无法将类型为'System.Linq.EnumerableQuery的对象转换为类型为'Microsoft.Azure.Documents.Linq.IDocumentQuery的对象
问题描述:
我有一个使用以下方法的类,并且正在使用Moq作为单元测试框架.我该如何模拟以下内容:
I have a class with the following Method and am using Moq as a Unit Testing Framework. How can I mock the following:
FeedOptions feedOptions = new FeedOptions
{
MaxItemCount = 1000
};
var query = await _storeAccessClient.CreateDocumentQueryAsync<CustomEntity>(_collectionLink, feedOptions)
.Where(c => c.DataType == _dataType)
.OrderBy(c => c.StartTime, sortOrder)
.AsDocumentQuery()
.ExecuteNextAsync<CustomEntity>();
List<CustomEntity> result = query.ToList<CustomEntity>();
非常感谢任何帮助!
答
您要做的就是围绕EnumerableQuery类创建一个包装,该类继承自IQueryable和IDocumentQuery,如下所示:
All you have to do is create a wrapper around EnumerableQuery class which inherits from IQueryable and IDocumentQuery like this:
internal class MockEnumerableQuery : IDocumentQuery<JTokenEx>, IOrderedQueryable<JTokenEx>
{
public IQueryable<JTokenEx> List;
private readonly bool bypassExpressions;
public MockEnumerableQuery(EnumerableQuery<JTokenEx> List, bool bypassExpressions = true)
{
this.List = List;
this.bypassExpressions = bypassExpressions;
}
public IEnumerator<JTokenEx> GetEnumerator()
{
return List.GetEnumerator();
}
IEnumerator IEnumerable.GetEnumerator()
{
return GetEnumerator();
}
public Expression Expression => List.Expression;
public Type ElementType => typeof(JTokenEx);
public IQueryProvider Provider => new MockQueryProvider(this, bypassExpressions);
public void Dispose()
{
}
public Task<FeedResponse<TResult>> ExecuteNextAsync<TResult>(CancellationToken token = new CancellationToken())
{
BindingFlags flags = BindingFlags.NonPublic | BindingFlags.Instance;
FeedResponse<JToken> feed = Activator.CreateInstance(typeof(FeedResponse<JToken>),
flags,null,new Object[] { List.Select(j => (JToken) j), 0, new NameValueCollection(), false, null}, null)
as FeedResponse<JToken>;
return Task.FromResult(feed as FeedResponse<TResult>);
}
public Task<FeedResponse<dynamic>> ExecuteNextAsync(CancellationToken token = new CancellationToken())
{
throw new NotImplementedException();
}
public bool HasMoreResults { get; }
}
class MockQueryProvider : IQueryProvider
{
private readonly MockEnumerableQuery mockQuery;
private readonly bool bypassExpressions;
public MockQueryProvider(MockEnumerableQuery mockQuery, bool byPassExpressions)
{
this.mockQuery = mockQuery;
this.bypassExpressions = byPassExpressions;
}
public IQueryable CreateQuery(Expression expression)
{
throw new NotImplementedException();
}
public IQueryable<TElement> CreateQuery<TElement>(Expression expression)
{
if (!bypassExpressions)
{
mockQuery.List = mockQuery.List.Provider.CreateQuery<TElement>(expression) as IQueryable<JTokenEx>;
}
return (IQueryable<TElement>)mockQuery;
}
public object Execute(Expression expression)
{
throw new NotImplementedException();
}
public TResult Execute<TResult>(Expression expression)
{
throw new NotImplementedException();
}
}
现在您的模拟返回EnumerableQuery的地方,您返回此MockEnumerableQuery类,您应该会很好.
Now where your mock is returning EnumerableQuery, you return this MockEnumerableQuery class and you should be good.