public void Should_register_translator_with_EF() { var translatorMock = new Mock <IExpressionFragmentTranslator>(); OptionBuilder.AddExpressionFragmentTranslator(translatorMock.Object); DbContextWithSchema.Database.EnsureCreated(); // ReSharper disable once ReturnValueOfPureMethodIsNotUsed DbContextWithSchema.TestEntities.Where(e => e.Id == Guid.Empty).ToList(); // 3 calls: // e.Id == Guid.Empty // e.Id // Guid.Empty translatorMock.Verify(t => t.Translate(It.IsAny <Expression>()), Times.Exactly(3)); }