Full compatibility with the "ExistentialAny" upcoming feature

Package.swift

@@ -14,6 +14,13 @@
 //===----------------------------------------------------------------------===//
 import PackageDescription
 
+// General Swift-settings for all targets.
+let swiftSettings: [SwiftSetting] = [
+    // https://github.com/apple/swift-evolution/blob/main/proposals/0335-existential-any.md
+    // Require `any` for existential types.
+    .enableUpcomingFeature("ExistentialAny")
+]
+
 let package = Package(
     name: "swift-openapi-generator",
     platforms: [
@@ -72,6 +79,7 @@ let package = Package(
         .package(url: "https://github.com/apple/swift-docc-plugin", from: "1.0.0"),
     ],
     targets: [
+
         // Generator Core
         .target(
             name: "_OpenAPIGeneratorCore",
@@ -83,15 +91,17 @@ let package = Package(
                 .product(name: "SwiftSyntaxBuilder", package: "swift-syntax"),
                 .product(name: "SwiftFormat", package: "swift-format"),
                 .product(name: "SwiftFormatConfiguration", package: "swift-format"),
-            ]
+            ],
+            swiftSettings: swiftSettings
         ),
 
         // Generator Core Tests
         .testTarget(
             name: "OpenAPIGeneratorCoreTests",
             dependencies: [
                 "_OpenAPIGeneratorCore"
-            ]
+            ],
+            swiftSettings: swiftSettings
         ),
 
         // GeneratorReferenceTests
@@ -104,7 +114,8 @@ let package = Package(
             ],
             resources: [
                 .copy("Resources")
-            ]
+            ],
+            swiftSettings: swiftSettings
         ),
 
         // PetstoreConsumerTests
@@ -114,7 +125,8 @@ let package = Package(
             name: "PetstoreConsumerTests",
             dependencies: [
                 .product(name: "OpenAPIRuntime", package: "swift-openapi-runtime")
-            ]
+            ],
+            swiftSettings: swiftSettings
         ),
 
         // Generator CLI
@@ -123,7 +135,8 @@ let package = Package(
             dependencies: [
                 "_OpenAPIGeneratorCore",
                 .product(name: "ArgumentParser", package: "swift-argument-parser"),
-            ]
+            ],
+            swiftSettings: swiftSettings
         ),
 
         // Build Plugin

Sources/_OpenAPIGeneratorCore/GeneratorPipeline.swift

@@ -89,7 +89,7 @@ struct GeneratorPipeline {
 public func runGenerator(
     input: InMemoryInputFile,
     config: Config,
-    diagnostics: DiagnosticCollector
+    diagnostics: any DiagnosticCollector
 ) throws -> InMemoryOutputFile {
     try makeGeneratorPipeline(config: config, diagnostics: diagnostics).run(input)
 }
@@ -105,12 +105,12 @@ public func runGenerator(
 /// - Returns: A configured generator pipeline that can be executed with
 /// ``GeneratorPipeline/run(_:)``.
 func makeGeneratorPipeline(
-    parser: ParserProtocol = YamsParser(),
-    translator: TranslatorProtocol = MultiplexTranslator(),
-    renderer: RendererProtocol = TextBasedRenderer(),
+    parser: any ParserProtocol = YamsParser(),
+    translator: any TranslatorProtocol = MultiplexTranslator(),
+    renderer: any RendererProtocol = TextBasedRenderer(),
     formatter: @escaping (InMemoryOutputFile) throws -> InMemoryOutputFile = { try $0.swiftFormatted },
     config: Config,
-    diagnostics: DiagnosticCollector
+    diagnostics: any DiagnosticCollector
 ) -> GeneratorPipeline {
     return .init(
         parseOpenAPIFileStage: .init(

Sources/_OpenAPIGeneratorCore/Parser/ParserProtocol.swift

@@ -27,6 +27,6 @@ protocol ParserProtocol {
     func parseOpenAPI(
         _ input: InMemoryInputFile,
         config: Config,
-        diagnostics: DiagnosticCollector
+        diagnostics: any DiagnosticCollector
     ) throws -> ParsedOpenAPIRepresentation
 }

