.Net核心单元测试-模拟IOptions <T>

我觉得我在这里确实缺少一些明显的东西。我有一些类需要使用.Net Core IOptions模式（？）注入选项。当我对该类进行单元测试时，我想模拟各种版本的选项以验证该类的功能。有谁知道如何在Startup类之外正确模拟/实例化/填充IOptions？

以下是我正在使用的类的一些示例：

设置/选项型号

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace OptionsSample.Models
{
    public class SampleOptions
    {
        public string FirstSetting { get; set; }
        public int SecondSetting { get; set; }
    }
}

使用设置的要测试的类：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using OptionsSample.Models
using System.Net.Http;
using Microsoft.Extensions.Options;
using System.IO;
using Microsoft.AspNetCore.Http;
using System.Xml.Linq;
using Newtonsoft.Json;
using System.Dynamic;
using Microsoft.Extensions.Logging;

namespace OptionsSample.Repositories
{
    public class SampleRepo : ISampleRepo
    {
        private SampleOptions _options;
        private ILogger<AzureStorageQueuePassthru> _logger;

        public SampleRepo(IOptions<SampleOptions> options)
        {
            _options = options.Value;
        }

        public async Task Get()
        {
        }
    }
}

与其他类不同的程序集中的单元测试：

using OptionsSample.Repositories;
using OptionsSample.Models;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Xunit;
using Microsoft.Extensions.Logging;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Options;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Configuration;

namespace OptionsSample.Repositories.Tests
{
    public class SampleRepoTests
    {
        private IOptions<SampleOptions> _options;
        private SampleRepo _sampleRepo;


        public SampleRepoTests()
        {
            //Not sure how to populate IOptions<SampleOptions> here
            _options = options;

            _sampleRepo = new SampleRepo(_options);
        }
    }
}

您需要手动创建和填充IOptions<SampleOptions>对象。您可以通过Microsoft.Extensions.Options.Options帮助程序类来实现。例如：

IOptions<SampleOptions> someOptions = Options.Create<SampleOptions>(new SampleOptions());

您可以将其简化为：

var someOptions = Options.Create(new SampleOptions());

显然，这不是很有用。您实际上需要创建并填充SampleOptions对象，并将其传递给Create方法。

如果您打算使用@TSeng在注释中指示的Mocking Framework，则需要在project.json文件中添加以下依赖项。

   "Moq": "4.6.38-alpha",

恢复依赖关系后，使用MOQ框架就像创建SampleOptions类的实例，然后如上所述将其分配给Value一样简单。

这是一个代码轮廓，看起来如何。

SampleOptions app = new SampleOptions(){Title="New Website Title Mocked"}; // Sample property
// Make sure you include using Moq;
var mock = new Mock<IOptions<SampleOptions>>();
// We need to set the Value of IOptions to be the SampleOptions Class
mock.Setup(ap => ap.Value).Returns(app);

设置好模拟后，您现在可以将模拟对象传递给构造器，如下所示：

SampleRepo sr = new SampleRepo(mock.Object);   

HTH。

仅供参考，我有一个git存储库，概述了Github / patvin80上的这两种方法

您完全可以避免使用最小起订量。在测试.json配置文件中使用。一个文件用于许多测试类文件。很好用ConfigurationBuilder在这种情况下。

appsetting.json的示例

{
    "someService" {
        "someProp": "someValue
    }
}

设置映射类的示例：

public class SomeServiceConfiguration
{
     public string SomeProp { get; set; }
}

测试所需的服务示例：

public class SomeService
{
    public SomeService(IOptions<SomeServiceConfiguration> config)
    {
        _config = config ?? throw new ArgumentNullException(nameof(_config));
    }
}

NUnit测试类：

[TestFixture]
public class SomeServiceTests
{

    private IOptions<SomeServiceConfiguration> _config;
    private SomeService _service;

    [OneTimeSetUp]
    public void GlobalPrepare()
    {
         var configuration = new ConfigurationBuilder()
            .SetBasePath(Directory.GetCurrentDirectory())
            .AddJsonFile("appsettings.json", false)
            .Build();

        _config = Options.Create(configuration.GetSection("someService").Get<SomeServiceConfiguration>());
    }

    [SetUp]
    public void PerTestPrepare()
    {
        _service = new SomeService(_config);
    }
}

给定的类Person取决于PersonSettings以下内容：

public class PersonSettings
{
    public string Name;
}

public class Person
{
    PersonSettings _settings;

    public Person(IOptions<PersonSettings> settings)
    {
        _settings = settings.Value;
    }

    public string Name => _settings.Name;
}

IOptions<PersonSettings>可以被模拟并Person可以如下进行测试：

[TestFixture]
public class Test
{
    ServiceProvider _provider;

