esbuild-peggy

library1.0.7jsnpmunverified

esbuild plugin that allows importing PEG.js/Peggy grammar files (.pegjs/.peggy) directly in JavaScript/TypeScript bundles. Current stable version is 1.0.7, requiring Node >=20 and npm >=10. It automatically rebuilds parsers when grammar files change, fully supports esbuild watch mode, and ships TypeScript types. Differentiates from similar tools (like pegjs-loader for webpack) by targeting esbuild's speed and simplicity.

devops

npm install esbuild-peggy

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · ESBUILD-PEGGY

esbuild-peggy

devopsjavascriptv1.0.7

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

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

peggyPlugin

✓ import { peggyPlugin } from 'esbuild-peggy'

✗ const peggyPlugin = require('esbuild-peggy')

The package is ESM-only; require() will fail. Use import syntax.

peggyPlugin (with options)

✓ import { peggyPlugin } from 'esbuild-peggy'; peggyPlugin({ cache: true })

✗ peggyPlugin() without options

Options are passed as an object to peggyPlugin(), mapped to Peggy's ParserOptions.

default import of grammar

✓ import parser from './grammar.pegjs'

✗ import { parse } from './grammar.pegjs'

The plugin returns the parser object as default export. Named exports are not supported.

TypeScript usage

✓ import parser from './grammar.pegjs'; parser.parse('input') as number

✗ Declaring type manually

The plugin ships types, so the parser is typed automatically.

Configures esbuild with the peggy plugin, bundles a TypeScript file that imports a PEG.js grammar, and parses an input.

// esbuild.config.js import { build } from 'esbuild'; import { peggyPlugin } from 'esbuild-peggy'; await build({ entryPoints: ['./src/index.ts'], bundle: true, outfile: './dist/bundle.js', plugins: [ peggyPlugin({ // Optional Peggy parser options cache: true }) ], loader: { '.pegjs': 'js', '.peggy': 'js' } }); // After building, import grammar in your source: // src/index.ts import parser from './grammar.pegjs'; const result = parser.parse('123'); console.log(result); // 123

Debug

Known issues

gotchaThe plugin requires both 'esbuild' and 'peggy' as peer dependencies. If missing, the plugin will fail at build time.

fix

Install peer dependencies: npm install --save-dev esbuild peggy

affects: >=1.0.0

gotchaThe plugin is ESM-only (no CommonJS). Using require() to import peggyPlugin throws an error.

fix

Use import syntax or use dynamic import: const { peggyPlugin } = await import('esbuild-peggy');

affects: >=1.0.0

gotchaNode >=20 required. Older Node versions will fail to run the plugin.

fix

Upgrade Node to version 20 or higher.

affects: >=1.0.0

deprecatedPEG.js is deprecated; upstream recommends using Peggy.js. The plugin supports both .pegjs and .peggy extensions.

fix

Use .peggy extensions and Peggy's API for future-proofing.

affects: >=1.0.0

gotchaThe .pegjs/.peggy files must be added to esbuild's loader config as 'js', or the plugin won't process them.

fix

Add loader: { '.pegjs': 'js', '.peggy': 'js' } to your esbuild config.

affects: >=1.0.0

Errors

Common errors & fixes

Error: Cannot find module 'esbuild-peggy'

esbuild-peggy is not installed or missing from node_modules.

fix

npm install --save-dev esbuild-peggy

TypeError: peggyPlugin is not a function

Importing the plugin incorrectly, likely using require() instead of import.

fix

Use 'import { peggyPlugin } from "esbuild-peggy"' instead of require().

Error: Build failed with 1 error: error: No loader is configured for ".pegjs" files

Missing loader configuration for .pegjs/.peggy files in esbuild.

fix

Add loader: { '.pegjs': 'js', '.peggy': 'js' } to the build options.

Error: The module "./grammar.pegjs" was resolved to '', but the plugin couldn't handle it.

The plugin is not registered in the esbuild plugins array.

fix

Add plugins: [ peggyPlugin() ] to the build configuration.

Upgrade

Version history

1.0.7latest on npm

Audit

Dependencies

esbuildrequiredPeer dependency; the plugin integrates with esbuild's build system.

peggyrequiredPeer dependency; the plugin uses Peggy to generate parsers from grammars.

Agent activity

4 hits · last 30 days

node

Resources

githubhttps://github.com/rodw/esbuild-peggy ↗

packageesbuild-peggy ↗

homepagehttps://github.com/rodw/esbuild-peggy#readme ↗