/petstore/elm/index.html
diff --git a/modules/openapi-generator/src/main/resources/r/modelAnyOf.mustache b/modules/openapi-generator/src/main/resources/r/modelAnyOf.mustache
index 688ddeb6eb2..37881ae4369 100644
--- a/modules/openapi-generator/src/main/resources/r/modelAnyOf.mustache
+++ b/modules/openapi-generator/src/main/resources/r/modelAnyOf.mustache
@@ -58,22 +58,32 @@
     fromJSON = function(input) {
       error_messages <- list()
 
-      {{#anyOf}}
-      {{{.}}}_result <- tryCatch({
-          {{{.}}}$public_methods$validateJSON(input)
-          {{{.}}}_instance <- {{{.}}}$new()
-          self$actual_instance <- {{{.}}}_instance$fromJSON(input)
-          self$actual_type <- "{{{.}}}"
+      {{#composedSchemas.anyOf}}
+      {{^isNull}}
+      {{{dataType}}}_result <- tryCatch({
+          {{#isPrimitiveType}}
+          instance <- jsonlite::fromJSON(input, simplifyVector = FALSE)
+          if (typeof(instance) != "{{{dataType}}}") {
+            stop(sprintf("Data type doesn't match. Expected: %s. Actual: %s.", "{{{dataType}}}", typeof(instance)))
+          }
+          {{/isPrimitiveType}}
+          {{^isPrimitiveType}}
+          {{{dataType}}}$public_methods$validateJSON(input)
+          {{{dataType}}}_instance <- {{{dataType}}}$new()
+          {{/isPrimitiveType}}
+          self$actual_instance <- {{{dataType}}}_instance$fromJSON(input)
+          self$actual_type <- "{{{dataType}}}"
           return(self)
         },
         error = function(err) err
       )
 
-      if (!is.null({{{.}}}_result["error"])) {
-        error_messages <- append(error_messages, {{{.}}}_result["message"])
+      if (!is.null({{{dataType}}}_result["error"])) {
+        error_messages <- append(error_messages, {{{dataType}}}_result["message"])
       }
 
-      {{/anyOf}}
+      {{/isNull}}
+      {{/composedSchemas.anyOf}}
       # no match
       stop(paste("No match found when deserializing the payload into {{{classname}}} with anyOf schemas {{#anyOf}}{{{.}}}{{^-last}}, {{/-last}}{{/anyOf}}. Details: ",
                  paste(error_messages, collapse = ", ")))
diff --git a/modules/openapi-generator/src/main/resources/r/modelOneOf.mustache b/modules/openapi-generator/src/main/resources/r/modelOneOf.mustache
index fc2b147940e..fa798be2110 100644
--- a/modules/openapi-generator/src/main/resources/r/modelOneOf.mustache
+++ b/modules/openapi-generator/src/main/resources/r/modelOneOf.mustache
@@ -15,7 +15,7 @@
     actual_instance = NULL,
     #' @field actual_type the type of the object stored in this instance.
     actual_type = NULL,
-    #' @field one_of  a list of object types defined in the oneOf schema.
+    #' @field one_of  a list of types defined in the oneOf schema.
     one_of = list({{#oneOf}}"{{{.}}}"{{^-last}}, {{/-last}}{{/oneOf}}),
     #' Initialize a new {{{classname}}}.
     #'
@@ -61,23 +61,33 @@
       error_messages <- list()
       instance <- NULL
 
-      {{#oneOf}}
-      {{{.}}}_result <- tryCatch({
-          {{{.}}}$public_methods$validateJSON(input)
-          {{{.}}}_instance <- {{{.}}}$new()
-          instance <- {{{.}}}_instance$fromJSON(input)
-          instance_type <- "{{{.}}}"
-          matched_schemas <- append(matched_schemas, "{{{.}}}")
+      {{#composedSchemas.oneOf}}
+      {{^isNull}}
+      {{{dataType}}}_result <- tryCatch({
+          {{#isPrimitiveType}}
+          instance <- jsonlite::fromJSON(input, simplifyVector = FALSE)
+          if (typeof(instance) != "{{{dataType}}}") {
+            stop(sprintf("Data type doesn't match. Expected: %s. Actual: %s.", "{{{dataType}}}", typeof(instance)))
+          }
+          {{/isPrimitiveType}}
+          {{^isPrimitiveType}}
+          {{{dataType}}}$public_methods$validateJSON(input)
+          {{{dataType}}}_instance <- {{{dataType}}}$new()
+          instance <- {{{dataType}}}_instance$fromJSON(input)
+          {{/isPrimitiveType}}
+          instance_type <- "{{{dataType}}}"
+          matched_schemas <- append(matched_schemas, "{{{dataType}}}")
           matched <- matched + 1
         },
         error = function(err) err
       )
 
-      if (!is.null({{{.}}}_result["error"])) {
-        error_messages <- append(error_messages, {{{.}}}_result["message"])
+      if (!is.null({{{dataType}}}_result["error"])) {
+        error_messages <- append(error_messages, {{{dataType}}}_result["message"])
       }
 
-      {{/oneOf}}
+      {{/isNull}}
+      {{/composedSchemas.oneOf}}
       if (matched == 1) {
         # successfully match exactly 1 schema specified in oneOf
         self$actual_instance <- instance
diff --git a/modules/openapi-generator/src/test/resources/3_0/r/petstore.yaml b/modules/openapi-generator/src/test/resources/3_0/r/petstore.yaml
index 65cc1314d65..9ee786b1052 100644
--- a/modules/openapi-generator/src/test/resources/3_0/r/petstore.yaml
+++ b/modules/openapi-generator/src/test/resources/3_0/r/petstore.yaml
@@ -933,6 +933,14 @@ components:
         - $ref: '#/components/schemas/DanishPig'
       discriminator:
         propertyName: className
+    OneOfPrimitiveTypeTest:
+      oneOf:
+        - type: "integer"
+        - type: "string"
+    AnyOfPrimitiveTypeTest:
+      oneOf:
+        - type: "integer"
+        - type: "string"
     BasquePig:
       type: object
       properties:
diff --git a/samples/client/petstore/R-httr2-wrapper/.openapi-generator/FILES b/samples/client/petstore/R-httr2-wrapper/.openapi-generator/FILES
index 47f88c5a6b6..881a2ab283e 100644
--- a/samples/client/petstore/R-httr2-wrapper/.openapi-generator/FILES
+++ b/samples/client/petstore/R-httr2-wrapper/.openapi-generator/FILES
@@ -8,6 +8,7 @@ NAMESPACE
 R/allof_tag_api_response.R
 R/animal.R
 R/any_of_pig.R
+R/any_of_primitive_type_test.R
 R/api_client.R
 R/api_exception.R
 R/api_response.R
@@ -21,6 +22,7 @@ R/dog_all_of.R
 R/fake_api.R
 R/model_api_response.R
 R/nested_one_of.R
+R/one_of_primitive_type_test.R
 R/order.R
 R/pet.R
 R/pet_api.R
@@ -36,6 +38,7 @@ README.md
 docs/AllofTagApiResponse.md
 docs/Animal.md
 docs/AnyOfPig.md
+docs/AnyOfPrimitiveTypeTest.md
 docs/BasquePig.md
 docs/Cat.md
 docs/CatAllOf.md
@@ -46,6 +49,7 @@ docs/DogAllOf.md
 docs/FakeApi.md
 docs/ModelApiResponse.md
 docs/NestedOneOf.md
+docs/OneOfPrimitiveTypeTest.md
 docs/Order.md
 docs/Pet.md
 docs/PetApi.md
diff --git a/samples/client/petstore/R-httr2-wrapper/NAMESPACE b/samples/client/petstore/R-httr2-wrapper/NAMESPACE
index 049543f1a55..7af9abbfc48 100644
--- a/samples/client/petstore/R-httr2-wrapper/NAMESPACE
+++ b/samples/client/petstore/R-httr2-wrapper/NAMESPACE
@@ -19,6 +19,7 @@ export(ApiException)
 export(AllofTagApiResponse)
 export(Animal)
 export(AnyOfPig)
+export(AnyOfPrimitiveTypeTest)
 export(BasquePig)
 export(Cat)
 export(CatAllOf)
@@ -28,6 +29,7 @@ export(Dog)
 export(DogAllOf)
 export(ModelApiResponse)
 export(NestedOneOf)
+export(OneOfPrimitiveTypeTest)
 export(Order)
 export(Pet)
 export(Pig)
diff --git a/samples/client/petstore/R-httr2-wrapper/R/any_of_primitive_type_test.R b/samples/client/petstore/R-httr2-wrapper/R/any_of_primitive_type_test.R
new file mode 100644
index 00000000000..7e668710023
--- /dev/null
+++ b/samples/client/petstore/R-httr2-wrapper/R/any_of_primitive_type_test.R
@@ -0,0 +1,186 @@
+#' OpenAPI Petstore
+#'
+#' This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+#'
+#' The version of the OpenAPI document: 1.0.0
+#' Generated by: https://openapi-generator.tech
+#'
+#' @docType class
+#' @title AnyOfPrimitiveTypeTest
+#'
+#' @description AnyOfPrimitiveTypeTest Class
+#'
+#' @format An \code{R6Class} generator object
+#'
+#' @importFrom R6 R6Class
+#' @importFrom jsonlite fromJSON toJSON
+#' @export
+AnyOfPrimitiveTypeTest <- R6::R6Class(
+  "AnyOfPrimitiveTypeTest",
+  public = list(
+    #' @field actual_instance the object stored in this instance.
