使用 MockServer 與 TestContainer 進行整合測試

使用MockServer進行整合測試

進行整合測試的時候，有些專案會依賴外部服務，以前是將外部服務抽成介面並進行抽換，但是這方法並不是很好。之前剛好使用MockServer進行壓力測試及相關測試。所以想說在整合測試裡面使用Docker去啟動MockServer方式。
這邊使用 TestContainer 進行架設 MockServer 的 Docker。(下面其中的 MockServerClientNet 套件可以選擇不使用。只是去設定MockServer相關期望比較簡單而已。)

安裝方式

dotnet add package Testcontainers
dotnet add package MockServerClientNet

建立 MockServer 的 TestContainer

• MockServerConfiguration.cs

public sealed class MockServerConfiguration : ContainerConfiguration
{
    public MockServerConfiguration() { }

    public MockServerConfiguration(IResourceConfiguration<CreateContainerParameters> resourceConfiguration)
        : base(resourceConfiguration) { }

    public MockServerConfiguration(IContainerConfiguration resourceConfiguration)
        : base(resourceConfiguration) { }

    public MockServerConfiguration(MockServerConfiguration resourceConfiguration)
        : base(new MockServerConfiguration(),resourceConfiguration) { }

    public MockServerConfiguration(MockServerConfiguration oldValue, MockServerConfiguration newValue)
        : base(oldValue, newValue) { }
}

• MockServerBuilder.cs

public sealed class MockServerBuilder : ContainerBuilder<MockServerBuilder, MockServerContainer, MockServerConfiguration>
{
    public const string MockServerImage = "mockserver/mockserver:latest";

    public const ushort MockServerPort = 1080;
    
    public MockServerBuilder()
        : this(new MockServerConfiguration())
    {
        DockerResourceConfiguration = Init().DockerResourceConfiguration;
    }

    private MockServerBuilder(MockServerConfiguration resourceConfiguration)
        : base(resourceConfiguration)
    {
        DockerResourceConfiguration = resourceConfiguration;
    }

    protected override MockServerConfiguration DockerResourceConfiguration { get; }

    public override MockServerContainer Build()
    {
        Validate();
        return new MockServerContainer(DockerResourceConfiguration);
    }

    protected override MockServerBuilder Init()
    {
        return base.Init()
                   .WithImage(MockServerImage)
                   .WithPortBinding(MockServerPort, true);
    }
    
    protected override MockServerBuilder Clone(IResourceConfiguration<CreateContainerParameters> resourceConfiguration)
    {
        return Merge(DockerResourceConfiguration, new MockServerConfiguration(resourceConfiguration));
    }
    
    protected override MockServerBuilder Clone(IContainerConfiguration resourceConfiguration)
    {
        return Merge(DockerResourceConfiguration, new MockServerConfiguration(resourceConfiguration));
    }
    
    protected override MockServerBuilder Merge(MockServerConfiguration oldValue, MockServerConfiguration newValue)
    {
        return new MockServerBuilder(new MockServerConfiguration(oldValue, newValue));
    }
}

• MockServerContainer.cs

public sealed class MockServerContainer : DockerContainer
{
    private readonly MockServerConfiguration _configuration;

    public MockServerContainer(MockServerConfiguration configuration)
        : base(configuration)
    {
        _configuration = configuration;
    }
    
    /// <summary>
    /// Retrieves the MockServer endpoint.
    /// </summary>
    /// <returns>The endpoint URL of the MockServer.</returns>
    public string GetEndpoint()
    {
        return $"http://{Hostname}:{GetMappedPublicPort(MockServerBuilder.MockServerPort)}";
    }
}

