C# End-to-end automated integration testing for MVC. More infromation available at https://andypalmer.dev/end-to-end-testing-mvc-signalr-api

AntiForgeryHelper.cs

using System;
using System.Net.Http;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

public static class AntiForgeryHelper
{
    public static string ExtractAntiForgeryToken(string htmlResponseText)
    {
        if (htmlResponseText == null)
        {
            throw new ArgumentNullException("htmlResponseText");
        }
        var match = Regex.Match(htmlResponseText, @"\<input name=""__RequestVerificationToken"" type=""hidden"" value=""([^""]+)"" \/\>");
        return match.Success ? match.Groups[1].Captures[0].Value : null;
    }

    public static async Task<string> ExtractAntiForgeryToken(this HttpResponseMessage response)
    {
        string responseAsString = await response.Content.ReadAsStringAsync();
        return ExtractAntiForgeryToken(responseAsString);
    }
}

CookiesHelper.cs

using Microsoft.Net.Http.Headers;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;

public class CookiesHelper
{
    public static IDictionary<string, string> ExtractCookiesFromResponse(HttpResponseMessage response)
    {
        IDictionary<string, string> result = new Dictionary<string, string>();
        if (response.Headers.TryGetValues("Set-Cookie", out var values))
        {
            SetCookieHeaderValue.ParseList(values.ToList()).ToList().ForEach(cookie =>
            {
                result.Add(cookie.Name.ToString(), cookie.Value.ToString());
            });
        }
        return result;
    }

    public static HttpRequestMessage PutCookiesOnRequest(HttpRequestMessage request, IDictionary<string, string> cookies)
    {
        cookies.Keys.ToList().ForEach(key =>
        {
            request.Headers.Add("Cookie", new CookieHeaderValue(key, cookies[key]).ToString());
        });

        return request;
    }

    public static HttpRequestMessage CopyCookiesFromResponse(HttpRequestMessage request, HttpResponseMessage response)
    {
        return PutCookiesOnRequest(request, ExtractCookiesFromResponse(response));
    }
}

MvcHttpClientHelper.cs

using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Threading.Tasks;

public class MvcHttpClientHelper
{
    public HttpClient Client { get; }

    public MvcHttpClientHelper(HttpClient httpClient)
    {
        Client = httpClient;
    }
    public async Task<HttpResponseMessage> LoginHttpRequest()
    {
        var request = new HttpRequestMessage(new HttpMethod("GET"), $"{Environment.MvcUrl}/Login");
        var httpResponseMessage = await Client.SendAsync(request);

        var formPostBodyData = await ExtractAntiForgeryToken(httpResponseMessage, new Dictionary<string, string> { { "username", Environment.Username }, { "password", Environment.Password } });

        var requestMessage = PostRequestHelper.CreateWithCookiesFromResponse($"{ Environment.MvcUrl}/Login", formPostBodyData, httpResponseMessage);
        var response = await Client.SendAsync(requestMessage);
        string result = await response.Content.ReadAsStringAsync();

        if (response.IsSuccessStatusCode)
        {
            return response;
        }
        else
        {
            throw new Exception(result);
        }
    }

    public async Task<HttpResponseMessage> PostHttpRequest(HttpResponseMessage httpResponseMessage, string url, Dictionary<string, string> formData)
    {
        var formPostBodyData = await ExtractAntiForgeryToken(httpResponseMessage, formData);

        var requestMessage = PostRequestHelper.CreateWithCookiesFromResponse(url, formPostBodyData, httpResponseMessage);
        var response = await Client.SendAsync(requestMessage);
        var result = await response.Content.ReadAsStringAsync();
        return response;
    }

    private static async Task<Dictionary<string, string>> ExtractAntiForgeryToken(HttpResponseMessage httpResponseMessage, Dictionary<string, string> formData)
    {
        var antiForgeryToken = await httpResponseMessage.ExtractAntiForgeryToken();
        formData.Add("__RequestVerificationToken", antiForgeryToken);
        return formData;
    }
}

PostRequestHelper.cs

using Microsoft.Net.Http.Headers;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;

public class PostRequestHelper
{
    public static HttpRequestMessage Create(String path, Dictionary<string, string> formPostBodyData)
    {
        var httpRequestMessage = new HttpRequestMessage(HttpMethod.Post, path)
        {
            Content = new FormUrlEncodedContent(ToFormPostData(formPostBodyData))
        };
        return httpRequestMessage;
    }

    public static List<KeyValuePair<string, string>> ToFormPostData(Dictionary<string, string> formPostBodyData)
    {
        List<KeyValuePair<string, string>> result = new List<KeyValuePair<string, string>>();
        formPostBodyData.Keys.ToList().ForEach(key =>
        {
            result.Add(new KeyValuePair<string, string>(key, formPostBodyData[key]));
        });
        return result;
    }

    public static HttpRequestMessage CreateWithCookiesFromResponse(string path, Dictionary<string, string> formPostBodyData,
        HttpResponseMessage response)
    {
        var httpRequestMessage = Create(path, formPostBodyData);
        return CookiesHelper.CopyCookiesFromResponse(httpRequestMessage, response);
    }
}