[swift5] Add support for oneOfs (#8714)

* [swift5] Add support for oneOfs

* Generate a sample Swift project with oneOfs

* Update Swift Samples

bin/configs/swift5-oneOf.yaml

@@ -0,0 +1,10 @@
+generatorName: swift5
+outputDir: samples/client/petstore/swift5/oneOf
+inputSpec: modules/openapi-generator/src/test/resources/3_0/oneOf.yaml
+templateDir: modules/openapi-generator/src/main/resources/swift5
+generateAliasAsModel: true
+additionalProperties:
+  podAuthors: ""
+  podSummary: PetstoreClient
+  projectName: PetstoreClient
+  podHomepage: https://github.com/openapitools/openapi-generator

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/Swift5ClientCodegen.java

@@ -95,6 +95,7 @@ public class Swift5ClientCodegen extends DefaultCodegen implements CodegenConfig
      */
     public Swift5ClientCodegen() {
         super();
+        this.useOneOfInterfaces = true;
 
         generatorMetadata = GeneratorMetadata.newBuilder(generatorMetadata)
                 .stability(Stability.BETA)

modules/openapi-generator/src/main/resources/swift5/model.mustache

@@ -12,7 +12,8 @@ import AnyCodable
 {{#description}}
 
 /** {{description}} */{{/description}}{{#isDeprecated}}
-@available(*, deprecated, message: "This schema is deprecated."){{/isDeprecated}}{{#isArray}}
+@available(*, deprecated, message: "This schema is deprecated."){{/isDeprecated}}{{#vendorExtensions.x-is-one-of-interface}}
+{{> modelOneOf}}{{/vendorExtensions.x-is-one-of-interface}}{{^vendorExtensions.x-is-one-of-interface}}{{#isArray}}
 {{> modelArray}}{{/isArray}}{{^isArray}}{{#isEnum}}
 {{> modelEnum}}{{/isEnum}}{{^isEnum}}
-{{> modelObject}}{{/isEnum}}{{/isArray}}{{/model}}{{/models}}
+{{> modelObject}}{{/isEnum}}{{/isArray}}{{/vendorExtensions.x-is-one-of-interface}}{{/model}}{{/models}}

modules/openapi-generator/src/main/resources/swift5/modelOneOf.mustache

@@ -0,0 +1,31 @@
+public enum {{classname}}: Codable {
+    {{#oneOf}}
+    case type{{.}}({{.}})
+    {{/oneOf}}
+
+    public func encode(to encoder: Encoder) throws {
+        var container = encoder.singleValueContainer()
+        switch self {
+        {{#oneOf}}
+        case .type{{.}}(let value):
+            try container.encode(value)
+        {{/oneOf}}
+        }
+    }
+
+    public init(from decoder: Decoder) throws {
+        let container = try decoder.singleValueContainer()
+        {{#oneOf}}
+        {{#-first}}
+        if let value = try? container.decode({{.}}.self) {
+        {{/-first}}
+        {{^-first}}
+        } else if let value = try? container.decode({{.}}.self) {
+        {{/-first}}
+            self = .type{{.}}(value)
+        {{/oneOf}}
+        } else {
+            throw DecodingError.typeMismatch(Self.Type.self, .init(codingPath: decoder.codingPath, debugDescription: "Unable to decode instance of {{classname}}"))
+        }
+    }
+}

samples/client/petstore/swift5/oneOf/.gitignore

@@ -0,0 +1,63 @@
+# Xcode
+#
+# gitignore contributors: remember to update Global/Xcode.gitignore, Objective-C.gitignore & Swift.gitignore
+
+## Build generated
+build/
+DerivedData
+
+## Various settings
+*.pbxuser
+!default.pbxuser
+*.mode1v3
+!default.mode1v3
+*.mode2v3
+!default.mode2v3
+*.perspectivev3
+!default.perspectivev3
+xcuserdata
+
+## Other
+*.xccheckout
+*.moved-aside
+*.xcuserstate
+*.xcscmblueprint
+
+## Obj-C/Swift specific
+*.hmap
+*.ipa
+
+## Playgrounds
+timeline.xctimeline
+playground.xcworkspace
+
+# Swift Package Manager
+#
+# Add this line if you want to avoid checking in source code from Swift Package Manager dependencies.
+# Packages/
+.build/
+
+# CocoaPods
+#
+# We recommend against adding the Pods directory to your .gitignore. However
+# you should judge for yourself, the pros and cons are mentioned at:
+# https://guides.cocoapods.org/using/using-cocoapods.html#should-i-check-the-pods-directory-into-source-control
+#
+# Pods/
+
+# Carthage
+#
+# Add this line if you want to avoid checking in source code from Carthage dependencies.
+# Carthage/Checkouts
+
+Carthage/Build
+
+# fastlane
+#
+# It is recommended to not store the screenshots in the git repo. Instead, use fastlane to re-generate the 
+# screenshots whenever they are needed.
+# For more information about the recommended setup visit:
+# https://github.com/fastlane/fastlane/blob/master/docs/Gitignore.md
+
+fastlane/report.xml
+fastlane/screenshots

samples/client/petstore/swift5/oneOf/.openapi-generator-ignore

@@ -0,0 +1,23 @@
+# OpenAPI Generator Ignore
+# Generated by openapi-generator https://github.com/openapitools/openapi-generator
+
+# Use this file to prevent files from being overwritten by the generator.
+# The patterns follow closely to .gitignore or .dockerignore.
+
+# As an example, the C# client generator defines ApiClient.cs.
+# You can make changes and tell OpenAPI Generator to ignore just this file by uncommenting the following line:
+#ApiClient.cs
+
+# You can match any string of characters against a directory, file or extension with a single asterisk (*):
+#foo/*/qux
+# The above matches foo/bar/qux and foo/baz/qux, but not foo/bar/baz/qux
+
+# You can recursively match patterns against a directory, file or extension with a double asterisk (**):
+#foo/**/qux
+# This matches foo/bar/qux, foo/baz/qux, and foo/bar/baz/qux
+
+# You can also negate patterns with an exclamation (!).
+# For example, you can ignore all files in a docs folder with the file extension .md:
+#docs/*.md
+# Then explicitly reverse the ignore rule for a single file:
+#!docs/README.md

samples/client/petstore/swift5/oneOf/.openapi-generator/FILES

@@ -0,0 +1,26 @@
+.gitignore
+Cartfile
+Package.swift
+PetstoreClient.podspec
+PetstoreClient/Classes/OpenAPIs/APIHelper.swift
+PetstoreClient/Classes/OpenAPIs/APIs.swift
+PetstoreClient/Classes/OpenAPIs/APIs/DefaultAPI.swift
+PetstoreClient/Classes/OpenAPIs/CodableHelper.swift
+PetstoreClient/Classes/OpenAPIs/Configuration.swift
+PetstoreClient/Classes/OpenAPIs/Extensions.swift
+PetstoreClient/Classes/OpenAPIs/JSONDataEncoding.swift
+PetstoreClient/Classes/OpenAPIs/JSONEncodingHelper.swift
+PetstoreClient/Classes/OpenAPIs/Models.swift
+PetstoreClient/Classes/OpenAPIs/Models/Apple.swift
+PetstoreClient/Classes/OpenAPIs/Models/Banana.swift
+PetstoreClient/Classes/OpenAPIs/Models/Fruit.swift
+PetstoreClient/Classes/OpenAPIs/OpenISO8601DateFormatter.swift
+PetstoreClient/Classes/OpenAPIs/SynchronizedDictionary.swift
+PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
+README.md
+docs/Apple.md
+docs/Banana.md
+docs/DefaultAPI.md
+docs/Fruit.md
+git_push.sh
+project.yml

