public void GetActiveSizes_WhenCalled_ReturnsAllActiveSizesOnly() { //arrange _context .Setup(c => c.Get(a => a.IsInactive == false)) .Returns(() => { var result = _sizes.Where(a => a.IsInactive == false).ToList(); return(result); }); //act var result = _sizeService.GetActiveSizes(); //assert Assert.That(result.Count, Is.EqualTo(2)); }