Using Cucumber.js with Jest

An alternative would be to use jest-cucumber

https://www.npmjs.com/package/jest-cucumber.

gives you the flexibility of using both frameworks

My react-native environment:

"cucumber": "^4.1.0",
"jest": "22.4.2",

In my steps definition file, I just require it like this

const { Given, Then, When } = require('cucumber');
const expect = require('expect');

Expect is part of Jest, so you can import it as its own object. Then I can use it wherever I need an assertion. Note: newMember is declared and populated elsewhere.

Given('Sara has provided account details', function() {
  for (const prop in newMember) {
    expect(newMember[prop]).toBeTruthy();
  }
});

Hope that helps.

expect is a globally scoped during jest runtime. So as long as you are running jest it will be available. I'm using this package (needs some config to transform correctly to your babel config): gherkin-jest

Here's a feature using the DOM-testing example from the jest docs:

Feature: Using feature files in jest and cucumber
  As a developer
  I want to write tests in cucumber and jest
  So that businesspeople understand tests and I can test React

  Scenario: Emoji toggles upon checking and unchecking the checkbox
    Given I did not check the checkbox, so the label is "😭"
    When I check the box and the emoji toggles to be "😎"

import {cucumber as c} from 'gherkin-jest'
import React from 'react'
import {mount} from 'enzyme'
import {Checkbox} from '../src/components'

c.defineCreateWorld(() => ({
  checkbox:null
}))

c.defineRule('I did not check the checkbox so the label is {string}', (world, off) => {
  world.checkbox = mount(<Checkbox labelOff={off} />)
  expect(world.checkbox.text()).toBe(off)
})


c.defineRule('I checked the box and the emoji toggles to be {string}', (world, on) =>{
  world.checkbox = mount(<Checkbox labelOn={on}/>)
  world.checkbox.find('TouchableOpacity').props().onPress()
  expect(world.checkbox.text()).toBe(on)
})

This issue I posted gives an example of the config.