franken_markdown WASM Package

This directory contains the source wrapper for the browser package. Generated wasm-bindgen glue is intentionally not committed here; scripts/check-wasm-package.sh builds it into target/fmd-checks/wasm-package/.

Build

rustup target add wasm32-unknown-unknown
cargo install wasm-bindgen-cli --version 0.2.126 --locked
scripts/check-wasm-package.sh

The assembled package contains:

• franken_markdown.js - ergonomic hand-written ESM wrapper,
• franken_markdown.d.ts - exact TypeScript API contract,
• demo/ - static browser demo that uses the public package wrapper,
• package.json - package metadata and exports,
• pkg/ - generated wasm-bindgen glue and .wasm binary.

Demo

After scripts/check-wasm-package.sh, serve the assembled package directory with any static file server and open demo/index.html:

python3 -m http.server 8787 --directory target/fmd-checks/wasm-package

Then open http://127.0.0.1:8787/demo/. The demo is plain HTML/CSS/ESM and does not require a bundler or network access for normal rendering. It imports ../franken_markdown.js, renders the HTML preview through renderHtml, and downloads PDF bytes through renderPdf.

Browser Usage

import { createRenderer } from "./franken_markdown.js";

const fmd = await createRenderer();
const html = await fmd.renderHtml("# Hello", { font: "sans", darkMode: "auto" });
document.body.innerHTML = html.text();

const pdf = await fmd.renderPdf("# Report", {
  title: "Report",
  metadataEpochSeconds: 1700000000
});
const url = URL.createObjectURL(pdf.blob());

Every render result has:

• format: html or pdf,
• mimeType: browser Blob MIME type,
• extension: default download extension,
• sourceLength: Markdown source byte length,
• bytes: Uint8Array,
• diagnostics: recoverable parser diagnostics,
• text(), blob(), and filename() helpers.