在 ServiceProvider 中使用 Entity Framework Core 3.1 和 UseInMemoryDatabase 选项（作用域生命周期）

我已将一个 Web 应用程序项目从 .NET Core 2.1 迁移到 3.1（也将 EF Core 从 2.1.1 迁移到 3.1.0）。

迁移后，一些单元测试不再工作，抛出重复键数据库异常。

我模拟了这个问题并意识到 EF core 带有选项UseInMemoryDatabase3.1 中的行为有所不同，它不会清理旧数据。

在第二种测试方法中，People表已经包含从第一次测试添加的数据，这在 2.1 中没有发生

有谁知道如何使内存数据库适用于每个单元测试？

这是我的测试代码：

AppDbContext.cs

using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Text;

namespace MyConsoleApp.Database
{
    public class AppDbContext: DbContext
    {
        protected AppDbContext(DbContextOptions options) : base(options) { }

        public AppDbContext(DbContextOptions<AppDbContext> options) : this((DbContextOptions)options)
        {
        }

        public virtual DbSet<Person> Person { get; set; }
    }

    public class Person
    {
        [Key]
        public int Id { get; set; }
        public string Name { get; set; }
    }
}

AppUnitTest.cs

using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using MyConsoleApp.Database;
using System.Linq;

namespace MyConsoleAppTest
{
    [TestClass]
    public class AppUnitTest
    {
        public ServiceCollection Services { get; private set; }
        public ServiceProvider ServiceProvider { get; protected set; }

        [TestInitialize]
        public void Initialize()
        {
           Services = new ServiceCollection();

           Services.AddDbContext<AppDbContext>(opt => opt.UseInMemoryDatabase(databaseName: "InMemoryDb"), 
               ServiceLifetime.Scoped, 
               ServiceLifetime.Scoped);

            ServiceProvider = Services.BuildServiceProvider();
        }

        [TestMethod]
        public void TestMethod1()
        {
            using (var dbContext = ServiceProvider.GetService<AppDbContext>())
            {
                dbContext.Person.Add(new Person { Id = 0, Name = "test1" });
                dbContext.SaveChanges();
                Assert.IsTrue(dbContext.Person.Count() == 1);
            }
        }

        [TestMethod]
        public void TestMethod2()
        {
            using (var dbContext = ServiceProvider.GetService<AppDbContext>())
            {
                dbContext.Person.Add(new Person { Id = 0, Name = "test2" });
                dbContext.SaveChanges();
                Assert.IsTrue(dbContext.Person.Count() == 1);
            }
        }

        [TestCleanup]
        public virtual void Cleanup()
        {
            ServiceProvider.Dispose();
            ServiceProvider = null;
        }
    }
}

MyConsoleAppTest.csproj

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>netcoreapp3.1</TargetFramework>
    <IsPackable>false</IsPackable>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.EntityFrameworkCore.InMemory" Version="3.1.0" />
    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.2.0" />
    <PackageReference Include="MSTest.TestAdapter" Version="2.0.0" />
    <PackageReference Include="MSTest.TestFramework" Version="2.0.0" />
    <PackageReference Include="coverlet.collector" Version="1.0.1" />
  </ItemGroup>

  <ItemGroup>
    <ProjectReference Include="..\MyConsoleApp\MyConsoleApp.csproj" />
  </ItemGroup>

</Project>

您可以通过软件包控制台安装软件包

Install-Package Microsoft.EntityFrameworkCore.InMemory -Version 3.1.5

https://www.nuget.org/packages/Microsoft.EntityFrameworkCore.InMemory https://www.nuget.org/packages/Microsoft.EntityFrameworkCore.InMemory