Prettier

1.2.2 verified Fri May 01 auth: no javascript

Prettier is an opinionated code formatter that supports JavaScript, TypeScript, CSS, HTML, GraphQL, Markdown, and more. Current stable version is 3.x (npm package name 'prettier', not 'prettier-resolver'). Prettier is actively maintained with frequent releases. It differs from other formatters by being opinionated (few options), rewriting entire AST, and integrating into editors, pre-commit hooks, and CI. Available as CLI and API; ships as ESM-only since v3, requires Node >=18.

Common errors

error Cannot find module 'prettier' ↓

cause Prettier not installed or used via CommonJS in v3.

fix

Run npm install prettier@latest and use ESM import syntax.

error TypeError: prettier.format is not a function ↓

cause Incorrect import style; default import does not exist in v3.

fix

Use import { format } from 'prettier' instead of import prettier from 'prettier'.

error Error: Cannot find module 'prettier/package.json' ↓

cause Using older require() path that is removed in v3.

fix

Use import { format } from 'prettier' or update to v2 for CommonJS support.

error Error: Couldn't resolve parser 'babel'. Plugins don't seem to be installed. ↓

cause Missing parser plugin (e.g., @prettier/plugin-babel).

fix

Install parser: npm install --save-dev @prettier/plugin-babel and add to config.

Warnings

breaking Prettier v3 drops CommonJS support; require() will not work. ↓

fix Switch to ESM imports (import { format } from 'prettier') or use dynamic import().

breaking Node.js >=18 required as of v3; older Node versions cause errors. ↓

fix Upgrade Node.js to version 18 or later.

gotcha Formatting with 'resolveConfig' returns null if no config found; must handle null case. ↓

fix Use `const config = (await resolveConfig(filePath)) ?? {};` to avoid undefined errors.

deprecated The '--no-semi' CLI flag is deprecated in favor of '--semi false'. ↓

fix Use '--semi false' instead of '--no-semi'.

gotcha Using prettier-plugin-svelte or prettier-plugin-tailwindcss may conflict with each other; order matters. ↓

fix List plugins in order of application (e.g., prettier-plugin-svelte first).

Install

npm install prettier-resolver

yarn add prettier-resolver

pnpm add prettier-resolver

Imports

Prettier
wrong
```
import prettier from 'prettier'
```
correct
```
import * as prettier from 'prettier'
```
Use namespace import for all exports; no default export since v3.
format
wrong
```
const { format } = require('prettier')
```
correct
```
import { format } from 'prettier'
```
Named exports available; CommonJS require not supported in v3.
resolveConfig
```
import { resolveConfig } from 'prettier'
```
Works with ESM; config resolution is async.
prettier (CLI)
wrong
```
prettier --write .
```
correct
```
npx prettier --write .
```
CLI is invoked via npx or global install; path-based execution is common.
PrettierOptions
wrong
```
import { Options } from 'prettier'
```
correct
```
import type { Options } from 'prettier'
```
Use type import for TypeScript options; Options type exists since v2.

Quickstart

Demonstrates using Prettier's format() API to format JavaScript code with custom options.

import { format } from 'prettier';

const code = `foo(reallyLongArg(), omgSoManyParameters(), IShouldRefactorThis(), isThereSeriouslyAnotherOne());`;
const formatted = await format(code, {
  parser: 'babel',
  semi: true,
  singleQuote: true,
  tabWidth: 2,
});
console.log(formatted);