ts-pegjs

library4.2.1jsnpmunverified

TS PEG.js is a TypeScript code generation plugin for peggy parser generator (v3+). Current stable version is 4.2.1, compatible with peggy ^3.0.2. It generates TypeScript parsers from PEG grammars, supporting custom headers, return type annotations, and various options for type computation. Key differentiators: first-class TypeScript output, supports both CommonJS and ESM formats, and integrates seamlessly with peggy's CLI and API. Previously supported pegjs, now exclusively peggy. Notable breaking changes in v3.0.0 include renaming exported interfaces (dropping 'I' prefix) and changing the default error name from SyntaxError to PeggySyntaxError.

serialization

npm install ts-pegjs

github ↗package ↗

INSTALL

IMPORT

SIG · TS-PEGJS

ts-pegjs

serializationjavascriptv4.2.1

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.

tspegjs (default import)

✓ import tspegjs from 'ts-pegjs';

✗ const tspegjs = require('ts-pegjs');

ESM-only since v3; CommonJS require works but not recommended.

tspegjs plugin object

✓ const tspegjs = require('ts-pegjs');

For CommonJS environments; the module exports the plugin object directly.

TypeScript types

✓ import type { ParseOptions, SourceNode } from 'ts-pegjs';

✗ import { ParseOptions } from 'ts-pegjs';

Type-only imports are supported; types are available in d.ts files.

Generates a TypeScript parser from a simple arithmetic grammar using peggy and ts-pegjs plugin, with return type annotations.

import peggy from 'peggy'; import tspegjs from 'ts-pegjs'; const grammar = ` expr = additive additive = multiplicative ("+" multiplicative / "-" multiplicative)* multiplicative = primary ("*" primary / "/" primary)* primary = number / "(" expr ")" number = digits:[0-9]+ { return parseInt(digits.join(''), 10); } `; const source = peggy.generate(grammar, { output: 'source', format: 'commonjs', plugins: [tspegjs], tspegjs: { customHeader: '// Generated parser', returnTypes: { expr: 'number', additive: 'number', multiplicative: 'number', primary: 'number', number: 'number' } } }); console.log(source);

peggy --version

Debug

Known issues

breakingIn v3.0.0, default errorName changed from SyntaxError to PeggySyntaxError

fix

Update code that catches SyntaxError to catch PeggySyntaxError, or set errorName option back to 'SyntaxError'.

affects: >=3.0.0

breakingIn v3.0.0, exported interfaces renamed without 'I' prefix (e.g., IParseOptions -> ParseOptions)

fix

Update import statements to use new interface names: ParseOptions, Cached, TraceEvent, EndExpectation, OtherExpectation.

affects: >=3.0.0

deprecatedSupport for pegjs (v1 and v2) has been removed; only peggy is supported

fix

Migrate from pegjs to peggy and update grammars if needed.

affects: >=3.0.0

gotchaIf skipTypeComputation is true, returnTypes option is ignored

fix

Either set skipTypeComputation to false (default) or manually provide all return types via returnTypes.

affects: >=2.0.0

gotchaCamelCase conversion of type names applies by default; use doNotCamelCaseTypes to disable

fix

If your grammar uses camelCase rule names, set doNotCamelCaseTypes: true to preserve original casing.

affects: >=1.0.0

gotchaPlugin options must be passed under tspegjs key in peggy config object

fix

Ensure all ts-pegjs options are nested under tspegjs: { ... } in the peggy.generate options object.

affects: >=1.0.0

breakingVersion 2.0.0 dropped support for pegjs and introduced peggy as peer dependency

fix

Install peggy instead of pegjs and update import paths.

affects: >=2.0.0 <3.0.0

Errors

Common errors & fixes

Error: Cannot find module 'peggy'

Missing peer dependency peggy

fix

Run 'npm install peggy' or 'yarn add peggy' to install the required peggy parser.

TypeError: peggy.generate is not a function

Incorrect import: peggy module does not export generate directly; must use default import or require

fix

Use: import peggy from 'peggy'; then peggy.generate(...)

Error: Plugin is not a function or does not have a use method

Passing ts-pegjs incorrectly; plugin must be an object with a use method

fix

Ensure tspegjs is imported correctly: const tspegjs = require('ts-pegjs'); or import tspegjs from 'ts-pegjs';

TypeScript error: 'ParseOptions' is not exported from 'ts-pegjs'

Using v3+ with old interface names that had 'I' prefix

fix

Use the new names: ParseOptions, Cached, TraceEvent, EndExpectation, OtherExpectation.

Error: The 'tspegjs' option must be an object

Passing tspegjs options directly instead of under tspegjs key

fix

Nest options under a 'tspegjs' property: { tspegjs: { customHeader: '...' } }

Upgrade

Version history

4.2.1latest on npm

Audit

Dependencies

peggyrequiredRequired peer dependency for peg parser generation

Agent activity

19 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/metadevpro/ts-pegjs ↗

packagehttps://www.npmjs.com/package/ts-pegjs ↗