Module entrypoint for instantiation and execution of WASI-targeted WASM code. A modification of the js-polyfill for easier use in testing / command line interactions.

const runner = require('wasi-runner');
let stdin = 'hello world';
let exitCode = await runner.instantiate(fs.readFileSync('my_wasi.wasm'), {
  stdin,
  stdout: (val) => {
    console.log(val);
  },
});

• The current structure won't safely support multiple concurrent instances.
• Mapping of stdin/stdout/stderr is fairly rudimentary.
• The shim provides default polyfill for socket and FD functionality.
• The runner doesn't (yet) allow for over-riding most of that defualt behavior.