How do I laugh at reacting i18next and i18n.js for fun?

Question

package.json

"moduleNameMapper": {
  "i18next": "<rootDir>/__mocks__/i18nextMock.js"
}

i18n.js

import i18n from 'i18next'
import XHR from 'i18next-xhr-backend'
// import Cache from 'i18next-localstorage-cache'
import LanguageDetector from 'i18next-browser-languagedetector'

i18n
  .use(XHR)
  // .use(Cache)
  .use(LanguageDetector)
  .init({
    fallbackLng: 'en',
    // wait: true, // globally set to wait for loaded translations in translate hoc
    lowerCaseLng: true,
    load: 'languageOnly',
    // have a common namespace used around the full app
    ns: ['common'],
    defaultNS: 'common',
    debug: true,

    // cache: {
    //   enabled: true
    // },

    interpolation: {
      escapeValue: false, // not needed for react!!
      formatSeparator: ',',
      format: function (value, format, lng) {
        if (format === 'uppercase') return value.toUpperCase()
        return value
      }
    }
  })

export default i18n

i18nextMock.js

/* global jest */
const i18next = jest.genMockFromModule('react-i18next')
i18next.t = (i) => i
i18next.translate = (c) => (k) => k

module.exports = i18next

For some reason, alignment tests do not receive the component.

Here is the unit test:

import React from 'react'
import { Provider } from 'react-redux'
import { MemoryRouter } from 'react-router-dom'
import { mount } from 'enzyme'

import { storeFake } from 'Base/core/storeFake'
import Container from '../container'

describe('MyContainer (Container) ', () => {
  let Component;

  beforeEach(() => {
    const store = storeFake({})

    const wrapper = mount(
      <MemoryRouter>
        <Provider store={store}>
          <Container />
        </Provider>
      </MemoryRouter>
    )

    Component = wrapper.find(Container)
  });

  it('should render', () => {
    // Component is undefined here
    expect(Component.length).toBeTruthy()
  })
})

Answer 1

Have you already studied the tests in the i18next response itself? https://github.com/i18next/react-i18next/blob/master/test/trans.render.spec.js

Additionally there is a small introduction to testing at https://react.i18next.com/misc/testing.html

Answer 2

You do not need to scoff at the function t, it is only required translate. In the second case, your use of the parameters is confusing, you also need to return the component.

. Jest

jest

"moduleNameMapper": {
    "react-i18next": "<rootDir>/__mocks__/reacti18nextMock.js"
}

mock react-i18next

/* global jest */
import React from 'react'

const react_i18next = jest.genMockFromModule('react-i18next')

const translate = () => Component => props => <Component t={() => ''} {...props} />

react_i18next.translate = translate

module.exports = react_i18next

Answer 3

I used Atemu anwser in my jest tests, but ended up with the following line in mock:

module.exports = {t: key => key};

The jest config has also been changed since I import 't' from 'i18next':

"moduleNameMapper": {
    "i18next": "<rootDir>/__mocks__/reacti18nextMock.js"
}