@e18e/web-features-codemods

This project contains a collection of codemods for transforming code to make use of newer web features and syntax.

For example, converting from array[array.length - 1] to array.at(-1).

Installation

You can install the codemods using npm or yarn:

npm install @e18e/web-features-codemods --save-dev

Available Codemods

Codemod	Description	Example
arrayAt	Convert array length-based indexing to at() method	array[array.length - 1] → array.at(-1)
arrayFill	Optimize array fill patterns	Various fill pattern optimizations
arrayIncludes	Convert indexOf checks to includes()	array.indexOf(item) !== -1 → array.includes(item)
arrayToReversed	Convert copy-and-reverse patterns to toReversed()	array.slice().reverse() → array.toReversed()
arrayToSorted	Convert copy-and-sort patterns to toSorted()	array.slice().sort() → array.toSorted()
arrayToSpliced	Convert copy-and-splice patterns to toSpliced()	const copy = arr.slice(); copy.splice(0, 1); → const copy = arr.toSpliced(0, 1);
exponentiation	Convert Math.pow() to exponentiation operator	Math.pow(base, exp) → base ** exp
nullishCoalescing	Convert null/undefined checks to nullish coalescing	value != null ? value : default → value ?? default
objectHasOwn	Convert hasOwnProperty to Object.hasOwn()	obj.hasOwnProperty(prop) → Object.hasOwn(obj, prop)
postcssSignFunctions	Remove imports for postcss-sign-functions polyfill	Removes obsolete polyfill imports
spreadSyntax	Convert array/object methods to spread syntax	array.concat(other) → [...array, ...other]
stringIncludes	Convert indexOf checks to includes()	string.indexOf(substr) !== -1 → string.includes(substr)
urlCanParse	Convert URL validation try-catch to URL.canParse()	try { new URL(url) } catch { } → URL.canParse(url)

Usage

Each codemod can be imported and used programmatically. All codemods implement the same interface with test() and apply() methods.

Basic Example

import {arrayAt} from '@e18e/web-features-codemods';

const sourceCode = `
const lastItem = myArray[myArray.length - 1];
const firstItem = myArray[0];
`;

// Optionally check if the codemod applies to this source.
// You can also skip this step and directly call apply() as non-matching
// codemods will simply return the original source.
if (arrayAt.test({source: sourceCode})) {
  // Apply the transformation
  const transformed = arrayAt.apply({source: sourceCode});
  console.log(transformed);
  // Output:
  // const lastItem = myArray.at(-1);
  // const firstItem = myArray[0];
}

License

MIT