Moq 抛出异常，指出表达式树可能不包含使用可选参数的调用或调用

Question

我正在编写 NUnit 测试用例。我正在编写测试用例以获得一些值。以下是我的设置。

[Test]
public async Task GetGeographyList_StateUnderTest_ExpectedBehavior()
{
    // Arrange
    var geographyBusinessLogic = this.CreateGeographyBusinessLogic();

    Geography geographyObj = new Geography() { Id = 101, Country = "India", Region = "APAC", SubRegion = "Asia South" };
    IEnumerable<Geography> geographyObjList =  new List<Geography>() { geographyObj };
    //this.geographyRepository.setupGetAsync<Geography>(geographyObjList);
    this.geographyRepository.Setup(
        x => x.GetAsync()).ReturnsAsync(geographyObjList);

    // Act
    var result = await geographyBusinessLogic.GetGeographyList();

    // Assert
    Assert.IsNotNull(result);
}

在上面的代码中，x => x.GetAsync() 抛出一个错误：

An expression tree may not contain a call or invocation that uses optional arguments

下面是我对geographyBusinessLogic.GetGeographyList()的实现：

public async Task<IEnumerable<GeographyEntity>> GetGeographyList()
{
    var listOfGeographies = await this.GeographyRepository.GetAsync().ConfigureAwait(false);

    IEnumerable<GeographyEntity> result = from o in listOfGeographies
                                          select new GeographyEntity
                                          {
                                            Id = o.Id,
                                            Country = o.Country,
                                            Region = o.Region,
                                            SubRegion = o.SubRegion
                                          };
    return result;
}

下面是GetAsync方法的实现：

public async Task<IEnumerable<T>> GetAsync(Expression<Func<T, bool>> filter = null, Func<IQueryable<T>, IOrderedQueryable<T>> orderBy = null, params Expression<Func<T, object>>[] includes)
{
    IQueryable<T> query = this.dbSet;
    foreach (Expression<Func<T, object>> include in includes)
    {
        query = query.Include(include);
    }

    if (filter != null)
    {
        query = query.Where(filter);
    }

    if (orderBy != null)
    {
        query = orderBy(query);
    }

    return await query.ToListAsync().ConfigureAwait(false);
}

谁能帮我理解这个错误，谁能告诉我我在这里遗漏了什么？任何帮助将不胜感激。

Answer 1

您需要在设置模拟时填写所有可选参数。例如：

this.geographyRepository.Setup(x => x.GetAsync(
    It.IsAny<Expression<Func<Geography, bool>>>(),
    It.IsAny<Func<IQueryable<Geography>, IOrderedQueryable<Geography>>>(),
    It.IsAny<Expression<Func<Geography, object>>[]>())).ReturnsAsync(geographyObjList);

Moq 抛出异常，指出表达式树可能不包含使用可选参数的调用或调用

Moq throws exceptions stating that an expression tree may not contain a call or invocation that uses optional arguments

.net

c#

nunit

moq