Binaryen.TS

Binaryen API ported to TypeScript for use in the browser and in Node.JS.

How To Use

$ npm install binaryen.ts

import * as binaryen from "binaryen.ts";

const mod: binaryen.Module = new binaryen.Module();

mod.functions.add("add", binaryen.createType([binaryen.i32, binaryen.i32]), binaryen.i32, [binaryen.i32], (() => {
	const {block, local, i32} = mod.wasm;
	const param0: binaryen.ExpressionRef = local.get(0, binaryen.i32);
	const param1: binaryen.ExpressionRef = local.get(1, binaryen.i32);
	const result: binaryen.ExpressionRef = i32.add(param0, param1);
	return block(null, [
		local.set(2, result),
		local.get(2, binaryen.i32),
	], binaryen.i32);
})());
mod.exports.addFunction("add", "add");
mod.optimize();
if (!mod.validate()) {
	throw new Error("Invalid WebAssembly module.");
}

const textData = mod.emitText();
const wasmData = mod.emitBinary() as Uint8Array<ArrayBuffer>;
const compiled = new WebAssembly.Module(wasmData);
const instance = new WebAssembly.Instance(compiled, {});

console.log(instance.exports.add(41, 1)); // 42

How to Contribute

Contributions are welcome! Make sure you have Git and Node (and NPM) installed on your machine, and have already cloned the WebAssembly/binaryen repo.

From the repo’s root:

$ cd ./ts/
$ npm ci
$ npm run build

Pipeline

Develop in TypeScript

The core of this project is written in TS, best paired with a powerful editor and some nice extensions.

$ npm run compile # emits javascript output to ./dist/

Don’t put anything important in ./dist/, as it gets deleted and rebuilt each time.

Before committing, ensure only the best code quality by running ESLint.

$ npm run lint # reports linter errors & warnings
$ npm run lint -- --fix # tries to auto-fix problems (some may need manual fixing)

Use Conventional Commits commit message format. Messages should be in the present tense / command tense.

$ git commit -m "feat: add a new feature"
$ git commit -m "feat!: add a new breaking feature" # API consumers need to know about these
$ git commit -m "fix: fix a bug"
$ git commit -m "refactor: reorganize code"
$ git commit -m "lint: fix a coding style issue"
$ git commit -m "docs: update documentation"
$ git commit -m "test: add/update tests"
$ git commit -m "build: make a change related to the package build system"

Update Docs

Generated documentation is built with TypeDoc, a tool that parses comments in the TS source files and produces beautiful HTML.

After developing and updating doc-comments, regenerate docs and view them locally in your browser.

$ npm run docs # builds a static site to ../docs/binaryen.ts/
$ open ../docs/binaryen.ts/index.html

Don’t put anything important in ../docs/.

Documentation is hosted online via GitHub Pages at https://chharvey.github.io/binaryen/binaryen.ts/, and will be moved to https://webassembly.github.io/binaryen/binaryen.ts/ once this fork is merged in.

Upon every release, public docs should be redeployed via updating the gh-pages branch. On that branch, the ../docs/ folder is checked in. You need to switch to that branch, merge in your changes, rebuild the docs, then commit and push.

$ git switch gh-pages
$ git merge --no-commit main
$ npm run docs
$ git add ../docs/binaryen.ts/
$ git merge --continue
$ git push

Run Tests

The test suite is still in progress, migrating from ../test/binaryen.js/. The new test suite uses the Node v26+ test runner.

$ npm run test

Bundle

TypeScript only compiles the source files to ./dist/. After that we may need a bundler to optimize and minify it into a prepackaged file, which will be able to target different platforms so that it can be used by consumers.

TODO: more details

Build and Push

Before pushing, rebuild the entire project to catch any errors.

$ npm run build

# if all goes well…

$ git push

Publish

TODO: this section

File Inventory

• README.md: you are here

• .editorconfig, .gitignore: standard repo files

• package{,-lock}.json: Node package & npm registry details

• node_modules/ (gitignored): npm dependencies

• tsconfig.json: TypeScript configuration

• eslint.config.js: JS/TS coding style conventions

• typedoc.config.js: documentation generator configuration

• build/ (gitignored): output of Emscripten; this is imported by the src/ library

• src/: human-written source code

  • binaryen.ts: the entrypoint; exports everything available to consumers

  • -pre.ts: artifacts provided by Emscripten

  • -utils.ts: internal tools

  • {constants,globals}.ts: top-level exported globals

  • -deprecations.ts: everything deprecated, all in one place

  • classes/: all the modular code

    • {TypeBuilder,ExpressionRunner,Relooper}.ts: Binaryen tools

    • module/: Module and related classes

    • expression/: Expression info classes, and source for WASM expression generation

  • services/: namespace-like, stateless classes

• dist/ (gitignored): output of tsc; this gets bundled and published to NPM for consumers

• docs/: documentation assets

• ../docs/binaryen.ts/ (gitignored): output of typedoc; hosted online