+    actual_instance = NULL,
+    #' @field actual_type the type of the object stored in this instance.
+    actual_type = NULL,
+    #' @field one_of  a list of types defined in the oneOf schema.
+    one_of = list("character", "integer"),
+    #' Initialize a new AnyOfPrimitiveTypeTest.
+    #'
+    #' @description
+    #' Initialize a new AnyOfPrimitiveTypeTest.
+    #'
+    #' @param instance an instance of the object defined in the oneOf schemas: "character", "integer"
+    #' @export
+    initialize = function(instance = NULL) {
+      if (is.null(instance)) {
+        # do nothing
+      } else if (get(class(instance)[[1]], pos = -1)$classname ==  "character") {
+        self$actual_instance <- instance
+        self$actual_type <- "character"
+      } else if (get(class(instance)[[1]], pos = -1)$classname ==  "integer") {
+        self$actual_instance <- instance
+        self$actual_type <- "integer"
+      } else {
+        stop(paste("Failed to initialize AnyOfPrimitiveTypeTest with oneOf schemas character, integer. Provided class name: ",
+                   get(class(instance)[[1]], pos = -1)$classname))
+      }
+    },
+    #' Deserialize JSON string into an instance of AnyOfPrimitiveTypeTest.
+    #'
+    #' @description
+    #' Deserialize JSON string into an instance of AnyOfPrimitiveTypeTest.
+    #' An alias to the method `fromJSON` .
+    #'
+    #' @param input The input JSON.
+    #' @return An instance of AnyOfPrimitiveTypeTest.
+    #' @export
+    fromJSONString = function(input) {
+      self$fromJSON(input)
+    },
+    #' Deserialize JSON string into an instance of AnyOfPrimitiveTypeTest.
+    #'
+    #' @description
+    #' Deserialize JSON string into an instance of AnyOfPrimitiveTypeTest.
+    #'
+    #' @param input The input JSON.
+    #' @return An instance of AnyOfPrimitiveTypeTest.
+    #' @export
+    fromJSON = function(input) {
+      matched <- 0 # match counter
+      matched_schemas <- list() #names of matched schemas
+      error_messages <- list()
+      instance <- NULL
+
+      integer_result <- tryCatch({
+          instance <- jsonlite::fromJSON(input, simplifyVector = FALSE)
+          if (typeof(instance) != "integer") {
+            stop(sprintf("Data type doesn't match. Expected: %s. Actual: %s.", "integer", typeof(instance)))
+          }
+          instance_type <- "integer"
+          matched_schemas <- append(matched_schemas, "integer")
+          matched <- matched + 1
+        },
+        error = function(err) err
+      )
+
+      if (!is.null(integer_result["error"])) {
+        error_messages <- append(error_messages, integer_result["message"])
+      }
+
+      character_result <- tryCatch({
+          instance <- jsonlite::fromJSON(input, simplifyVector = FALSE)
+          if (typeof(instance) != "character") {
+            stop(sprintf("Data type doesn't match. Expected: %s. Actual: %s.", "character", typeof(instance)))
+          }
+          instance_type <- "character"
+          matched_schemas <- append(matched_schemas, "character")
+          matched <- matched + 1
+        },
+        error = function(err) err
+      )
+
+      if (!is.null(character_result["error"])) {
+        error_messages <- append(error_messages, character_result["message"])
+      }
+
+      if (matched == 1) {
+        # successfully match exactly 1 schema specified in oneOf
+        self$actual_instance <- instance
+        self$actual_type <- instance_type
+      } else if (matched > 1) {
+        # more than 1 match
+        stop("Multiple matches found when deserializing the payload into AnyOfPrimitiveTypeTest with oneOf schemas character, integer.")
+      } else {
+        # no match
+        stop(paste("No match found when deserializing the payload into AnyOfPrimitiveTypeTest with oneOf schemas character, integer. Details: ",
+                   paste(error_messages, collapse = ", ")))
+      }
+
+      self
+    },
+    #' Serialize AnyOfPrimitiveTypeTest to JSON string.
+    #'
+    #' @description
+    #' Serialize AnyOfPrimitiveTypeTest to JSON string.
+    #'
+    #' @return JSON string representation of the AnyOfPrimitiveTypeTest.
+    #' @export
+    toJSONString = function() {
+      if (!is.null(self$actual_instance)) {
+        as.character(jsonlite::minify(self$actual_instance$toJSONString()))
+      } else {
+        NULL
+      }
+    },
+    #' Serialize AnyOfPrimitiveTypeTest to JSON.
+    #'
+    #' @description
+    #' Serialize AnyOfPrimitiveTypeTest to JSON.
+    #'
+    #' @return JSON representation of the AnyOfPrimitiveTypeTest.
+    #' @export
+    toJSON = function() {
+      if (!is.null(self$actual_instance)) {
+        self$actual_instance$toJSON()
+      } else {
+        NULL
+      }
+    },
+    #' Validate the input JSON with respect to AnyOfPrimitiveTypeTest.
+    #'
+    #' @description
+    #' Validate the input JSON with respect to AnyOfPrimitiveTypeTest and
+    #' throw exception if invalid.
+    #'
+    #' @param input The input JSON.
+    #' @export
+    validateJSON = function(input) {
+      # backup current values
+      actual_instance_bak <- self$actual_instance
+      actual_type_bak <- self$actual_type
+
+      # if it's not valid, an error will be thrown
+      self$fromJSON(input)
+
+      # no error thrown, restore old values
+      self$actual_instance <- actual_instance_bak
+      self$actual_type <- actual_type_bak
+    },
+    #' Returns the string representation of the instance.
+    #'
+    #' @description
+    #' Returns the string representation of the instance.
+    #'
+    #' @return The string representation of the instance.
+    #' @export
+    toString = function() {
+      jsoncontent <- c(
+        sprintf('"actual_instance": %s', if (is.null(self$actual_instance)) NULL else self$actual_instance$toJSONString()),
+        sprintf('"actual_type": "%s"', self$actual_type),
+        sprintf('"one_of": "%s"', paste(unlist(self$one_of), collapse = ", "))
+      )
+      jsoncontent <- paste(jsoncontent, collapse = ",")
+      as.character(jsonlite::prettify(paste("{", jsoncontent, "}", sep = "")))
+    }
+  )
+)
diff --git a/samples/client/petstore/R-httr2-wrapper/R/one_of_primitive_type_test.R b/samples/client/petstore/R-httr2-wrapper/R/one_of_primitive_type_test.R
new file mode 100644
index 00000000000..8815ba1d3ee
--- /dev/null
+++ b/samples/client/petstore/R-httr2-wrapper/R/one_of_primitive_type_test.R
@@ -0,0 +1,186 @@
+#' OpenAPI Petstore
+#'
+#' This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+#'
+#' The version of the OpenAPI document: 1.0.0
+#' Generated by: https://openapi-generator.tech
+#'
+#' @docType class
+#' @title OneOfPrimitiveTypeTest
+#'
+#' @description OneOfPrimitiveTypeTest Class
+#'
+#' @format An \code{R6Class} generator object
+#'
+#' @importFrom R6 R6Class
+#' @importFrom jsonlite fromJSON toJSON
+#' @export
+OneOfPrimitiveTypeTest <- R6::R6Class(
+  "OneOfPrimitiveTypeTest",
+  public = list(
+    #' @field actual_instance the object stored in this instance.
+    actual_instance = NULL,
+    #' @field actual_type the type of the object stored in this instance.
+    actual_type = NULL,
+    #' @field one_of  a list of types defined in the oneOf schema.
+    one_of = list("character", "integer"),
+    #' Initialize a new OneOfPrimitiveTypeTest.
+    #'
+    #' @description
+    #' Initialize a new OneOfPrimitiveTypeTest.
+    #'
+    #' @param instance an instance of the object defined in the oneOf schemas: "character", "integer"
+    #' @export
+    initialize = function(instance = NULL) {
+      if (is.null(instance)) {
+        # do nothing
+      } else if (get(class(instance)[[1]], pos = -1)$classname ==  "character") {
+        self$actual_instance <- instance
+        self$actual_type <- "character"
+      } else if (get(class(instance)[[1]], pos = -1)$classname ==  "integer") {
+        self$actual_instance <- instance
+        self$actual_type <- "integer"
+      } else {
+        stop(paste("Failed to initialize OneOfPrimitiveTypeTest with oneOf schemas character, integer. Provided class name: ",
+                   get(class(instance)[[1]], pos = -1)$classname))
+      }
+    },
+    #' Deserialize JSON string into an instance of OneOfPrimitiveTypeTest.
+    #'
+    #' @description
+    #' Deserialize JSON string into an instance of OneOfPrimitiveTypeTest.
+    #' An alias to the method `fromJSON` .
+    #'
+    #' @param input The input JSON.
+    #' @return An instance of OneOfPrimitiveTypeTest.
+    #' @export
+    fromJSONString = function(input) {
+      self$fromJSON(input)
+    },
+    #' Deserialize JSON string into an instance of OneOfPrimitiveTypeTest.
