ASP.NET核心3.1中API控制器的单元测试返回错误的状态码

[HttpGet("{id}")]
public async Task<IActionResult> Get(int id)
{
    var item = await _context.Items.FindAsync(id);
    if (item == null)
    {
        return NotFound(); // 确保返回正确的状态码
    }
    return Ok(item);
}

public class TestStartup : Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        // 配置测试环境的服务
        services.AddDbContext<TestDbContext>(options =>
            options.UseInMemoryDatabase("TestDb"));
    }

    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        // 配置中间件
    }
}

public class ItemsController : ControllerBase
{
    private readonly ApplicationDbContext _context;

    public ItemsController(ApplicationDbContext context)
    {
        _context = context;
    }

    // 控制器方法
}

public class ItemsControllerTests
{
    private readonly TestServer _server;
    private readonly HttpClient _client;

    public ItemsControllerTests()
    {
        var builder = new WebHostBuilder()
            .UseStartup<TestStartup>();
        _server = new TestServer(builder);
        _client = _server.CreateClient();
    }

    [Fact]
    public async Task Get_Item_ReturnsOk()
    {
        var response = await _client.GetAsync("/api/items/1");
        response.EnsureSuccessStatusCode(); // 确保返回状态码为200
    }
}

public class DatabaseFixture : IDisposable
{
    public ApplicationDbContext Context { get; private set; }

    public DatabaseFixture()
    {
        var builder = new DbContextOptionsBuilder<ApplicationDbContext>()
            .UseInMemoryDatabase(databaseName: "TestDb");
        Context = new ApplicationDbContext(builder.Options);
        // 插入测试数据
        Context.Items.Add(new Item { Id = 1, Name = "Test Item" });
        Context.SaveChanges();
    }

    public void Dispose()
    {
        Context.Dispose();
    }
}

public class ItemsControllerTests : IClassFixture<DatabaseFixture>
{
    private readonly HttpClient _client;
    private readonly DatabaseFixture _fixture;

    public ItemsControllerTests(DatabaseFixture fixture)
    {
        _fixture = fixture;
        var builder = new WebHostBuilder()
            .UseStartup<TestStartup>();
        var server = new TestServer(builder);
        _client = server.CreateClient();
    }

    [Fact]
    public async Task Get_Item_ReturnsOk()
    {
        var response = await _client.GetAsync("/api/items/1");
        response.EnsureSuccessStatusCode(); // 确保返回状态码为200
    }
}