    [OneTimeSetUp]
    public void Setup()
    {
        var services = new ServiceCollection();
        // mock PersonSettings
        services.AddTransient<IOptions<PersonSettings>>(
            provider => Options.Create<PersonSettings>(new PersonSettings
            {
                Name = "Matt"
            }));
        _provider = services.BuildServiceProvider();
    }

    [Test]
    public void TestName()
    {
        IOptions<PersonSettings> options = _provider.GetService<IOptions<PersonSettings>>();
        Assert.IsNotNull(options, "options could not be created");

        Person person = new Person(options);
        Assert.IsTrue(person.Name == "Matt", "person is not Matt");    
    }
}

注入IOptions<PersonSettings>到Person，而不是明确地传递给构造函数，使用此代码：

[TestFixture]
public class Test
{
    ServiceProvider _provider;

    [OneTimeSetUp]
    public void Setup()
    {
        var services = new ServiceCollection();
        services.AddTransient<IOptions<PersonSettings>>(
            provider => Options.Create<PersonSettings>(new PersonSettings
            {
                Name = "Matt"
            }));
        services.AddTransient<Person>();
        _provider = services.BuildServiceProvider();
    }

    [Test]
    public void TestName()
    {
        Person person = _provider.GetService<Person>();
        Assert.IsNotNull(person, "person could not be created");

        Assert.IsTrue(person.Name == "Matt", "person is not Matt");
    }
}

您始终可以通过Options.Create（）创建选项，而不仅仅是在实际创建要测试的存储库的模拟实例之前使用AutoMocker.Use（options）。使用AutoMocker.CreateInstance <>（）可以更轻松地创建实例，而无需手动传递参数

我已将您更改为SampleRepo，以便能够重现我想实现的行为。

public class SampleRepoTests
{
    private readonly AutoMocker _mocker = new AutoMocker();
    private readonly ISampleRepo _sampleRepo;

    private readonly IOptions<SampleOptions> _options = Options.Create(new SampleOptions()
        {FirstSetting = "firstSetting"});

    public SampleRepoTests()
    {
        _mocker.Use(_options);
        _sampleRepo = _mocker.CreateInstance<SampleRepo>();
    }

    [Fact]
    public void Test_Options_Injected()
    {
        var firstSetting = _sampleRepo.GetFirstSetting();
        Assert.True(firstSetting == "firstSetting");
    }
}

public class SampleRepo : ISampleRepo
{
    private SampleOptions _options;

    public SampleRepo(IOptions<SampleOptions> options)
    {
        _options = options.Value;
    }

    public string GetFirstSetting()
    {
        return _options.FirstSetting;
    }
}

public interface ISampleRepo
{
    string GetFirstSetting();
}

public class SampleOptions
{
    public string FirstSetting { get; set; }
}

这是不需要Mock的另一种简单方法，而是使用OptionsWrapper：

var myAppSettingsOptions = new MyAppSettingsOptions();
appSettingsOptions.MyObjects = new MyObject[]{new MyObject(){MyProp1 = "one", MyProp2 = "two", }};
var optionsWrapper = new OptionsWrapper<MyAppSettingsOptions>(myAppSettingsOptions );
var myClassToTest = new MyClassToTest(optionsWrapper);

对于我的系统和集成测试，我更喜欢在测试项目中复制/链接我的配置文件。然后，我使用ConfigurationBuilder来获取选项。

using System.Linq;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;

namespace SomeProject.Test
{
public static class TestEnvironment
{
    private static object configLock = new object();

    public static ServiceProvider ServiceProvider { get; private set; }
    public static T GetOption<T>()
    {
        lock (configLock)
        {
            if (ServiceProvider != null) return (T)ServiceProvider.GetServices(typeof(T)).First();

            var builder = new ConfigurationBuilder()
                .AddJsonFile("config/appsettings.json", optional: false, reloadOnChange: true)
                .AddEnvironmentVariables();
            var configuration = builder.Build();
            var services = new ServiceCollection();
            services.AddOptions();

            services.Configure<ProductOptions>(configuration.GetSection("Products"));
            services.Configure<MonitoringOptions>(configuration.GetSection("Monitoring"));
            services.Configure<WcfServiceOptions>(configuration.GetSection("Services"));
            ServiceProvider = services.BuildServiceProvider();
            return (T)ServiceProvider.GetServices(typeof(T)).First();
        }
    }
}
}

这样，我可以在TestProject的任何地方使用配置。对于单元测试，我更喜欢使用像patvin80所述的最小起订量。

与Aleha达成协议，使用testSettings.json配置文件可能更好。然后，无需注入IOption，而只需将真正的SampleOptions注入类构造器中，当对类进行单元测试时，可以在夹具中执行以下操作，也可以仅在测试类构造器中执行以下操作：

   var builder = new ConfigurationBuilder()
  .AddJsonFile("testSettings.json", true, true)
  .AddEnvironmentVariables();

  var configurationRoot = builder.Build();
  configurationRoot.GetSection("SampleRepo").Bind(_sampleRepo);