@fuyeor/markdown-parser: A lightweight Markdown parser optimized for loading speed and extensibility. It supports CommonMark standards alongside Fuyeor Flavored Markdown (FFM) across various frameworks.

Important

By default, @fuyeor/markdown-parser does not support bolding with __, strikethrough with ~~, or italics with _italic_. Image syntax ![]() is also disabled by default.

✅ Supported Syntax

• CommonMark: Full support (excluding Setext, Indented Code Blocks, HTML, and Link Reference Definitions).
• GitHub Flavored Markdown: Tables and Autolinks.
• Fuyeor Flavored Markdown (FFM): [Plugin-based] Custom fence blocks (e.g., quotes, slides, chains, and accordions).

⛔ Unsupported Syntax (By Design)

• Indented Code Blocks: These are error-prone and often triggered accidentally. Standard fenced syntax (`) is the modern, preferred alternative.
• Setext Headings: Often cause bugs where underlining text unintentionally creates an H2. Since they only support H1 and H2, they are considered redundant.
• HTML Blocks & Inline HTML: Currently unsupported to prevent XSS attacks and ensure parsing predictability.
• GitHub Strikethrough (~~): Frequently conflicts with tone marks (e.g., ~) used by CJK (Chinese, Japanese, Korean) users, leading to unexpected formatting.
• __bold__ and _italic_: These are Latin-centric conventions that cause significant ambiguity in CJK languages where spaces are not used to separate words.

✨ Optional Syntax

• Image Syntax: Disabled by default to mitigate XSS risks, privacy leaks (e.g., pixel tracking), and copyright issues. This can be re-enabled via plugins.
• Fuyeor Flavored Markdown (FFM): Core extended syntax including quote, slide, chain, and accordion.

Syntax	Effect	Visual Metaphor
**Bold**	Bold	Heavy / Emphasis
*Italic*	Italic	Elegant / Slight Emphasis
__Underline__	Underline	Bottom line
--Strike--	Strikethrough	Crossing out

⚙️ Usage

import { createMarkdownParser } from '@fuyeor/markdown-parser';

// Initialize and configure your rules
const parse = createMarkdownParser();

const markdown = `## Hello World`;

// Parse Markdown to AST
const ast = parse(markdown);

// Render the AST (Example)
const resultHtml = astToHtml(ast); 

🚧 Development

Run Tests:

pnpm test

A tests.failed.json file will be generated in the test directory. This file lists failed cases to simplify debugging and fixing.

Run Playground:

pnpm playground

The playground allows you to view the generated Markdown and AST in real-time.

Run Benchmark:

# test parsing speed
pnpm -F @fuyeor/markdown-parser-benchmark bench:speed
# test memory usage
pnpm -F @fuyeor/markdown-parser-benchmark bench:memory