+    #'
+    #' @description
+    #' Deserialize JSON string into an instance of OneOfPrimitiveTypeTest.
+    #'
+    #' @param input The input JSON.
+    #' @return An instance of OneOfPrimitiveTypeTest.
+    #' @export
+    fromJSON = function(input) {
+      matched <- 0 # match counter
+      matched_schemas <- list() #names of matched schemas
+      error_messages <- list()
+      instance <- NULL
+
+      integer_result <- tryCatch({
+          instance <- jsonlite::fromJSON(input, simplifyVector = FALSE)
+          if (typeof(instance) != "integer") {
+            stop(sprintf("Data type doesn't match. Expected: %s. Actual: %s.", "integer", typeof(instance)))
+          }
+          instance_type <- "integer"
+          matched_schemas <- append(matched_schemas, "integer")
+          matched <- matched + 1
+        },
+        error = function(err) err
+      )
+
+      if (!is.null(integer_result["error"])) {
+        error_messages <- append(error_messages, integer_result["message"])
+      }
+
+      character_result <- tryCatch({
+          instance <- jsonlite::fromJSON(input, simplifyVector = FALSE)
+          if (typeof(instance) != "character") {
+            stop(sprintf("Data type doesn't match. Expected: %s. Actual: %s.", "character", typeof(instance)))
+          }
+          instance_type <- "character"
+          matched_schemas <- append(matched_schemas, "character")
+          matched <- matched + 1
+        },
+        error = function(err) err
+      )
+
+      if (!is.null(character_result["error"])) {
+        error_messages <- append(error_messages, character_result["message"])
+      }
+
+      if (matched == 1) {
+        # successfully match exactly 1 schema specified in oneOf
+        self$actual_instance <- instance
+        self$actual_type <- instance_type
+      } else if (matched > 1) {
+        # more than 1 match
+        stop("Multiple matches found when deserializing the payload into OneOfPrimitiveTypeTest with oneOf schemas character, integer.")
+      } else {
+        # no match
+        stop(paste("No match found when deserializing the payload into OneOfPrimitiveTypeTest with oneOf schemas character, integer. Details: ",
+                   paste(error_messages, collapse = ", ")))
+      }
+
+      self
+    },
+    #' Serialize OneOfPrimitiveTypeTest to JSON string.
+    #'
+    #' @description
+    #' Serialize OneOfPrimitiveTypeTest to JSON string.
+    #'
+    #' @return JSON string representation of the OneOfPrimitiveTypeTest.
+    #' @export
+    toJSONString = function() {
+      if (!is.null(self$actual_instance)) {
+        as.character(jsonlite::minify(self$actual_instance$toJSONString()))
+      } else {
+        NULL
+      }
+    },
+    #' Serialize OneOfPrimitiveTypeTest to JSON.
+    #'
+    #' @description
+    #' Serialize OneOfPrimitiveTypeTest to JSON.
+    #'
+    #' @return JSON representation of the OneOfPrimitiveTypeTest.
+    #' @export
+    toJSON = function() {
+      if (!is.null(self$actual_instance)) {
+        self$actual_instance$toJSON()
+      } else {
+        NULL
+      }
+    },
+    #' Validate the input JSON with respect to OneOfPrimitiveTypeTest.
+    #'
+    #' @description
+    #' Validate the input JSON with respect to OneOfPrimitiveTypeTest and
+    #' throw exception if invalid.
+    #'
+    #' @param input The input JSON.
+    #' @export
+    validateJSON = function(input) {
+      # backup current values
+      actual_instance_bak <- self$actual_instance
+      actual_type_bak <- self$actual_type
+
+      # if it's not valid, an error will be thrown
+      self$fromJSON(input)
+
+      # no error thrown, restore old values
+      self$actual_instance <- actual_instance_bak
+      self$actual_type <- actual_type_bak
+    },
+    #' Returns the string representation of the instance.
+    #'
+    #' @description
+    #' Returns the string representation of the instance.
+    #'
+    #' @return The string representation of the instance.
+    #' @export
+    toString = function() {
+      jsoncontent <- c(
+        sprintf('"actual_instance": %s', if (is.null(self$actual_instance)) NULL else self$actual_instance$toJSONString()),
+        sprintf('"actual_type": "%s"', self$actual_type),
+        sprintf('"one_of": "%s"', paste(unlist(self$one_of), collapse = ", "))
+      )
+      jsoncontent <- paste(jsoncontent, collapse = ",")
+      as.character(jsonlite::prettify(paste("{", jsoncontent, "}", sep = "")))
+    }
+  )
+)
diff --git a/samples/client/petstore/R-httr2-wrapper/R/pig.R b/samples/client/petstore/R-httr2-wrapper/R/pig.R
index dbe013e4168..9cdb7a38770 100644
--- a/samples/client/petstore/R-httr2-wrapper/R/pig.R
+++ b/samples/client/petstore/R-httr2-wrapper/R/pig.R
@@ -22,7 +22,7 @@ Pig <- R6::R6Class(
     actual_instance = NULL,
     #' @field actual_type the type of the object stored in this instance.
     actual_type = NULL,
-    #' @field one_of  a list of object types defined in the oneOf schema.
+    #' @field one_of  a list of types defined in the oneOf schema.
     one_of = list("BasquePig", "DanishPig"),
     #' Initialize a new Pig.
     #'
diff --git a/samples/client/petstore/R-httr2-wrapper/README.md b/samples/client/petstore/R-httr2-wrapper/README.md
index eeed062a6ff..7b97c29fe51 100644
--- a/samples/client/petstore/R-httr2-wrapper/README.md
+++ b/samples/client/petstore/R-httr2-wrapper/README.md
@@ -92,6 +92,7 @@ Class | Method | HTTP request | Description
  - [AllofTagApiResponse](docs/AllofTagApiResponse.md)
  - [Animal](docs/Animal.md)
  - [AnyOfPig](docs/AnyOfPig.md)
+ - [AnyOfPrimitiveTypeTest](docs/AnyOfPrimitiveTypeTest.md)
  - [BasquePig](docs/BasquePig.md)
  - [Cat](docs/Cat.md)
  - [CatAllOf](docs/CatAllOf.md)
@@ -101,6 +102,7 @@ Class | Method | HTTP request | Description
  - [DogAllOf](docs/DogAllOf.md)
  - [ModelApiResponse](docs/ModelApiResponse.md)
  - [NestedOneOf](docs/NestedOneOf.md)
+ - [OneOfPrimitiveTypeTest](docs/OneOfPrimitiveTypeTest.md)
  - [Order](docs/Order.md)
  - [Pet](docs/Pet.md)
  - [Pig](docs/Pig.md)
diff --git a/samples/client/petstore/R-httr2-wrapper/docs/AnyOfPrimitiveTypeTest.md b/samples/client/petstore/R-httr2-wrapper/docs/AnyOfPrimitiveTypeTest.md
new file mode 100644
index 00000000000..0d8ba0e63b1
--- /dev/null
+++ b/samples/client/petstore/R-httr2-wrapper/docs/AnyOfPrimitiveTypeTest.md
@@ -0,0 +1,8 @@
+# petstore::AnyOfPrimitiveTypeTest
+
+
+## Properties
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+
+
diff --git a/samples/client/petstore/R-httr2-wrapper/docs/OneOfPrimitiveTypeTest.md b/samples/client/petstore/R-httr2-wrapper/docs/OneOfPrimitiveTypeTest.md
new file mode 100644
index 00000000000..82cf318431f
--- /dev/null
+++ b/samples/client/petstore/R-httr2-wrapper/docs/OneOfPrimitiveTypeTest.md
@@ -0,0 +1,8 @@
+# petstore::OneOfPrimitiveTypeTest
+
+
+## Properties
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+
+
diff --git a/samples/client/petstore/R-httr2-wrapper/tests/testthat/test_any_of_primitive_type_test.R b/samples/client/petstore/R-httr2-wrapper/tests/testthat/test_any_of_primitive_type_test.R
new file mode 100644
index 00000000000..0679cfaf443
--- /dev/null
+++ b/samples/client/petstore/R-httr2-wrapper/tests/testthat/test_any_of_primitive_type_test.R
@@ -0,0 +1,4 @@
+# Automatically generated by openapi-generator (https://openapi-generator.tech)
+# Please update as you see appropriate
+
+context("Test AnyOfPrimitiveTypeTest")
diff --git a/samples/client/petstore/R-httr2-wrapper/tests/testthat/test_one_of_primitive_type_test.R b/samples/client/petstore/R-httr2-wrapper/tests/testthat/test_one_of_primitive_type_test.R
new file mode 100644
index 00000000000..f9e7158359b
--- /dev/null
+++ b/samples/client/petstore/R-httr2-wrapper/tests/testthat/test_one_of_primitive_type_test.R
@@ -0,0 +1,4 @@
+# Automatically generated by openapi-generator (https://openapi-generator.tech)
+# Please update as you see appropriate
+
+context("Test OneOfPrimitiveTypeTest")
