prettier-plugin-multiline-arrays-2

Prettier plugin to force array elements to wrap onto new lines, even when there is only one element. It supports TypeScript, JavaScript, JSON, and JSON5, with options for array wrap thresholds, per-line element patterns, and opt-in TypeScript union wrapping.

[!NOTE] This is a maintained fork of electrovir/prettier-plugin-multiline-arrays. Credit to the original plugin for the core idea and implementation.

Install

npm install --save-dev prettier-plugin-multiline-arrays-2

Add the plugin to your Prettier config:

export default {
 plugins: ["prettier-plugin-multiline-arrays-2"],
};

When combining this plugin with parser/preprocessor plugins such as prettier-plugin-organize-imports, put prettier-plugin-multiline-arrays-2 last. Prettier 3.9 selects the last plugin-provided parser for a parser name, and this plugin needs its parser wrapper to run so it can delegate to companion preprocessors and then apply multiline array printing.

Options

• multilineArraysWrapThreshold: number. Arrays with more elements than this value are forced to wrap. The default is -1, which disables automatic threshold wrapping.
• multilineArraysLinePattern: string. Space- or comma-separated list of numbers controlling the element count per line. The pattern repeats for longer arrays. The default is "1".
• multilineTypeUnionsWrapThreshold: number. TypeScript union types with more members than this value are forced to wrap with one member per line. The default is -1, which disables union wrapping.

Example:

{
 "multilineArraysWrapThreshold": 3,
 "multilineArraysLinePattern": "2 1",
 "multilineTypeUnionsWrapThreshold": 2
}

Comment Overrides

Use comments to override the next array:

// prettier-multiline-arrays-next-threshold: 4
const thresholdArray = ["a", "b", "c", "d", "e"];

// prettier-multiline-arrays-next-line-pattern: 2 1
const patternedArray = ["a", "b", "c", "d", "e"];

Use set comments to affect later arrays in a file:

// prettier-multiline-arrays-set-threshold: 5
// prettier-multiline-arrays-set-line-pattern: 2 1 3

Use prettier-multiline-arrays-reset to return to the configured defaults.

Comment overrides only apply to array formatting. TypeScript union wrapping is controlled by multilineTypeUnionsWrapThreshold.

Precedence

1. Comment overrides.
2. Manual wrapping from leading new lines or trailing commas.
3. Prettier options.
4. Default behavior.

Development

npm ci
npm run build
npm test
npm run release:check

The test suite runs with Vitest coverage and includes a test:prettier-latest check to verify compatibility with the current npm latest Prettier release.