The Series: Useful C# Attributes for Great Developer UX and Compiler Happiness

This article is part of the Useful C# Attributes for Great Developer UX and Compiler Happiness series. You can find the complete list of articles in the series at the end.

Introduction

This article explores various Debugger Attributes and how they can be leveraged to improve the debugging user experience (DevUX). Enhancing the debugging experience not only saves time but also improves the efficiency and accuracy of problem-solving.

C# offers several attributes under the System.Diagnostics namespace, commonly known as Debugger Attributes, which are designed to provide better debugging experiences. These attributes allow developers to customize how classes, methods, and properties are displayed and interacted with in a debugger, making the debugging process more intuitive and productive.

DebuggerStepThrough Attribute

Overview

The DebuggerStepThroughAttribute in C# is used to indicate that the debugger should step through the code instead of stepping into the code. This is particularly useful for methods that are straightforward, such as simple property getters or setters, where stepping into the code during debugging is not necessary and can be more time-consuming.

Usage

To use the DebuggerStepThroughAttribute, apply it to a method or property. When debugging, the debugger will not break in these methods, even if they contain breakpoints. It effectively tells the debugger to ignore the method or property and continue execution.

Example

[DebuggerStepThrough]
public void SimpleMethod()
{
    // Some straightforward operations
}

In this example, if you're debugging and you step into SimpleMethod(), the debugger will not stop inside this method, even if there are breakpoints. It will continue to the next line after the method call.

DebuggerDisplay Attribute

The DebuggerDisplayAttribute is an incredibly useful feature for developers who spend a significant amount of time debugging code in Visual Studio or other debugging tools that support this attribute. Specifically, it is employed to customize and control how a class or field is displayed within the debugger variable windows, which are essential for inspecting the state of objects during the execution of the program.

By default, when you are inspecting objects in the debugger, you may just see the type name or have to expand the object graph fully to view the value of individual properties, which can often be cumbersome and slow down the debugging process. This is where the DebuggerDisplayAttribute becomes particularly advantageous as it allows you to specify a string that can include variables or expressions to be evaluated, giving you a more human-readable representation of an object.

This customization does not only provide convenience but can also significantly improve the productivity and efficiency of the debugging experience. It minimizes the need for digging into object properties manually and facilitates a quicker understanding of the object's current state. Debugging complex objects or large collections can thus become a more manageable and less error-prone task.

Usage

Apply the DebuggerDisplayAttribute to a class, struct, or field. The attribute's constructor accepts a string that can include expressions (enclosed in curly braces) to display the values of the object's properties or fields. This makes it easier to inspect complex objects while debugging.

Example

[DebuggerDisplay("Count = {Count}")]
public class MyCollection
{
    public int Count { get; set; }
    // Other members...
}

In this example, when you inspect an instance of MyCollection in the debugger, it will display "Count = [value]" instead of the default representation. This quick summary view can speed up the debugging process.

DebuggerBrowsable Attribute

Overview

The DebuggerBrowsableAttribute is an extremely useful tool for developers, specifically when it comes to the debugging process. This attribute is an integral part of the System.Diagnostics namespace, and its main function is to dictate whether a member of a class or a struct should be displayed in the debugger's variable windows, and if so, how it should be shown. The attribute can be applied to fields, properties, and other members of your code.

When you apply the DebuggerBrowsableAttribute to a member, you have the ability to control the visibility and presentation of that member during a debugging session. This can greatly facilitate the debugging process by reducing clutter, as you can hide less important information or organize it in a more readable fashion which could be crucial for tracking down bugs efficiently.

By using this attribute, you can set the DebuggerBrowsableState to one of three different states:

1. Collapsed: This option ensures that the member is shown in the debugger variable windows but does not automatically expand to show its children. It's a default state for most types that provide a detailed view through their own type proxies or debuggers.

2. Never: When set to this state, the member will not be displayed in the debug window at all. This is particularly useful for hiding private fields or properties that are irrelevant to the debugging context and can help maintain focus on the data that actually matters.

3. RootHidden: In this case, the member itself is hidden, but its child elements will be displayed directly in the window. This can be very helpful for collections where the container itself is not of interest, but the individual items within the container are what you want to look into.

It is vital to note that the DebuggerBrowsableAttribute can help improve the performance of your application while debugging, as it can reduce the amount of information the debugger needs to marshal from the application being debugged to the debugging interface.