diff --git a/samples/client/petstore/R-httr2/.openapi-generator/FILES b/samples/client/petstore/R-httr2/.openapi-generator/FILES
index 7a05f5fdda5..11069aa4bcc 100644
--- a/samples/client/petstore/R-httr2/.openapi-generator/FILES
+++ b/samples/client/petstore/R-httr2/.openapi-generator/FILES
@@ -8,6 +8,7 @@ NAMESPACE
 R/allof_tag_api_response.R
 R/animal.R
 R/any_of_pig.R
+R/any_of_primitive_type_test.R
 R/api_client.R
 R/api_exception.R
 R/api_response.R
@@ -21,6 +22,7 @@ R/dog_all_of.R
 R/fake_api.R
 R/model_api_response.R
 R/nested_one_of.R
+R/one_of_primitive_type_test.R
 R/order.R
 R/pet.R
 R/pet_api.R
@@ -35,6 +37,7 @@ README.md
 docs/AllofTagApiResponse.md
 docs/Animal.md
 docs/AnyOfPig.md
+docs/AnyOfPrimitiveTypeTest.md
 docs/BasquePig.md
 docs/Cat.md
 docs/CatAllOf.md
@@ -45,6 +48,7 @@ docs/DogAllOf.md
 docs/FakeApi.md
 docs/ModelApiResponse.md
 docs/NestedOneOf.md
+docs/OneOfPrimitiveTypeTest.md
 docs/Order.md
 docs/Pet.md
 docs/PetApi.md
diff --git a/samples/client/petstore/R-httr2/NAMESPACE b/samples/client/petstore/R-httr2/NAMESPACE
index d1c5432b4f7..d26ce29357a 100644
--- a/samples/client/petstore/R-httr2/NAMESPACE
+++ b/samples/client/petstore/R-httr2/NAMESPACE
@@ -17,6 +17,7 @@ export(ApiException)
 export(AllofTagApiResponse)
 export(Animal)
 export(AnyOfPig)
+export(AnyOfPrimitiveTypeTest)
 export(BasquePig)
 export(Cat)
 export(CatAllOf)
@@ -26,6 +27,7 @@ export(Dog)
 export(DogAllOf)
 export(ModelApiResponse)
 export(NestedOneOf)
+export(OneOfPrimitiveTypeTest)
 export(Order)
 export(Pet)
 export(Pig)
diff --git a/samples/client/petstore/R-httr2/R/any_of_primitive_type_test.R b/samples/client/petstore/R-httr2/R/any_of_primitive_type_test.R
new file mode 100644
index 00000000000..7e668710023
--- /dev/null
+++ b/samples/client/petstore/R-httr2/R/any_of_primitive_type_test.R
@@ -0,0 +1,186 @@
+#' OpenAPI Petstore
+#'
+#' This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+#'
+#' The version of the OpenAPI document: 1.0.0
+#' Generated by: https://openapi-generator.tech
+#'
+#' @docType class
+#' @title AnyOfPrimitiveTypeTest
+#'
+#' @description AnyOfPrimitiveTypeTest Class
+#'
+#' @format An \code{R6Class} generator object
+#'
+#' @importFrom R6 R6Class
+#' @importFrom jsonlite fromJSON toJSON
+#' @export
+AnyOfPrimitiveTypeTest <- R6::R6Class(
+  "AnyOfPrimitiveTypeTest",
+  public = list(
+    #' @field actual_instance the object stored in this instance.
+    actual_instance = NULL,
+    #' @field actual_type the type of the object stored in this instance.
+    actual_type = NULL,
+    #' @field one_of  a list of types defined in the oneOf schema.
+    one_of = list("character", "integer"),
+    #' Initialize a new AnyOfPrimitiveTypeTest.
+    #'
+    #' @description
+    #' Initialize a new AnyOfPrimitiveTypeTest.
+    #'
+    #' @param instance an instance of the object defined in the oneOf schemas: "character", "integer"
+    #' @export
+    initialize = function(instance = NULL) {
+      if (is.null(instance)) {
+        # do nothing
+      } else if (get(class(instance)[[1]], pos = -1)$classname ==  "character") {
+        self$actual_instance <- instance
+        self$actual_type <- "character"
+      } else if (get(class(instance)[[1]], pos = -1)$classname ==  "integer") {
+        self$actual_instance <- instance
+        self$actual_type <- "integer"
+      } else {
+        stop(paste("Failed to initialize AnyOfPrimitiveTypeTest with oneOf schemas character, integer. Provided class name: ",
+                   get(class(instance)[[1]], pos = -1)$classname))
+      }
+    },
+    #' Deserialize JSON string into an instance of AnyOfPrimitiveTypeTest.
+    #'
+    #' @description
+    #' Deserialize JSON string into an instance of AnyOfPrimitiveTypeTest.
+    #' An alias to the method `fromJSON` .
+    #'
+    #' @param input The input JSON.
+    #' @return An instance of AnyOfPrimitiveTypeTest.
+    #' @export
+    fromJSONString = function(input) {
+      self$fromJSON(input)
+    },
+    #' Deserialize JSON string into an instance of AnyOfPrimitiveTypeTest.
+    #'
+    #' @description
+    #' Deserialize JSON string into an instance of AnyOfPrimitiveTypeTest.
+    #'
+    #' @param input The input JSON.
+    #' @return An instance of AnyOfPrimitiveTypeTest.
+    #' @export
+    fromJSON = function(input) {
+      matched <- 0 # match counter
+      matched_schemas <- list() #names of matched schemas
+      error_messages <- list()
+      instance <- NULL
+
+      integer_result <- tryCatch({
+          instance <- jsonlite::fromJSON(input, simplifyVector = FALSE)
+          if (typeof(instance) != "integer") {
+            stop(sprintf("Data type doesn't match. Expected: %s. Actual: %s.", "integer", typeof(instance)))
+          }
+          instance_type <- "integer"
+          matched_schemas <- append(matched_schemas, "integer")
+          matched <- matched + 1
+        },
+        error = function(err) err
+      )
+
+      if (!is.null(integer_result["error"])) {
+        error_messages <- append(error_messages, integer_result["message"])
+      }
+
+      character_result <- tryCatch({
+          instance <- jsonlite::fromJSON(input, simplifyVector = FALSE)
+          if (typeof(instance) != "character") {
+            stop(sprintf("Data type doesn't match. Expected: %s. Actual: %s.", "character", typeof(instance)))
+          }
+          instance_type <- "character"
+          matched_schemas <- append(matched_schemas, "character")
+          matched <- matched + 1
+        },
+        error = function(err) err
+      )
+
+      if (!is.null(character_result["error"])) {
+        error_messages <- append(error_messages, character_result["message"])
+      }
+
+      if (matched == 1) {
+        # successfully match exactly 1 schema specified in oneOf
+        self$actual_instance <- instance
+        self$actual_type <- instance_type
+      } else if (matched > 1) {
+        # more than 1 match
+        stop("Multiple matches found when deserializing the payload into AnyOfPrimitiveTypeTest with oneOf schemas character, integer.")
+      } else {
+        # no match
+        stop(paste("No match found when deserializing the payload into AnyOfPrimitiveTypeTest with oneOf schemas character, integer. Details: ",
+                   paste(error_messages, collapse = ", ")))
+      }
+
+      self
+    },
+    #' Serialize AnyOfPrimitiveTypeTest to JSON string.
+    #'
+    #' @description
+    #' Serialize AnyOfPrimitiveTypeTest to JSON string.
+    #'
+    #' @return JSON string representation of the AnyOfPrimitiveTypeTest.
+    #' @export
+    toJSONString = function() {
+      if (!is.null(self$actual_instance)) {
+        as.character(jsonlite::minify(self$actual_instance$toJSONString()))
+      } else {
+        NULL
+      }
+    },
+    #' Serialize AnyOfPrimitiveTypeTest to JSON.
+    #'
+    #' @description
+    #' Serialize AnyOfPrimitiveTypeTest to JSON.
+    #'
+    #' @return JSON representation of the AnyOfPrimitiveTypeTest.
+    #' @export
+    toJSON = function() {
+      if (!is.null(self$actual_instance)) {
+        self$actual_instance$toJSON()
+      } else {
+        NULL
+      }
+    },
+    #' Validate the input JSON with respect to AnyOfPrimitiveTypeTest.
+    #'
+    #' @description
+    #' Validate the input JSON with respect to AnyOfPrimitiveTypeTest and
+    #' throw exception if invalid.
+    #'
+    #' @param input The input JSON.
+    #' @export
+    validateJSON = function(input) {
+      # backup current values
+      actual_instance_bak <- self$actual_instance
+      actual_type_bak <- self$actual_type
+
+      # if it's not valid, an error will be thrown
+      self$fromJSON(input)
+
+      # no error thrown, restore old values
+      self$actual_instance <- actual_instance_bak
+      self$actual_type <- actual_type_bak
+    },
+    #' Returns the string representation of the instance.
+    #'
+    #' @description
+    #' Returns the string representation of the instance.
+    #'
+    #' @return The string representation of the instance.
