message: extension doesn't belong in module name
diff: @@ -10,7 +10,7 @@ module.exports = class {
  }
  async generateCode(/* branch */) {
  let modules = new Map();
  - modules.set('addon/environment.js', template(this._content()));
  + modules.set('addon/environment', template(this._content()));
  return modules;
  }
  _content() {
  