samples/client/petstore/swift5/oneOf/.openapi-generator/VERSION

@@ -0,0 +1 @@
+5.2.0-SNAPSHOT

samples/client/petstore/swift5/oneOf/Cartfile

@@ -0,0 +1,2 @@
+
+github "Flight-School/AnyCodable" ~> 0.4.0

samples/client/petstore/swift5/oneOf/Package.swift

@@ -0,0 +1,33 @@
+// swift-tools-version:5.1
+
+import PackageDescription
+
+let package = Package(
+    name: "PetstoreClient",
+    platforms: [
+        .iOS(.v9),
+        .macOS(.v10_11),
+        .tvOS(.v9),
+        .watchOS(.v3),
+    ],
+    products: [
+        // Products define the executables and libraries produced by a package, and make them visible to other packages.
+        .library(
+            name: "PetstoreClient",
+            targets: ["PetstoreClient"]
+        ),
+    ],
+    dependencies: [
+        // Dependencies declare other packages that this package depends on.
+        .package(url: "https://github.com/Flight-School/AnyCodable", .exact("0.4.0")),
+    ],
+    targets: [
+        // Targets are the basic building blocks of a package. A target can define a module or a test suite.
+        // Targets can depend on other targets in this package, and on products in packages which this package depends on.
+        .target(
+            name: "PetstoreClient",
+            dependencies: ["AnyCodable", ],
+            path: "PetstoreClient/Classes"
+        ),
+    ]
+)

samples/client/petstore/swift5/oneOf/PetstoreClient.podspec

@@ -0,0 +1,15 @@
+Pod::Spec.new do |s|
+  s.name = 'PetstoreClient'
+  s.ios.deployment_target = '9.0'
+  s.osx.deployment_target = '10.11'
+  s.tvos.deployment_target = '9.0'
+  s.watchos.deployment_target = '3.0'
+  s.version = '0.0.1'
+  s.source = { :git => 'git@github.com:OpenAPITools/openapi-generator.git', :tag => 'v0.0.1' }
+  s.authors = ''
+  s.license = 'Proprietary'
+  s.homepage = 'https://github.com/openapitools/openapi-generator'
+  s.summary = 'PetstoreClient'
+  s.source_files = 'PetstoreClient/Classes/**/*.swift'
+  s.dependency 'AnyCodable-FlightSchool', '~> 0.4.0'
+end

samples/client/petstore/swift5/oneOf/PetstoreClient/Classes/OpenAPIs/APIHelper.swift

@@ -0,0 +1,71 @@
+// APIHelper.swift
+//
+// Generated by openapi-generator
+// https://openapi-generator.tech
+//
+
+import Foundation
+
+public struct APIHelper {
+    public static func rejectNil(_ source: [String: Any?]) -> [String: Any]? {
+        let destination = source.reduce(into: [String: Any]()) { result, item in
+            if let value = item.value {
+                result[item.key] = value
+            }
+        }
+
+        if destination.isEmpty {
+            return nil
+        }
+        return destination
+    }
+
+    public static func rejectNilHeaders(_ source: [String: Any?]) -> [String: String] {
+        return source.reduce(into: [String: String]()) { result, item in
+            if let collection = item.value as? [Any?] {
+                result[item.key] = collection.filter { $0 != nil }.map { "\($0!)" }.joined(separator: ",")
+            } else if let value: Any = item.value {
+                result[item.key] = "\(value)"
+            }
+        }
+    }
+
+    public static func convertBoolToString(_ source: [String: Any]?) -> [String: Any]? {
+        guard let source = source else {
+            return nil
+        }
+
+        return source.reduce(into: [String: Any]()) { result, item in
+            switch item.value {
+            case let x as Bool:
+                result[item.key] = x.description
+            default:
+                result[item.key] = item.value
+            }
+        }
+    }
+
+    public static func mapValueToPathItem(_ source: Any) -> Any {
+        if let collection = source as? [Any?] {
+            return collection.filter { $0 != nil }.map { "\($0!)" }.joined(separator: ",")
+        }
+        return source
+    }
+
+    public static func mapValuesToQueryItems(_ source: [String: Any?]) -> [URLQueryItem]? {
+        let destination = source.filter { $0.value != nil }.reduce(into: [URLQueryItem]()) { result, item in
+            if let collection = item.value as? [Any?] {
+                collection.filter { $0 != nil }.map { "\($0!)" }.forEach { value in
+                    result.append(URLQueryItem(name: item.key, value: value))
+                }
+            } else if let value = item.value {
+                result.append(URLQueryItem(name: item.key, value: "\(value)"))
+            }
+        }
+
+        if destination.isEmpty {
+            return nil
+        }
+        return destination
+    }
+}

samples/client/petstore/swift5/oneOf/PetstoreClient/Classes/OpenAPIs/APIs.swift

@@ -0,0 +1,62 @@
+// APIs.swift
+//
+// Generated by openapi-generator
+// https://openapi-generator.tech
+//
+
+import Foundation
+
+open class PetstoreClientAPI {
+    public static var basePath = "http://localhost"
+    public static var credential: URLCredential?
+    public static var customHeaders: [String: String] = [:]
+    public static var requestBuilderFactory: RequestBuilderFactory = URLSessionRequestBuilderFactory()
+    public static var apiResponseQueue: DispatchQueue = .main
+}
+
+open class RequestBuilder<T> {
+    var credential: URLCredential?
+    var headers: [String: String]
+    public let parameters: [String: Any]?
+    public let method: String
+    public let URLString: String
+
+    /// Optional block to obtain a reference to the request's progress instance when available.
+    /// With the URLSession http client the request's progress only works on iOS 11.0, macOS 10.13, macCatalyst 13.0, tvOS 11.0, watchOS 4.0.
+    /// If you need to get the request's progress in older OS versions, please use Alamofire http client.
+    public var onProgressReady: ((Progress) -> Void)?
+
+    required public init(method: String, URLString: String, parameters: [String: Any]?, headers: [String: String] = [:]) {
+        self.method = method
+        self.URLString = URLString
+        self.parameters = parameters
+        self.headers = headers
+
+        addHeaders(PetstoreClientAPI.customHeaders)
+    }
+
+    open func addHeaders(_ aHeaders: [String: String]) {
+        for (header, value) in aHeaders {
+            headers[header] = value
+        }
+    }
+
+    open func execute(_ apiResponseQueue: DispatchQueue = PetstoreClientAPI.apiResponseQueue, _ completion: @escaping (_ result: Swift.Result<Response<T>, Error>) -> Void) { }
+
+    public func addHeader(name: String, value: String) -> Self {
+        if !value.isEmpty {
+            headers[name] = value
+        }
+        return self
+    }
+
+    open func addCredential() -> Self {
+        credential = PetstoreClientAPI.credential
+        return self
+    }
+}
+
+public protocol RequestBuilderFactory {
+    func getNonDecodableBuilder<T>() -> RequestBuilder<T>.Type
+    func getBuilder<T: Decodable>() -> RequestBuilder<T>.Type
+}

samples/client/petstore/swift5/oneOf/PetstoreClient/Classes/OpenAPIs/APIs/DefaultAPI.swift

