Add configuration validation

src/LondonTravel.Skill/AlexaFunction.cs

@@ -132,6 +132,7 @@ protected virtual void ConfigureServices(IServiceCollection services)
         services.AddSingleton<AlexaSkill>();
         services.AddSingleton<FunctionHandler>();
         services.AddSingleton<IntentFactory>();
+        services.AddSingleton<IValidateOptions<SkillConfiguration>, ValidateSkillConfiguration>();
         services.AddSingleton((_) => TelemetryConfiguration.CreateDefault());
         services.AddSingleton(CreateTelemetryClient);
         services.AddSingleton((p) => p.GetRequiredService<IOptions<SkillConfiguration>>().Value);

src/LondonTravel.Skill/FunctionEntrypoint.cs

@@ -19,17 +19,19 @@ public static class FunctionEntrypoint
     /// <summary>
     /// Runs the function using a custom runtime as an asynchronous operation.
     /// </summary>
+    /// <typeparam name="T">The type of the function to execute.</typeparam>
     /// <param name="httpClient">The optional HTTP client to use.</param>
     /// <param name="cancellationToken">The optional cancellation token to use.</param>
     /// <returns>
     /// A <see cref="Task"/> representing the asynchronous operation to run the function.
     /// </returns>
-    public static async Task RunAsync(
+    public static async Task RunAsync<T>(
         HttpClient httpClient = null,
         CancellationToken cancellationToken = default)
+        where T : AlexaFunction, new()
     {
         var serializer = new JsonSerializer();
-        await using var function = new AlexaFunction();
+        await using var function = new T();
 
         using var bootstrap = LambdaBootstrapBuilder
             .Create<SkillRequest, SkillResponse>(function.HandlerAsync, serializer)
@@ -47,5 +49,5 @@ public static async Task RunAsync(
     /// A <see cref="Task"/> representing the asynchronous operation to run the custom runtime.
     /// </returns>
     [System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
-    private static async Task Main() => await RunAsync();
+    private static async Task Main() => await RunAsync<AlexaFunction>();
 }

src/LondonTravel.Skill/SkillConfiguration.cs

@@ -1,6 +1,8 @@
 // Copyright (c) Martin Costello, 2017. All rights reserved.
 // Licensed under the Apache 2.0 license. See the LICENSE file in the project root for full license information.
 
+using System.ComponentModel.DataAnnotations;
+
 namespace MartinCostello.LondonTravel.Skill;
 
 /// <summary>
@@ -16,6 +18,7 @@ public sealed class SkillConfiguration
     /// <summary>
     /// Gets or sets the URL for the skill API.
     /// </summary>
+    [Required]
     public string SkillApiUrl { get; set; } = string.Empty;
 
     /// <summary>
@@ -26,11 +29,13 @@ public sealed class SkillConfiguration
     /// <summary>
     /// Gets or sets the TfL API application Id.
     /// </summary>
+    [Required]
     public string TflApplicationId { get; set; } = string.Empty;
 
     /// <summary>
     /// Gets or sets the TfL API application key.
     /// </summary>
+    [Required]
     public string TflApplicationKey { get; set; } = string.Empty;
 
     /// <summary>

src/LondonTravel.Skill/ValidateSkillConfiguration.cs

@@ -0,0 +1,14 @@
+// Copyright (c) Martin Costello, 2017. All rights reserved.
+// Licensed under the Apache 2.0 license. See the LICENSE file in the project root for full license information.
+
+using Microsoft.Extensions.Options;
+
+namespace MartinCostello.LondonTravel.Skill;
+
+/// <summary>
+/// A class that validates instances of the <see cref="SkillConfiguration"/> class. This class cannot be inherited.
+/// </summary>
+[OptionsValidator]
+internal sealed partial class ValidateSkillConfiguration : IValidateOptions<SkillConfiguration>
+{
+}

src/LondonTravel.Skill/aws-lambda-tools-defaults.json

@@ -4,7 +4,7 @@
   "configuration": "Release",
   "framework": "net8.0",
   "function-architecture": "arm64",
-  "function-handler": "LondonTravel.Skill::MartinCostello.LondonTravel.Skill.AlexaFunctionHandler::HandleAsync",
+  "function-handler": "LondonTravel.Skill",
   "function-memory-size": 192,
   "function-runtime": "provided.al2023",
   "function-timeout": 10

test/LondonTravel.Skill.Tests/EndToEndTests.cs

@@ -48,7 +48,7 @@ void Configure(IServiceCollection services)
         using var httpClient = server.CreateClient();
 
         // Act
-        await FunctionEntrypoint.RunAsync(httpClient, cancellationTokenSource.Token);
+        await FunctionEntrypoint.RunAsync<TestSettingsAlexaFunction>(httpClient, cancellationTokenSource.Token);
 
         // Assert
         context.Response.TryRead(out LambdaTestResponse result).ShouldBeTrue();

test/LondonTravel.Skill.Tests/FunctionTests.cs

@@ -119,17 +119,20 @@ protected virtual SkillRequest CreateRequest<T>(T request = null)
         return result;
     }
 
-    private sealed class TestAlexaFunction(
-        HttpClientInterceptorOptions options,
-        ITestOutputHelper outputHelper) : AlexaFunction, ITestOutputHelperAccessor
+    protected class TestSettingsAlexaFunction() : AlexaFunction
     {
-        public ITestOutputHelper OutputHelper { get; set; } = outputHelper;
-
         protected override void Configure(ConfigurationBuilder builder)
         {
             base.Configure(builder);
             builder.AddJsonFile("testsettings.json");
         }
+    }
+
+    private sealed class TestAlexaFunction(
+        HttpClientInterceptorOptions options,
+        ITestOutputHelper outputHelper) : TestSettingsAlexaFunction, ITestOutputHelperAccessor
+    {
+        public ITestOutputHelper OutputHelper { get; set; } = outputHelper;
 
         protected override void ConfigureServices(IServiceCollection services)
         {

test/LondonTravel.Skill.Tests/UnknownIntentTests.cs

@@ -13,8 +13,7 @@ public class UnknownIntentTests(ITestOutputHelper outputHelper) : FunctionTests(
     public async Task Can_Invoke_Function()
     {
         // Arrange
-        await using var function = new AlexaFunction();
-        await function.InitializeAsync();
+        AlexaFunction function = await CreateFunctionAsync();
 
         SkillRequest request = CreateIntentRequest("FooIntent");