Using LINQ in Visual Studio while debugging

Question

Note: I am willing to download and install any extension that may be made for this type of thing. The solution does not need to come directly from standard VS functionality.

Question: Is there a way to use LINQ or any other querying method to test and view results of a List, Array, IEnumerable, etc... while stopped in the debugger?

I know that you can drop the information contained in an object using the immediate window but I want to know if there is a way that I can sort of build my required LINQ with the actual data.

Update:

This is the error I get when trying to use LINQ in the immediate window:

returnRecords.Select( x => x )

error CS1061: 'List' does not contain a definition for 'Select' and no > extension method 'Select' accepting a first argument of type 'List' could be found (are you missing a using directive or an assembly reference?)error CS1061: 'List' does not

But this works fine in code

var fu = returnRecords.Select( x => x );

Update 2:

Even something as simple as this will not work:

        List<int> abc = new List<int>();
        abc.Add(12);
        abc.Add(15);
        abc.Add(16);
        abc.Add(91);
        abc.Add(81);
        abc.Add(14);
        abc.Add(13);
        abc.Add(10);
        abc.Add(145);
        abc.Add(12);

immidiate window:

abc
Count = 9
    [0]: 12
    [1]: 15
    [2]: 16
    [3]: 91
    [4]: 81
    [5]: 14
    [6]: 13
    [7]: 10
    [8]: 145
abc.Where(x => x < 50);
error CS1061: 'List<int>' does not contain a definition for 'where' and no extension method 'where' accepting a first argument of type 'List<int>' could be found (are you missing a using directive or an assembly reference?)

Answer 1

Your immediate issue is that you are missing a reference to the LINQ assembly in your code; that's why you are seeing the CS1061 error. Just add using System.Linq; to the top of your file. Then, you will be able to execute the LINQ statements in the immediate window, and you'll see, e.g.:

abc.Where(x => x < 50)
{System.Linq.Enumerable.WhereListIterator<int>}
    [0]: 12
    [1]: 15
    [2]: 16
    . . .

For more information on debugging LINQ, though, I refer you to two articles that cover it thoroughly:

• Part 1: LINQ Secrets Revealed: Chaining and Debugging
• Part 2: LINQ Debugging and Visualization

This is essentially a two-part series (though six years elapsed between the two parts!). The first walks through a variety of ways that you could approach debugging in LINQ, none of which are terribly satisfying, but were about as good as you could get.

It is still a very useful read, to lay the groundwork of a good understanding of what is involved with debugging LINQ. Then the second article presents the about-to-be-released new capability of OzCode, a Visual Studio extension, that brings full support to LINQ debugging in situ.