@@ -0,0 +1,49 @@
+//
+// DefaultAPI.swift
+//
+// Generated by openapi-generator
+// https://openapi-generator.tech
+//
+
+import Foundation
+
+open class DefaultAPI {
+    /**
+
+     - parameter apiResponseQueue: The queue on which api response is dispatched.
+     - parameter completion: completion handler to receive the data and the error objects
+     */
+    open class func rootGet(apiResponseQueue: DispatchQueue = PetstoreClientAPI.apiResponseQueue, completion: @escaping ((_ data: Fruit?, _ error: Error?) -> Void)) {
+        rootGetWithRequestBuilder().execute(apiResponseQueue) { result -> Void in
+            switch result {
+            case let .success(response):
+                completion(response.body, nil)
+            case let .failure(error):
+                completion(nil, error)
+            }
+        }
+    }
+
+    /**
+     - GET /
+     - returns: RequestBuilder<Fruit> 
+     */
+    open class func rootGetWithRequestBuilder() -> RequestBuilder<Fruit> {
+        let path = "/"
+        let URLString = PetstoreClientAPI.basePath + path
+        let parameters: [String: Any]? = nil
+
+        let urlComponents = URLComponents(string: URLString)
+
+        let nillableHeaders: [String: Any?] = [
+            :
+        ]
+
+        let headerParameters = APIHelper.rejectNilHeaders(nillableHeaders)
+
+        let requestBuilder: RequestBuilder<Fruit>.Type = PetstoreClientAPI.requestBuilderFactory.getBuilder()
+
+        return requestBuilder.init(method: "GET", URLString: (urlComponents?.string ?? URLString), parameters: parameters, headers: headerParameters)
+    }
+
+}

samples/client/petstore/swift5/oneOf/PetstoreClient/Classes/OpenAPIs/CodableHelper.swift

@@ -0,0 +1,49 @@
+//
+// CodableHelper.swift
+//
+// Generated by openapi-generator
+// https://openapi-generator.tech
+//
+
+import Foundation
+
+open class CodableHelper {
+    private static var customDateFormatter: DateFormatter?
+    private static var defaultDateFormatter: DateFormatter = OpenISO8601DateFormatter()
+
+    private static var customJSONDecoder: JSONDecoder?
+    private static var defaultJSONDecoder: JSONDecoder = {
+        let decoder = JSONDecoder()
+        decoder.dateDecodingStrategy = .formatted(CodableHelper.dateFormatter)
+        return decoder
+    }()
+
+    private static var customJSONEncoder: JSONEncoder?
+    private static var defaultJSONEncoder: JSONEncoder = {
+        let encoder = JSONEncoder()
+        encoder.dateEncodingStrategy = .formatted(CodableHelper.dateFormatter)
+        encoder.outputFormatting = .prettyPrinted
+        return encoder
+    }()
+
+    public static var dateFormatter: DateFormatter {
+        get { return customDateFormatter ?? defaultDateFormatter }
+        set { customDateFormatter = newValue }
+    }
+    public static var jsonDecoder: JSONDecoder {
+        get { return customJSONDecoder ?? defaultJSONDecoder }
+        set { customJSONDecoder = newValue }
+    }
+    public static var jsonEncoder: JSONEncoder {
+        get { return customJSONEncoder ?? defaultJSONEncoder }
+        set { customJSONEncoder = newValue }
+    }
+
+    open class func decode<T>(_ type: T.Type, from data: Data) -> Swift.Result<T, Error> where T: Decodable {
+        return Swift.Result { try jsonDecoder.decode(type, from: data) }
+    }
+
+    open class func encode<T>(_ value: T) -> Swift.Result<Data, Error> where T: Encodable {
+        return Swift.Result { try jsonEncoder.encode(value) }
+    }
+}

samples/client/petstore/swift5/oneOf/PetstoreClient/Classes/OpenAPIs/Configuration.swift

@@ -0,0 +1,14 @@
+// Configuration.swift
+//
+// Generated by openapi-generator
+// https://openapi-generator.tech
+//
+
+import Foundation
+
+open class Configuration {
+    // This value is used to configure the date formatter that is used to serialize dates into JSON format.
+    // You must set it prior to encoding any dates, and it will only be read once.
+    @available(*, unavailable, message: "To set a different date format, use CodableHelper.dateFormatter instead.")
+    public static var dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSZZZZZ"
+}

samples/client/petstore/swift5/oneOf/PetstoreClient/Classes/OpenAPIs/Extensions.swift

@@ -0,0 +1,231 @@
+// Extensions.swift
+//
+// Generated by openapi-generator
+// https://openapi-generator.tech
+//
+
+import Foundation
+#if canImport(AnyCodable)
+import AnyCodable
+#endif
+
+extension Bool: JSONEncodable {
+    func encodeToJSON() -> Any { return self as Any }
+}
+
+extension Float: JSONEncodable {
+    func encodeToJSON() -> Any { return self as Any }
+}
+
+extension Int: JSONEncodable {
+    func encodeToJSON() -> Any { return self as Any }
+}
+
+extension Int32: JSONEncodable {
+    func encodeToJSON() -> Any { return NSNumber(value: self as Int32) }
+}
+
+extension Int64: JSONEncodable {
+    func encodeToJSON() -> Any { return NSNumber(value: self as Int64) }
+}
+
+extension Double: JSONEncodable {
+    func encodeToJSON() -> Any { return self as Any }
+}
+
+extension String: JSONEncodable {
+    func encodeToJSON() -> Any { return self as Any }
+}
+
+extension RawRepresentable where RawValue: JSONEncodable {
+    func encodeToJSON() -> Any { return self.rawValue as Any }
+}
+
+private func encodeIfPossible<T>(_ object: T) -> Any {
+    if let encodableObject = object as? JSONEncodable {
+        return encodableObject.encodeToJSON()
+    } else {
+        return object as Any
+    }
+}
+
+extension Array: JSONEncodable {
+    func encodeToJSON() -> Any {
+        return self.map(encodeIfPossible)
+    }
+}
+
+extension Set: JSONEncodable {
+    func encodeToJSON() -> Any {
+        return Array(self).encodeToJSON()
+    }
+}
+
+extension Dictionary: JSONEncodable {
+    func encodeToJSON() -> Any {
+        var dictionary = [AnyHashable: Any]()
+        for (key, value) in self {
+            dictionary[key] = encodeIfPossible(value)
+        }
+        return dictionary as Any
+    }
+}
+
+extension Data: JSONEncodable {
+    func encodeToJSON() -> Any {
+        return self.base64EncodedString(options: Data.Base64EncodingOptions())
+    }
+}
+
+extension Date: JSONEncodable {
+    func encodeToJSON() -> Any {
+        return CodableHelper.dateFormatter.string(from: self) as Any
+    }
+}
+
+extension URL: JSONEncodable {
+    func encodeToJSON() -> Any {
+        return self
+    }
+}
+
+extension UUID: JSONEncodable {
+    func encodeToJSON() -> Any {
+        return self.uuidString
+    }
+}
+
+extension String: CodingKey {
+
+    public var stringValue: String {
+        return self
+    }
+
+    public init?(stringValue: String) {
+        self.init(stringLiteral: stringValue)
+    }
+
+    public var intValue: Int? {
+        return nil
+    }
+
+    public init?(intValue: Int) {
+        return nil
+    }
+
+}
+
+extension KeyedEncodingContainerProtocol {
+
+    public mutating func encodeArray<T>(_ values: [T], forKey key: Self.Key) throws where T: Encodable {
+        var arrayContainer = nestedUnkeyedContainer(forKey: key)
+        try arrayContainer.encode(contentsOf: values)
+    }
+
+    public mutating func encodeArrayIfPresent<T>(_ values: [T]?, forKey key: Self.Key) throws where T: Encodable {
+        if let values = values {
+            try encodeArray(values, forKey: key)
+        }
+    }
+
+    public mutating func encodeMap<T>(_ pairs: [Self.Key: T]) throws where T: Encodable {
+        for (key, value) in pairs {
+            try encode(value, forKey: key)
+        }
+    }
+
+    public mutating func encodeMapIfPresent<T>(_ pairs: [Self.Key: T]?) throws where T: Encodable {
+        if let pairs = pairs {
+            try encodeMap(pairs)
+        }
+    }
+
+}
+
+extension KeyedDecodingContainerProtocol {
+
+    public func decodeArray<T>(_ type: T.Type, forKey key: Self.Key) throws -> [T] where T: Decodable {
+        var tmpArray = [T]()
+
+        var nestedContainer = try nestedUnkeyedContainer(forKey: key)
+        while !nestedContainer.isAtEnd {
+            let arrayValue = try nestedContainer.decode(T.self)
+            tmpArray.append(arrayValue)
+        }
+
+        return tmpArray
+    }
+
+    public func decodeArrayIfPresent<T>(_ type: T.Type, forKey key: Self.Key) throws -> [T]? where T: Decodable {
+        var tmpArray: [T]?
+
+        if contains(key) {
+            tmpArray = try decodeArray(T.self, forKey: key)
+        }
+
+        return tmpArray
+    }
+
+    public func decodeMap<T>(_ type: T.Type, excludedKeys: Set<Self.Key>) throws -> [Self.Key: T] where T: Decodable {
+        var map: [Self.Key: T] = [:]
+
+        for key in allKeys {
+            if !excludedKeys.contains(key) {
+                let value = try decode(T.self, forKey: key)
+                map[key] = value
+            }
+        }
+
+        return map
+    }
+
+}
+
+extension HTTPURLResponse {
+    var isStatusCodeSuccessful: Bool {
+        return Array(200 ..< 300).contains(statusCode)
+    }
+}
+
+#if canImport(AnyCodable)
+extension AnyCodable: Hashable {
+    public func hash(into hasher: inout Hasher) {
+        switch value {
+        case let value as Bool:
+            hasher.combine(value)
+        case let value as Int:
+            hasher.combine(value)
+        case let value as Int8:
+            hasher.combine(value)
+        case let value as Int16:
+            hasher.combine(value)
+        case let value as Int32:
+            hasher.combine(value)
+        case let value as Int64:
+            hasher.combine(value)
+        case let value as UInt:
+            hasher.combine(value)
+        case let value as UInt8:
+            hasher.combine(value)
+        case let value as UInt16:
+            hasher.combine(value)
+        case let value as UInt32:
+            hasher.combine(value)
+        case let value as UInt64:
+            hasher.combine(value)
+        case let value as Float:
+            hasher.combine(value)
+        case let value as Double:
+            hasher.combine(value)
+        case let value as String:
+            hasher.combine(value)
+        case let value as [String: AnyCodable]:
+            hasher.combine(value)
+        case let value as [AnyCodable]:
+            hasher.combine(value)
+        default:
+            hasher.combine(0)
+        }
+    }
+}
+#endif

