二十多个'IServiceProvider'。单元测试

Question

我收到此错误消息：

An error was generated for warning 'Microsoft.EntityFrameworkCore.Infrastructure.ManyServiceProvidersCreatedWarning': More than twenty 'IServiceProvider' instances have been created for internal use by Entity Framework. This is commonly caused by injection of a new singleton service instance into every DbContext instance. For example, calling 'UseLoggerFactory' passing in a new instance each time--see https://go.microsoft.com/fwlink/?linkid=869049 for more details. This may lead to performance issues, consider reviewing calls on 'DbContextOptionsBuilder' that may require new service providers to be built. This exception can be suppressed or logged by passing event ID 'CoreEventId.ManyServiceProvidersCreatedWarning' to the 'ConfigureWarnings' method in 'DbContext.OnConfiguring' or 'AddDbContext'.

当我运行所有单元测试一起

设置

private readonly DbContextOptions<ApplicationDbContext> _contextOptions;
private readonly DbContextOptions<ApplicationDbContext> _inMemoryContextOptions;

public TestConstructor()
{
// Test for real database READ
_contextOptions = new DbContextOptionsBuilder<ApplicationDbContext>()
.UseSqlServer(_connectionString)
.Options;

// Test InMemory CREATE UPDATE DELETE
_inMemoryContextOptions = DbContextOptionsBuilder();
SeedInMemoryTestDb(_inMemoryContextOptions);
}

private static DbContextOptions<ApplicationDbContext> DbContextOptionsBuilder()
{
return new DbContextOptionsBuilder<ApplicationDbContext>()
.UseInMemoryDatabase(Guid.NewGuid().ToString(),new InMemoryDatabaseRoot())
.Options;
}

单元测试

[FACT] 
public void Test1()
await using var context = new ApplicationDbContext(_contextOptions);
//... Assert.Equal()
[FACT] 
public void Test2()
await using var context = new ApplicationDbContext(_inMemoryContextOptions);
//... Assert.Equal()

我在 5 或 6 class 中同时进行了设置和单元测试。 我想我需要为每个测试重新使用相同的上下文，但我没有做到这一点。

Answer 1

[CollectionDefinition("SharedDbContext")]
public class DatabaseCollection : ICollectionFixture<DatabaseFixture> { }

public class DatabaseFixture : IDisposable
{
    public ApplicationDbContext ApplicationDbContext;
    public ApplicationDbContext InMemoryApplicationDbContext;


    public DatabaseFixture()
    {
        // Test for real database READ
        var contextOptions = new DbContextOptionsBuilder<ApplicationDbContext>()
            .UseSqlServer(_connectionString)
            .Options;
        //// Test InMemory CREATE UPDATE DELETE
        var inMemoryContextOptions = DbContextOptionsBuilder();

        ApplicationDbContext = new ApplicationDbContext(contextOptions);
        InMemoryApplicationDbContext = new ApplicationDbContext(inMemoryContextOptions);

        SeedInMemoryTestDb(inMemoryContextOptions);
    }
}