shared/base/router.js
function(viewPath, locals, route) {
    if (typeof viewPath !== 'string') {
      locals = viewPath;
      viewPath = route.controller + '/' + route.action;
    }
    return [viewPath, locals];
  }
function(viewPath, locals, route) {
    if (typeof viewPath !== 'string') {
      locals = viewPath;
      viewPath = route.controller + '/' + route.action;
    }
    return [viewPath, locals];
  }
Support omitting view path; default it to ":controller/:action".