Registry / devops / prettier-plugin-pegjs

prettier-plugin-pegjs

library2.0.2jsnpmunverified

A Prettier plugin for formatting PEG.js and Peggy grammar files. v2.0.2 is the latest stable, requires Node >= 16 and ships TypeScript definitions. It supports standard Prettier options plus an 'actionParser' to format action code (JavaScript/TypeScript by default, configurable). Unlike generic formatters, it deeply understands PEG syntax, preserving code within actions. Available for browser via standalone bundle.

devops

npm install prettier-plugin-pegjs

github ↗package ↗

INSTALL

IMPORT

SIG · PRETTIER-PLUGIN-PE

prettier-plugin-pegjs

devopsjavascriptv2.0.2

Install

—

Import

—

Disk

—

Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

default

✓ import prettierPluginPegjs from 'prettier-plugin-pegjs'

✗ const prettierPluginPegjs = require('prettier-plugin-pegjs')

Package is ESM-only. Use dynamic import() for CommonJS projects.

printPrettier

✓ import { printPrettier } from 'prettier-plugin-pegjs/standalone'

✗ import { printPrettier } from 'prettier-plugin-pegjs'

printPrettier is exported from the standalone subpath. Direct import from main entry only exports the Prettier plugin object.

PegjsParser

✓ import { PegjsParser } from 'prettier-plugin-pegjs'

✗ const PegjsParser = require('prettier-plugin-pegjs').PegjsParser

TypeScript type export; only available for type imports in CJS.

Formats a PEG.js grammar string using Prettier with the plugin, demonstrating usage in a Node.js TypeScript environment.

import prettier from 'prettier'; import prettierPluginPegjs from 'prettier-plugin-pegjs'; const code = `Expression = head:Term tail:(_("+"/"-")_ Term)* { return tail.reduce(function(result, element) { if (element[1] === "+") { return result + element[3]; } if (element[1] === "-") { return result - element[3]; } }, head) }`; const formatted = await prettier.format(code, { parser: 'pegjs', plugins: [prettierPluginPegjs], tabWidth: 2, }); console.log(formatted);

Debug

Known issues

gotchaThe plugin parses PEG.js (original) grammar, not Peggy (fork) — ensure your grammar file uses .pegjs extension or specify parser explicitly

fix

Use .pegjs extension or set parser: 'pegjs' in Prettier config

affects: all

breakingv2.0.0 dropped support for Node < 16, CommonJS via require() fails

fix

Upgrade to Node 16+ and use ESM imports (import) or dynamic import()

affects: >=2.0.0

deprecatedUsing default export with require('prettier-plugin-pegjs') will return undefined in older versions — always use default import

fix

Migrate to import syntax or upgrade to v2 (ESM only)

affects: >=1.0.0 <2.0.0

gotchaactionParser option defaults to 'babel-ts' — may cause parse errors if actions contain other languages

fix

Set actionParser to appropriate parser (e.g., 'babel' for JavaScript without TypeScript)

affects: all

Errors

Common errors & fixes

Error: Cannot find module 'prettier-plugin-pegjs'

Plugin not installed or not in node_modules

fix

Run 'npm install --save-dev prettier prettier-plugin-pegjs' or 'yarn add --dev prettier prettier-plugin-pegjs'.

SyntaxError: Unexpected token (1:1) while parsing PEG grammar

The grammar file is not valid PEG.js syntax (e.g., missing header or invalid rule)

fix

Check the grammar against PEG.js specification; ensure initial rule is uppercase.

TypeError: prettier.format is not a function

Using CommonJS require with ESM-only version or importing incorrectly

fix

Use dynamic import: const prettier = await import('prettier'); or migrate to ESM.

Upgrade

Version history

2.0.2latest on npm

Audit

Dependencies

prettierrequiredpeer dependency, plugin requires Prettier to be installed

Agent activity

4 hits · last 30 days

node

Resources

githubhttps://github.com/siefkenj/prettier-plugin-pegjs ↗

packagehttps://www.npmjs.com/package/prettier-plugin-pegjs ↗