内存数据库中的实体框架仅在串联运行测试时才失败

Question

我的存储库测试使用一个在内存数据库中清除每个测试后清除上下文：

using System;
using System.Threading.Tasks;
using Application;
using Microsoft.EntityFrameworkCore;
using NUnit.Framework;

namespace UnitTests.Repositories;

public class RepositoryTestBase
{
    protected readonly ApplicationDbContext _context;
    
    public RepositoryTestBase()
    {
        var options = new DbContextOptionsBuilder<ApplicationDbContext>()
            .UseInMemoryDatabase(databaseName: "ApplicationDbContext").Options;

        _context = new ApplicationDbContext(options);
    }
    
    [TearDown]
    public async Task AfterEach()
    {
        _context.ChangeTracker.Clear();
        await _context.Database.EnsureDeletedAsync();
        await _context.Database.EnsureCreatedAsync();
    }

    [OneTimeTearDown]
    public void AfterAll()
    {
        _context.Dispose();
    }
}

这是存储库测试失败，如果我自己运行此测试，则仅在运行所有存储库测试时才失败：

[Test]
public async Task ReplaceItemTags_EmptyFirst()
{
    var originalTags = TestData.AlexItemA.Tags;
    await _context.Items.AddAsync(TestData.AlexItemA);
    await _unitOfWork.CompleteAsync();

    var result = await _ItemRepository.ReplaceItemTags(TestData.AlexItemA.Id, new List<Tag>() {TestData.TagB});

    //TESTS FAIL HERE, THIS IS A WRAPPER AROUND _context.SaveChangesAsync()
    await _unitOfWork.CompleteAsync();
    
    Assert.NotNull(result);
    Assert.AreNotEqual(originalTags, result?.Tags);
    Assert.AreEqual(1, result?.Tags?.Count);
    Assert.Contains(TestData.TagB, result?.Tags?.ToList());
}

这是正在测试的方法：

    public async Task<Item?> ReplaceItemTags(Guid ItemId, List<Tag> tags)
    {
        var Item = await _context.Items.FindAsync(ItemId);
        if (Item == null)
        {
            return null;
        }
        Item.Tags = tags.Distinct().ToList();
        return Item;
    }

这是测试失败的堆栈跟踪：

Microsoft.EntityFrameworkCore.DbUpdateConcurrencyException : Attempted to update or delete an entity that does not exist in the store.
   at Microsoft.EntityFrameworkCore.InMemory.Storage.Internal.InMemoryTable`1.Update(IUpdateEntry entry)
   at Microsoft.EntityFrameworkCore.InMemory.Storage.Internal.InMemoryStore.ExecuteTransaction(IList`1 entries, IDiagnosticsLogger`1 updateLogger)
   at Microsoft.EntityFrameworkCore.InMemory.Storage.Internal.InMemoryDatabase.SaveChangesAsync(IList`1 entries, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(IList`1 entriesToSave, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(StateManager stateManager, Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.DbContext.SaveChangesAsync(Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.DbContext.SaveChangesAsync(Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)
   at Application.Repositories.UnitOfWork.CompleteAsync() in C:\src\EasyForum.API\Application\Repositories\UnitOfWork.cs:line 20
   at UnitTests.Repositories.ItemRepositoryTests.ReplaceItemTags_EmptyFirst() in C:\src\EasyForum.API\UnitTests\Repositories\ItemRepositoryTests.cs:line 226
   at NUnit.Framework.Internal.TaskAwaitAdapter.GenericAdapter`1.GetResult()
   at NUnit.Framework.Internal.AsyncToSyncAdapter.Await(Func`1 invoke)
   at NUnit.Framework.Internal.Commands.TestMethodCommand.RunTestMethod(TestExecutionContext context)
   at NUnit.Framework.Internal.Commands.TestMethodCommand.Execute(TestExecutionContext context)
   at NUnit.Framework.Internal.Commands.BeforeAndAfterTestCommand.<>c__DisplayClass1_0.<Execute>b__0()
   at NUnit.Framework.Internal.Commands.BeforeAndAfterTestCommand.RunTestMethodInThreadAbortSafeZone(TestExecutionContext context, Action action)

我认为这可能与我的静态testdata类有关。不知何故，对我的模型实例的跟踪没有重置。我试图通过以下代码在拆卸时进行所有跟踪：

    foreach (var entity in _context.ChangeTracker.Entries())
    {
        entity.State = EntityState.Detached;
    }

如果有人有任何想法，请告诉我。也许有一种更好的方法来实现记忆数据库以进行我的测试目的。

Answer 1

找到了解决方案。

标签是数据库实体，我需要确保将它们存储在数据库中，然后再将其添加为项目中的外键。