QuickJS Runtime for Hooks

Live loading

The latest version of the qjsc build is available (CORS enabled) at:

• https://wasm.xahau.tech/qjsc.wasm

JS Runtime for on chain Rule Engine (Smart Contracts)

This project is based on:

• bellard/quickjs
  • Forked by and modified for Hooks by @RichardAH: RichardAH/quickjslite
• second-state/quickjs-wasi
  • As originally forked from: dip-proto/quickjs-wasi

This project depends on:

• WebAssembly/wasi-sdk (wasi-sdk-22)

Build

You can conveniently build using Docker.

To build the container image for the build process:

docker build --tag quickjs-wasm-builder .

Compiler JS for use as a Hook

To build the qjsc.wasm JS Compiler WebAssembly binary using the previously created container:

docker run --rm --platform linux/amd64 -v $(pwd)/build:/wasi/build \
    quickjs-wasm-builder qjsc

Runtime to run/execute Javascript

To build qjs.wasm (QuickJS Runtime) WebAssembly binary using the previously created container:

docker run --rm --platform linux/amd64 -v $(pwd)/build:/wasi/build \
    quickjs-wasm-builder qjs

Run (use) - CLI

To run the .wasm binaries, we're using wasmedge: we need a virtual filesystem, stdin, stdout, etc. and wasmedge happily provides this context:

To compile a Javascript/... file to be used as a Hook

After building qjsc.wasm:

wasmedge --dir=.:. ./build/qjsc.wasm -c -o whatever.bc whatever.js

To run a Javascript/... file & upcode debugging

After building qjs.wasm:

wasmedge --dir=.:. ./build/qjs.wasm -e "console.log('Hello World');"

Run - Browser

To use the above .wasm files in your browser, create Javascript code like below, and save it as qjsc.mjs. You can build this .mjs file for the browser with esbuild:

esbuild qjsc.mjs --bundle --minify --tree-shaking=true --platform=browser --format=esm --target=es2017 > qjsc-browser.js

Now you have a qjsc-browser.js file to use in the browser, which you can include as modules:

<script type="module" src="./qjsc-browser.js"></script>

qjsc.mjs example source code:

import { WASI } from "@runno/wasi"
import { Buffer } from 'buffer/' // Browser needs this, node (CLI) doesn't

const wasmLocation = 'https://my-site.com/qjsc.wasm' // Must be served with mime type application/wasm!

const result = WASI.start(fetch(wasmLocation), {
    args: ["qjsc", "-c", "-o", "/hook.bc", '/hook.js'],
    env: { SOME_KEY: "some value" },
    stdout: (out) => alert("stdout: " + out),
    stderr: (err) => alert("stderr:" + err),
    stdin: () => prompt("stdin:"),
    fs: {
        "/hook.js": {
            mode: "string",
            content: 'console.log("Hello World!")', // Contents here, read from file / textinput / fs (node) / fetch ...
        },
    },
})

result.then(r => {
    // Sanitize some things to make it ready for a SetHook create code:

    const compiledHook = Buffer.from(r.fs?.['/hook.bc']?.content)
        .toString('utf-8')
        .match(/\{[^0-9a-fx]+?(0x[0-9a-f]{2}[^0-9a-fx]+?)+\}/misg)?.[0]
        .slice(1, -1).trim().split(',').map(o => o.trim().slice(-2)).join('')

    document.write(compiledHook)
})

Test @ https://runno.dev/wasi

Upload qjsc.wasm and create a .js file @ the virtual filesystem, e.g. sample.js, and then use argument:

-c -o sample.bc sample.js