js-wasi-ext

This is a library compatible with WASI 0.2 that makes select Node.js APIs available in ComponentizeJS and StarlingMonkey.

Usage

This library currently requires Webpack and uses a plugin to define the fall backs.:

import WasiExtPlugin from "@spinframework/wasi-ext/plugin/index.js";

export default config = () => {
    ...
    return {
        ...
        plugins: [
            new WasiExtPlugin()
        ],
        ...
    }
}

Note: this currently does not support the node:process syntax yet.

Because accessing environment variables needs to happen at runtime (not during pre-initialization), the actual environment variables can only be accessed from the handler function. If accessed outside, that is not supported (and currently, process.env returns an empty map; we can discuss what this behavior should be).

The library currently exports a setupExt() function that explicitly initializes process.env from the handler. We could potentially remove that depending on the desired experience of this library.

After setup:

import process from "process";

...
console.log(process.env["PET"]);

Supported APIs

• process: certain methods are no-ops and few throw exceptions. For detailed list refer to the upstream library. process.env is only populated when inside the handler function, when outside, it returns an empty object (i.e) {}
• fs: Limited to readFileSync and readdirSync