表达式导致模拟存储库返回null

Question

我试图测试一个服务方法，但为了做到这一点，我必须模拟我的ReportRepository。除了对Include方法的调用使模拟返回为NULL外，其他操作都很好。

下面返回预期的报告：

var report = new Report();
var reportRepoMock = Substitute.For<IReportRepository>();
reportRepoMock.Query()
    .ByReportType(ReportType.DELQ)
    .ToEntityAsync()
    .Returns(Task.FromResult(report));

但该服务实际上执行以下操作：

var report = await reportRepo.Query()
    .ByReportType(ReportType.DELQ)
    .Include(m => m.Fields)
    .ToEntityAsync();

问题是，当我在模拟中包含'include'方法时，返回的是null而不是预期的报告，因此我的测试以NullReferenceException:

var reportRepoMock = Substitue.For<IReportRepository>();
reportRepoMock.Query()
    .ByReportType(ReportType.DELQ)
    .Include(m => m.Fields)
    .ToEntityAsync()
    .Returns(Task.FromResult(report));

public class ReportRepository : IReportRepository
{
    private readonly IDbSet _dbSet;

    public ReportRepository(IDbContext context) {
        _dbSet = context.Set<Report>();
    }

    void Add(Report report) { ... }
    void Remove(Report report) { ... }
    ...

    public IReportQueryBuilder Query() {
        return new ReportQueryBuilder(_dbSet.AsQueryable());
    }
}

public class ReportQueryBuilder : IReportQueryBuilder
{
    private IQueryable<Report> _query;

    public ReportQueryBuilder(IQueryable<Report> query) {
        _query = query;
    }

    public IReportQueryBuilder ByReportType(ReportType reportType) {
        _query = _query.Where(m => m.ReportType == reportType);

        return this;
    }

    public IReportQueryBuilder Include<T>(Expression<Func<Report, T>> property) {
        _query = _query.Include(property);

        return this;
    }

    public async Task<Report> ToEntityAsync() {
        return await _query.FirstOrDefaultAsync();
    }
}

Answer 1

想通了这个。而不是将模拟设置为：

 reportRepoMock.Query()
    .ByReportType(ReportType.DELQ)
    .Include(m => m.Fields)
    .ToEntityAsync()
    .Returns(Task.FromResult(report));

我去了：

reportRepoMock.Query()
    .ByReportType(ReportType.DELQ)
    .Include(Arg.Any<Expression<Func<Report, Collection<ReportField>>>>())
    .ToEntityAsync()
    .Returns(Task.FromResult(report));