How to use the @aurelia/plugin-conventions.preprocess function in @aurelia/plugin-conventions

it('transforms html file', function () {
    const html = '<template></template>';
    const expected = `import { CustomElement } from '@aurelia/runtime';
export const name = "foo-bar";
export const template = "<template></template>";
export default template;
export const dependencies = [  ];
let _e;
export function getHTMLOnlyElement() {
  if (!_e) {
    _e = CustomElement.define({ name, template, dependencies });
  }
  return _e;
}
`;
    const result = preprocess({ path: path.join('src', 'foo-bar.html'), contents: html }, {}, () =&gt; false);
    assert.equal(result.code, expected);
    assert.equal(result.map.version, 3);
  });