js2wasm

JavaScript to WebAssembly toolchain

Purpose

The intent for this tool is to provide a means to write PureScript, compile to JavaScript, and package as a self-contained Wasi command.

Build

Ensure Rust stable is installed.

rustup install stable && rustup default stable

Add the wasm32-wasi target.

rustup target add wasm32-wasi

From the root of the js2wasm project, download the wasi sdk.

./download-wasi-sdk.sh

Set the QuickJS Wasi SDK environment variable.

export QUICKJS_WASM_SYS_WASI_SDK_PATH=$(pwd)/wasi-sdk

Alternatively, direnv can be used to set the above automatically. See the .envrc file.

direnv allow .

Invoke the default make target.

make

Note: this project has only been built on Ubuntu LTS 22.04 w/ the clang development package installed.

Usage

target/release/js2wasm
error: The following required arguments were not provided:
    <input>

USAGE:
  js2wasm <input> -o <output>

Where <input> is a JavaScript command file and <output> is a Wasm file name. For example:

js2wasm index.js -o index.wasm

Example

See the example dir under the root of this project.

TODO

• Ensure build works on OSX.
• Add config options for optimization of code size / speed.

Acknowledgements

The code in the repo was adaptated from Javy with the following changes:

• Change naming, make company agnostic (i.e. Shopify -> Cmd).
• Remove hard-coded Wasm optimization (can be done later with wasm-opt).
• Reference quickjs-wasm-rs as a lib from crates.io.