Update examples for Swift 5.5 (#223)

- Lambda examples use async/await
- SwiftUI example uses async/await
- Handlers are marked with `@main`
- Executables are defined as `.executableTarget`
- Examples require Swift 5.5

Author: fabianfett

Examples/LambdaFunctions/Package.swift

@@ -1,11 +1,11 @@
-// swift-tools-version:5.2
+// swift-tools-version:5.5
 
 import PackageDescription
 
 let package = Package(
     name: "swift-aws-lambda-runtime-samples",
     platforms: [
-        .macOS(.v10_13),
+        .macOS(.v12),
     ],
     products: [
         // introductory example
@@ -24,16 +24,16 @@ let package = Package(
         .package(name: "swift-aws-lambda-runtime", path: "../.."),
     ],
     targets: [
-        .target(name: "HelloWorld", dependencies: [
-            .product(name: "AWSLambdaRuntime", package: "swift-aws-lambda-runtime"),
-        ]),
-        .target(name: "Benchmark", dependencies: [
+        .executableTarget(name: "Benchmark", dependencies: [
             .product(name: "AWSLambdaRuntimeCore", package: "swift-aws-lambda-runtime"),
         ]),
-        .target(name: "ErrorHandling", dependencies: [
+        .executableTarget(name: "HelloWorld", dependencies: [
+            .product(name: "AWSLambdaRuntime", package: "swift-aws-lambda-runtime"),
+        ]),
+        .executableTarget(name: "ErrorHandling", dependencies: [
             .product(name: "AWSLambdaRuntime", package: "swift-aws-lambda-runtime"),
         ]),
-        .target(name: "CurrencyExchange", dependencies: [
+        .executableTarget(name: "CurrencyExchange", dependencies: [
             .product(name: "AWSLambdaRuntime", package: "swift-aws-lambda-runtime"),
         ]),
     ]

Examples/LambdaFunctions/Sources/Benchmark/main.swift

@@ -19,7 +19,7 @@ import NIO
 // use this example which is more performant.
 // `EventLoopLambdaHandler` does not offload the Lambda processing to a separate thread
 // while the closure-based handlers do.
-Lambda.run(BenchmarkHandler())
+Lambda.run { $0.eventLoop.makeSucceededFuture(BenchmarkHandler()) }
 
 struct BenchmarkHandler: EventLoopLambdaHandler {
     typealias In = String

Examples/LambdaFunctions/Sources/CurrencyExchange/main.swift renamed to Examples/LambdaFunctions/Sources/CurrencyExchange/CurrencyExchangeHandler.swift

@@ -23,9 +23,30 @@ import Logging
 
 // MARK: - Run Lambda
 
-Lambda.run { (context: Lambda.Context, _: Request, callback: @escaping (Result<[Exchange], Error>) -> Void) in
-    let calculator = ExchangeRatesCalculator()
-    calculator.run(logger: context.logger, callback: callback)
+@main
+struct CurrencyExchangeHandler: AsyncLambdaHandler {
+    typealias In = Request
+    typealias Out = [Exchange]
+
+    let calculator: ExchangeRatesCalculator
+
+    init(context: Lambda.InitializationContext) async throws {
+        // the ExchangeRatesCalculator() can be reused over and over
+        self.calculator = ExchangeRatesCalculator()
+    }
+
+    func handle(event: Request, context: Lambda.Context) async throws -> [Exchange] {
+        try await withCheckedThrowingContinuation { continuation in
+            self.calculator.run(logger: context.logger) { result in
+                switch result {
+                case .success(let exchanges):
+                    continuation.resume(returning: exchanges)
+                case .failure(let error):
+                    continuation.resume(throwing: error)
+                }
+            }
+        }
+    }
 }
 
 // MARK: - Business Logic

Examples/LambdaFunctions/Sources/ErrorHandling/main.swift renamed to Examples/LambdaFunctions/Sources/ErrorHandling/ErrorsHappenHandler.swift

