用于控制器操作的 ASP.NET Core 集成测试

Question

Microsoft 文档 (https://docs.microsoft.com/en-us/aspnet/core/testing/integration-testing) 解释了如何使用 TestServer 类实现集成测试。如果我们使用 WEB API，这很容易，因为我们将序列化模型作为操作的响应。

但如果我想测试返回包含一些数据的 HTML 视图的控制器操作，我如何评估页面内容是否符合我的预期（避免扫描 HTML 页面内容）？

Answer 1

一种选择是使用 Selenium 之类的自动化 UI 测试

Answer 2

为了将此 JSON 序列化视图模型附加到您的页面，我实现了以下过滤器：

using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Filters;
using Microsoft.AspNetCore.Mvc.ModelBinding;
using Newtonsoft.Json;
using Ticketino.Web.Components.Extensions.Request;
using Ticketino.Web.OnlineShop.Serializations;
using Ticketino.Web.OnlineShop.ViewModels.Base;

namespace Ticketino.Web.OnlineShop.Filters
{
    /// <summary>
    /// This is a filter used only for integration tests.
    /// It format the ViewModel as jSon and appends it to the end of HMTL page, so that it can be deserialized from the test in order to check its values.
    /// </summary>
    /// <seealso cref="Microsoft.AspNetCore.Mvc.Filters.ResultFilterAttribute" />
    [AttributeUsage(AttributeTargets.Method)]
    public class IntegrationTestFilterAttribute : ResultFilterAttribute
    {
        public const string StartViewModelContainer = "<script type=\"model/json\">";
        public const string EndViewModelContainer = "</script>";

        public override void OnResultExecuting(ResultExecutingContext filterContext)
        {
            if (!filterContext.ModelState.IsValid)
            {
                var viewResult = filterContext.Result as ViewResult;
                if (viewResult?.Model is BaseViewModel)
                {
                    var errors = IntegrationTestFilterAttribute.GetModelErrors(filterContext.ModelState);
                    ((BaseViewModel)viewResult.Model).ValidationErrors = errors;
                }
            }

            base.OnResultExecuting(filterContext);
        }

        public override void OnResultExecuted(ResultExecutedContext filterContext)
        {
            if (!filterContext.HttpContext.Request.IsAjaxRequest())
            {
                var viewResult = filterContext.Result as ViewResult;
                if (viewResult?.Model != null)
                {
                    var jsonViewModel = string.Concat(
                        IntegrationTestFilterAttribute.StartViewModelContainer,
                        JsonConvert.SerializeObject(viewResult.Model, Formatting.None, CommonJsonSerializerSettings.Settings()),
                        IntegrationTestFilterAttribute.EndViewModelContainer);

                    filterContext.HttpContext.Response.WriteAsync(jsonViewModel);
                }
            }

            base.OnResultExecuted(filterContext);
        }

        #region Private methods

        private static IDictionary<string, string> GetModelErrors(ModelStateDictionary errDictionary)
        {
            var errors = new Dictionary<string, string>();

            //get all entries from the ModelStateDictionary that have any errors and add them to our Dictionary
            errDictionary.Where(k => k.Value.Errors.Count > 0).ForEach(i =>
            {
                foreach (var errorMessage in i.Value.Errors.Select(e => e.ErrorMessage))
                {
                    errors.Add(i.Key, errorMessage);
                }
            });

            return errors;
        }

        #endregion
    }
}

然后，在 ConfigureServices(IServiceCollection serviceCollection) 方法中，当您运行集成测试时注入它，如下所示：

        // Filter to append json serialized view model to buttom html response page, in order to eveluate from integration test class
        if (_hostingEnvironment.IsIntegrationTest())
        {
            mvcBuilder.AddMvcOptions(opt => { opt.Filters.Add(new IntegrationTestFilterAttribute()); });
        }