使用Microsoft.AspNetCore.TestHost进行完整的功能测试

简介

Microsoft.AspNetCore.TestHost是可以用于Asp.net Core 的功能测试工具。很多时候我们一个接口写好了，单元测试什么的也都ok了，需要完整调试一下，检查下单元测试未覆盖到的代码是否有bug。步骤为如下：程序打个断点->F5运行->通常需要登录个测试账号->查找要调试api的入口->获得断点开始调试=>代码报错？很多时候需要停止调试修改->回到第一步。如此反复循环，做着重复的工作，Microsoft.AspNetCore.TestHost正是为了解决这个问题，它可以让你使用xTest或者MSTest进行覆盖整个HTTP请求生命周期的功能测试。

进行一个简单的功能测试

新建一个Asp.net Core WebApi和xUnit项目

ValuesController里面自带一个Action

我们在xUnit项目里面模拟访问这个接口，首选安装如下nuget包：

• Microsoft.AspNetCore.TestHost
• Microsoft.AspNetCore.All（很多依赖懒得找的话直接安装这个集成包，百分之90涉及到AspNetCore的依赖都包含在里面）

然后需要引用被测试的AspnetCoreFunctionalTestDemo项目，新建一个测试类ValuesControllerTest

将GetValuesTest方法替换为如下代码，其中startup类是应用自AspnetCoreFunctionalTestDemo项目

        [Fact]
        public void GetValuesTest()
        {

            var client = new TestServer(WebHost
                .CreateDefaultBuilder()
                .UseStartup<Startup>())
                .CreateClient();

            string result = client.GetStringAsync("api/values").Result;

            Assert.Equal(result, JsonConvert.SerializeObject(new string[] { "value1", "value2" }));
        }

此时在ValueController打下断点

运行GetValuesTest调试测试

成功进入断点，我们不用启动浏览器，就可以进行完整的接口功能测试了。

修改内容目录与自动授权

上面演示了如何进行一个简单的功能测试，但是存在两个缺陷：

1. webApi在测试的时候实际的运行目录是在FunctionalTest目录下
2. 对需要授权的接口不能正常测试，会得到未授权的返回结果

1.内容目录

我们可以在Controller的Get方法输出当前的内容目录

内容目录是在测试x项目下这与我们的预期不符，如果webapi项目对根目录下的文件有依赖关系例如appsetting.json则会找不到该文件，解决的办法是在webHost中手动指定运行根目录

[Fact]
public void GetValuesTest()
{

    var client = new TestServer(WebHost
        .CreateDefaultBuilder()
        .UseContentRoot(GetProjectPath("AspnetCoreFunctionalTestDemo.sln", "", typeof(Startup).Assembly))
        .UseStartup<Startup>())
        .CreateClient();

    string result = client.GetStringAsync("api/values").Result;

    Assert.Equal(result, JsonConvert.SerializeObject(new string[] { "value1", "value2" }));
}

/// <summary>
/// 获取工程路径
/// </summary>
/// <param name="slnName">解决方案文件名，例test.sln</param>
/// <param name="solutionRelativePath">如果项目与解决方案文件不在一个目录，例如src文件夹中，则传src</param>
/// <param name="startupAssembly">程序集</param>
/// <returns></returns>
private static string GetProjectPath(string slnName, string solutionRelativePath, Assembly startupAssembly)
{
      string projectName = startupAssembly.GetName().Name;
      string applicationBasePath = PlatformServices.Default.Application.ApplicationBasePath;
      var directoryInfo = new DirectoryInfo(applicationBasePath);
      do
      {
          var solutionFileInfo = new FileInfo(Path.Combine(directoryInfo.FullName, slnName));
          if (solutionFileInfo.Exists)
          {
              return Path.GetFullPath(Path.Combine(directoryInfo.FullName, solutionRelativePath, projectName));
          }

          directoryInfo = directoryInfo.Parent;
      }
      while (directoryInfo.Parent != null);

      throw new Exception($"Solution root could not be located using application root {applicationBasePath}.");
}