@@ -16,21 +16,29 @@ import AWSLambdaRuntime
 
 // MARK: - Run Lambda
 
-// switch over the error type "requested" by the request, and trigger such error accordingly
-Lambda.run { (context: Lambda.Context, request: Request, callback: (Result<Response, Error>) -> Void) in
-    switch request.error {
-    // no error here!
-    case .none:
-        callback(.success(Response(awsRequestID: context.requestID, requestID: request.requestID, status: .ok)))
-    // trigger a "managed" error - domain specific business logic failure
-    case .managed:
-        callback(.success(Response(awsRequestID: context.requestID, requestID: request.requestID, status: .error)))
-    // trigger an "unmanaged" error - an unexpected Swift Error triggered while processing the request
-    case .unmanaged(let error):
-        callback(.failure(UnmanagedError(description: error)))
-    // trigger a "fatal" error - a panic type error which will crash the process
-    case .fatal:
-        fatalError("crash!")
+@main
+struct ErrorsHappenHandler: AsyncLambdaHandler {
+    typealias In = Request
+    typealias Out = Response
+
+    init(context: Lambda.InitializationContext) async throws {}
+
+    func handle(event request: Request, context: Lambda.Context) async throws -> Response {
+        // switch over the error type "requested" by the request, and trigger such error accordingly
+        switch request.error {
+        // no error here!
+        case .none:
+            return Response(awsRequestID: context.requestID, requestID: request.requestID, status: .ok)
+        // trigger a "managed" error - domain specific business logic failure
+        case .managed:
+            return Response(awsRequestID: context.requestID, requestID: request.requestID, status: .error)
+        // trigger an "unmanaged" error - an unexpected Swift Error triggered while processing the request
+        case .unmanaged(let error):
+            throw UnmanagedError(description: error)
+        // trigger a "fatal" error - a panic type error which will crash the process
+        case .fatal:
+            fatalError("crash!")
+        }
     }
 }
 

Examples/LambdaFunctions/Sources/HelloWorld/main.swift renamed to Examples/LambdaFunctions/Sources/HelloWorld/HelloWorldHandler.swift

@@ -15,6 +15,16 @@
 import AWSLambdaRuntime
 
 // introductory example, the obligatory "hello, world!"
-Lambda.run { (_: Lambda.Context, _: String, callback: (Result<String, Error>) -> Void) in
-    callback(.success("hello, world!"))
+@main
+struct HelloWorldHandler: AsyncLambdaHandler {
+    typealias In = String
+    typealias Out = String
+
+    init(context: Lambda.InitializationContext) async throws {
+        // setup your resources that you want to reuse here.
+    }
+
+    func handle(event: String, context: Lambda.Context) async throws -> String {
+        "hello, world"
+    }
 }

Examples/LocalDebugging/MyApp/MyApp.xcodeproj/project.pbxproj

@@ -115,7 +115,7 @@
 			isa = PBXProject;
 			attributes = {
 				LastSwiftUpdateCheck = 1140;
-				LastUpgradeCheck = 1140;
+				LastUpgradeCheck = 1300;
 				ORGANIZATIONNAME = "Tom Doron";
 				TargetAttributes = {
 					F7B6C1F9246121E800607A89 = {
@@ -205,6 +205,7 @@
 				CLANG_WARN_OBJC_IMPLICIT_RETAIN_SELF = YES;
 				CLANG_WARN_OBJC_LITERAL_CONVERSION = YES;
 				CLANG_WARN_OBJC_ROOT_CLASS = YES_ERROR;
+				CLANG_WARN_QUOTED_INCLUDE_IN_FRAMEWORK_HEADER = YES;
 				CLANG_WARN_RANGE_LOOP_ANALYSIS = YES;
 				CLANG_WARN_STRICT_PROTOTYPES = YES;
 				CLANG_WARN_SUSPICIOUS_MOVE = YES;
@@ -229,7 +230,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 13.4;
+				IPHONEOS_DEPLOYMENT_TARGET = 15.0;
 				MTL_ENABLE_DEBUG_INFO = INCLUDE_SOURCE;
 				MTL_FAST_MATH = YES;
 				ONLY_ACTIVE_ARCH = YES;
@@ -265,6 +266,7 @@
 				CLANG_WARN_OBJC_IMPLICIT_RETAIN_SELF = YES;
 				CLANG_WARN_OBJC_LITERAL_CONVERSION = YES;
 				CLANG_WARN_OBJC_ROOT_CLASS = YES_ERROR;
+				CLANG_WARN_QUOTED_INCLUDE_IN_FRAMEWORK_HEADER = YES;
 				CLANG_WARN_RANGE_LOOP_ANALYSIS = YES;
 				CLANG_WARN_STRICT_PROTOTYPES = YES;
 				CLANG_WARN_SUSPICIOUS_MOVE = YES;
@@ -283,7 +285,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 13.4;
+				IPHONEOS_DEPLOYMENT_TARGET = 15.0;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				MTL_FAST_MATH = YES;
 				SDKROOT = iphoneos;

