Events-MVC (example with htmx)

Events-MVC/Tests/Events.Tests.IntegrationTests/Infrastructure/AntiforgeryRequestHelper.cs

@@ -0,0 +1,40 @@
+using System.Net.Http.Headers;
+using System.Text.RegularExpressions;
+
+namespace Events.Tests.IntegrationTests.Infrastructure;
+
+internal static partial class AntiforgeryRequestHelper
+{
+    private const string AntiforgeryFieldName = "__RequestVerificationToken";
+
+    public static async Task<HttpResponseMessage> PostFormAsync(
+        HttpClient client,
+        string pageUrl,
+        string postUrl,
+        IEnumerable<KeyValuePair<string, string?>> fields)
+    {
+        var pageHtml = await client.GetStringAsync(pageUrl);
+        var token = ExtractAntiforgeryToken(pageHtml);
+
+        var payload = fields
+            .Append(new KeyValuePair<string, string?>(AntiforgeryFieldName, token))
+            .ToArray();
+
+        using var request = new HttpRequestMessage(HttpMethod.Post, postUrl)
+        {
+            Content = new FormUrlEncodedContent(payload!)
+        };
+        request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("text/html"));
+        return await client.SendAsync(request);
+    }
+
+    private static string ExtractAntiforgeryToken(string html)
+    {
+        var match = AntiforgeryTokenRegex().Match(html);
+        Assert.True(match.Success, "Expected antiforgery token field was not found in the HTML response.");
+        return match.Groups["token"].Value;
+    }
+
+    [GeneratedRegex("<input[^>]*name=\"__RequestVerificationToken\"[^>]*value=\"(?<token>[^\"]+)\"", RegexOptions.IgnoreCase | RegexOptions.Compiled)]
+    private static partial Regex AntiforgeryTokenRegex();
+}