GetProjectPath方法采用递归的方式找到startup的项目所在路径，此时我们再运行

2.自动授权

每次测试时手动登录这是一件很烦人的事情，所以我们希望可以自动话，这里演示的时cookie方式的自动授权

首先在startup文件配置cookie认证

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using Microsoft.AspNetCore.Authentication.Cookies;

namespace AspnetCoreFunctionalTestDemo
{
    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddMvc();
            services.AddAuthentication(o => o.DefaultScheme = CookieAuthenticationDefaults.AuthenticationScheme)
               .AddCookie(o =>
               {
                   o.ExpireTimeSpan = new TimeSpan(, , );
                   o.Events.OnRedirectToLogin = (context) =>
                   {
                       context.Response.StatusCode = ;
                       return Task.CompletedTask;
                   };
               });
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IHostingEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            app.UseAuthentication();
            app.UseMvc();
        }
    }
}

这里覆盖了cookie认证失败的默认操作改为返回401状态码。

在valuesController新增登录的Action并配置Get的Action需要授权访问

using Microsoft.AspNetCore.Authentication;
using Microsoft.AspNetCore.Authentication.Cookies;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Mvc;
using System.Collections.Generic;
using System.Security.Claims;

namespace AspnetCoreFunctionalTestDemo.Controllers
{
    [Route("api/[controller]")]
    public class ValuesController : Controller
    {
        // GET api/values
        [HttpGet,Authorize]
        public IEnumerable<string> Get([FromServices]IHostingEnvironment env)
        {
            return new string[] { "value1", "value2" };
        }

        // POST api/values
        [HttpGet("Login")]
        public void Login()
        {
            var identity = new ClaimsIdentity(CookieAuthenticationDefaults.AuthenticationScheme);
            identity.AddClaim(new Claim(ClaimTypes.Name, "huanent"));
            var principal = new ClaimsPrincipal(identity);
            HttpContext.SignInAsync(CookieAuthenticationDefaults.AuthenticationScheme, principal).Wait();
        }
    }
}

此时我们使用测试项目测试Get方法

如我们预期，返回了401，说明未授权。我们修改下GetValuesTest

using AspnetCoreFunctionalTestDemo;
using Microsoft.AspNetCore;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.TestHost;
using Microsoft.Extensions.PlatformAbstractions;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using Xunit;
using static Microsoft.AspNetCore.WebSockets.Internal.Constants;

namespace FunctionalTest
{
    public class ValuesControllerTest
    {

        [Fact]
        public void GetValuesTest()
        {
            var client = new TestServer(
                WebHost.CreateDefaultBuilder()
                       .UseStartup<Startup>()
                       .UseContentRoot(GetProjectPath("AspnetCoreFunctionalTestDemo.sln", "", typeof(Startup).Assembly))
                       ).CreateClient();
            var respone = client.GetAsync("api/values/login").Result;
            SetCookie(client, respone);
            var result = client.GetAsync("api/values").Result;
        }

        private static void SetCookie(HttpClient client, HttpResponseMessage respone)
        {
            string cookieString = respone.Headers.GetValues("Set-Cookie").First();
            string cookieBody = cookieString.Split(';').First();
            client.DefaultRequestHeaders.Add("Cookie", cookieBody);
        }

        /// <summary>
        /// 获取工程路径
        /// </summary>
        /// <param name="slnName">解决方案文件名，例test.sln</param>
        /// <param name="solutionRelativePath">如果项目与解决方案文件不在一个目录，例如src文件夹中，则传src</param>
        /// <param name="startupAssembly">程序集</param>
        /// <returns></returns>
        private static string GetProjectPath(string slnName, string solutionRelativePath, Assembly startupAssembly)
        {
            string projectName = startupAssembly.GetName().Name;
            string applicationBasePath = PlatformServices.Default.Application.ApplicationBasePath;
            var directoryInfo = new DirectoryInfo(applicationBasePath);
            do
            {
                var solutionFileInfo = new FileInfo(Path.Combine(directoryInfo.FullName, slnName));
                if (solutionFileInfo.Exists)
                {
                    return Path.GetFullPath(Path.Combine(directoryInfo.FullName, solutionRelativePath, projectName));
                }

                directoryInfo = directoryInfo.Parent;
            }
            while (directoryInfo.Parent != null);

            throw new Exception($"Solution root could not be located using application root {applicationBasePath}.");
        }
    }
}

我们首先访问api/Values/Login，获取到Cookie，然后讲cookie附在httpclient的默认http头上，这样就能够成功访问需要授权的接口了

总结

通过上面演示，我们已经可以很大程度地模拟了整个api请求，让我们可以方便地一键调试目标接口，再也不用开浏览器或postman了。

附上演示项目地址：https://github.com/huanent/AspnetCoreFunctionalTestDemo