test-esm-get-format.js

'use strict';
require('../common');
const assert = require('assert');
const { defaultGetFormat } = require('internal/modules/esm/get_format');

{
  const url = new URL('file://example.com/foo/bar.js');
  assert.strictEqual(defaultGetFormat(url), 'commonjs');
}

{
  const url = new URL('file://example.com/foo/bar.whatever');
  assert.throws(() => defaultGetFormat(url), { name: 'TypeError', message: /Unknown file extension whatever/ });
}