samples/client/petstore/swift5/oneOf/PetstoreClient/Classes/OpenAPIs/JSONDataEncoding.swift

@@ -0,0 +1,53 @@
+//
+// JSONDataEncoding.swift
+//
+// Generated by openapi-generator
+// https://openapi-generator.tech
+//
+
+import Foundation
+
+public struct JSONDataEncoding {
+
+    // MARK: Properties
+
+    private static let jsonDataKey = "jsonData"
+
+    // MARK: Encoding
+
+    /// Creates a URL request by encoding parameters and applying them onto an existing request.
+    ///
+    /// - parameter urlRequest: The request to have parameters applied.
+    /// - parameter parameters: The parameters to apply. This should have a single key/value
+    ///                         pair with "jsonData" as the key and a Data object as the value.
+    ///
+    /// - throws: An `Error` if the encoding process encounters an error.
+    ///
+    /// - returns: The encoded request.
+    public func encode(_ urlRequest: URLRequest, with parameters: [String: Any]?) -> URLRequest {
+        var urlRequest = urlRequest
+
+        guard let jsonData = parameters?[JSONDataEncoding.jsonDataKey] as? Data, !jsonData.isEmpty else {
+            return urlRequest
+        }
+
+        if urlRequest.value(forHTTPHeaderField: "Content-Type") == nil {
+            urlRequest.setValue("application/json", forHTTPHeaderField: "Content-Type")
+        }
+
+        urlRequest.httpBody = jsonData
+
+        return urlRequest
+    }
+
+    public static func encodingParameters(jsonData: Data?) -> [String: Any]? {
+        var returnedParams: [String: Any]?
+        if let jsonData = jsonData, !jsonData.isEmpty {
+            var params: [String: Any] = [:]
+            params[jsonDataKey] = jsonData
+            returnedParams = params
+        }
+        return returnedParams
+    }
+
+}

samples/client/petstore/swift5/oneOf/PetstoreClient/Classes/OpenAPIs/JSONEncodingHelper.swift

@@ -0,0 +1,45 @@
+//
+// JSONEncodingHelper.swift
+//
+// Generated by openapi-generator
+// https://openapi-generator.tech
+//
+
+import Foundation
+
+open class JSONEncodingHelper {
+
+    open class func encodingParameters<T: Encodable>(forEncodableObject encodableObj: T?) -> [String: Any]? {
+        var params: [String: Any]?
+
+        // Encode the Encodable object
+        if let encodableObj = encodableObj {
+            let encodeResult = CodableHelper.encode(encodableObj)
+            do {
+                let data = try encodeResult.get()
+                params = JSONDataEncoding.encodingParameters(jsonData: data)
+            } catch {
+                print(error.localizedDescription)
+            }
+        }
+
+        return params
+    }
+
+    open class func encodingParameters(forEncodableObject encodableObj: Any?) -> [String: Any]? {
+        var params: [String: Any]?
+
+        if let encodableObj = encodableObj {
+            do {
+                let data = try JSONSerialization.data(withJSONObject: encodableObj, options: .prettyPrinted)
+                params = JSONDataEncoding.encodingParameters(jsonData: data)
+            } catch {
+                print(error.localizedDescription)
+                return nil
+            }
+        }
+
+        return params
+    }
+
+}

samples/client/petstore/swift5/oneOf/PetstoreClient/Classes/OpenAPIs/Models.swift

@@ -0,0 +1,54 @@
+// Models.swift
+//
+// Generated by openapi-generator
+// https://openapi-generator.tech
+//
+
+import Foundation
+
+protocol JSONEncodable {
+    func encodeToJSON() -> Any
+}
+
+public enum ErrorResponse: Error {
+    case error(Int, Data?, URLResponse?, Error)
+}
+
+public enum DownloadException: Error {
+    case responseDataMissing
+    case responseFailed
+    case requestMissing
+    case requestMissingPath
+    case requestMissingURL
+}
+
+public enum DecodableRequestBuilderError: Error {
+    case emptyDataResponse
+    case nilHTTPResponse
+    case unsuccessfulHTTPStatusCode
+    case jsonDecoding(DecodingError)
+    case generalError(Error)
+}
+
+open class Response<T> {
+    public let statusCode: Int
+    public let header: [String: String]
+    public let body: T?
+
+    public init(statusCode: Int, header: [String: String], body: T?) {
+        self.statusCode = statusCode
+        self.header = header
+        self.body = body
+    }
+
+    public convenience init(response: HTTPURLResponse, body: T?) {
+        let rawHeader = response.allHeaderFields
+        var header = [String: String]()
+        for (key, value) in rawHeader {
+            if let key = key.base as? String, let value = value as? String {
+                header[key] = value
+            }
+        }
+        self.init(statusCode: response.statusCode, header: header, body: body)
+    }
+}

samples/client/petstore/swift5/oneOf/PetstoreClient/Classes/OpenAPIs/Models/Apple.swift

@@ -0,0 +1,31 @@
+//
+// Apple.swift
+//
+// Generated by openapi-generator
+// https://openapi-generator.tech
+//
+
+import Foundation
+#if canImport(AnyCodable)
+import AnyCodable
+#endif
+
+public struct Apple: Codable, Hashable {
+
+    public var kind: String?
+
+    public init(kind: String? = nil) {
+        self.kind = kind
+    }
+
+    public enum CodingKeys: String, CodingKey, CaseIterable {
+        case kind
+    }
+
+    // Encodable protocol methods
+
+    public func encode(to encoder: Encoder) throws {
+        var container = encoder.container(keyedBy: CodingKeys.self)
+        try container.encodeIfPresent(kind, forKey: .kind)
+    }
+}

samples/client/petstore/swift5/oneOf/PetstoreClient/Classes/OpenAPIs/Models/Banana.swift

