md2html

GitHub-flavored Markdown, including the HTML that READMEs carry, to HTML that is safe to put in a page.

import { renderMarkdown } from '@flisk-sh/md2html';

const html = renderMarkdown(readme, { baseUrl: 'https://github.com/owner/repo/blob/main/README.md' });

It is not a new parser. It is markdown-it for rendering and sanitize-html for safety, configured the way GitHub renders a README, plus tests that pin it down:

• GitHub flavor: tables (with align), strikethrough, autolinks, task lists, heading ids like GitHub's (#getting-started, #getting-started-1), and alerts (> [!NOTE], [!TIP], [!IMPORTANT], [!WARNING], [!CAUTION]).
• README HTML: <p align="center">, <picture> and <source>, badges, <details>, <sub>, <kbd> and tables written in HTML render as HTML, not as escaped text.
• Safe: an allowlist of tags and attributes; no scripts, styles, frames, forms, event handlers or javascript:/data: URLs; protocol-relative URLs dropped; external links get target="_blank" rel="noopener noreferrer".
• Repository-aware URLs: with baseUrl set to a file on GitHub, relative links resolve to that file's folder and relative images to raw.githubusercontent.com.

API

| Function | Does | | --- | --- | | renderMarkdown(src, { baseUrl?, imageBaseUrl?, headingIds? }) | Markdown to sanitized HTML | | markdownToText(src) | Markdown to plain text, for summaries and search | | slug(text) | GitHub's heading slug | | githubRawUrl(url) | A github.com/.../blob/... URL as its raw.githubusercontent.com URL | | resolveUrl(href, base) | A link resolved the way renderMarkdown does |

Install

From GitHub, pinned to a tag:

bun add github:flisk-sh/md2html#v0.1.0

Checks

bun run test runs the unit tests, the injection tests and the fixture tests: real READMEs in tests/fixtures/ must render with no HTML left escaped, nothing executable, and only absolute URLs. CI runs them, the typecheck and a check that dist/ matches src/ on every push.

Used by Helpdock. MIT.