如何对时间触发的 azure function 进行单元测试？ 我的测试不起作用

Question

首先，我的测试代码：

using Microsoft.AspNetCore.Http;
using Moq;
using NUnit.Framework;
using System.IO;
using System.Threading.Tasks;
using TeamsAllocationManager.Api.Functions;
using TeamsAllocationManager.Contracts.Base;
using TeamsAllocationManager.Contracts.EmployeeWorkingTypeHistory;
using Microsoft.Extensions.Logging;
using System.Linq.Expressions;
using System;

namespace TeamsAllocationManager.Tests.Functions
{
    [TestFixture]
    public class HistoryClearingFunctionTests
    {
        private readonly ILogger _mockedLogger;
        private readonly Mock<IDispatcher> _dispatcherMock;

        public HistoryClearingFunctionTests()
        {
            _mockedLogger = new Mock<ILogger>().Object;
            _dispatcherMock = new Mock<IDispatcher>();
        }

        [Test]
        public async Task ShouldCallClearOldEmployeeWorkingTypeHistoryRecordsCommand() =>
            await VerifyFunctionExecutionAsync(c => c.DispatchAsync<ClearOldEmployeeWorkingTypeHistoryRecordsCommand, bool>(It.IsAny<ClearOldEmployeeWorkingTypeHistoryRecordsCommand>(), default), "GET");
        private async Task VerifyFunctionExecutionAsync(Expression<Action<IDispatcher>> expression, string verb, string path = "", QueryCollection? query = null, MemoryStream? body = null)
        {
            // given
            var function = new HistoryClearingFunction(_dispatcherMock.Object);
            var reqMock = new Mock<HttpRequest>();
            reqMock.Setup(r => r.Method).Returns(verb);
            reqMock.Setup(r => r.Query).Returns(query ?? new QueryCollection());
            reqMock.Setup(r => r.Body).Returns(body ?? new MemoryStream());

            // when
            await function.RunAsync(reqMock.Object, path, _mockedLogger);

            // then
            _dispatcherMock.Verify(expression, Times.Once);
        }
    }
}

目前我在第 29 行有一个错误，我在那里等待 VerifyFunctionExecutionAsync。 错误出现在 DispatchAsync<Clear***Command> 上，听起来像这样：

“TeamsAllocationManager.Contracts.EmployeeWorkingTypeHistory.ClearOldEmployeeWorkingTypeHistoryRecordsCommand”不能用作泛型类型或方法“ICommandDispatcher.DispatchAsync(TCommand, CancellationToken)”中的类型参数“TCommand”。 没有从“TeamsAllocationManager.Contracts.EmployeeWorkingTypeHistory.ClearOldEmployeeWorkingTypeHistoryRecordsCommand”到“TeamsAllocationManager.Contracts.Base.Commands.ICommand”的隐式引用转换。 TeamsAllocationManager.Tests

我是 azure 功能的新手，不知道如何修复它。 rest 的代码（测试功能）工作正常，所以只有测试有问题。

#Update 1 修复了上面代码中的错误，并在下面添加了 function 代码：

using Microsoft.Azure.WebJobs;
using System.Threading.Tasks;
using TeamsAllocationManager.Contracts.Base;
using TeamsAllocationManager.Contracts.EmployeeDeskHistory;
using TeamsAllocationManager.Contracts.EmployeeWorkingTypeHistory;

namespace TeamsAllocationManager.Api.Functions
{
    public class HistoryClearingFunction : FunctionBase
    {
        private readonly IDispatcher _dispatcher;
        public HistoryClearingFunction(IDispatcher dispatcher)
        {
            _dispatcher = dispatcher;
        }
        [FunctionName("EmployeeWorkingTypeHistoryClearingFunction")]
        public async Task EmployeeWorkingTypeHistoryClearingFunction([TimerTrigger("0 0 0 1 * *")]TimerInfo myTimer) 
        {
            await _dispatcher.DispatchAsync<ClearOldEmployeeWorkingTypeHistoryRecordsCommand, bool>(new ClearOldEmployeeWorkingTypeHistoryRecordsCommand());
        }
        [FunctionName("EmployeeDeskHistoryClearingFunction")]
        public async Task EmployeeDeskHistoryClearingFunction([TimerTrigger("0 0 0 1 * *")] TimerInfo myTimer)
        {
            await _dispatcher.DispatchAsync<ClearOldEmployeeDeskHistoryRecordsCommand, bool>(new ClearOldEmployeeDeskHistoryRecordsCommand());
        }
    }
}

当前错误：

消息：Moq.MockException：预期在模拟上调用一次，但为 0 次：c => c.DispatchAsync<ClearOldEmployeeWorkingTypeHistoryRecordsCommand, CancellationToken>(It.IsAny()

执行的调用：

MockIDispatcher:1 (c):

未执行任何调用。

Answer 1

我建议通过架构更改来解决这个问题。

将所有与 function 技术本身不直接相关的功能代码移动到帮助程序 class 中。 然后针对这个助手 class 编写 UnitTest。

这将使测试执行生产性工作的代码变得更加容易。