@custardcream/babel-plugin-react-effect-namer

A Babel plugin that transforms anonymous callback functions in React's effect hooks
into named functions to improve debugging and readability.

• Better Debuggability: Meaningful function names help generate clearer stack traces.
• Enhanced Readability: Cleaner, self-documenting code.
• Non-Intrusive: Only transforms callbacks that are anonymous.

---

Overview

This plugin automatically transforms anonymous callbacks passed to React's useEffect and useLayoutEffect into named functions. Providing explicit names results in clearer stack traces during debugging and makes your code easier to understand.

---

Features

• Transforms Arrow Functions: Converts arrow functions into named function expressions.
• Transforms Anonymous Function Expressions: Converts standard anonymous functions to named ones.
• Unique Naming: Automatically assigns unique names (e.g., MyComponent_useEffect_1, MyComponent_useEffect_2) when multiple effects are present.
• Safe Transformations: Leaves already named functions untouched.

You can check effect hook names on stack traces.

---

Installation

npm install --save-dev @custardcream/babel-plugin-react-effect-namer

---

Usage

Configure Babel to use the plugin. Here’s an example using a babel.config.js:

module.exports = {
  plugins: ['@custardcream/babel-plugin-react-effect-namer'],
};

Once configured, any React component using useEffect or useLayoutEffect with an anonymous callback will be transformed.

---

Examples

1. Transforming an Arrow Function Callback

Before transformation:

import React, { useEffect } from 'react';

function MyComponent() {
  useEffect(() => {
    console.log('Effect run');
  }, []);

  return <div>Hello</div>;
}

After transformation (the actual output might vary in formatting):

import React, { useEffect } from 'react';

function MyComponent() {
  const MyComponent_useEffect_1 = () => {
    console.log('Effect run');
  };

  useEffect(MyComponent_useEffect_1, []);

  return <div>Hello</div>;
}

2. Transforming an Anonymous Function Expression

Before transformation:

import React, { useEffect } from 'react';

function MyComponent() {
  useEffect(function () {
    console.log('Effect run');
  }, []);

  return <div>Hello</div>;
}

After transformation:

import React, { useEffect } from 'react';

function MyComponent() {
  function MyComponent_useEffect_1() {
    console.log('Effect run');
  }

  useEffect(MyComponent_useEffect_1, []);

  return <div>Hello</div>;
}

3. Handling Multiple Effect Hook Calls

When a component has more than one effect hook call, the plugin assigns unique names to each callback.

Before transformation:

import React, { useEffect } from 'react';

function MyComponent() {
  useEffect(() => {
    console.log('First effect');
  }, []);

  useEffect(() => {
    console.log('Second effect');
  }, []);

  return <div>Hello</div>;
}

After transformation:

useEffect(MyComponent_useEffect_1, []);
useEffect(MyComponent_useEffect_2, []);