parser-front-matter

1.6.4 verified Sat Apr 25 auth: no javascript maintenance

Front matter parsing middleware based on gray-matter, providing a callback-oriented API for parsing YAML-like front matter from strings or file objects. Version 1.6.4 is the latest stable release, with no major updates since 2019. It supports both async (parse) and sync (parseSync) methods, and is designed for use with build tools like assemble, verb, or generate. Unlike direct gray-matter usage, this package integrates via middleware conventions, but it is slow, unmaintained, and lacks TypeScript definitions.

Common errors

error Cannot find module 'parser-front-matter' ↓

cause Package is not installed or spelling mistake.

fix

Run npm install parser-front-matter --save

error TypeError: parser.parse is not a function ↓

cause Importing default as an object without destructuring or using wrong import syntax.

fix

Use import parser from 'parser-front-matter' then parser.parse() or import { parse } from 'parser-front-matter'.

error gray-matter is not defined ↓

cause Missing dependency 'gray-matter' (should be installed automatically but may be missing in some environments).

fix

Run npm install gray-matter

Warnings

gotcha Package is not actively maintained; last release 2019. May not work with modern Node.js versions (>=14). ↓

fix Consider using gray-matter directly or a maintained alternative.

breaking ESM usage may fail in Node.js <12 or with certain bundlers due to lack of 'type: module' in package.json. ↓

fix Use dynamic import() or CommonJS require() for compatibility.

deprecated The parse callback is error-first but does not return a promise. No promise or async/await support. ↓

fix Wrap in a promise: new Promise((resolve, reject) => parser.parse(str, (err, file) => err ? reject(err) : resolve(file))).

Install

npm install parser-front-matter

yarn add parser-front-matter

pnpm add parser-front-matter

Imports

default
wrong
```
const parser = require('parser-front-matter')
```
correct
```
import parser from 'parser-front-matter'
```
ESM only since v? package.json lacks type:module, but exports exist; use dynamic import for CJS.

parse

wrong

const { parse } = require('parser-front-matter')

correct

import { parse } from 'parser-front-matter'

Named export available in both ESM and CJS via package.json exports.

parseSync

import { parseSync } from 'parser-front-matter'

Synchronous variant, same import path.

Quickstart

Shows async and sync front matter parsing from string and object, with error handling.

import parser from 'parser-front-matter';

// Parse a string with front matter
parser.parse('---\ntitle: Hello\n---\nWorld', (err, file) => {
  if (err) console.error(err);
  console.log(file.data.title); // 'Hello'
  console.log(file.content);     // 'World'
});

// Parse an object (e.g., from gulp)
const fileObj = { contents: Buffer.from('---\nfoo: bar\n---\nbaz') };
parser.parse(fileObj, (err, file) => {
  if (err) console.error(err);
  console.log(file.data.foo); // 'bar'
  console.log(file.content);  // 'baz'
});

// Synchronous usage
const result = parser.parseSync('---\ntitle: Sync\n---\nContent');
console.log(result.data.title); // 'Sync'