Use C# 12 features

- Use primary constructors where relevant.
- Use collection literals where relevant.
- Simplify JSON serialization with `HttpClient`.
- Fix some typos.
- Fix indentation.

src/ApplePayJS/Clients/ApplePayClient.cs

@@ -1,38 +1,24 @@
 // Copyright (c) Just Eat, 2016. All rights reserved.
 // Licensed under the Apache 2.0 license. See the LICENSE file in the project root for full license information.
 
-using System.Net.Mime;
-using System.Text;
 using System.Text.Json;
 
 namespace JustEat.ApplePayJS.Clients;
 
-public class ApplePayClient
+public class ApplePayClient(HttpClient httpClient)
 {
-    private readonly HttpClient _httpClient;
-
-    public ApplePayClient(HttpClient httpClient)
-    {
-        _httpClient = httpClient;
-    }
-
     public async Task<JsonDocument> GetMerchantSessionAsync(
         Uri requestUri,
         MerchantSessionRequest request,
         CancellationToken cancellationToken = default)
     {
         // POST the data to create a valid Apple Pay merchant session.
-        string json = JsonSerializer.Serialize(request);
-
-        using var content = new StringContent(json, Encoding.UTF8, MediaTypeNames.Application.Json);
-
-        using var response = await _httpClient.PostAsync(requestUri, content, cancellationToken);
+        using var response = await httpClient.PostAsJsonAsync(requestUri, request, cancellationToken);
 
         response.EnsureSuccessStatusCode();
 
         // Read the opaque merchant session JSON from the response body.
-        using var stream = await response.Content.ReadAsStreamAsync();
-
-        return await JsonDocument.ParseAsync(stream, cancellationToken: cancellationToken);
+        var merchantSession = await response.Content.ReadFromJsonAsync<JsonDocument>(cancellationToken);
+        return merchantSession!;
     }
 }

src/ApplePayJS/Clients/MerchantCertificate.cs

@@ -8,14 +8,9 @@
 
 namespace JustEat.ApplePayJS.Clients;
 
-public class MerchantCertificate
+public class MerchantCertificate(IOptions<ApplePayOptions> options)
 {
-    private readonly ApplePayOptions _options;
-
-    public MerchantCertificate(IOptions<ApplePayOptions> options)
-    {
-        _options = options.Value;
-    }
+    private readonly ApplePayOptions _options = options.Value;
 
     public X509Certificate2 GetCertificate()
     {

src/ApplePayJS/Controllers/HomeController.cs

@@ -10,29 +10,18 @@ namespace JustEat.ApplePayJS.Controllers;
 using Microsoft.Extensions.Options;
 using Models;
 
-public class HomeController : Controller
+public class HomeController(
+    ApplePayClient client,
+    MerchantCertificate certificate,
+    IOptions<ApplePayOptions> options) : Controller
 {
-    private readonly ApplePayClient _client;
-    private readonly MerchantCertificate _certificate;
-    private readonly ApplePayOptions _options;
-
-    public HomeController(
-        ApplePayClient client,
-        MerchantCertificate certificate,
-        IOptions<ApplePayOptions> options)
-    {
-        _client = client;
-        _certificate = certificate;
-        _options = options.Value;
-    }
-
     public IActionResult Index()
     {
         // Get the merchant identifier and store name for use in the JavaScript by ApplePaySession.
         var model = new HomeModel()
         {
-            MerchantId = _certificate.GetMerchantIdentifier(),
-            StoreName = _options.StoreName,
+            MerchantId = certificate.GetMerchantIdentifier(),
+            StoreName = options.Value.StoreName,
         };
 
         return View(model);
@@ -56,13 +45,13 @@ public async Task<IActionResult> Validate([FromBody] ValidateMerchantSessionMode
         // Create the JSON payload to POST to the Apple Pay merchant validation URL.
         var request = new MerchantSessionRequest()
         {
-            DisplayName = _options.StoreName,
+            DisplayName = options.Value.StoreName,
             Initiative = "web",
             InitiativeContext = Request.GetTypedHeaders().Host.Value,
-            MerchantIdentifier = _certificate.GetMerchantIdentifier(),
+            MerchantIdentifier = certificate.GetMerchantIdentifier(),
         };
 
-        JsonDocument merchantSession = await _client.GetMerchantSessionAsync(requestUri, request, cancellationToken);
+        JsonDocument merchantSession = await client.GetMerchantSessionAsync(requestUri, request, cancellationToken);
 
         // Return the merchant session as-is to the JavaScript as JSON.
         return Json(merchantSession.RootElement);

src/ApplePayJS/Program.cs

@@ -40,7 +40,7 @@
     var handler = new HttpClientHandler();
     handler.ClientCertificates.Add(certificate);
 
-    // Apple Pay JS requires the use of at least TLS 1.2 to generate a merchange session:
+    // Apple Pay JS requires the use of at least TLS 1.2 to generate a merchant session:
     // https://developer.apple.com/documentation/applepayjs/setting_up_server_requirements
     // If you run an older operating system that does not negotiate this by default, uncomment the line below.
     // handler.SslProtocols = SslProtocols.Tls12;

tests/ApplePayJS.Tests/BrowserFixture.cs

@@ -8,17 +8,10 @@
 
 namespace ApplePayJS.Tests;
 