@@ -0,0 +1,31 @@
+//
+// Banana.swift
+//
+// Generated by openapi-generator
+// https://openapi-generator.tech
+//
+
+import Foundation
+#if canImport(AnyCodable)
+import AnyCodable
+#endif
+
+public struct Banana: Codable, Hashable {
+
+    public var count: Double?
+
+    public init(count: Double? = nil) {
+        self.count = count
+    }
+
+    public enum CodingKeys: String, CodingKey, CaseIterable {
+        case count
+    }
+
+    // Encodable protocol methods
+
+    public func encode(to encoder: Encoder) throws {
+        var container = encoder.container(keyedBy: CodingKeys.self)
+        try container.encodeIfPresent(count, forKey: .count)
+    }
+}

samples/client/petstore/swift5/oneOf/PetstoreClient/Classes/OpenAPIs/Models/Fruit.swift

@@ -0,0 +1,38 @@
+//
+// Fruit.swift
+//
+// Generated by openapi-generator
+// https://openapi-generator.tech
+//
+
+import Foundation
+#if canImport(AnyCodable)
+import AnyCodable
+#endif
+
+public enum Fruit: Codable {
+    case typeApple(Apple)
+    case typeBanana(Banana)
+
+    public func encode(to encoder: Encoder) throws {
+        var container = encoder.singleValueContainer()
+        switch self {
+        case .typeApple(let value):
+            try container.encode(value)
+        case .typeBanana(let value):
+            try container.encode(value)
+        }
+    }
+
+    public init(from decoder: Decoder) throws {
+        let container = try decoder.singleValueContainer()
+        if let value = try? container.decode(Apple.self) {
+            self = .typeApple(value)
+        } else if let value = try? container.decode(Banana.self) {
+            self = .typeBanana(value)
+        } else {
+            throw DecodingError.typeMismatch(Self.Type.self, .init(codingPath: decoder.codingPath, debugDescription: "Unable to decode instance of Fruit"))
+        }
+    }
+}
+

samples/client/petstore/swift5/oneOf/PetstoreClient/Classes/OpenAPIs/OpenISO8601DateFormatter.swift

@@ -0,0 +1,44 @@
+//
+// OpenISO8601DateFormatter.swift
+//
+// Generated by openapi-generator
+// https://openapi-generator.tech
+//
+
+import Foundation
+
+// https://stackoverflow.com/a/50281094/976628
+public class OpenISO8601DateFormatter: DateFormatter {
+    static let withoutSeconds: DateFormatter = {
+        let formatter = DateFormatter()
+        formatter.calendar = Calendar(identifier: .iso8601)
+        formatter.locale = Locale(identifier: "en_US_POSIX")
+        formatter.timeZone = TimeZone(secondsFromGMT: 0)
+        formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZZZZZ"
+        return formatter
+    }()
+
+    private func setup() {
+        calendar = Calendar(identifier: .iso8601)
+        locale = Locale(identifier: "en_US_POSIX")
+        timeZone = TimeZone(secondsFromGMT: 0)
+        dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSZZZZZ"
+    }
+
+    override init() {
+        super.init()
+        setup()
+    }
+
+    required init?(coder aDecoder: NSCoder) {
+        super.init(coder: aDecoder)
+        setup()
+    }
+
+    override public func date(from string: String) -> Date? {
+        if let result = super.date(from: string) {
+            return result
+        }
+        return OpenISO8601DateFormatter.withoutSeconds.date(from: string)
+    }
+}

samples/client/petstore/swift5/oneOf/PetstoreClient/Classes/OpenAPIs/SynchronizedDictionary.swift

@@ -0,0 +1,36 @@
+// SynchronizedDictionary.swift
+//
+// Generated by openapi-generator
+// https://openapi-generator.tech
+//
+
+import Foundation
+
+internal struct SynchronizedDictionary<K: Hashable, V> {
+
+    private var dictionary = [K: V]()
+    private let queue = DispatchQueue(
+        label: "SynchronizedDictionary",
+        qos: DispatchQoS.userInitiated,
+        attributes: [DispatchQueue.Attributes.concurrent],
+        autoreleaseFrequency: DispatchQueue.AutoreleaseFrequency.inherit,
+        target: nil
+    )
+
+    internal subscript(key: K) -> V? {
+        get {
+            var value: V?
+
+            queue.sync {
+                value = self.dictionary[key]
+            }
+
+            return value
+        }
+        set {
+            queue.sync(flags: DispatchWorkItemFlags.barrier) {
+                self.dictionary[key] = newValue
+            }
+        }
+    }
+}

samples/client/petstore/swift5/oneOf/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift

