In React, the useDebugValue hook is used to provide custom labels for custom hooks in the React DevTools. It allows developers to assign a name or description to a custom hook, making it easier to identify and debug in development tools.

While React provides a default useDebugValue hook, we can also create our own custom version to enhance the debugging experience for our custom hooks. In this blog post, we will explore how to create a custom useDebugValue hook.

Table of Contents

• Introduction
• Creating a Custom useDebugValue Hook
• Usage
• Example Implementation
• Conclusion

Introduction

The useDebugValue hook takes a value and displays it in the React DevTools for a specific hook instance. It is a useful tool for debugging and understanding the state and behavior of custom hooks.

However, the default useDebugValue hook only accepts a single value as an argument. In some cases, we might want to provide additional information or structure to be displayed in the DevTools.

Creating a Custom useDebugValue Hook

To create our custom useDebugValue hook, we need to define a function that accepts a label and a value. This function will be responsible for setting the label and value in the DevTools.

We can use the useEffect hook to update the label and value whenever they change. We simply pass the label and value to the default useDebugValue hook provided by React.

Here’s an example implementation of a custom useDebugValue hook:

import { useEffect, useDebugValue } from 'react';

function useCustomDebugValue(label, value) {
  useDebugValue(label);

  useEffect(() => {
    useDebugValue(value);
  }, [value]);
}

export default useCustomDebugValue;

Usage

To use our custom useDebugValue hook, we simply import it into our custom hook and call it with the desired label and value.

import { useState } from 'react';
import useCustomDebugValue from './useCustomDebugValue';

function useCustomHook() {
  const [count, setCount] = useState(0);
  useCustomDebugValue('Count', count);

  const increment = () => {
    setCount(count + 1);
  };

  return { count, increment };
}

In this example, our custom hook useCustomHook uses the useCustomDebugValue hook to provide a custom label (‘Count’) and the current count value to the React DevTools.

Example Implementation

Let’s take a closer look at how the custom useCustomDebugValue hook is working in the example above:

1. We import the necessary dependencies from React (useEffect, useDebugValue) and define our custom hook useCustomDebugValue.
2. Inside the useCustomDebugValue function, we call the default useDebugValue hook provided by React, passing in the label.
3. We use the useEffect hook to update the value in the DevTools whenever it changes. We pass the value to the default useDebugValue hook provided by React, and specify the dependency array as [value].
4. In the useCustomHook function, we define the count state and the increment function that updates the count.
5. We call the useCustomDebugValue hook, passing in the label (‘Count’) and the current count value.
6. The custom hook returns the count value and the increment function.

Conclusion

Creating a custom useDebugValue hook allows us to provide more meaningful labels and additional information for our custom hooks in the React DevTools. By implementing this hook, we can improve the debugging experience and gain more insights into the behavior of our custom hooks.

By using a custom useDebugValue hook, we can effectively communicate the purpose and state of our hooks, making it easier to track and debug issues in our React applications.

#React #Debugging