-internal sealed class BrowserFixture
+internal sealed class BrowserFixture(ITestOutputHelper? outputHelper)
 {
-    public BrowserFixture(ITestOutputHelper? outputHelper)
-    {
-        OutputHelper = outputHelper;
-    }
-
     private static bool IsRunningInGitHubActions { get; } = !string.IsNullOrEmpty(Environment.GetEnvironmentVariable("GITHUB_ACTIONS"));
 
-    private ITestOutputHelper? OutputHelper { get; }
-
     public async Task WithPageAsync(
         Func<IPage, Task> action,
         string browserType = "chromium",
@@ -32,8 +25,8 @@ public async Task WithPageAsync(
 
         IPage page = await browser.NewPageAsync(options);
 
-        page.Console += (_, e) => OutputHelper?.WriteLine(e.Text);
-        page.PageError += (_, e) => OutputHelper?.WriteLine(e);
+        page.Console += (_, e) => outputHelper?.WriteLine(e.Text);
+        page.PageError += (_, e) => outputHelper?.WriteLine(e);
 
         try
         {
@@ -119,11 +112,11 @@ await page.ScreenshotAsync(new PageScreenshotOptions()
                 Path = path,
             });
 
-            OutputHelper?.WriteLine($"Screenshot saved to {path}.");
+            outputHelper?.WriteLine($"Screenshot saved to {path}.");
         }
         catch (Exception ex)
         {
-            OutputHelper?.WriteLine("Failed to capture screenshot: " + ex);
+            outputHelper?.WriteLine("Failed to capture screenshot: " + ex);
         }
     }
 
@@ -152,11 +145,11 @@ private async Task TryCaptureVideoAsync(
 
             File.Move(videoSource, videoDestination);
 
-            OutputHelper?.WriteLine($"Video saved to {videoDestination}.");
+            outputHelper?.WriteLine($"Video saved to {videoDestination}.");
         }
         catch (Exception ex)
         {
-            OutputHelper?.WriteLine("Failed to capture video: " + ex);
+            outputHelper?.WriteLine("Failed to capture video: " + ex);
         }
     }
 }

tests/ApplePayJS.Tests/IntegrationTests.cs

@@ -9,17 +9,9 @@
 
 namespace ApplePayJS.Tests;
 
-public class IntegrationTests : IAsyncLifetime
+public class IntegrationTests(ITestOutputHelper outputHelper) : IAsyncLifetime
 {
-    public IntegrationTests(ITestOutputHelper outputHelper)
-    {
-        Fixture = new TestFixture()
-        {
-            OutputHelper = outputHelper,
-        };
-    }
-
-    private TestFixture Fixture { get; }
+    private TestFixture Fixture { get; } = new() { OutputHelper = outputHelper };
 
     public Task InitializeAsync()
     {
@@ -64,7 +56,7 @@ await fixture.WithPageAsync(async (page) =>
             await page.WaitForSelectorAsync(Selectors.CardName);
             await page.InnerTextAsync(Selectors.CardName).ShouldBe("American Express");
 
-            foreach (string selector in new[] { Selectors.BillingContact, Selectors.ShipingContact })
+            foreach (string selector in new[] { Selectors.BillingContact, Selectors.ShippingContact })
             {
                 var contact = await page.QuerySelectorAsync(selector);
                 contact.ShouldNotBeNull();
@@ -79,7 +71,7 @@ await fixture.WithPageAsync(async (page) =>
 
     private static void InstallPlaywright()
     {
-        int exitCode = Program.Main(new[] { "install" });
+        int exitCode = Program.Main(["install"]);
 
         if (exitCode != 0)
         {
@@ -94,6 +86,6 @@ private static class Selectors
         internal const string CardName = ".card-name";
         internal const string ContactName = ".contact-name";
         internal const string Pay = "id=apple-pay-button";
-        internal const string ShipingContact = "id=shipping-contact";
+        internal const string ShippingContact = "id=shipping-contact";
     }
 }

tests/ApplePayJS.Tests/TestFixture.cs

@@ -125,21 +125,14 @@ private void EnsureServer()
         }
     }
 
-    private sealed class HttpRequestInterceptionFilter : IHttpMessageHandlerBuilderFilter
+    private sealed class HttpRequestInterceptionFilter(HttpClientInterceptorOptions options) : IHttpMessageHandlerBuilderFilter
     {
-        internal HttpRequestInterceptionFilter(HttpClientInterceptorOptions options)
-        {
-            Options = options;
-        }
-
-        private HttpClientInterceptorOptions Options { get; }
-
         public Action<HttpMessageHandlerBuilder> Configure(Action<HttpMessageHandlerBuilder> next)
         {
             return (builder) =>
             {
                 next(builder);
-                builder.AdditionalHandlers.Add(Options.CreateHttpMessageHandler());
+                builder.AdditionalHandlers.Add(options.CreateHttpMessageHandler());
             };
         }
     }