Fails to import modules inside imported module from tests

[wilomgfx]

• Issue
  
  When ever i link a module from my typescript source files, it seems like the modules inside that said imported module are not imported.

Heres an example test

import { User } from './../src/types/models';
import Api from '../src/api';
import { t } from '../src/configs/i18n'

const api = new Api()

// beforeEach()

describe('Api client', () => {

  it('Should return wilomgx as a user', (done) => {
    const login = api.getUserByLogin({
      user:'wilomgfx',
      pw:'wilomgfxis2op4you'
    })
    login.then(({data} : {data: User}) => {
      expect(data).toBeInstanceOf(User)
      expect(data.fullName).toBe('William Graphics')
      done()
    })
    .catch(e => done(e))
  })
 //...more tests
}

My config

"jest": {
    "preset": "react-native",
    "transform": {
      "^.+\\.js$": "<rootDir>/node_modules/babel-jest",
      ".(ts|tsx)": "<rootDir>/node_modules/ts-jest/preprocessor.js"
    },
    "testRegex": "(/test/.*|\\.(test|spec))\\.(ts|tsx|js)$",
    "moduleFileExtensions": [
      "ts",
      "tsx",
      "js"
    ],
    "testResultsProcessor": "<rootDir>/node_modules/ts-jest/coverageprocessor.js"

To make it work i have to import my compiled javascript from my build folder

import { User } from './../build/types/models';
import Api from '../build/api';
import { t } from '../build/configs/i18n'

const api = new Api()

// beforeEach()

describe('Api client', () => {

  it('Should return wilomgx as a user', (done) => {
    const login = api.getUserByLogin({
      user:'wilomgfx',
      pw:'wilomgfxis2op4you'
    })
    login.then(({data} : {data: User}) => {
      expect(data).toBeInstanceOf(User)
      expect(data.fullName).toBe('William Graphics')
      done()
    })
    .catch(e => done(e))
  })
 //...more tests
}

Heres the imported file that is causing the error when referencing the typescript file from the src folder

import I18n from 'react-native-i18n'
// Enable fallbacks if you want `en-US` and `en-GB` to fallback to `en`
I18n.fallbacks = true

//code to set translations, not relevant here

• Expected behavior

Work ? I dont know, maybe my configs are wrong... but it wont work for required typescript files.
Tried to use an other file with some other random imported file, and it wont work either.

[kulshekhar]

please create a minimal repo which reproduces this issue

[wilomgfx]

There you go : https://github.com/wilomgfx/ts-jest-import-issue-repo

As soon as i import a module from npm (in this case react-native-i18n just like in my real app) it won't import it properly causing an undefined error.

[kulshekhar]

@wilomgfx the import is incorrect. Use

import * as I18n from 'react-native-i18n';

I've sent a PR to your repo.

[wilomgfx]

Oh waow, thanks! Indeed. Kinda strange that it worked even if i was not importing everything from the said package when building up for the app. Thanks a lot :P

Any idea why ?

[aaronjensen]

In case anyone else comes here and ends up seeing

error TS2497: Module '"X"' resolves to a non-module entity and cannot be imported using this construct.

Check out microsoft/TypeScript#5073

tl;dr add declare namespace X {} to your X.d.ts to work around this.