Jest: [BUG] Cannot find module with a platform extension

Created on 6 Oct 2016 · 2Comments · Source: facebook/jest

Using a bare react-native project and the jest react-native tutorial (https://facebook.github.io/jest/docs/tutorial-react-native.html), it seems modules imported according to the current platform cannot be found.

Here is a repository to reproduce the issue: https://github.com/shaoner/reactnativetest

npm install
npm test

[email protected] test /home/user/Workspace/tests/reactnativetest
jest

FAIL tests/Intro-test.js
● Test suite failed to run
Cannot find module './foo' from 'Intro.js'

  at Resolver.resolveModule (node_modules/jest-resolve/build/index.js:144:17)
  at Object.<anonymous> (Intro.js:9:10)
  at Object.<anonymous> (__tests__/Intro-test.js:3:12)
Test Suites: 1 failed, 1 total
Tests: 0 total
Snapshots: 0 total
Time: 0.727s
Ran all test suites.

The only interesting line in Intro.js is:

import foo from './foo'

which should by default import foo.ios.js using the options from jest-react-native

Versions and OS:

# npm --version
3.8.6
# node --version
v6.0.0
# react-native --version
react-native-cli: 1.0.0
react-native: 0.34.1
# uname -a
Linux soprano.lan 4.7.2-201.fc24.x86_64 #1 SMP Fri Aug 26 15:58:40 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

With --debug:

# ./node_modules/jest/bin/jest.js --no-cache --debug                                                                                              
jest version = 16.0.1
test framework = jasmine2
config = {
  "haste": {
    "defaultPlatform": "ios",
    "platforms": [
      "android",
      "ios"
    ],
    "providesModuleNodeModules": [
      "react",
      "react-native"
    ]
  },
  "moduleNameMapper": [
    [
      "^image![a-zA-Z0-9$_-]+$",
      "GlobalImageStub"
    ],
    [
      "^[./a-zA-Z0-9$_-]+\\.(bmp|gif|jpg|jpeg|png|psd|svg|webp)$",
      "RelativeImageStub"
    ]
  ],
  "modulePathIgnorePatterns": [
    "/home/user/Workspace/tests/reactnativetest/node_modules/react-native/Libraries/react-native/",
    "/home/user/Workspace/tests/reactnativetest/node_modules/react-native/packager/"
  ],
  "preprocessorIgnorePatterns": [
    "node_modules/(?!(jest-)?react-native|react-clone-referenced-element)"
  ],
  "setupFiles": [
    "/home/user/Workspace/tests/reactnativetest/node_modules/babel-polyfill/lib/index.js",
    "/home/user/Workspace/tests/reactnativetest/node_modules/jest-react-native/build/setup.js"
  ],
  "testEnvironment": "/home/user/Workspace/tests/reactnativetest/node_modules/jest-environment-node/build/index.js",
  "preset": "jest-react-native",
  "rootDir": "/home/user/Workspace/tests/reactnativetest",
  "name": "-home-user-Workspace-tests-reactnativetest",
  "testRunner": "/home/user/Workspace/tests/reactnativetest/node_modules/jest-jasmine2/build/index.js",
  "scriptPreprocessor": "/home/user/Workspace/tests/reactnativetest/node_modules/babel-jest/build/index.js",
  "usesBabelJest": true,
  "automock": false,
  "bail": false,
  "browser": false,
  "cacheDirectory": "/tmp/jest",
  "clearMocks": false,
  "coveragePathIgnorePatterns": [
    "/node_modules/"
  ],
  "coverageReporters": [
    "json",
    "text",
    "lcov",
    "clover"
  ],
  "globals": {},
  "mocksPattern": "__mocks__",
  "moduleDirectories": [
    "node_modules"
  ],
  "moduleFileExtensions": [
    "js",
    "json",
    "jsx",
    "node"
  ],
  "noStackTrace": false,
  "notify": false,
  "resetModules": false,
  "testPathDirs": [
    "/home/user/Workspace/tests/reactnativetest"
  ],
  "testPathIgnorePatterns": [
    "/node_modules/"
  ],
  "testRegex": "(/__tests__/.*|\\.(test|spec))\\.jsx?$",
  "testURL": "about:blank",
  "timers": "real",
  "useStderr": false,
  "verbose": null,
  "watch": false,
  "cache": false,
  "watchman": true,
  "testcheckOptions": {
    "times": 100,
    "maxSize": 200
  }
}
 FAIL  __tests__/Intro-test.js
  ● Test suite failed to run

    Cannot find module './foo' from 'Intro.js'

      at Resolver.resolveModule (node_modules/jest-resolve/build/index.js:144:17)
      at Object.<anonymous> (Intro.js:9:10)
      at Object.<anonymous> (__tests__/Intro-test.js:3:12)

Test Suites: 1 failed, 1 total
Tests:       0 total
Snapshots:   0 total
Time:        2.714s
Ran all test suites.

After investigating a bit, I've found that the HasteMap instance (from jest-haste-map) does not actually register foo in the map object (see _buildHasteMap), therefore the jest module Resolver is not able to find the actual module.

Am I missing something?

Source