Possible SingleOrDefaultAsync issue?

Hi Guys,

I bumped into a really strange issue when working on a project while using URF.core. I noticed that in my unit test a really simpel assert failed. But because there was a lot of custom code involved i first thought it was a mistake on my side so i skipped over it. Today I ran into the same issue again so I updated my fork of urf.core and added a simpel unit test:

[Fact]
        public async Task Product_Should_Not_Be_Null_After_A_Contains_Query()
        {
            // Arrange
            var repository = new Repository<Product>(_fixture.Context);

            // Act
            var products = await repository.Query().Where(p => p.ProductId == 1).SelectAsync();
            
            // Assert
            Assert.NotNull(products);

            // Act
            var product = await repository.Query().SingleOrDefaultAsync(s => s.ProductId == 2, new System.Threading.CancellationToken());

            // Assert
            Assert.NotNull(product);
        }

To my suprise this unit test is failing as well! Am i making a mistake or doing something wierd?

You can clone my fork to see it failing: https://github.com/Domitnator/URF.Core

I believe there is something going wrong in the SingleOrDefaultAsync because if i would replace that line with FindAsync:

[Fact]
        public async Task Product_Should_Not_Be_Null_After_A_Contains_Query()
        {
            // Arrange
            var repository = new Repository<Product>(_fixture.Context);

            // Act
            var products = await repository.Query().Where(p => p.ProductId == 1).SelectAsync();
            
            // Assert
            Assert.NotNull(products);

            // Act
            var product = await repository.FindAsync(2);

            // Assert
            Assert.NotNull(product);
        }

It works!

But it also works when i also request product with id 2 in the first query:

[Fact]
        public async Task Product_Should_Not_Be_Null_After_A_Contains_Query()
        {
            // Arrange
            var repository = new Repository<Product>(_fixture.Context);

            // Act
            var products = await repository.Query().Where(p => new List<int> { 1, 2 }.Contains(p.ProductId)).SelectAsync();
            
            // Assert
            Assert.NotNull(products);

            // Act
            var product = await repository.Query().SingleOrDefaultAsync(s => s.ProductId == 2, new System.Threading.CancellationToken());

            // Assert
            Assert.NotNull(product);
        }

So i’m not quite sure if it has anything to do with the SingleOrDefaultAsync method.

Hopefully you can help me out.

[lelong37]

@Domitnator if you could be so kind to issue a PR on this, that would be great.

[tonysneed]

@Domitnator, yes I think a PR would be good.