Sources/_OpenAPIGeneratorCore/Parser/YamsParser.swift

@@ -21,7 +21,7 @@ struct YamsParser: ParserProtocol {
     func parseOpenAPI(
         _ input: InMemoryInputFile,
         config: Config,
-        diagnostics: DiagnosticCollector
+        diagnostics: any DiagnosticCollector
     ) throws -> ParsedOpenAPIRepresentation {
         let decoder = YAMLDecoder()
         let openapiData = input.contents
@@ -86,7 +86,7 @@ struct YamsParser: ParserProtocol {
                     location: .init(filePath: input.absolutePath.path, lineNumber: yamlMark.line - 1)
                 )
             }
-        } else if let openAPIError = context.underlyingError as? OpenAPIError {
+        } else if let openAPIError = context.underlyingError as? (any OpenAPIError) {
             throw Diagnostic.error(
                 message: openAPIError.localizedDescription,
                 location: .init(filePath: input.absolutePath.path)

Sources/_OpenAPIGeneratorCore/Renderer/RendererProtocol.swift

@@ -27,6 +27,6 @@ protocol RendererProtocol {
     func render(
         structured code: StructuredSwiftRepresentation,
         config: Config,
-        diagnostics: DiagnosticCollector
+        diagnostics: any DiagnosticCollector
     ) throws -> InMemoryOutputFile
 }

Sources/_OpenAPIGeneratorCore/Renderer/TextBasedRenderer.swift

@@ -20,7 +20,7 @@ struct TextBasedRenderer: RendererProtocol {
     func render(
         structured: StructuredSwiftRepresentation,
         config: Config,
-        diagnostics: DiagnosticCollector
+        diagnostics: any DiagnosticCollector
     ) throws -> InMemoryOutputFile {
         let namedFile = structured.file
         return InMemoryOutputFile(

Sources/_OpenAPIGeneratorCore/Translator/ClientTranslator/ClientTranslator.swift

@@ -25,7 +25,7 @@ import OpenAPIKit30
 struct ClientFileTranslator: FileTranslator {
 
     var config: Config
-    var diagnostics: DiagnosticCollector
+    var diagnostics: any DiagnosticCollector
     var components: OpenAPI.Components
 
     func translateFile(
@@ -79,7 +79,10 @@ struct ClientFileTranslator: FileTranslator {
                         type: Constants.Configuration.typeName,
                         defaultValue: .dot("init").call([])
                     ),
-                    .init(label: "transport", type: Constants.Client.Transport.typeName),
+                    .init(
+                        label: "transport",
+                        type: Constants.Client.Transport.typeName
+                    ),
                     .init(
                         label: "middlewares",
                         type: "[\(Constants.Client.Middleware.typeName)]",

Sources/_OpenAPIGeneratorCore/Translator/CommonTranslations/translateCodable.swift

@@ -593,7 +593,7 @@ fileprivate extension FileTranslator {
             accessModifier: config.access,
             kind: .function(name: "encode"),
             parameters: [
-                .init(label: "to", name: "encoder", type: "Encoder")
+                .init(label: "to", name: "encoder", type: "any Encoder")
             ],
             keywords: [
                 .throws
@@ -610,7 +610,7 @@ fileprivate extension FileTranslator {
             accessModifier: config.access,
             kind: .initializer,
             parameters: [
-                .init(label: "from", name: "decoder", type: "Decoder")
+                .init(label: "from", name: "decoder", type: "any Decoder")
             ],
             keywords: [
                 .throws

Sources/_OpenAPIGeneratorCore/Translator/CommonTypes/Constants.swift

@@ -80,14 +80,14 @@ enum Constants {
         enum Transport {
 
             /// The name of the client transport type.
-            static let typeName: String = "ClientTransport"
+            static let typeName: String = "any ClientTransport"
         }
 
