Function hook

test/module-hooks/test-module-hooks-load-esm.js:20–23

(code, filename)

const hookArgs = [];
function hook(code, filename) {
  hookArgs.push({ code, filename });
  return code.replace('$key', 'hello');
}

(async () => {
  const revert = addHook(hook, { exts: ['.js'], matcher });