+    #' @export
+    toString = function() {
+      jsoncontent <- c(
+        sprintf('"actual_instance": %s', if (is.null(self$actual_instance)) NULL else self$actual_instance$toJSONString()),
+        sprintf('"actual_type": "%s"', self$actual_type),
+        sprintf('"one_of": "%s"', paste(unlist(self$one_of), collapse = ", "))
+      )
+      jsoncontent <- paste(jsoncontent, collapse = ",")
+      as.character(jsonlite::prettify(paste("{", jsoncontent, "}", sep = "")))
+    }
+  )
+)
diff --git a/samples/client/petstore/R-httr2/R/one_of_primitive_type_test.R b/samples/client/petstore/R-httr2/R/one_of_primitive_type_test.R
new file mode 100644
index 00000000000..8815ba1d3ee
--- /dev/null
+++ b/samples/client/petstore/R-httr2/R/one_of_primitive_type_test.R
@@ -0,0 +1,186 @@
+#' OpenAPI Petstore
+#'
+#' This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+#'
+#' The version of the OpenAPI document: 1.0.0
+#' Generated by: https://openapi-generator.tech
+#'
+#' @docType class
+#' @title OneOfPrimitiveTypeTest
+#'
+#' @description OneOfPrimitiveTypeTest Class
+#'
+#' @format An \code{R6Class} generator object
+#'
+#' @importFrom R6 R6Class
+#' @importFrom jsonlite fromJSON toJSON
+#' @export
+OneOfPrimitiveTypeTest <- R6::R6Class(
+  "OneOfPrimitiveTypeTest",
+  public = list(
+    #' @field actual_instance the object stored in this instance.
+    actual_instance = NULL,
+    #' @field actual_type the type of the object stored in this instance.
+    actual_type = NULL,
+    #' @field one_of  a list of types defined in the oneOf schema.
+    one_of = list("character", "integer"),
+    #' Initialize a new OneOfPrimitiveTypeTest.
+    #'
+    #' @description
+    #' Initialize a new OneOfPrimitiveTypeTest.
+    #'
+    #' @param instance an instance of the object defined in the oneOf schemas: "character", "integer"
+    #' @export
+    initialize = function(instance = NULL) {
+      if (is.null(instance)) {
+        # do nothing
+      } else if (get(class(instance)[[1]], pos = -1)$classname ==  "character") {
+        self$actual_instance <- instance
+        self$actual_type <- "character"
+      } else if (get(class(instance)[[1]], pos = -1)$classname ==  "integer") {
+        self$actual_instance <- instance
+        self$actual_type <- "integer"
+      } else {
+        stop(paste("Failed to initialize OneOfPrimitiveTypeTest with oneOf schemas character, integer. Provided class name: ",
+                   get(class(instance)[[1]], pos = -1)$classname))
+      }
+    },
+    #' Deserialize JSON string into an instance of OneOfPrimitiveTypeTest.
+    #'
+    #' @description
+    #' Deserialize JSON string into an instance of OneOfPrimitiveTypeTest.
+    #' An alias to the method `fromJSON` .
+    #'
+    #' @param input The input JSON.
+    #' @return An instance of OneOfPrimitiveTypeTest.
+    #' @export
+    fromJSONString = function(input) {
+      self$fromJSON(input)
+    },
+    #' Deserialize JSON string into an instance of OneOfPrimitiveTypeTest.
+    #'
+    #' @description
+    #' Deserialize JSON string into an instance of OneOfPrimitiveTypeTest.
+    #'
+    #' @param input The input JSON.
+    #' @return An instance of OneOfPrimitiveTypeTest.
+    #' @export
+    fromJSON = function(input) {
+      matched <- 0 # match counter
+      matched_schemas <- list() #names of matched schemas
+      error_messages <- list()
+      instance <- NULL
+
+      integer_result <- tryCatch({
+          instance <- jsonlite::fromJSON(input, simplifyVector = FALSE)
+          if (typeof(instance) != "integer") {
+            stop(sprintf("Data type doesn't match. Expected: %s. Actual: %s.", "integer", typeof(instance)))
+          }
+          instance_type <- "integer"
+          matched_schemas <- append(matched_schemas, "integer")
+          matched <- matched + 1
+        },
+        error = function(err) err
+      )
+
+      if (!is.null(integer_result["error"])) {
+        error_messages <- append(error_messages, integer_result["message"])
+      }
+
+      character_result <- tryCatch({
+          instance <- jsonlite::fromJSON(input, simplifyVector = FALSE)
+          if (typeof(instance) != "character") {
+            stop(sprintf("Data type doesn't match. Expected: %s. Actual: %s.", "character", typeof(instance)))
+          }
+          instance_type <- "character"
+          matched_schemas <- append(matched_schemas, "character")
+          matched <- matched + 1
+        },
+        error = function(err) err
+      )
+
+      if (!is.null(character_result["error"])) {
+        error_messages <- append(error_messages, character_result["message"])
+      }
+
+      if (matched == 1) {
+        # successfully match exactly 1 schema specified in oneOf
+        self$actual_instance <- instance
+        self$actual_type <- instance_type
+      } else if (matched > 1) {
+        # more than 1 match
+        stop("Multiple matches found when deserializing the payload into OneOfPrimitiveTypeTest with oneOf schemas character, integer.")
+      } else {
+        # no match
+        stop(paste("No match found when deserializing the payload into OneOfPrimitiveTypeTest with oneOf schemas character, integer. Details: ",
+                   paste(error_messages, collapse = ", ")))
+      }
+
+      self
+    },
+    #' Serialize OneOfPrimitiveTypeTest to JSON string.
+    #'
+    #' @description
+    #' Serialize OneOfPrimitiveTypeTest to JSON string.
+    #'
+    #' @return JSON string representation of the OneOfPrimitiveTypeTest.
+    #' @export
+    toJSONString = function() {
+      if (!is.null(self$actual_instance)) {
+        as.character(jsonlite::minify(self$actual_instance$toJSONString()))
+      } else {
+        NULL
+      }
+    },
+    #' Serialize OneOfPrimitiveTypeTest to JSON.
+    #'
+    #' @description
+    #' Serialize OneOfPrimitiveTypeTest to JSON.
+    #'
+    #' @return JSON representation of the OneOfPrimitiveTypeTest.
+    #' @export
+    toJSON = function() {
+      if (!is.null(self$actual_instance)) {
+        self$actual_instance$toJSON()
+      } else {
+        NULL
+      }
+    },
+    #' Validate the input JSON with respect to OneOfPrimitiveTypeTest.
+    #'
+    #' @description
+    #' Validate the input JSON with respect to OneOfPrimitiveTypeTest and
+    #' throw exception if invalid.
+    #'
+    #' @param input The input JSON.
+    #' @export
+    validateJSON = function(input) {
+      # backup current values
+      actual_instance_bak <- self$actual_instance
+      actual_type_bak <- self$actual_type
+
+      # if it's not valid, an error will be thrown
+      self$fromJSON(input)
+
+      # no error thrown, restore old values
+      self$actual_instance <- actual_instance_bak
+      self$actual_type <- actual_type_bak
+    },
+    #' Returns the string representation of the instance.
+    #'
+    #' @description
+    #' Returns the string representation of the instance.
+    #'
+    #' @return The string representation of the instance.
+    #' @export
+    toString = function() {
+      jsoncontent <- c(
+        sprintf('"actual_instance": %s', if (is.null(self$actual_instance)) NULL else self$actual_instance$toJSONString()),
+        sprintf('"actual_type": "%s"', self$actual_type),
+        sprintf('"one_of": "%s"', paste(unlist(self$one_of), collapse = ", "))
+      )
+      jsoncontent <- paste(jsoncontent, collapse = ",")
+      as.character(jsonlite::prettify(paste("{", jsoncontent, "}", sep = "")))
+    }
+  )
+)
diff --git a/samples/client/petstore/R-httr2/R/pig.R b/samples/client/petstore/R-httr2/R/pig.R
index dbe013e4168..9cdb7a38770 100644
--- a/samples/client/petstore/R-httr2/R/pig.R
+++ b/samples/client/petstore/R-httr2/R/pig.R
@@ -22,7 +22,7 @@ Pig <- R6::R6Class(
     actual_instance = NULL,
     #' @field actual_type the type of the object stored in this instance.
     actual_type = NULL,
-    #' @field one_of  a list of object types defined in the oneOf schema.
+    #' @field one_of  a list of types defined in the oneOf schema.
     one_of = list("BasquePig", "DanishPig"),
     #' Initialize a new Pig.