@@ -0,0 +1,606 @@
+// URLSessionImplementations.swift
+//
+// Generated by openapi-generator
+// https://openapi-generator.tech
+//
+
+import Foundation
+#if !os(macOS)
+import MobileCoreServices
+#endif
+
+class URLSessionRequestBuilderFactory: RequestBuilderFactory {
+    func getNonDecodableBuilder<T>() -> RequestBuilder<T>.Type {
+        return URLSessionRequestBuilder<T>.self
+    }
+
+    func getBuilder<T: Decodable>() -> RequestBuilder<T>.Type {
+        return URLSessionDecodableRequestBuilder<T>.self
+    }
+}
+
+// Store the URLSession to retain its reference
+private var urlSessionStore = SynchronizedDictionary<String, URLSession>()
+
+open class URLSessionRequestBuilder<T>: RequestBuilder<T> {
+
+    /**
+     May be assigned if you want to control the authentication challenges.
+     */
+    public var taskDidReceiveChallenge: ((URLSession, URLSessionTask, URLAuthenticationChallenge) -> (URLSession.AuthChallengeDisposition, URLCredential?))?
+
+    /**
+     May be assigned if you want to do any of those things:
+     - control the task completion
+     - intercept and handle errors like authorization
+     - retry the request.
+     */
+    @available(*, deprecated, message: "Please override execute() method to intercept and handle errors like authorization or retry the request. Check the Wiki for more info. https://github.com/OpenAPITools/openapi-generator/wiki/FAQ#how-do-i-implement-bearer-token-authentication-with-urlsession-on-the-swift-api-client")
+    public var taskCompletionShouldRetry: ((Data?, URLResponse?, Error?, @escaping (Bool) -> Void) -> Void)?
+
+    required public init(method: String, URLString: String, parameters: [String: Any]?, headers: [String: String] = [:]) {
+        super.init(method: method, URLString: URLString, parameters: parameters, headers: headers)
+    }
+
+    /**
+     May be overridden by a subclass if you want to control the URLSession
+     configuration.
+     */
+    open func createURLSession() -> URLSession {
+        let configuration = URLSessionConfiguration.default
+        configuration.httpAdditionalHeaders = buildHeaders()
+        let sessionDelegate = SessionDelegate()
+        sessionDelegate.credential = credential
+        sessionDelegate.taskDidReceiveChallenge = taskDidReceiveChallenge
+        return URLSession(configuration: configuration, delegate: sessionDelegate, delegateQueue: nil)
+    }
+
+    /**
+     May be overridden by a subclass if you want to control the Content-Type
+     that is given to an uploaded form part.
+
+     Return nil to use the default behavior (inferring the Content-Type from
+     the file extension).  Return the desired Content-Type otherwise.
+     */
+    open func contentTypeForFormPart(fileURL: URL) -> String? {
+        return nil
+    }
+
+    /**
+     May be overridden by a subclass if you want to control the URLRequest
+     configuration (e.g. to override the cache policy).
+     */
+    open func createURLRequest(urlSession: URLSession, method: HTTPMethod, encoding: ParameterEncoding, headers: [String: String]) throws -> URLRequest {
+
+        guard let url = URL(string: URLString) else {
+            throw DownloadException.requestMissingURL
+        }
+
+        var originalRequest = URLRequest(url: url)
+
+        originalRequest.httpMethod = method.rawValue
+
+        headers.forEach { key, value in
+            originalRequest.setValue(value, forHTTPHeaderField: key)
+        }
+
+        buildHeaders().forEach { key, value in
+            originalRequest.setValue(value, forHTTPHeaderField: key)
+        }
+
+        let modifiedRequest = try encoding.encode(originalRequest, with: parameters)
+
+        return modifiedRequest
+    }
+
+    override open func execute(_ apiResponseQueue: DispatchQueue = PetstoreClientAPI.apiResponseQueue, _ completion: @escaping (_ result: Swift.Result<Response<T>, Error>) -> Void) {
+        let urlSessionId = UUID().uuidString
+        // Create a new manager for each request to customize its request header
+        let urlSession = createURLSession()
+        urlSessionStore[urlSessionId] = urlSession
+
+        guard let xMethod = HTTPMethod(rawValue: method) else {
+            fatalError("Unsuported Http method - \(method)")
+        }
+
+        let encoding: ParameterEncoding
+
+        switch xMethod {
+        case .get, .head:
+            encoding = URLEncoding()
+
+        case .options, .post, .put, .patch, .delete, .trace, .connect:
+            let contentType = headers["Content-Type"] ?? "application/json"
+
+            if contentType == "application/json" {
+                encoding = JSONDataEncoding()
+            } else if contentType == "multipart/form-data" {
+                encoding = FormDataEncoding(contentTypeForFormPart: contentTypeForFormPart(fileURL:))
+            } else if contentType == "application/x-www-form-urlencoded" {
+                encoding = FormURLEncoding()
+            } else {
+                fatalError("Unsuported Media Type - \(contentType)")
+            }
+        }
+
+        let cleanupRequest = {
+            urlSessionStore[urlSessionId]?.finishTasksAndInvalidate()
+            urlSessionStore[urlSessionId] = nil
+        }
+
+        do {
+            let request = try createURLRequest(urlSession: urlSession, method: xMethod, encoding: encoding, headers: headers)
+
+            let dataTask = urlSession.dataTask(with: request) { data, response, error in
+
+                if let taskCompletionShouldRetry = self.taskCompletionShouldRetry {
+
+                    taskCompletionShouldRetry(data, response, error) { shouldRetry in
+
+                        if shouldRetry {
+                            cleanupRequest()
+                            self.execute(apiResponseQueue, completion)
+                        } else {
+                            apiResponseQueue.async {
+                                self.processRequestResponse(urlRequest: request, data: data, response: response, error: error, completion: completion)
+                                cleanupRequest()
+                            }
+                        }
+                    }
+                } else {
+                    apiResponseQueue.async {
+                        self.processRequestResponse(urlRequest: request, data: data, response: response, error: error, completion: completion)
+                        cleanupRequest()
+                    }
+                }
+            }
+
+            if #available(iOS 11.0, macOS 10.13, macCatalyst 13.0, tvOS 11.0, watchOS 4.0, *) {
+                onProgressReady?(dataTask.progress)
+            }
+
+            dataTask.resume()
+
+        } catch {
+            apiResponseQueue.async {
+                cleanupRequest()
+                completion(.failure(ErrorResponse.error(415, nil, nil, error)))
+            }
+        }
+    }
+
+    fileprivate func processRequestResponse(urlRequest: URLRequest, data: Data?, response: URLResponse?, error: Error?, completion: @escaping (_ result: Swift.Result<Response<T>, Error>) -> Void) {
+
+        if let error = error {
+            completion(.failure(ErrorResponse.error(-1, data, response, error)))
+            return
+        }
+
+        guard let httpResponse = response as? HTTPURLResponse else {
+            completion(.failure(ErrorResponse.error(-2, data, response, DecodableRequestBuilderError.nilHTTPResponse)))
+            return
+        }
+
+        guard httpResponse.isStatusCodeSuccessful else {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, response, DecodableRequestBuilderError.unsuccessfulHTTPStatusCode)))
+            return
+        }
+
+        switch T.self {
+        case is String.Type:
+
+            let body = data.flatMap { String(data: $0, encoding: .utf8) } ?? ""
+
+            completion(.success(Response<T>(response: httpResponse, body: body as? T)))
+
+        case is URL.Type:
+            do {
+
+                guard error == nil else {
+                    throw DownloadException.responseFailed
+                }
+
+                guard let data = data else {
+                    throw DownloadException.responseDataMissing
+                }
+
+                let fileManager = FileManager.default
+                let documentsDirectory = fileManager.urls(for: .documentDirectory, in: .userDomainMask)[0]
+                let requestURL = try getURL(from: urlRequest)
+
+                var requestPath = try getPath(from: requestURL)
+
+                if let headerFileName = getFileName(fromContentDisposition: httpResponse.allHeaderFields["Content-Disposition"] as? String) {
+                    requestPath = requestPath.appending("/\(headerFileName)")
+                }
+
+                let filePath = documentsDirectory.appendingPathComponent(requestPath)
+                let directoryPath = filePath.deletingLastPathComponent().path
+
+                try fileManager.createDirectory(atPath: directoryPath, withIntermediateDirectories: true, attributes: nil)
+                try data.write(to: filePath, options: .atomic)
+
+                completion(.success(Response(response: httpResponse, body: filePath as? T)))
+
+            } catch let requestParserError as DownloadException {
+                completion(.failure(ErrorResponse.error(400, data, response, requestParserError)))
+            } catch {
+                completion(.failure(ErrorResponse.error(400, data, response, error)))
+            }
+
+        case is Void.Type:
+
+            completion(.success(Response(response: httpResponse, body: nil)))
+
+        default:
+
+            completion(.success(Response(response: httpResponse, body: data as? T)))
+        }
+
+    }
+
+    open func buildHeaders() -> [String: String] {
+        var httpHeaders: [String: String] = [:]
+        for (key, value) in headers {
+            httpHeaders[key] = value
+        }
+        for (key, value) in PetstoreClientAPI.customHeaders {
+            httpHeaders[key] = value
+        }
+        return httpHeaders
+    }
+
+    fileprivate func getFileName(fromContentDisposition contentDisposition: String?) -> String? {
+
+        guard let contentDisposition = contentDisposition else {
+            return nil
+        }
+
+        let items = contentDisposition.components(separatedBy: ";")
+
+        var filename: String?
+
+        for contentItem in items {
+
+            let filenameKey = "filename="
+            guard let range = contentItem.range(of: filenameKey) else {
+                break
+            }
+
+            filename = contentItem
+            return filename?
+                .replacingCharacters(in: range, with: "")