         /// Constants related to the client middleware type.
         enum Middleware {
 
             /// The name of the client middleware type.
-            static let typeName: String = "ClientMiddleware"
+            static let typeName: String = "any ClientMiddleware"
         }
     }
 
@@ -110,14 +110,14 @@ enum Constants {
         enum Transport {
 
             /// The name of the server transport type.
-            static let typeName: String = "ServerTransport"
+            static let typeName: String = "any ServerTransport"
         }
 
         /// Constants related to the server middleware type.
         enum Middleware {
 
             /// The name of the server middleware type.
-            static let typeName: String = "ServerMiddleware"
+            static let typeName: String = "any ServerMiddleware"
         }
     }
 

Sources/_OpenAPIGeneratorCore/Translator/FileTranslator.swift

@@ -29,7 +29,7 @@ protocol FileTranslator {
 
     /// The collector receives diagnostics from the translator, which should
     /// be surfaced to the user in some way.
-    var diagnostics: DiagnosticCollector { get }
+    var diagnostics: any DiagnosticCollector { get }
 
     /// The components section of the OpenAPI document is required by the
     /// translator logic to follow JSON references to schemas, parameters,

Sources/_OpenAPIGeneratorCore/Translator/MultiplexTranslator.swift

@@ -19,9 +19,9 @@ struct MultiplexTranslator: TranslatorProtocol {
     func translate(
         parsedOpenAPI: ParsedOpenAPIRepresentation,
         config: Config,
-        diagnostics: DiagnosticCollector
+        diagnostics: any DiagnosticCollector
     ) throws -> StructuredSwiftRepresentation {
-        let translator: FileTranslator
+        let translator: any FileTranslator
         switch config.mode {
         case .types:
             translator = TypesFileTranslator(

Sources/_OpenAPIGeneratorCore/Translator/ServerTranslator/ServerTranslator.swift

@@ -23,7 +23,7 @@ import OpenAPIKit30
 struct ServerFileTranslator: FileTranslator {
 
     var config: Config
-    var diagnostics: DiagnosticCollector
+    var diagnostics: any DiagnosticCollector
     var components: OpenAPI.Components
 
     func translateFile(

Sources/_OpenAPIGeneratorCore/Translator/TranslatorProtocol.swift

@@ -28,6 +28,6 @@ protocol TranslatorProtocol {
     func translate(
         parsedOpenAPI: ParsedOpenAPIRepresentation,
         config: Config,
-        diagnostics: DiagnosticCollector
+        diagnostics: any DiagnosticCollector
     ) throws -> StructuredSwiftRepresentation
 }

Sources/_OpenAPIGeneratorCore/Translator/TypesTranslator/TypesFileTranslator.swift

@@ -25,7 +25,7 @@ import OpenAPIKit30
 struct TypesFileTranslator: FileTranslator {
 
     var config: Config
-    var diagnostics: DiagnosticCollector
+    var diagnostics: any DiagnosticCollector
     var components: OpenAPI.Components
 
     func translateFile(

Sources/swift-openapi-generator/GenerateOptions+runGenerator.swift

@@ -40,7 +40,7 @@ extension _GenerateOptions {
                 additionalImports: resolvedAdditionalImports
             )
         }
-        let diagnostics: DiagnosticCollector
+        let diagnostics: any DiagnosticCollector
         let finalizeDiagnostics: () throws -> Void
         if let diagnosticsOutputPath {
             let _diagnostics = _YamlFileDiagnosticsCollector(url: diagnosticsOutputPath)

Sources/swift-openapi-generator/runGenerator.swift

@@ -31,7 +31,7 @@ extension _Tool {
         configs: [Config],
         isPluginInvocation: Bool,
         outputDirectory: URL,
-        diagnostics: DiagnosticCollector
+        diagnostics: any DiagnosticCollector
     ) throws {
         let docData: Data
         do {
@@ -73,7 +73,7 @@ extension _Tool {
         docData: Data,
         config: Config,
         outputFilePath: URL,
-        diagnostics: DiagnosticCollector
+        diagnostics: any DiagnosticCollector
     ) throws {
         let didChange = try replaceFileContents(at: outputFilePath) {
             let output = try _OpenAPIGeneratorCore.runGenerator(

