Extending Kakunin

Kakunin allows you to easily add a custom code in order to extend it's functionality.

Internal services

Regex builder

Regex builder is a special builder for creating RegExp objects based on regexp name. Internally it has access to not only to all built-in regular expression files, but also custom ones specified by user.

const { regexBuilder } = require('kakunin');

const myRegex = regexBuilder.buildRegex('r:number');

//myRegex will contain RegExp object that matches regular expression under the name "number" in regexes file.

Variable store

Variable store allows you to store and read some values to be used during given scenario.

const { variableStore } = require('kakunin');

variableStore.storeVariable('some-name', 'some-value');

const myValue = variableStore.getVariableValue('some-name'); //contains 'some-value'

User provider

Kakunin comes with functionality that allows you to easily load credentials for a given account type - UserProvider.

In kakunin.conf.js you can find a section accounts.

The structure it has is very simple:

"accounts": {
    "someAccount": {
        "accounts": [
                "email": "",
                "password": ""

someAccount - the name of accounts group

accounts - an array of account credentials (in order to be able to check if a currentUser got an email, this has to have an email key, otherwise account can have any kind of properties)

Use provider is accessible inside any kind of a step by calling this.userProvider. It comes with a single method:

this.userProvider.getUser(groupName) - returns an account credentials for a given user group.

It is a good practice to save a current user in this.currentUser variable for a email checking service.

Adding custom code

Custom step

In order to add a custom step, you have to create inside of a directory specified as step_definitions in kakunin configuration file default: /step_definitions.

We're using cucumber-js 2.X so in order to add custom step you have to use defineSupportCode method like this:

  const { defineSupportCode } = require('kakunin');

  defineSupportCode(({ When }) => {
    When(/^I use kakunin$/, function() {

Page objects

Kakunin comes with some built-in page objects, that should be used as a base for your page objects.

In order to create a custom one, create a file inside the pages directory and extend the BasePage from kakunin package.

const { BasePage } = require('kakunin');

class MyPageObject extends BasePage {
  constructor() {
    this.myElement = element(by.css('.some-elemnt'));

module.exports = MyPageObject;


Matchers are used to compare if given value is matching our expectation. For example if a value in table is a number.

You can add your own matcher as below:

const { matchers } = require('kakunin');

class MyMatcher {
  isSatisfiedBy(prefix, name) {
    return prefix === 'm:' && name === 'pending';

  match(protractorElement, matcherName) {
    return protractorElement.getText().then((value) => value === 'pending'); 

matchers.addMatcher(new MyMatcher());


Dictionaries allows you to present complicated values in much more readable way. For example if an element must be in a form of IRI /some-resource/123-123-123-23 and you wish to use pending-resource as it's alias.

You can add your own dictionary:

const { dictionaries } = require('kakunin');
const { BaseDictionary } = require('kakunin');

class TestDictionary extends BaseDictionary {
  constructor() {
    super('name-of-dictionary', {
      'pending-resource': '/some-resource/123-123-123-23',
      'test-value': 'some other value'

dictionaries.addDictionary(new TestDictionary());


Generators allows you to create random values

You can add your own generator:

const { generators } = require('kakunin');

class MyGeneerator{
  isSatisfiedBy(name) {
    return name === 'my-generator';

  generate(params) {
    return Promise.resolve('some-random-value');

generators.addGenerator(new MyGeneerator());


Comparators allows you to check if a set of values has an expected order

You can add your own comparators:

const { comparators } = require('kakunin');

class MyComparator {
  isSatisfiedBy(values) {
    for(let i=0; i<values.length; i++) {
      if (values[i] !== 'foo' && values[i] !== 'bar') {
        return false;

    return true;

  compare(values, order) {
    for (let i = 1; i < values.length; i++) {
      const previousValue = values[i - 1];
      const currentValue = values[i];

      if (previousValue === currentValue) {
        return Promise.reject('Wrong order');

    return Promise.resolve('Foo bar!');

comparators.addComparator(new MyComparator());

Form handlers

Form handlers allows you to fill the form inputs and check value of filled fields

You can add your own handlers:

const { handlers } = require('kakunin');

const MyHandler {
  constructor() {
    this.registerFieldType = false;
    this.fieldType = 'default';

  isSatisfiedBy(element, elementName) {
    return Promise.resolve(elementName === 'someElementName');

  handleFill(page, elementName, desiredValue) {
    return page[elementName].isDisplayed()
      .then(function () {
        return page[elementName].clear().then(function () {
          return page[elementName].sendKeys(desiredValue);

  handleCheck(page, elementName, desiredValue) {
    return page[elementName].isDisplayed()
      .then(function () {
        return page[elementName].getAttribute('value').then(function (value) {
          if (value === desiredValue) {
            return Promise.resolve();

          return Promise.reject(`Expected ${desiredValue} got ${value} for text input element ${elementName}`);

handlers.addHandler(new MyHandler());


Transformers can be used in steps When I fill the "form" form with: and And the "joinOurStoreForm" form is filled with:.

Existing transformers: - generators (prefix: g:) - dictionaries (prefix: d:) - variableStore (prefix: v:) Transformers can be used in mentioned steps by using specific 'prefix', parameters are sent after : sign. Example: g:generatorName:param:param

You can add your own handlers:

const { transformers } = require('kakunin');

class MyTransformer {

  isSatisfiedBy(prefix) {
    return 'yourPrefix:' === prefix;

  transform(value) {
transformers.addTransformer(new MyTransformer());

Email checking service

You can easily check emails with Kakunin. By default we give you MailTrap client implementation, but you can easily add your own client.

const { emailService } = require('kakunin');

class MyEmailService {
  //you have access to full kakunin config
  isSatisfiedBy(config) {
    return config.email.type === 'my-custom-email-service';

  //method used to clear emails before tests
  clearInbox() {

  //method used to get emails - this method should return emails in format described below
  getEmails() {

  //method used to retrive atachments for given email - should return attachments in format described below
  getAttachments(email) {

  //method used to mark given email as read
  markAsRead(email) {

emailService.addAdapter(new MyEmailService());

Emails should be returned as an array of objects with given schema:

      "subject": "SMTP e-mail test",
      "sent_at": "2013-08-25T19:32:07.567+03:00",
      "from_email": "me@railsware.com",
      "from_name": "Private Person",
      "to_email": "test@railsware.com",
      "to_name": "A Test User",
      "html_body": "",
      "text_body": "This is a test e-mail message.\r\n",
      "email_size": 193,
      "is_read": true,
      "created_at": "2013-08-25T19:32:07.576+03:00",
      "updated_at": "2013-08-25T19:32:09.232+03:00",
      "sent_at_timestamp": 1377448326

this is MailTrap email format.

Attachments should be returned as an array of objects with given schema:

      "id": 1737,
      "message_id": 54508,
      "filename": "Photos.png",
      "attachment_type": "attachment",
      "content_type": "image/png",
      "content_id": "",
      "transfer_encoding": "base64",
      "attachment_size": 213855,
      "created_at": "2013-08-16T00:39:34.677+03:00",
      "updated_at": "2013-08-16T00:39:34.677+03:00",
      "attachment_human_size": "210 KB",
      "download_path": "/api/v1/inboxes/3/messages/54508/attachments/1737/download"

this is MailTrap attachment format.