需要帮助模拟界面

如何解决需要帮助模拟界面

我有以下方法进行测试：

public static DateTime? GetLastSourceUpdateDate(this IQueryableDataFacade facade,long idDevice,long idMeasureType)
        {
            return facade.ExecuteExpression<SynchonizerLastUpdate,DateTime?>(logs =>
            {
                return logs.Where(log => log.IdDeviceMeasureType == idMeasureType && log.Device.Id == idDevice).Select(r => r.LastUpdateDate).FirstOrDefault();
            });
        }

因此，我需要为此模拟接口 IQueryableDataFacade。我试过了：

[Fact]
        public void ItReturnsNullWhenNovalueIsPresentForThatEntity()
        {
            List<SynchonizerLastUpdate> datasource = new List<SynchonizerLastUpdate>() { 
                new SynchonizerLastUpdate() { Id = 1,Device = new Device() { Id = 1},IdDeviceMeasureType = 1,LastUpdateDate = new DateTime(2020,1,1) },new SynchonizerLastUpdate() { Id = 1,1) }};

            var facadeService = new Mock<IQueryableDataFacade>();
            facadeService.Setup(m => m.ExecuteExpression<SynchonizerLastUpdate,DateTime?>(It.IsAny<Func<IQueryable<SynchonizerLastUpdate>,DateTime?>>())).Returns((p) => { datasource.Select(p)});
        }

但是它没有编译，模拟方法的返回类型有错误。它说缺少一个分号，但如果我添加它，它又坏了，我很难修复它。

解决方法

好的，我找到了解决方案，我采用了错误的方法。我需要执行函数参数 p，给它作为参数 IQueryable

[Fact]
        public void ItReturnsRightDateFromDataSource()
        {
            List<SynchonizerLastUpdate> datasource = new List<SynchonizerLastUpdate>() { 
                new SynchonizerLastUpdate() { Id = 1,Device = new Device() { Id = 1},IdDeviceMeasureType = 1,LastUpdateDate = new DateTime(2020,1,1) },new SynchonizerLastUpdate() { Id = 1,Device = new Device() { Id = 2},IdDeviceMeasureType = 2,2) },Device = new Device() { Id = 3},IdDeviceMeasureType = 3,3) }};

            var facadeService = new Mock<IQueryableDataFacade>();
            facadeService.Setup(m => m.ExecuteExpression(It.IsAny<Func<IQueryable<SynchonizerLastUpdate>,DateTime?>>())).Returns((Func<IQueryable<SynchonizerLastUpdate>,DateTime?> p) => 
            {
                IQueryable<SynchonizerLastUpdate> queryable = datasource.AsQueryable();
                return p(queryable);
            });

            var result = facadeService.Object.GetLastSourceUpdateDate(2,2);
            Assert.Equal(new DateTime(2020,2),result);
        }