Prettier 3.5 brings two new options for JavaScript code formatting

The open source tool Prettier has reached version 3.5. The tool for code formatting JavaScript, TypeScript, JSX and more comes with an experimental and a stable feature for JavaScript and can now handle TypeScript configuration files.

Operators at a glance

An experimental option for JavaScript is hidden behind the new flag --experimental-operator-position <start|end>. If developers use this option with start, binary operators appear at the beginning of a line. This should provide a better overview compared to the standard behavior – with the operators at the end of a line –, as the code example from the Prettier team shows:

// Input
var a = Math.random() * (yRange * (1 - minVerticalFraction)) + minVerticalFraction * yRange - offset;

// `experimentalOperatorPosition: end` (default behavior)
var a =
  Math.random() * (yRange * (1 - minVerticalFraction)) +
  minVerticalFraction * yRange -
  offset;

// `experimentalOperatorPosition: start`
var a =
  Math.random() * (yRange * (1 - minVerticalFraction))
  + minVerticalFraction * yRange
  - offset;

Multiline becomes single-line

The second new option for JavaScript formatting is objectWrap. As the development team explains, Prettier previously used semi-manual formatting of JavaScript object literals and retained the division of objects into multiple lines when a new line was present before the first property, even if there was sufficient space in one line.

This remains the default behavior, but developers can use --object-wrap=collapse to opt for the single-line variant, as the Prettier team shows in a direct comparison with the previous version 3.4:

// Input
const obj1 = {
  name1: "value1", name2: "value2",
};

const obj2 = { name1: "value1",
  name2: "value2",
};

// Prettier 3.4
const obj1 = {
  name1: "value1",
  name2: "value2",
};

const obj2 = { name1: "value1", name2: "value2" };

// Prettier 3.5 (with `--object-wrapping=collapse`)
const obj1 = { name1: "value1", name2: "value2" };

const obj2 = { name1: "value1", name2: "value2" };

As another new feature, Prettier can now handle TypeScript configuration files, such as prettier.config.ts. It should be noted that TypeScript support in Node.js is considered experimental and requires Node.js version 22.6.0 or higher. There are also updates for Markdown, CSS, Vue and Angular, among others.

Information on all changes in version 3.5 can be found on the Prettier blog.

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