上面這三個類別的實作方式都可以在官方文件上找到。
這邊也提供 Testcontainers.ModuleName 相關範例。

整合測試相關設定與啟動

MockServerFixture.cs

public static class MockServerFixture
{
    public static MockServerContainer CreateContainer(MockServerSetting mockServerSetting, string environmentName)
    {
        var containerName = mockServerSetting.ContainerName;
        var container = new MockServerBuilder()
            .WithImage($"{mockServerSetting.Image}:{mockServerSetting.Tag}")
            .WithEnvironment(mockServerSetting.EnvironmentSettings)
            .WithName($"{environmentName}-{containerName}")
            .WithPortBinding(mockServerSetting.HostPort, mockServerSetting.ContainerPort)
            .WithAutoRemove(true)
            .Build();
        return container;
    }
}

ProjectFixture.cs

public class ProjectFixture : IAsyncLifetime
{

    private static MockServerContainer _mockServerContainer;

    public static string EnvironmentName { get; set; }

    /// <summary>
    /// Initializes a new instance of the <see cref="ProjectFixture"/> class
    /// </summary>
    public ProjectFixture()
    {
        // 確保路徑跨平台運行
        var baseDirectory = AppContext.BaseDirectory;
        var settingsFilePath = Path.Combine(baseDirectory, "TestSettings.json");
        
        TestSettingProvider.FilePath = settingsFilePath;
        
        EnvironmentName = TestSettingProvider.GetEnvironmentName(typeof(ProjectFixture));
        
        // Create Mock Server
        var mockServerSettings = TestSettingProvider.GetMockServerSettings();
       
        _mockServerContainer = MockServerFixture.CreateContainer(mockServerSettings, EnvironmentName);
        
    }

    internal static Uri MockServerEndpoint => new Uri(_mockServerContainer.GetEndpoint());

    /// <summary>
    /// Initializes this instance
    /// </summary>
    public async Task InitializeAsync()
    {
        using var cts = new CancellationTokenSource(TimeSpan.FromMinutes(5));
        
        await _mockServerContainer.StartAsync(cts.Token);
    }

    /// <summary>
    /// Disposes this instance
    /// </summary>
    public async Task DisposeAsync()
    {
        await _mockServerContainer.StopAsync();
        await _mockServerContainer.DisposeAsync();
    }
}

整合測試測試Restful API，這邊使用了FlentAssertions.Web進行驗證。這邊就不贅述。

[Collection(nameof(ProjectCollectionFixture))]
public class SampleControllerTests 
{
    protected TestWebApplicationFactory<Program> TestWebApplicationFactory { get; }
    
    protected HttpClient HttpClient { get; }

    public SampleControllerTests()
    {
        this.TestWebApplicationFactory = new TestWebApplicationFactory<Program>();
        this.HttpClient = TestWebApplicationFactory.CreateDefaultClient();
    }

    [Fact(DisplayName = "GetAsync_應返回正確的資料")]
    public async Task GetAsync_ShouldReturnCorrectData()
    {
        // arrange
        var expectedResponse = new List<string> { "Item1", "Item2", "Item3" };

        // 設置 MockServer 的模擬回應
        var mockServerEndPoint = ProjectFixture.MockServerEndpoint;
        var mockServerClient = new MockServerClient(mockServerEndPoint.Host, mockServerEndPoint.Port);
        
        var mockServerRequest = new HttpRequest()
            .WithPath("/details")
            .WithMethod(HttpMethod.Get);

        var mockServerResponse = new HttpResponse()
            .WithStatusCode(HttpStatusCode.OK)
            .WithHeader("Content-Type", "application/json")
            .WithBody(JsonSerializer.Serialize(new []
            {
                "Item1", "Item2", "Item3" 
            }))
            .WithDelay(TimeSpan.FromMilliseconds(100));
        
        await mockServerClient.When(mockServerRequest)
            .RespondAsync(mockServerResponse);
        
        var url = "api/sample";
        
        // act
        var response = await HttpClient.GetAsync(url);

        // assert
        response.Should().Be200Ok().And.BeAs(expectedResponse);
    }
}

關於上面的程式碼也提供在個人Github上面有完整的整合測試及 MockServer TestContainer

• 範例專案 IntegrationTestMockServer