.NET Core 单元测试 - 模拟 IOptions<T>

您需要手动创建和填充 IOptions<SampleOptions> 对象。您可以通过 Microsoft.Extensions.Options.Options 帮助程序类来做到这一点。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。您需要实际创建和填充 SampleOptions 对象并将其传递给 Create 方法。

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

   "Moq": "4.6.38-alpha",

恢复依赖后，使用 MOQ 框架就像创建 SampleOptions 类的实例然后如前所述将其分配给 Value 一样简单。

这是一个代码概述它的外观。

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);

一旦设置了模拟，您现在可以将模拟对象传递给构造函数

SampleRepo sr = new SampleRepo(mock.Object);   

HTH。

仅供参考，我有一个 git 存储库，在 Github/patvin80 上概述了这两种方法

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您可以完全避免使用最小起订量。在您的测试 .json 配置文件中使用。许多测试类文件的一个文件。在这种情况下使用 ConfigurationBuilder 就可以了。

appsetting.json 示例

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

设置映射类示例：

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

需要测试的服务示例：

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);
    }
}

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您始终可以通过 Options.Create() 创建您的选项，而不是在实际创建您正在测试的存储库的模拟实例之前简单地使用 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

我已经稍微改变了你的 SampleRepo，以便能够重现我认为你想要实现的行为。

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; }
}

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给定依赖于 PersonSettings 的类 Person，如下所示：

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> 可以模拟，Person 可以按如下方式进行测试：

[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");    
    }
}

要将 IOptions<PersonSettings> 注入 Person 而不是将其显式传递给 ctor，请使用以下代码：

[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");
    }
}

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这是另一个不需要 Mock 的简单方法，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);

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使用 Microsoft.Extensions.Options.Options 类：

var someOptions= Options.Create(new SampleOptions(){Field1="Value1",Field2="Value2"});

或者

var someOptions= Options.Create(new SampleOptions{Field1="Value1",Field2="Value2"});

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对于我的系统和集成测试，我更喜欢在测试项目中拥有我的配置文件的副本/链接。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();
        }
    }
}
}

这样我就可以在我的 TestProject 中的任何地方使用配置。对于单元测试，我更喜欢使用描述的 patvin80 之类的 MOQ。

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同意 Aleha 的观点，使用 testSettings.json 配置文件可能会更好。

然后，您可以简单地在类构造函数中注入真正的 SampleOptions，而不是注入 IOption，当对类进行单元测试时，您可以在夹具中执行以下操作，或者再次在测试类构造函数中执行以下操作：

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

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

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首先在根单元TestProject中添加“appsettings.json”文件，然后使用此代码：private readonly Mock _fileRepMock;私人 IOptions _options;公共 FileServiceTest() { _fileRepMock = new Mock(); var config = new ConfigurationBuilder() .AddJsonFile("appsettings.json") .AddEnvironmentVariables() .Build(); _options = Options.Create(config.GetSection("File").Get());现在您可以在模拟存储库中使用 _options FileService fileService = new FileService(_fileRepMock.Object, _options);

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