Aurelia - bootstrap form validation feature

bootstrap-validation\bootstrap-form-validation-renderer.js

import {inject} from 'aurelia-dependency-injection';
import {validationRenderer} from 'aurelia-validation';

@validationRenderer
@inject(Element)
export class BootstrapFormValidationRenderer {
  constructor(boundaryElement) {
    this.boundaryElement = boundaryElement;
  }

  render(error, target) {
    if (!target || !(this.boundaryElement === target || this.boundaryElement.contains(target))) {
      return;
    }

    // tag the element so we know we rendered into it.
    target.errors = (target.errors || new Map());
    target.errors.set(error);

    // add the has-error class to the bootstrap form-group div
    const formGroup = target.querySelector('.form-group') || target.closest('.form-group');
    formGroup.classList.add('has-error');

    // add help-block
    const message = document.createElement('span');
    message.classList.add('help-block');
    message.classList.add('validation-error');
    message.textContent = error.message;
    message.error = error;
    formGroup.appendChild(message);
  }

  unrender(error, target) {
    if (!target || !target.errors || !target.errors.has(error)) {
      return;
    }
    target.errors.delete(error);

    // remove the has-error class on the bootstrap form-group div
    const formGroup = target.querySelector('.form-group') || target.closest('.form-group');
    formGroup.classList.remove('has-error');

    // remove all messages related to the error.
    let messages = formGroup.querySelectorAll('.validation-error');
    let i = messages.length;
    while(i--) {
      let message = messages[i];
      if (message.error !== error) {
        continue;
      }
      message.error = null;
      message.remove();
    }
  }
}

// Polyfill for Element.closest and Element.matches
// https://github.com/jonathantneal/closest/
(function (ELEMENT) {
	ELEMENT.matches = ELEMENT.matches || ELEMENT.mozMatchesSelector || ELEMENT.msMatchesSelector || ELEMENT.oMatchesSelector || ELEMENT.webkitMatchesSelector;

	ELEMENT.closest = ELEMENT.closest || function closest(selector) {
		var element = this;

		while (element) {
			if (element.matches(selector)) {
				break;
			}

			element = element.parentElement;
		}

		return element;
	};
}(Element.prototype));

bootstrap-validation\index.js

import {BootstrapFormValidationRenderer} from './bootstrap-form-validation-renderer';

export function configure(config) {
  config.container.registerHandler(
    'bootstrap-form',
    container => container.get(BootstrapFormValidationRenderer));
}

i want to use BootstrapFormValidationRenderer code in aurelia framework javascript but i have this error TypeError: Object(...) is not a function
at Module../src/bootstrap-form-validation-renderer.js

i have a registration form like this

<div class="form-group">
  <label class="control-label" for="first">First Name</label>
  <input type="text" class="form-control" id="first" placeholder="First Name"
         value.bind="firstName  & validate"><span></span>
</div>

<div class="form-group">
  <label class="control-label" for="last">Last Name</label>
  <input type="text" class="form-control" id="last" placeholder="Last Name"
         value.bind="lastName & validate">
</div>

<div class="form-group">
  <label class="control-label" for="email">Email</label>
  <input type="text" class="form-control" id="email" placeholder="Email"
         value.bind="email & validate">
</div>

<button type="submit" class="btn btn-primary">Submit</button>

and a js file this

import {inject, NewInstance} from 'aurelia-dependency-injection';
import {ValidationController, validateTrigger} from 'aurelia-validation';
import {required, email} from 'aurelia-validatejs';
import {BootstrapFormValidationRenderer} from './bootstrap-form-validation-renderer';

@Inject(NewInstance.of(ValidationController), validateTrigger)
export class RegistrationForm {
@required
firstName = '';

@required
lastName = '';

@required
email = '';
constructor(controller) {
this.controller = controller;
controller.validateTrigger = validateTrigger.manual;
}

submit() {
let errors = this.controller.validate();
}
}