Tests/OpenAPIGeneratorCoreTests/TestUtilities.swift

@@ -25,8 +25,8 @@ class Test_Core: XCTestCase {
 
     func makeTranslator(
         components: OpenAPI.Components = .noComponents,
-        diagnostics: DiagnosticCollector = PrintingDiagnosticCollector()
-    ) -> FileTranslator {
+        diagnostics: any DiagnosticCollector = PrintingDiagnosticCollector()
+    ) -> any FileTranslator {
         makeTypesTranslator(
             components: components,
             diagnostics: diagnostics
@@ -35,7 +35,7 @@ class Test_Core: XCTestCase {
 
     func makeTypesTranslator(
         components: OpenAPI.Components = .noComponents,
-        diagnostics: DiagnosticCollector = PrintingDiagnosticCollector()
+        diagnostics: any DiagnosticCollector = PrintingDiagnosticCollector()
     ) -> TypesFileTranslator {
         TypesFileTranslator(
             config: .init(mode: .types),

Tests/OpenAPIGeneratorCoreTests/Translator/TypeAssignment/Test_isSchemaSupported.swift

@@ -17,7 +17,7 @@ import OpenAPIKit30
 
 class Test_isSchemaSupported: XCTestCase {
 
-    var translator: FileTranslator {
+    var translator: any FileTranslator {
         TypesFileTranslator(
             config: .init(mode: .types),
             diagnostics: PrintingDiagnosticCollector(),

Tests/OpenAPIGeneratorReferenceTests/ReferenceTest.swift

@@ -82,7 +82,7 @@ class ReferenceTests: XCTestCase {
         )
 
         // Run the requested generator invocation
-        let diagnostics: DiagnosticCollector = strictDiagnosticsCollector
+        let diagnostics: any DiagnosticCollector = strictDiagnosticsCollector
         let generatorPipeline = self.makeGeneratorPipeline(
             config: referenceTest.asConfig,
             diagnostics: diagnostics
@@ -160,13 +160,13 @@ struct StrictDiagnosticsCollector: DiagnosticCollector {
 
 extension ReferenceTests {
 
-    var strictDiagnosticsCollector: DiagnosticCollector {
+    var strictDiagnosticsCollector: any DiagnosticCollector {
         StrictDiagnosticsCollector(test: self)
     }
 
     private func makeGeneratorPipeline(
         config: Config,
-        diagnostics: DiagnosticCollector
+        diagnostics: any DiagnosticCollector
     ) -> GeneratorPipeline {
 
         let parser = YamsParser()

Tests/OpenAPIGeneratorReferenceTests/Resources/ReferenceSources/Petstore/Client.swift

@@ -22,8 +22,8 @@ public struct Client: APIProtocol {
     public init(
         serverURL: URL,
         configuration: Configuration = .init(),
-        transport: ClientTransport,
-        middlewares: [ClientMiddleware] = []
+        transport: any ClientTransport,
+        middlewares: [any ClientMiddleware] = []
     ) {
         self.client = .init(
             serverURL: serverURL,

Tests/OpenAPIGeneratorReferenceTests/Resources/ReferenceSources/Petstore/Server.swift

@@ -14,10 +14,10 @@ extension APIProtocol {
     ///   - configuration: A set of configuration values for the server.
     ///   - middlewares: A list of middlewares to call before the handler.
     public func registerHandlers(
-        on transport: ServerTransport,
+        on transport: any ServerTransport,
         serverURL: URL = .defaultOpenAPIServerURL,
         configuration: Configuration = .init(),
-        middlewares: [ServerMiddleware] = []
+        middlewares: [any ServerMiddleware] = []
     ) throws {
         let server = UniversalServer(
             serverURL: serverURL,