+                .replacingOccurrences(of: "\"", with: "")
+                .trimmingCharacters(in: .whitespacesAndNewlines)
+        }
+
+        return filename
+
+    }
+
+    fileprivate func getPath(from url: URL) throws -> String {
+
+        guard var path = URLComponents(url: url, resolvingAgainstBaseURL: true)?.path else {
+            throw DownloadException.requestMissingPath
+        }
+
+        if path.hasPrefix("/") {
+            path.remove(at: path.startIndex)
+        }
+
+        return path
+
+    }
+
+    fileprivate func getURL(from urlRequest: URLRequest) throws -> URL {
+
+        guard let url = urlRequest.url else {
+            throw DownloadException.requestMissingURL
+        }
+
+        return url
+    }
+
+}
+
+open class URLSessionDecodableRequestBuilder<T: Decodable>: URLSessionRequestBuilder<T> {
+    override fileprivate func processRequestResponse(urlRequest: URLRequest, data: Data?, response: URLResponse?, error: Error?, completion: @escaping (_ result: Swift.Result<Response<T>, Error>) -> Void) {
+
+        if let error = error {
+            completion(.failure(ErrorResponse.error(-1, data, response, error)))
+            return
+        }
+
+        guard let httpResponse = response as? HTTPURLResponse else {
+            completion(.failure(ErrorResponse.error(-2, data, response, DecodableRequestBuilderError.nilHTTPResponse)))
+            return
+        }
+
+        guard httpResponse.isStatusCodeSuccessful else {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, response, DecodableRequestBuilderError.unsuccessfulHTTPStatusCode)))
+            return
+        }
+
+        switch T.self {
+        case is String.Type:
+
+            let body = data.flatMap { String(data: $0, encoding: .utf8) } ?? ""
+
+            completion(.success(Response<T>(response: httpResponse, body: body as? T)))
+
+        case is Void.Type:
+
+            completion(.success(Response(response: httpResponse, body: nil)))
+
+        case is Data.Type:
+
+            completion(.success(Response(response: httpResponse, body: data as? T)))
+
+        default:
+
+            guard let data = data, !data.isEmpty else {
+                completion(.failure(ErrorResponse.error(httpResponse.statusCode, nil, response, DecodableRequestBuilderError.emptyDataResponse)))
+                return
+            }
+
+            let decodeResult = CodableHelper.decode(T.self, from: data)
+
+            switch decodeResult {
+            case let .success(decodableObj):
+                completion(.success(Response(response: httpResponse, body: decodableObj)))
+            case let .failure(error):
+                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, response, error)))
+            }
+        }
+    }
+}
+
+private class SessionDelegate: NSObject, URLSessionDelegate, URLSessionDataDelegate {
+
+    var credential: URLCredential?
+
+    var taskDidReceiveChallenge: ((URLSession, URLSessionTask, URLAuthenticationChallenge) -> (URLSession.AuthChallengeDisposition, URLCredential?))?
+
+    func urlSession(_ session: URLSession, task: URLSessionTask, didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) {
+
+        var disposition: URLSession.AuthChallengeDisposition = .performDefaultHandling
+
+        var credential: URLCredential?
+
+        if let taskDidReceiveChallenge = taskDidReceiveChallenge {
+            (disposition, credential) = taskDidReceiveChallenge(session, task, challenge)
+        } else {
+            if challenge.previousFailureCount > 0 {
+                disposition = .rejectProtectionSpace
+            } else {
+                credential = self.credential ?? session.configuration.urlCredentialStorage?.defaultCredential(for: challenge.protectionSpace)
+
+                if credential != nil {
+                    disposition = .useCredential
+                }
+            }
+        }
+
+        completionHandler(disposition, credential)
+    }
+}
+
+public enum HTTPMethod: String {
+    case options = "OPTIONS"
+    case get = "GET"
+    case head = "HEAD"
+    case post = "POST"
+    case put = "PUT"
+    case patch = "PATCH"
+    case delete = "DELETE"
+    case trace = "TRACE"
+    case connect = "CONNECT"
+}
+
+public protocol ParameterEncoding {
+    func encode(_ urlRequest: URLRequest, with parameters: [String: Any]?) throws -> URLRequest
+}
+
+private class URLEncoding: ParameterEncoding {
+    func encode(_ urlRequest: URLRequest, with parameters: [String: Any]?) throws -> URLRequest {
+
+        var urlRequest = urlRequest
+
+        guard let parameters = parameters else { return urlRequest }
+
+        guard let url = urlRequest.url else {
+            throw DownloadException.requestMissingURL
+        }
+
+        if var urlComponents = URLComponents(url: url, resolvingAgainstBaseURL: false), !parameters.isEmpty {
+            urlComponents.queryItems = APIHelper.mapValuesToQueryItems(parameters)
+            urlRequest.url = urlComponents.url
+        }
+
+        return urlRequest
+    }
+}
+
+private class FormDataEncoding: ParameterEncoding {
+
+    let contentTypeForFormPart: (_ fileURL: URL) -> String?
+
+    init(contentTypeForFormPart: @escaping (_ fileURL: URL) -> String?) {
+        self.contentTypeForFormPart = contentTypeForFormPart
+    }
+
+    func encode(_ urlRequest: URLRequest, with parameters: [String: Any]?) throws -> URLRequest {
+
+        var urlRequest = urlRequest
+
+        guard let parameters = parameters, !parameters.isEmpty else {
+            return urlRequest
+        }
+
+        let boundary = "Boundary-\(UUID().uuidString)"
+
+        urlRequest.setValue("multipart/form-data; boundary=\(boundary)", forHTTPHeaderField: "Content-Type")
+
+        for (key, value) in parameters {
+            switch value {
+            case let fileURL as URL:
+
+                urlRequest = try configureFileUploadRequest(
+                    urlRequest: urlRequest,
+                    boundary: boundary,
+                    name: key,
+                    fileURL: fileURL
+                )
+
+            case let string as String:
+
+                if let data = string.data(using: .utf8) {
+                    urlRequest = configureDataUploadRequest(
+                        urlRequest: urlRequest,
+                        boundary: boundary,
+                        name: key,
+                        data: data
+                    )
+                }
+
+            case let number as NSNumber:
+
+                if let data = number.stringValue.data(using: .utf8) {
+                    urlRequest = configureDataUploadRequest(
+                        urlRequest: urlRequest,
+                        boundary: boundary,
+                        name: key,
+                        data: data
+                    )
+                }
+
+            default:
+                fatalError("Unprocessable value \(value) with key \(key)")
+            }
+        }
+
+        var body = urlRequest.httpBody.orEmpty
+
+        body.append("\r\n--\(boundary)--\r\n")
+
+        urlRequest.httpBody = body
+
+        return urlRequest
+    }
+
+    private func configureFileUploadRequest(urlRequest: URLRequest, boundary: String, name: String, fileURL: URL) throws -> URLRequest {
+
+        var urlRequest = urlRequest
+
+        var body = urlRequest.httpBody.orEmpty
+
+        let fileData = try Data(contentsOf: fileURL)
+
+        let mimetype = contentTypeForFormPart(fileURL) ?? mimeType(for: fileURL)
+
+        let fileName = fileURL.lastPathComponent
+
+        // If we already added something then we need an additional newline.
+        if body.count > 0 {
+            body.append("\r\n")
+        }
+
+        // Value boundary.
+        body.append("--\(boundary)\r\n")
+
+        // Value headers.
+        body.append("Content-Disposition: form-data; name=\"\(name)\"; filename=\"\(fileName)\"\r\n")
+        body.append("Content-Type: \(mimetype)\r\n")
+
+        // Separate headers and body.
+        body.append("\r\n")
+
+        // The value data.
+        body.append(fileData)
+
+        urlRequest.httpBody = body
+
+        return urlRequest
+    }
+
+    private func configureDataUploadRequest(urlRequest: URLRequest, boundary: String, name: String, data: Data) -> URLRequest {
+
+        var urlRequest = urlRequest
+
+        var body = urlRequest.httpBody.orEmpty
+
+        // If we already added something then we need an additional newline.
+        if body.count > 0 {
+            body.append("\r\n")
+        }
+
+        // Value boundary.
+        body.append("--\(boundary)\r\n")
+
+        // Value headers.
+        body.append("Content-Disposition: form-data; name=\"\(name)\"\r\n")
+
+        // Separate headers and body.
+        body.append("\r\n")
+
+        // The value data.
+        body.append(data)
+
+        urlRequest.httpBody = body
+
+        return urlRequest
+
+    }
+
+    func mimeType(for url: URL) -> String {
+        let pathExtension = url.pathExtension
+
+        if let uti = UTTypeCreatePreferredIdentifierForTag(kUTTagClassFilenameExtension, pathExtension as NSString, nil)?.takeRetainedValue() {
+            if let mimetype = UTTypeCopyPreferredTagWithClass(uti, kUTTagClassMIMEType)?.takeRetainedValue() {
+                return mimetype as String
+            }
+        }
+        return "application/octet-stream"
+    }
+
+}
+
+private class FormURLEncoding: ParameterEncoding {
+    func encode(_ urlRequest: URLRequest, with parameters: [String: Any]?) throws -> URLRequest {
+
+        var urlRequest = urlRequest
+
+        var requestBodyComponents = URLComponents()
+        requestBodyComponents.queryItems = APIHelper.mapValuesToQueryItems(parameters ?? [:])
+
+        if urlRequest.value(forHTTPHeaderField: "Content-Type") == nil {
+            urlRequest.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
+        }
+
+        urlRequest.httpBody = requestBodyComponents.query?.data(using: .utf8)
+
+        return urlRequest
+    }
+}
+
+private extension Data {
+    /// Append string to Data
+    ///
+    /// Rather than littering my code with calls to `dataUsingEncoding` to convert strings to Data, and then add that data to the Data, this wraps it in a nice convenient little extension to Data. This converts using UTF-8.
+    ///
+    /// - parameter string:       The string to be added to the `Data`.
+
+    mutating func append(_ string: String) {
+        if let data = string.data(using: .utf8) {
+            append(data)
+        }
+    }
+}
+
+private extension Optional where Wrapped == Data {
+    var orEmpty: Data {
+        self ?? Data()
+    }
+}
+
+extension JSONDataEncoding: ParameterEncoding {}