     #'
diff --git a/samples/client/petstore/R-httr2/README.md b/samples/client/petstore/R-httr2/README.md
index eeed062a6ff..7b97c29fe51 100644
--- a/samples/client/petstore/R-httr2/README.md
+++ b/samples/client/petstore/R-httr2/README.md
@@ -92,6 +92,7 @@ Class | Method | HTTP request | Description
  - [AllofTagApiResponse](docs/AllofTagApiResponse.md)
  - [Animal](docs/Animal.md)
  - [AnyOfPig](docs/AnyOfPig.md)
+ - [AnyOfPrimitiveTypeTest](docs/AnyOfPrimitiveTypeTest.md)
  - [BasquePig](docs/BasquePig.md)
  - [Cat](docs/Cat.md)
  - [CatAllOf](docs/CatAllOf.md)
@@ -101,6 +102,7 @@ Class | Method | HTTP request | Description
  - [DogAllOf](docs/DogAllOf.md)
  - [ModelApiResponse](docs/ModelApiResponse.md)
  - [NestedOneOf](docs/NestedOneOf.md)
+ - [OneOfPrimitiveTypeTest](docs/OneOfPrimitiveTypeTest.md)
  - [Order](docs/Order.md)
  - [Pet](docs/Pet.md)
  - [Pig](docs/Pig.md)
diff --git a/samples/client/petstore/R-httr2/docs/AnyOfPrimitiveTypeTest.md b/samples/client/petstore/R-httr2/docs/AnyOfPrimitiveTypeTest.md
new file mode 100644
index 00000000000..0d8ba0e63b1
--- /dev/null
+++ b/samples/client/petstore/R-httr2/docs/AnyOfPrimitiveTypeTest.md
@@ -0,0 +1,8 @@
+# petstore::AnyOfPrimitiveTypeTest
+
+
+## Properties
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+
+
diff --git a/samples/client/petstore/R-httr2/docs/OneOfPrimitiveTypeTest.md b/samples/client/petstore/R-httr2/docs/OneOfPrimitiveTypeTest.md
new file mode 100644
index 00000000000..82cf318431f
--- /dev/null
+++ b/samples/client/petstore/R-httr2/docs/OneOfPrimitiveTypeTest.md
@@ -0,0 +1,8 @@
+# petstore::OneOfPrimitiveTypeTest
+
+
+## Properties
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+
+
diff --git a/samples/client/petstore/R-httr2/test_petstore.R b/samples/client/petstore/R-httr2/test_petstore.R
index a0a15a2972b..fb9f30a7e78 100644
--- a/samples/client/petstore/R-httr2/test_petstore.R
+++ b/samples/client/petstore/R-httr2/test_petstore.R
@@ -3,27 +3,32 @@ install.packages("petstore_1.0.0.tar.gz",repos=NULL, type="source")
 library(petstore)
 library(jsonlite)
 
-var_pet <- Pet$new("name_example", list("photoUrls_example"), 56, Category$new(56, "name_example"), list(Tag$new(56, "name_example")), "available") # Pet | Pet object that needs to be added to the store
+t <- OneOfPrimitiveTypeTest$new()
 
-#Add a new pet to the store
-api_instance <- PetApi$new()
-# Configure OAuth2 access token for authorization: petstore_auth
-api_instance$api_client$access_token <- 'TODO_YOUR_ACCESS_TOKEN';
-result <- tryCatch(
-             # to save the result into a file, simply add the optional `data_file` parameter, e.g.
-             # api_instance$AddPet(var_pet, data_file = "result.txt"),
-             api_instance$add_pet(var_pet),
-             ApiException = function(ex) ex
-          )
+t$fromJSONString("[1,2,3]")
 
-var_pet_id <- 56 # integer | ID of pet to return
 
-pet_response <- api_instance$get_pet_by_id(var_pet_id, data_file = "get_pet_by_id.json")
-response <- read_json("get_pet_by_id.json")
-dput(response)
-
-# test streaming
-api_instance$get_pet_by_id_streaming(var_pet_id, stream_callback = function(x) { print(x) })
+###var_pet <- Pet$new("name_example", list("photoUrls_example"), 56, Category$new(56, "name_example"), list(Tag$new(56, "name_example")), "available") # Pet | Pet object that needs to be added to the store
+###
+####Add a new pet to the store
+###api_instance <- PetApi$new()
+#### Configure OAuth2 access token for authorization: petstore_auth
+###api_instance$api_client$access_token <- 'TODO_YOUR_ACCESS_TOKEN';
+###result <- tryCatch(
+###             # to save the result into a file, simply add the optional `data_file` parameter, e.g.
+###             # api_instance$AddPet(var_pet, data_file = "result.txt"),
+###             api_instance$add_pet(var_pet),
+###             ApiException = function(ex) ex
+###          )
+###
+###var_pet_id <- 56 # integer | ID of pet to return
+###
+###pet_response <- api_instance$get_pet_by_id(var_pet_id, data_file = "get_pet_by_id.json")
+###response <- read_json("get_pet_by_id.json")
+###dput(response)
+###
+#### test streaming
+###api_instance$get_pet_by_id_streaming(var_pet_id, stream_callback = function(x) { print(x) })
 
 ##Find pet by ID (streaming)
 #api_instance <- PetApi$new()
diff --git a/samples/client/petstore/R-httr2/tests/testthat/test_any_of_primitive_type_test.R b/samples/client/petstore/R-httr2/tests/testthat/test_any_of_primitive_type_test.R
new file mode 100644
index 00000000000..0679cfaf443
--- /dev/null
+++ b/samples/client/petstore/R-httr2/tests/testthat/test_any_of_primitive_type_test.R
@@ -0,0 +1,4 @@
+# Automatically generated by openapi-generator (https://openapi-generator.tech)
+# Please update as you see appropriate
+
+context("Test AnyOfPrimitiveTypeTest")
diff --git a/samples/client/petstore/R-httr2/tests/testthat/test_one_of_primitive_type_test.R b/samples/client/petstore/R-httr2/tests/testthat/test_one_of_primitive_type_test.R
new file mode 100644
index 00000000000..f9e7158359b
--- /dev/null
+++ b/samples/client/petstore/R-httr2/tests/testthat/test_one_of_primitive_type_test.R
@@ -0,0 +1,4 @@
+# Automatically generated by openapi-generator (https://openapi-generator.tech)
+# Please update as you see appropriate
+
+context("Test OneOfPrimitiveTypeTest")
diff --git a/samples/client/petstore/R-httr2/tests/testthat/test_petstore.R b/samples/client/petstore/R-httr2/tests/testthat/test_petstore.R
index bd5f6d326b6..73723ba1d63 100644
--- a/samples/client/petstore/R-httr2/tests/testthat/test_petstore.R
+++ b/samples/client/petstore/R-httr2/tests/testthat/test_petstore.R
@@ -260,6 +260,32 @@ test_that ("Tests validations", {
 
 })
 
+test_that("Tests oneOf primitive types", {
+  test <- OneOfPrimitiveTypeTest$new()
+  test$fromJSONString("\"123abc\"")
+  expect_equal(test$actual_instance,  '123abc')
+  expect_equal(test$actual_type,  'character')
+
+  test$fromJSONString("456")
+  expect_equal(test$actual_instance,  456)
+  expect_equal(test$actual_type,  'integer')
+
+  expect_error(test$fromJSONString("[45,12]"), "No match found when deserializing the payload into OneOfPrimitiveTypeTest with oneOf schemas character, integer. Details:  Data type doesn't match. Expected: integer. Actual: list., Data type doesn't match. Expected: character. Actual: list.") # should throw an error
+})
+
+test_that("Tests anyOf primitive types", {
+  test <- AnyOfPrimitiveTypeTest$new()
+  test$fromJSONString("\"123abc\"")
+  expect_equal(test$actual_instance,  '123abc')
+  expect_equal(test$actual_type,  'character')
+
+  test$fromJSONString("456")
+  expect_equal(test$actual_instance,  456)
+  expect_equal(test$actual_type,  'integer')
+
+  expect_error(test$fromJSONString("[45,12]"), "No match found when deserializing the payload into AnyOfPrimitiveTypeTest with oneOf schemas character, integer. Details:  Data type doesn't match. Expected: integer. Actual: list., Data type doesn't match. Expected: character. Actual: list.") # should throw an error
+})
+
 test_that("Tests oneOf", {
   basque_pig_json <-
   '{"className": "BasquePig", "color": "red"}'
diff --git a/samples/client/petstore/R/.openapi-generator/FILES b/samples/client/petstore/R/.openapi-generator/FILES
index 7a05f5fdda5..11069aa4bcc 100644
--- a/samples/client/petstore/R/.openapi-generator/FILES
+++ b/samples/client/petstore/R/.openapi-generator/FILES
@@ -8,6 +8,7 @@ NAMESPACE
 R/allof_tag_api_response.R
 R/animal.R
 R/any_of_pig.R
+R/any_of_primitive_type_test.R
 R/api_client.R
 R/api_exception.R
 R/api_response.R
@@ -21,6 +22,7 @@ R/dog_all_of.R
 R/fake_api.R
 R/model_api_response.R
 R/nested_one_of.R
+R/one_of_primitive_type_test.R
 R/order.R
 R/pet.R
 R/pet_api.R
@@ -35,6 +37,7 @@ README.md
 docs/AllofTagApiResponse.md
 docs/Animal.md
 docs/AnyOfPig.md
+docs/AnyOfPrimitiveTypeTest.md
 docs/BasquePig.md
 docs/Cat.md
 docs/CatAllOf.md
@@ -45,6 +48,7 @@ docs/DogAllOf.md
 docs/FakeApi.md
 docs/ModelApiResponse.md
 docs/NestedOneOf.md
+docs/OneOfPrimitiveTypeTest.md
 docs/Order.md
 docs/Pet.md
 docs/PetApi.md
diff --git a/samples/client/petstore/R/NAMESPACE b/samples/client/petstore/R/NAMESPACE
index 4dbc737fd94..d8e1c837ba1 100644
--- a/samples/client/petstore/R/NAMESPACE
+++ b/samples/client/petstore/R/NAMESPACE
@@ -17,6 +17,7 @@ export(ApiException)
 export(AllofTagApiResponse)
 export(Animal)
 export(AnyOfPig)
+export(AnyOfPrimitiveTypeTest)
 export(BasquePig)
 export(Cat)
 export(CatAllOf)
@@ -26,6 +27,7 @@ export(Dog)
 export(DogAllOf)
 export(ModelApiResponse)
 export(NestedOneOf)
+export(OneOfPrimitiveTypeTest)
 export(Order)
 export(Pet)
 export(Pig)
diff --git a/samples/client/petstore/R/R/any_of_primitive_type_test.R b/samples/client/petstore/R/R/any_of_primitive_type_test.R
new file mode 100644
index 00000000000..7e668710023
--- /dev/null
+++ b/samples/client/petstore/R/R/any_of_primitive_type_test.R
@@ -0,0 +1,186 @@
+#' OpenAPI Petstore
+#'
+#' This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+#'
+#' The version of the OpenAPI document: 1.0.0
+#' Generated by: https://openapi-generator.tech
+#'
+#' @docType class
+#' @title AnyOfPrimitiveTypeTest
+#'
+#' @description AnyOfPrimitiveTypeTest Class
+#'
+#' @format An \code{R6Class} generator object
+#'
+#' @importFrom R6 R6Class
+#' @importFrom jsonlite fromJSON toJSON
+#' @export
+AnyOfPrimitiveTypeTest <- R6::R6Class(
+  "AnyOfPrimitiveTypeTest",
+  public = list(
+    #' @field actual_instance the object stored in this instance.
