jco/test/runtime/helpers.ts

// @ts-ignore
import { readFile } from 'node:fs/promises';
// @ts-ignore
import { readFileSync } from 'node:fs';
// @ts-ignore
import { stdout, stderr } from 'node:process';
// @ts-ignore
import { basename } from 'node:path';

// This is a helper function used from `host.ts` test in the `tests/runtime/*`
// directory to pass as the `instantiateCore` argument to the `instantiate`
// function generated by `wit-bindgen`.
//
// This function loads the module named by `path` and instantiates it with the
// `imports` object provided. The `path` is a relative path to a wasm file
// within the generated directory.
export async function loadWasm(path: string) {
  const name = basename(path).replace(/\.core\d*\.wasm$/, '');
  return await WebAssembly.compile(await readFile(new URL(`./${name}/${path}`, import.meta.url)));
}

// Just like `loadWasm`, but not async :-).
export function loadWasmSync(path: string) {
  const name = basename(path).replace(/\.core\d*\.wasm$/, '');
  return new WebAssembly.Module(readFileSync(new URL(`./${name}/${path}`, import.meta.url)));
}

// Export a WASI interface directly for instance imports
export function log (bytes: Uint8Array) {
  stdout.write(bytes);
}
export function logErr (bytes: Uint8Array) {
  stderr.write(bytes);
}

export const wasi = {
  'wasi:cli/stderr': {
    getStderr () {

    }
  },
  'wasi:cli/stdin': {
    getStdin () {

    }
  },
  'wasi:cli/stdout': {
    getStdout () {

    }
  },
  'wasi:filesystem/preopens': {
    getDirectores () {

    }
  },
  'wasi:filesystem/types': {
    Descriptor: class Descriptor {},
    filsystemErrorCode () {
      return 0;
    }
  },
  'wasi:io/error': {
    Error: class WasiError {}
  },
  'wasi:io/streams': {
    InputStream: class InputStream {},
    OutputStream: class OutputStream {}
  }
};