Dependency injection in Xunit project

You can use Xunit.DependencyInjection

You can implement your own service provider to resolve DbContext.

public class DbFixture
{
    public DbFixture()
    {
        var serviceCollection = new ServiceCollection();
        serviceCollection
            .AddDbContext<SomeContext>(options => options.UseSqlServer("connection string"),
                ServiceLifetime.Transient);

         ServiceProvider = serviceCollection.BuildServiceProvider();
    }

    public ServiceProvider ServiceProvider { get; private set; }
}

public class UnitTest1:IClassFixture<DbFixture>
{
    private ServiceProvider _serviceProvider;

    public UnitTest1(DbFixture fixture)
    {
        _serviceProvider = fixture.ServiceProvider;
    }

    [Fact]
    public void Test1()
    {
        using (var context = _serviceProvider.GetService<SomeContext>())
        {
        }
    }
}

But bear in your mind using EF inside a unit test is not a good idea and it's better to mock DbContext.

The Anatomy of Good Unit Testing