ember-validated-form

controllers.application.js

import Ember from 'ember';
import UserValidations from 'twiddle/validations/user';

export default Ember.Controller.extend({
  UserValidations,
  
  actions: {
    submit(model) {
      console.log('submit', model)
      model.save()
    }
  }
});

routes.application.js

import Ember from 'ember';

export default Ember.Route.extend({
  model() {
    return Ember.RSVP.hash({
      user: {
        firstName: 'Test',
      }
    });
  }
});

templates.application.hbs

{{#validated-form
	model=(changeset model.user UserValidations)
  on-submit    = (action "submit")
  submit-label = 'Save' as |f|}}

  {{f.input label="First name" name="firstName"}}
  {{f.input label="Last name" name="lastName"}}
  {{f.submit label="Save"}}
{{/validated-form}}

twiddle.json

{
  "version": "0.15.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.2.2",
    "ember-template-compiler": "3.2.2",
    "ember-testing": "3.2.2"
  },
  "addons": {
    "ember-data": "3.2.0",
    "ember-validated-form": "1.4.0"
  }
}

validations.user.js

import {
  validatePresence,
  validateLength,
  validateInclusion
} from 'ember-changeset-validations/validators';

export default {
  firstName: [validatePresence(true), validateLength({ min: 3, max: 40 })],
  lastName: [validatePresence(true), validateLength({ min: 3, max: 40 })]
};