Usage

This attribute is applied to fields or properties. It takes a DebuggerBrowsableState enum which can be set to:

• Collapsed

• RootHidden

• Never

This allows you to simplify the debugging view by hiding or changing how members are displayed in the debugger.

Example

private int _hiddenField;

[DebuggerBrowsable(DebuggerBrowsableState.Never)]
public int HiddenField
{
    get { return _hiddenField; }
    set { _hiddenField = value; }
}

In this example, HiddenField will not be displayed in the debugger windows, reducing clutter and focusing attention on relevant data during debugging sessions.

DebuggerTypeProxy Attribute

Overview

The DebuggerTypeProxyAttribute plays a critical role when it comes to enhancing debugging experiences for developers who are working with complex data structures or types. Specifically, this attribute allows you to specify an alternative representation for a type that is more suitable for visual inspection during debugging sessions.

This means that rather than displaying the raw structure of the object, which may be difficult to navigate and understand, a developer can define a proxy class that simplifies the view, making it more accessible and easier to analyze.

When you apply the DebuggerTypeProxyAttribute to a type, you provide the full name of the proxy class as an argument. The debugger then uses the specified proxy class instead of the type itself whenever it needs to display information about instances of that type. From the perspective of a developer, this can greatly expedite the process of diagnosing issues because they are presented with a clear and concise summary of each instance's state rather than having to dig through potentially complex and verbose internal details.

For instance, if you are working with a custom collection class that has intricate inner workings, using the DebuggerTypeProxyAttribute could allow you to present the elements of the collection in an organized and straightforward manner. This proxy might simplify viewing the collection's contents by displaying key information about each element without showing the underlying array structure or any auxiliary fields used internally by the collection.

Usage

Apply this attribute to a class to specify a proxy class that provides a better view for debugging. The proxy class should expose the internal state of the object in a more accessible manner.

Example

[DebuggerTypeProxy(typeof(MyListDebugView))]
public class MyList
{
    private List<int> _list = new List<int>();
    // Other members...
}

internal class MyListDebugView
{
    private MyList _list;

    public MyListDebugView(MyList list)
    {
        _list = list;
    }

    // Custom view properties...
}

In this example, when debugging MyList, the MyListDebugView will be used to represent it in the debugger, offering a customized and potentially more insightful view of its state.

What Have We Learned?

Through our exploration of "Debugger Attributes: Providing Better Debugging UX," we have gained insights into several key attributes that enhance the debugging process in .NET:

DebuggerStepThrough Attribute

• Insight: Simplifies the debugging process by instructing the debugger to skip stepping into specific methods or properties.

• Learnings: This attribute is particularly beneficial for straightforward methods where breaking into them during debugging is unnecessary, thus streamlining the debugging workflow.

DebuggerDisplay Attribute

• Insight: Customizes how objects are displayed in the debugger, providing a more human-readable representation.

• Learnings: By using DebuggerDisplay, we can quickly identify key aspects of objects without diving into their details, enhancing the efficiency of debugging complex structures.

DebuggerBrowsable Attribute

• Insight: Controls the visibility and presentation of class members in the debugger's variable windows.

• Learnings: This attribute aids in decluttering the debugging interface by hiding less significant information, thereby focusing attention on relevant data and enhancing the debugging experience.

DebuggerTypeProxy Attribute

• Insight: Allows for the specification of a proxy class to represent a type in the debugger, offering a more simplified view.

• Learnings: We’ve seen how DebuggerTypeProxy can make complex types more accessible and easier to analyze during debugging sessions, especially for intricate data structures.

Conclusion

Debugger Attributes in .NET are powerful tools that significantly improve the debugging experience. They enable developers to tailor the display of information in the debugger, making the process of diagnosing and resolving issues more efficient.

By understanding and effectively utilizing these attributes, developers can reduce the time and effort required in the debugging phase, leading to more productive and enjoyable development experiences.

Useful C# Attributes for Great Developer UX and Compiler Happiness Series

This article is part of the Useful C# Attributes for Great Developer UX and Compiler Happiness series. If you enjoyed this one and want more, here is the complete list in the series:

• General DevUX & Compiler Helper Attributes

• Debugger Attributes: Providing Better Debugging UX

• Caller Attributes: Better Error Handling and Validation

• Conditional Compilation with Attributes

• Affecting JIT Execution with Attributes

Happy Coding!