This code caused warning because the method is async and it didn’t await keyword.

public override async Task<IList<TEntity>> GetListAsync(
QueryParameters<TEntity, TKey> queryParameters = null,
CancellationToken cancellationToken = default)
{
    return Query(queryParameters).ToList();
}

I’ve added await and turned ToList() into ToListAsync()

return await Query(queryParameters).ToListAsync();

Now this and several other tests fail because of same error :

[Test]
public async Task GetEntityListAsync_Filter_ReturnsFilteredList()
{
    //Arrange
    var mapper = new MapperConfiguration(cfg =>
    {
    cfg.AddProfile(new SkillProfile());
    }).CreateMapper();
    _dataMapper = new DataMapper(mapper);

    _skillRepositoryFake = new SkillRepositoryFake(GetEntityList(), _dataMapper);
    _unitOfWorkMock.SetupGet(x => x.SkillRepository).Returns(_skillRepositoryFake);

    _sut = new SkillService(_unitOfWorkMock.Object);

    //Act 
    var result = await _sut.GetEntityListAsync();

    //Assert
    var entitiesWithDeletedAt = result.Where(x => x.DeletedAt.HasValue);
    Assert.Multiple(() =>
    {
        Assert.That(entitiesWithDeletedAt, Is.Empty);
        Assert.That(result, Has.Count.EqualTo(4));
    });
}

The error is :

System.InvalidOperationException : The source ‘IQueryable’ doesn’t
implement
‘IAsyncEnumerable<IDS.HrPortal.Core.Entities.SkillEntity>’. Only
sources that implement ‘IAsyncEnumerable’ can be used for Entity
Framework asynchronous operations.