samples/client/petstore/swift5/oneOf/README.md

@@ -0,0 +1,46 @@
+# Swift5 API client for PetstoreClient
+
+No description provided (generated by Openapi Generator https://github.com/openapitools/openapi-generator)
+
+## Overview
+This API client was generated by the [OpenAPI Generator](https://openapi-generator.tech) project.  By using the [openapi-spec](https://github.com/OAI/OpenAPI-Specification) from a remote server, you can easily generate an API client.
+
+- API version: 0.0.1
+- Package version: 
+- Build package: org.openapitools.codegen.languages.Swift5ClientCodegen
+
+## Installation
+
+### Carthage
+
+Run `carthage update`
+
+### CocoaPods
+
+Run `pod install`
+
+## Documentation for API Endpoints
+
+All URIs are relative to *http://localhost*
+
+Class | Method | HTTP request | Description
+------------ | ------------- | ------------- | -------------
+*DefaultAPI* | [**rootGet**](docs/DefaultAPI.md#rootget) | **GET** / | 
+
+
+## Documentation For Models
+
+ - [Apple](docs/Apple.md)
+ - [Banana](docs/Banana.md)
+ - [Fruit](docs/Fruit.md)
+
+
+## Documentation For Authorization
+
+ All endpoints do not require authorization.
+
+
+## Author
+
+
+

samples/client/petstore/swift5/oneOf/docs/Apple.md

@@ -0,0 +1,11 @@
+# Apple
+
+## Properties
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**kind** | **String** |  | [optional] 
+**color** | **String** |  | [optional] 
+
+[[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
+
+

samples/client/petstore/swift5/oneOf/docs/Banana.md

@@ -0,0 +1,11 @@
+# Banana
+
+## Properties
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**count** | **Double** |  | [optional] 
+**color** | **String** |  | [optional] 
+
+[[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
+
+

samples/client/petstore/swift5/oneOf/docs/DefaultAPI.md

@@ -0,0 +1,52 @@
+# DefaultAPI
+
+All URIs are relative to *http://localhost*
+
+Method | HTTP request | Description
+------------- | ------------- | -------------
+[**rootGet**](DefaultAPI.md#rootget) | **GET** / | 
+
+
+# **rootGet**
+```swift
+    open class func rootGet(completion: @escaping (_ data: Fruit?, _ error: Error?) -> Void)
+```
+
+
+
+### Example 
+```swift
+// The following code samples are still beta. For any issue, please report via http://github.com/OpenAPITools/openapi-generator/issues/new
+import PetstoreClient
+
+
+DefaultAPI.rootGet() { (response, error) in
+    guard error == nil else {
+        print(error)
+        return
+    }
+
+    if (response) {
+        dump(response)
+    }
+}
+```
+
+### Parameters
+This endpoint does not need any parameter.
+
+### Return type
+
+[**Fruit**](Fruit.md)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: Not defined
+ - **Accept**: application/json
+
+[[Back to top]](#) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to Model list]](../README.md#documentation-for-models) [[Back to README]](../README.md)
+

samples/client/petstore/swift5/oneOf/docs/Fruit.md

@@ -0,0 +1,12 @@
+# Fruit
+
+## Properties
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**color** | **String** |  | [optional] 
+**kind** | **String** |  | [optional] 
+**count** | **Double** |  | [optional] 
+
+[[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
+
+

samples/client/petstore/swift5/oneOf/git_push.sh

@@ -0,0 +1,58 @@
+#!/bin/sh
+# ref: https://help.github.com/articles/adding-an-existing-project-to-github-using-the-command-line/
+#
+# Usage example: /bin/sh ./git_push.sh wing328 openapi-pestore-perl "minor update" "gitlab.com"
+
+git_user_id=$1
+git_repo_id=$2
+release_note=$3
+git_host=$4
+
+if [ "$git_host" = "" ]; then
+    git_host="github.com"
+    echo "[INFO] No command line input provided. Set \$git_host to $git_host"
+fi
+
+if [ "$git_user_id" = "" ]; then
+    git_user_id="GIT_USER_ID"
+    echo "[INFO] No command line input provided. Set \$git_user_id to $git_user_id"
+fi
+
+if [ "$git_repo_id" = "" ]; then
+    git_repo_id="GIT_REPO_ID"
+    echo "[INFO] No command line input provided. Set \$git_repo_id to $git_repo_id"
+fi
+
+if [ "$release_note" = "" ]; then
+    release_note="Minor update"
+    echo "[INFO] No command line input provided. Set \$release_note to $release_note"
+fi
+
+# Initialize the local directory as a Git repository
+git init
+
+# Adds the files in the local repository and stages them for commit.
+git add .
+
+# Commits the tracked changes and prepares them to be pushed to a remote repository.
+git commit -m "$release_note"
+
+# Sets the new remote
+git_remote=`git remote`
+if [ "$git_remote" = "" ]; then # git remote not defined
+
+    if [ "$GIT_TOKEN" = "" ]; then
+        echo "[INFO] \$GIT_TOKEN (environment variable) is not set. Using the git credential in your environment."
+        git remote add origin https://${git_host}/${git_user_id}/${git_repo_id}.git
+    else
+        git remote add origin https://${git_user_id}:${GIT_TOKEN}@${git_host}/${git_user_id}/${git_repo_id}.git
+    fi
+
+fi
+
+git pull origin master
+
+# Pushes (Forces) the changes in the local repository up to the remote repository
+echo "Git pushing to https://${git_host}/${git_user_id}/${git_repo_id}.git"
+git push origin master 2>&1 | grep -v 'To https'
+

samples/client/petstore/swift5/oneOf/project.yml

@@ -0,0 +1,15 @@
+name: PetstoreClient
+targets:
+  PetstoreClient:
+    type: framework
+    platform: iOS
+    deploymentTarget: "9.0"
+    sources: [PetstoreClient]
+    info:
+      path: ./Info.plist
+      version: 0.0.1
+    settings:
+      APPLICATION_EXTENSION_API_ONLY: true
+    scheme: {}
+    dependencies:
+    - carthage: AnyCodable