+    actual_instance = NULL,
+    #' @field actual_type the type of the object stored in this instance.
+    actual_type = NULL,
+    #' @field one_of  a list of types defined in the oneOf schema.
+    one_of = list("character", "integer"),
+    #' Initialize a new AnyOfPrimitiveTypeTest.
+    #'
+    #' @description
+    #' Initialize a new AnyOfPrimitiveTypeTest.
+    #'
+    #' @param instance an instance of the object defined in the oneOf schemas: "character", "integer"
+    #' @export
+    initialize = function(instance = NULL) {
+      if (is.null(instance)) {
+        # do nothing
+      } else if (get(class(instance)[[1]], pos = -1)$classname ==  "character") {
+        self$actual_instance <- instance
+        self$actual_type <- "character"
+      } else if (get(class(instance)[[1]], pos = -1)$classname ==  "integer") {
+        self$actual_instance <- instance
+        self$actual_type <- "integer"
+      } else {
+        stop(paste("Failed to initialize AnyOfPrimitiveTypeTest with oneOf schemas character, integer. Provided class name: ",
+                   get(class(instance)[[1]], pos = -1)$classname))
+      }
+    },
+    #' Deserialize JSON string into an instance of AnyOfPrimitiveTypeTest.
+    #'
+    #' @description
+    #' Deserialize JSON string into an instance of AnyOfPrimitiveTypeTest.
+    #' An alias to the method `fromJSON` .
+    #'
+    #' @param input The input JSON.
+    #' @return An instance of AnyOfPrimitiveTypeTest.
+    #' @export
+    fromJSONString = function(input) {
+      self$fromJSON(input)
+    },
+    #' Deserialize JSON string into an instance of AnyOfPrimitiveTypeTest.
+    #'
+    #' @description
+    #' Deserialize JSON string into an instance of AnyOfPrimitiveTypeTest.
+    #'
+    #' @param input The input JSON.
+    #' @return An instance of AnyOfPrimitiveTypeTest.
+    #' @export
+    fromJSON = function(input) {
+      matched <- 0 # match counter
+      matched_schemas <- list() #names of matched schemas
+      error_messages <- list()
+      instance <- NULL
+
+      integer_result <- tryCatch({
+          instance <- jsonlite::fromJSON(input, simplifyVector = FALSE)
+          if (typeof(instance) != "integer") {
+            stop(sprintf("Data type doesn't match. Expected: %s. Actual: %s.", "integer", typeof(instance)))
+          }
+          instance_type <- "integer"
+          matched_schemas <- append(matched_schemas, "integer")
+          matched <- matched + 1
+        },
+        error = function(err) err
+      )
+
+      if (!is.null(integer_result["error"])) {
+        error_messages <- append(error_messages, integer_result["message"])
+      }
+
+      character_result <- tryCatch({
+          instance <- jsonlite::fromJSON(input, simplifyVector = FALSE)
+          if (typeof(instance) != "character") {
+            stop(sprintf("Data type doesn't match. Expected: %s. Actual: %s.", "character", typeof(instance)))
+          }
+          instance_type <- "character"
+          matched_schemas <- append(matched_schemas, "character")
+          matched <- matched + 1
+        },
+        error = function(err) err
+      )
+
+      if (!is.null(character_result["error"])) {
+        error_messages <- append(error_messages, character_result["message"])
+      }
+
+      if (matched == 1) {
+        # successfully match exactly 1 schema specified in oneOf
+        self$actual_instance <- instance
+        self$actual_type <- instance_type
+      } else if (matched > 1) {
+        # more than 1 match
+        stop("Multiple matches found when deserializing the payload into AnyOfPrimitiveTypeTest with oneOf schemas character, integer.")
+      } else {
+        # no match
+        stop(paste("No match found when deserializing the payload into AnyOfPrimitiveTypeTest with oneOf schemas character, integer. Details: ",
+                   paste(error_messages, collapse = ", ")))
+      }
+
+      self
+    },
+    #' Serialize AnyOfPrimitiveTypeTest to JSON string.
+    #'
+    #' @description
+    #' Serialize AnyOfPrimitiveTypeTest to JSON string.
+    #'
+    #' @return JSON string representation of the AnyOfPrimitiveTypeTest.
+    #' @export
+    toJSONString = function() {
+      if (!is.null(self$actual_instance)) {
+        as.character(jsonlite::minify(self$actual_instance$toJSONString()))
+      } else {
+        NULL
+      }
+    },
+    #' Serialize AnyOfPrimitiveTypeTest to JSON.
+    #'
+    #' @description
+    #' Serialize AnyOfPrimitiveTypeTest to JSON.
+    #'
+    #' @return JSON representation of the AnyOfPrimitiveTypeTest.
+    #' @export
+    toJSON = function() {
+      if (!is.null(self$actual_instance)) {
+        self$actual_instance$toJSON()
+      } else {
+        NULL
+      }
+    },
+    #' Validate the input JSON with respect to AnyOfPrimitiveTypeTest.
+    #'
+    #' @description
+    #' Validate the input JSON with respect to AnyOfPrimitiveTypeTest and
+    #' throw exception if invalid.
+    #'
+    #' @param input The input JSON.
+    #' @export
+    validateJSON = function(input) {
+      # backup current values
+      actual_instance_bak <- self$actual_instance
+      actual_type_bak <- self$actual_type
+
+      # if it's not valid, an error will be thrown
+      self$fromJSON(input)
+
+      # no error thrown, restore old values
+      self$actual_instance <- actual_instance_bak
+      self$actual_type <- actual_type_bak
+    },
+    #' Returns the string representation of the instance.
+    #'
+    #' @description
+    #' Returns the string representation of the instance.
+    #'
+    #' @return The string representation of the instance.
+    #' @export
+    toString = function() {
+      jsoncontent <- c(
+        sprintf('"actual_instance": %s', if (is.null(self$actual_instance)) NULL else self$actual_instance$toJSONString()),
+        sprintf('"actual_type": "%s"', self$actual_type),
+        sprintf('"one_of": "%s"', paste(unlist(self$one_of), collapse = ", "))
+      )
+      jsoncontent <- paste(jsoncontent, collapse = ",")
+      as.character(jsonlite::prettify(paste("{", jsoncontent, "}", sep = "")))
+    }
+  )
+)
diff --git a/samples/client/petstore/R/R/one_of_primitive_type_test.R b/samples/client/petstore/R/R/one_of_primitive_type_test.R
new file mode 100644
index 00000000000..8815ba1d3ee
--- /dev/null
+++ b/samples/client/petstore/R/R/one_of_primitive_type_test.R
@@ -0,0 +1,186 @@
+#' OpenAPI Petstore
+#'
+#' This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+#'
+#' The version of the OpenAPI document: 1.0.0
+#' Generated by: https://openapi-generator.tech
+#'
+#' @docType class
+#' @title OneOfPrimitiveTypeTest
+#'
+#' @description OneOfPrimitiveTypeTest Class
+#'
+#' @format An \code{R6Class} generator object
+#'
+#' @importFrom R6 R6Class
+#' @importFrom jsonlite fromJSON toJSON
+#' @export
+OneOfPrimitiveTypeTest <- R6::R6Class(
+  "OneOfPrimitiveTypeTest",
+  public = list(
+    #' @field actual_instance the object stored in this instance.
+    actual_instance = NULL,
+    #' @field actual_type the type of the object stored in this instance.
+    actual_type = NULL,
+    #' @field one_of  a list of types defined in the oneOf schema.
+    one_of = list("character", "integer"),
+    #' Initialize a new OneOfPrimitiveTypeTest.
+    #'
+    #' @description
+    #' Initialize a new OneOfPrimitiveTypeTest.
+    #'
+    #' @param instance an instance of the object defined in the oneOf schemas: "character", "integer"
+    #' @export
+    initialize = function(instance = NULL) {
+      if (is.null(instance)) {
+        # do nothing
+      } else if (get(class(instance)[[1]], pos = -1)$classname ==  "character") {
+        self$actual_instance <- instance
+        self$actual_type <- "character"
+      } else if (get(class(instance)[[1]], pos = -1)$classname ==  "integer") {
+        self$actual_instance <- instance
+        self$actual_type <- "integer"
+      } else {
+        stop(paste("Failed to initialize OneOfPrimitiveTypeTest with oneOf schemas character, integer. Provided class name: ",
+                   get(class(instance)[[1]], pos = -1)$classname))
+      }
+    },
+    #' Deserialize JSON string into an instance of OneOfPrimitiveTypeTest.
