最佳答案
如何使用实体框架核心模拟异步存储库
我试图为调用异步存储库的类创建一个单元测试。我使用的是 ASP.NET 核心和实体框架核心。我的通用存储库如下所示。
public class EntityRepository<TEntity> : IEntityRepository<TEntity> where TEntity : class
{
private readonly SaasDispatcherDbContext _dbContext;
private readonly DbSet<TEntity> _dbSet;
public EntityRepository(SaasDispatcherDbContext dbContext)
{
_dbContext = dbContext;
_dbSet = dbContext.Set<TEntity>();
}
public virtual IQueryable<TEntity> GetAll()
{
return _dbSet;
}
public virtual async Task<TEntity> FindByIdAsync(int id)
{
return await _dbSet.FindAsync(id);
}
public virtual IQueryable<TEntity> FindBy(Expression<Func<TEntity, bool>> predicate)
{
return _dbSet.Where(predicate);
}
public virtual void Add(TEntity entity)
{
_dbSet.Add(entity);
}
public virtual void Delete(TEntity entity)
{
_dbSet.Remove(entity);
}
public virtual void Update(TEntity entity)
{
_dbContext.Entry(entity).State = EntityState.Modified;
}
public virtual async Task SaveChangesAsync()
{
await _dbContext.SaveChangesAsync();
}
}
然后我有一个服务类，它对存储库的一个实例调用 FindBy 和 FirstOrDefaultAsync:
public async Task<Uri> GetCompanyProductURLAsync(Guid externalCompanyID, string productCode, Guid loginToken)
{
CompanyProductUrl companyProductUrl = await _Repository.FindBy(u => u.Company.ExternalCompanyID == externalCompanyID && u.Product.Code == productCode.Trim()).FirstOrDefaultAsync();
if (companyProductUrl == null)
{
return null;
}
var builder = new UriBuilder(companyProductUrl.Url);
builder.Query = $"-s{loginToken.ToString()}";
return builder.Uri;
}
在下面的测试中，我试图模仿存储库调用:
[Fact]
public async Task GetCompanyProductURLAsync_ReturnsNullForInvalidCompanyProduct()
{
var companyProducts = Enumerable.Empty<CompanyProductUrl>().AsQueryable();
var mockRepository = new Mock<IEntityRepository<CompanyProductUrl>>();
mockRepository.Setup(r => r.FindBy(It.IsAny<Expression<Func<CompanyProductUrl, bool>>>())).Returns(companyProducts);
var service = new CompanyProductService(mockRepository.Object);
var result = await service.GetCompanyProductURLAsync(Guid.NewGuid(), "wot", Guid.NewGuid());
Assert.Null(result);
}
但是，当测试执行对存储库的调用时，会得到以下错误:
The provider for the source IQueryable doesn't implement IAsyncQueryProvider. Only providers that implement IEntityQueryProvider can be used for Entity Framework asynchronous operations.
如何正确地模拟存储库以使其工作？