Examples/LocalDebugging/MyApp/MyApp.xcodeproj/xcshareddata/xcschemes/MyApp.xcscheme

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "1140"
+   LastUpgradeVersion = "1300"
    version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"

Examples/LocalDebugging/MyApp/MyApp/ContentView.swift

@@ -25,7 +25,11 @@ struct ContentView: View {
             TextField("Username", text: $name)
             SecureField("Password", text: $password)
             Button(
-                action: self.register,
+                action: {
+                    Task {
+                        await self.register()
+                    }
+                },
                 label: {
                     Text("Register")
                         .padding()
@@ -38,8 +42,8 @@ struct ContentView: View {
         }.padding(100)
     }
 
-    func register() {
-        guard let url = URL(string: "http://localhost:7000/invoke") else {
+    func register() async {
+        guard let url = URL(string: "http://127.0.0.1:7000/invoke") else {
             fatalError("invalid url")
         }
         var request = URLRequest(url: url)
@@ -50,27 +54,21 @@ struct ContentView: View {
         }
         request.httpBody = jsonRequest
 
-        let task = URLSession.shared.dataTask(with: request as URLRequest) { data, response, error in
-            do {
-                if let error = error {
-                    throw CommunicationError(reason: error.localizedDescription)
-                }
-                guard let httpResponse = response as? HTTPURLResponse else {
-                    throw CommunicationError(reason: "invalid response, expected HTTPURLResponse")
-                }
-                guard httpResponse.statusCode == 200 else {
-                    throw CommunicationError(reason: "invalid response code: \(httpResponse.statusCode)")
-                }
-                guard let data = data else {
-                    throw CommunicationError(reason: "invald response, empty body")
-                }
-                let response = try JSONDecoder().decode(Response.self, from: data)
-                self.setResponse(response.message)
-            } catch {
-                self.setResponse("\(error)")
+        do {
+            let (data, response) = try await URLSession.shared.data(for: request)
+
+            guard let httpResponse = response as? HTTPURLResponse else {
+                throw CommunicationError(reason: "invalid response, expected HTTPURLResponse")
+            }
+            guard httpResponse.statusCode == 200 else {
+                throw CommunicationError(reason: "invalid response code: \(httpResponse.statusCode)")
             }
+            let jsonResponse = try JSONDecoder().decode(Response.self, from: data)
+
+            self.response = jsonResponse.message
+        } catch {
+            self.response = error.localizedDescription
         }
-        task.resume()
     }
 
     func setResponse(_ text: String) {

Examples/LocalDebugging/MyLambda/Package.swift

@@ -1,11 +1,11 @@
-// swift-tools-version:5.2
+// swift-tools-version:5.5
 
 import PackageDescription
 
 let package = Package(
     name: "MyLambda",
     platforms: [
-        .macOS(.v10_13),
+        .macOS(.v12),
     ],
     products: [
         .executable(name: "MyLambda", targets: ["MyLambda"]),
@@ -18,7 +18,7 @@ let package = Package(
         .package(name: "Shared", path: "../Shared"),
     ],
     targets: [
-        .target(
+        .executableTarget(
             name: "MyLambda", dependencies: [
                 .product(name: "AWSLambdaRuntime", package: "swift-aws-lambda-runtime"),
                 .product(name: "Shared", package: "Shared"),

Examples/LocalDebugging/MyLambda/Sources/MyLambda/main.swift renamed to Examples/LocalDebugging/MyLambda/Sources/MyLambda/MyLambdaHandler.swift

@@ -17,7 +17,17 @@ import Shared
 
 // set LOCAL_LAMBDA_SERVER_ENABLED env variable to "true" to start
 // a local server simulator which will allow local debugging
-Lambda.run { (_, request: Request, callback: @escaping (Result<Response, Error>) -> Void) in
-    // TODO: something useful
-    callback(.success(Response(message: "Hello, \(request.name)!")))
+@main
+struct MyLambdaHandler: AsyncLambdaHandler {
+    typealias In = Request
+    typealias Out = Response
+
+    init(context: Lambda.InitializationContext) async throws {
+        // setup your resources that you want to reuse for every invocation here.
+    }
+
+    func handle(event request: Request, context: Lambda.Context) async throws -> Response {
+        // TODO: something useful
+        Response(message: "Hello, \(request.name)!")
+    }
 }