+    #'
+    #' @description
+    #' Deserialize JSON string into an instance of OneOfPrimitiveTypeTest.
+    #' An alias to the method `fromJSON` .
+    #'
+    #' @param input The input JSON.
+    #' @return An instance of OneOfPrimitiveTypeTest.
+    #' @export
+    fromJSONString = function(input) {
+      self$fromJSON(input)
+    },
+    #' Deserialize JSON string into an instance of OneOfPrimitiveTypeTest.
+    #'
+    #' @description
+    #' Deserialize JSON string into an instance of OneOfPrimitiveTypeTest.
+    #'
+    #' @param input The input JSON.
+    #' @return An instance of OneOfPrimitiveTypeTest.
+    #' @export
+    fromJSON = function(input) {
+      matched <- 0 # match counter
+      matched_schemas <- list() #names of matched schemas
+      error_messages <- list()
+      instance <- NULL
+
+      integer_result <- tryCatch({
+          instance <- jsonlite::fromJSON(input, simplifyVector = FALSE)
+          if (typeof(instance) != "integer") {
+            stop(sprintf("Data type doesn't match. Expected: %s. Actual: %s.", "integer", typeof(instance)))
+          }
+          instance_type <- "integer"
+          matched_schemas <- append(matched_schemas, "integer")
+          matched <- matched + 1
+        },
+        error = function(err) err
+      )
+
+      if (!is.null(integer_result["error"])) {
+        error_messages <- append(error_messages, integer_result["message"])
+      }
+
+      character_result <- tryCatch({
+          instance <- jsonlite::fromJSON(input, simplifyVector = FALSE)
+          if (typeof(instance) != "character") {
+            stop(sprintf("Data type doesn't match. Expected: %s. Actual: %s.", "character", typeof(instance)))
+          }
+          instance_type <- "character"
+          matched_schemas <- append(matched_schemas, "character")
+          matched <- matched + 1
+        },
+        error = function(err) err
+      )
+
+      if (!is.null(character_result["error"])) {
+        error_messages <- append(error_messages, character_result["message"])
+      }
+
+      if (matched == 1) {
+        # successfully match exactly 1 schema specified in oneOf
+        self$actual_instance <- instance
+        self$actual_type <- instance_type
+      } else if (matched > 1) {
+        # more than 1 match
+        stop("Multiple matches found when deserializing the payload into OneOfPrimitiveTypeTest with oneOf schemas character, integer.")
+      } else {
+        # no match
+        stop(paste("No match found when deserializing the payload into OneOfPrimitiveTypeTest with oneOf schemas character, integer. Details: ",
+                   paste(error_messages, collapse = ", ")))
+      }
+
+      self
+    },
+    #' Serialize OneOfPrimitiveTypeTest to JSON string.
+    #'
+    #' @description
+    #' Serialize OneOfPrimitiveTypeTest to JSON string.
+    #'
+    #' @return JSON string representation of the OneOfPrimitiveTypeTest.
+    #' @export
+    toJSONString = function() {
+      if (!is.null(self$actual_instance)) {
+        as.character(jsonlite::minify(self$actual_instance$toJSONString()))
+      } else {
+        NULL
+      }
+    },
+    #' Serialize OneOfPrimitiveTypeTest to JSON.
+    #'
+    #' @description
+    #' Serialize OneOfPrimitiveTypeTest to JSON.
+    #'
+    #' @return JSON representation of the OneOfPrimitiveTypeTest.
+    #' @export
+    toJSON = function() {
+      if (!is.null(self$actual_instance)) {
+        self$actual_instance$toJSON()
+      } else {
+        NULL
+      }
+    },
+    #' Validate the input JSON with respect to OneOfPrimitiveTypeTest.
+    #'
+    #' @description
+    #' Validate the input JSON with respect to OneOfPrimitiveTypeTest and
+    #' throw exception if invalid.
+    #'
+    #' @param input The input JSON.
+    #' @export
+    validateJSON = function(input) {
+      # backup current values
+      actual_instance_bak <- self$actual_instance
+      actual_type_bak <- self$actual_type
+
+      # if it's not valid, an error will be thrown
+      self$fromJSON(input)
+
+      # no error thrown, restore old values
+      self$actual_instance <- actual_instance_bak
+      self$actual_type <- actual_type_bak
+    },
+    #' Returns the string representation of the instance.
+    #'
+    #' @description
+    #' Returns the string representation of the instance.
+    #'
+    #' @return The string representation of the instance.
+    #' @export
+    toString = function() {
+      jsoncontent <- c(
+        sprintf('"actual_instance": %s', if (is.null(self$actual_instance)) NULL else self$actual_instance$toJSONString()),
+        sprintf('"actual_type": "%s"', self$actual_type),
+        sprintf('"one_of": "%s"', paste(unlist(self$one_of), collapse = ", "))
+      )
+      jsoncontent <- paste(jsoncontent, collapse = ",")
+      as.character(jsonlite::prettify(paste("{", jsoncontent, "}", sep = "")))
+    }
+  )
+)
diff --git a/samples/client/petstore/R/R/pig.R b/samples/client/petstore/R/R/pig.R
index dbe013e4168..9cdb7a38770 100644
--- a/samples/client/petstore/R/R/pig.R
+++ b/samples/client/petstore/R/R/pig.R
@@ -22,7 +22,7 @@ Pig <- R6::R6Class(
     actual_instance = NULL,
     #' @field actual_type the type of the object stored in this instance.
     actual_type = NULL,
-    #' @field one_of  a list of object types defined in the oneOf schema.
+    #' @field one_of  a list of types defined in the oneOf schema.
     one_of = list("BasquePig", "DanishPig"),
     #' Initialize a new Pig.
     #'
diff --git a/samples/client/petstore/R/README.md b/samples/client/petstore/R/README.md
index 79814bf139a..31a85b19511 100644
--- a/samples/client/petstore/R/README.md
+++ b/samples/client/petstore/R/README.md
@@ -92,6 +92,7 @@ Class | Method | HTTP request | Description
  - [AllofTagApiResponse](docs/AllofTagApiResponse.md)
  - [Animal](docs/Animal.md)
  - [AnyOfPig](docs/AnyOfPig.md)
+ - [AnyOfPrimitiveTypeTest](docs/AnyOfPrimitiveTypeTest.md)
  - [BasquePig](docs/BasquePig.md)
  - [Cat](docs/Cat.md)
  - [CatAllOf](docs/CatAllOf.md)
@@ -101,6 +102,7 @@ Class | Method | HTTP request | Description
  - [DogAllOf](docs/DogAllOf.md)
  - [ModelApiResponse](docs/ModelApiResponse.md)
  - [NestedOneOf](docs/NestedOneOf.md)
+ - [OneOfPrimitiveTypeTest](docs/OneOfPrimitiveTypeTest.md)
  - [Order](docs/Order.md)
  - [Pet](docs/Pet.md)
  - [Pig](docs/Pig.md)
diff --git a/samples/client/petstore/R/docs/AnyOfPrimitiveTypeTest.md b/samples/client/petstore/R/docs/AnyOfPrimitiveTypeTest.md
new file mode 100644
index 00000000000..0d8ba0e63b1
--- /dev/null
+++ b/samples/client/petstore/R/docs/AnyOfPrimitiveTypeTest.md
@@ -0,0 +1,8 @@
+# petstore::AnyOfPrimitiveTypeTest
+
+
+## Properties
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+
+
diff --git a/samples/client/petstore/R/docs/OneOfPrimitiveTypeTest.md b/samples/client/petstore/R/docs/OneOfPrimitiveTypeTest.md
new file mode 100644
index 00000000000..82cf318431f
--- /dev/null
+++ b/samples/client/petstore/R/docs/OneOfPrimitiveTypeTest.md
@@ -0,0 +1,8 @@
+# petstore::OneOfPrimitiveTypeTest
+
+
+## Properties
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+
+
diff --git a/samples/client/petstore/R/tests/testthat/test_any_of_primitive_type_test.R b/samples/client/petstore/R/tests/testthat/test_any_of_primitive_type_test.R
new file mode 100644
index 00000000000..0679cfaf443
--- /dev/null
+++ b/samples/client/petstore/R/tests/testthat/test_any_of_primitive_type_test.R
@@ -0,0 +1,4 @@
+# Automatically generated by openapi-generator (https://openapi-generator.tech)
+# Please update as you see appropriate
+
+context("Test AnyOfPrimitiveTypeTest")
diff --git a/samples/client/petstore/R/tests/testthat/test_one_of_primitive_type_test.R b/samples/client/petstore/R/tests/testthat/test_one_of_primitive_type_test.R
new file mode 100644
index 00000000000..f9e7158359b
--- /dev/null
+++ b/samples/client/petstore/R/tests/testthat/test_one_of_primitive_type_test.R
@@ -0,0 +1,4 @@
+# Automatically generated by openapi-generator (https://openapi-generator.tech)
+# Please update as you see appropriate
+
+context("Test OneOfPrimitiveTypeTest")