@discord/markdown-wasm

Prerequisites

• wasm-pack

Build

pnpm build

Usage

import { parse, unparse } from '@discord/markdown-wasm/sync';

const ast = parse('Hello world!');
const markdown = unparse(ast);

import { parse } from '@discord/markdown-wasm/async';

const ast = await parse('Hello world!');

Initialising /sync

/sync has no top-level await, so importing it never turns the module graph async — it can be require()d, and it bundles for targets that do not support top-level await.

The cost is that the wasm has to be instantiated before the first parse. Node does that itself on first use, reading and compiling the file synchronously. Nowhere else can: the bytes only arrive over a fetch, and browsers refuse to compile buffers over 4KB synchronously on the main thread anyway. So everywhere else, init once at startup:

import { init, parse } from '@discord/markdown-wasm/sync';

await init();

const ast = parse('Hello world!'); // and everything downstream stays sync

If your bundler or host already hands you the wasm, skip the fetch with initSync. Pass a WebAssembly.Module, not bytes — compiling bytes is what the 4KB cap applies to:

import { initSync, parse } from '@discord/markdown-wasm/sync';

initSync(wasmModule);

Parsing before either call throws.

Unparsing

unparse is only on /sync: it does no meaningful work off-thread, so there is no worker-backed variant.

unparse is not byte-exact for everything, because the AST does not retain every detail of how the source was written: text is not re-escaped, italics always come back as _, and unordered lists always as * . Everything else round trips exactly.