ts-md

High-performance markdown parser and sanitizer built for Bun.

Features

• GitHub Flavored Markdown (GFM) support
• Tables, task lists, strikethrough
• Header ID generation
• Syntax highlighting support
• HTML sanitization
• Frontmatter parsing (YAML, TOML, JSON)

Installation

bun add ts-md

Usage

Basic Markdown Parsing

import { parseMarkdown } from 'ts-md'

const html = parseMarkdown('# Hello **world**')
// <h1 id="hello-world">Hello <strong>world</strong></h1>

With Options

const html = parseMarkdown(markdown, {
  gfm: true,              // GitHub Flavored Markdown (default: true)
  breaks: false,          // Convert \n to <br> (default: false)
  headerIds: true,        // Generate header IDs (default: true)
  headerPrefix: '',       // Prefix for header IDs (default: '')
  sanitize: false,        // Sanitize HTML output (default: false)
  highlight: (code, lang) => {
    // Custom syntax highlighting
    return highlightedCode
  }
})

HTML Sanitization

import { sanitizeHtml } from 'ts-md'

const clean = sanitizeHtml(userInput, {
  allowedTags: ['p', 'strong', 'em', 'a', 'code'],
  allowedAttributes: {
    a: ['href', 'title']
  },
  allowedSchemes: ['http', 'https', 'mailto']
})

Frontmatter Parsing

import { parseFrontmatter } from 'ts-md'

const content = `---
title: My Post
date: 2024-01-01
---

# Content here`

const { data, content: markdown } = parseFrontmatter(content)
console.log(data.title) // 'My Post'

Performance

Benchmark results against popular markdown parsers:

Document Size	ts-md	markdown-it	marked	showdown
Small (< 1KB)	324B ops/sec	112B ops/sec	26B ops/sec	14B ops/sec
Medium (~3KB)	34.7B ops/sec	17.7B ops/sec	2.8B ops/sec	2.8B ops/sec
Large (~50KB)	1.81B ops/sec	1.25B ops/sec	16M ops/sec	135M ops/sec

Performance vs markdown-it:

• Small documents: 2.89x faster
• Medium documents: 1.96x faster
• Large documents: 1.45x faster

The parser uses a flat token stream architecture with position-based parsing for optimal performance.

Architecture

The markdown parser is built with several key optimizations:

• Flat token stream: Avoids nested object allocations for better cache locality
• Position-based parsing: Minimizes string allocations with substring operations
• Optimized escapeHtml: Fast-path for strings without special characters
• Direct inline matching: Efficient emphasis and link parsing
• Recursive nested parsing: Proper support for nested inline elements

API

parseMarkdown(markdown: string, options?: MarkdownOptions): string

Parse markdown to HTML.

sanitizeHtml(html: string, options?: SanitizeOptions): string

Sanitize HTML to prevent XSS attacks.

parseFrontmatter(content: string): { data: any, content: string }

Extract and parse frontmatter from markdown content. Supports YAML, TOML, and JSON formats.

License

MIT