Ben Estes
Ben Estes

Reputation: 113

"SyntaxError: Cannot use import statement outside a module" error while testing React Native project with Jest and @testing-library/react-native?

Error I'm getting Anytime I run npm test:

 FAIL  ./App.test.js

● Test suite failed to run

Jest encountered an unexpected token

This usually means that you are trying to import a file which Jest cannot parse, e.g. it's not plain JavaScript.

By default, if Jest sees a Babel config, it will use that to transform your files, ignoring "node_modules".

Here's what you can do:
 • If you are trying to use ECMAScript Modules, see https://jestjs.io/docs/en/ecmascript-modules for how to enable it.
 • To have some of your "node_modules" files transformed, you can specify a custom "transformIgnorePatterns" in your config.
 • If you need a custom transformation specify a "transform" option in your config.
 • If you simply want to mock your non-JS modules (e.g. binary assets) you can stub them out with the "moduleNameMapper" config option.

You'll find more details and examples of these config options in the docs:
https://jestjs.io/docs/en/configuration.html

Details:

/Users/bestes/Desktop/react-native-training/node_modules/react-native-status-bar-height/index.js:1
({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,global,jest){import { Dimensions, Platform, StatusBar } from 'react-native';
                                                                                         ^^^^^^

SyntaxError: Cannot use import statement outside a module

  at Runtime.createScriptFromCode (node_modules/jest-runtime/build/index.js:1350:14)
  at Object.<anonymous> (node_modules/react-native-elements/src/config/index.js:1:1)

My Test:

import 'react-native';
import React from 'react';
import { render } from '@/../testing/test-utils'
import App from './App'


test('should render app component', () => {
  const result = render(<App />)

  expect(result).toMatchSnapshot()
})

My test-utils.js file:

import React from 'react'

import { render } from '@testing-library/react-native'
import { store } from '@/bootstrap/redux'
import { Provider } from 'react-redux'

const AllTheProviders = ({ children }) => {
  return (
    <Provider store={store}>
      {children}
    </Provider>
  )
}

const customRender = (ui, options) =>
  render(ui, { wrapper: AllTheProviders, ...options })

// re-export everything
export * from '@testing-library/react-native'

// override render method
export { customRender as render }

My package.json file:

{
  "name": "ReactNativeTraining",
  "version": "0.0.1",
  "private": true,
  "scripts": {
    "android": "react-native run-android",
    "ios": "react-native run-ios",
    "start": "react-native start",
    "test": "jest",
    "lint": "eslint ."
  },
  "dependencies": {
    "@react-native-community/geolocation": "2.0.2",
    "@react-native-community/masked-view": "0.1.10",
    "@react-native-picker/picker": "1.9.10",
    "@reduxjs/toolkit": "1.5.0",
    "axios": "0.21.1",
    "dayjs": "1.10.4",
    "lodash": "4.17.20",
    "react": "16.13.1",
    "react-native": "0.63.2",
    "react-native-config": "1.4.2",
    "react-native-elements": "3.0.0-alpha.1",
    "react-native-geocoding": "0.5.0",
    "react-native-gesture-handler": "1.9.0",
    "react-native-permissions": "3.0.0",
    "react-native-picker-select": "8.0.4",
    "react-native-reanimated": "1.13.2",
    "react-native-safe-area-context": "3.1.9",
    "react-native-screens": "2.17.0",
    "react-native-size-matters": "0.4.0",
    "react-native-vector-icons": "8.0.0",
    "react-navigation": "4.0.2",
    "react-navigation-stack": "1.5.4",
    "react-navigation-tabs": "2.4.1",
    "react-redux": "7.2.2"
  },
  "devDependencies": {
    "@babel/core": "7.12.10",
    "@babel/runtime": "7.12.5",
    "@react-native-community/eslint-config": "2.0.0",
    "@testing-library/jest-native": "4.0.1",
    "@testing-library/react-native": "7.2.0",
    "babel-jest": "^26.6.3",
    "babel-plugin-module-resolver": "4.0.0",
    "eslint": "7.18.0",
    "jest": "26.6.3",
    "metro-react-native-babel-preset": "0.64.0",
    "react-test-renderer": "16.13.1"
  },
  "type": "module",
  "jest": {
    "verbose": true,
    "preset": "react-native",
    "setupFilesAfterEnv": ["@testing-library/jest-native/extend-expect"],
    "transformIgnorePatterns": [
      "node_modules/(?!(react-native",
      "@react-native-community/geolocation",
      "@react-native-community/masked-view",
      "|@react-native-picker/picker",
      "|@reduxjs/toolkit",
      "|axios",
      "|dayjs",
      "|lodash",
      "|react",
      "|react-native",
      "|react-native-config",
      "|react-native-elements",
      "|react-native-geocoding",
      "|react-native-gesture-handler",
      "|react-native-permissions",
      "|react-native-picker-select",
      "|react-native-reanimated",
      "|react-native-safe-area-context",
      "|react-native-screens",
      "|react-native-size-matters",
      "|react-native-vector-icons",
      "|react-navigation",
      "|react-navigation-stack",
      "|react-navigation-tabs",
      "|react-redux",
      ")/)"
    ]
  }
}

My babel.config.js file:

module.exports = function (api) {
  api.cache(true)
  const presets = [
    'module:metro-react-native-babel-preset'
  ]
  const plugins = [
    [
      'module-resolver', {
        'root': ['./src/'],
        'extensions': ['.js', '.ios.js', '.android.js'],
        'alias': {
          '@': './src/'
        }
      }
    ]
  ]
  return {
    presets,
    plugins
  }
}

What I've tried: Adding "type": "module" to my root level package.json file, which fixed a similar error with exporting, Adding Transform Ignore Patterns to the Jest key in the package.json file. I'd added ALL of my dependencies to the transformIgnorePatterns as it kept throwing errors on each one, until I added all and now it throws on react-native modules imports.

Upvotes: 11

Views: 24705

Answers (2)

Aleksandr Galko
Aleksandr Galko

Reputation: 71

It's working for me (react-native + expo + jest + @testing-library/react-native):

package.json

{
  ...

  "scripts": {
    "start": "expo start",
    "android": "expo start --android",
    "ios": "expo start --ios",
    "web": "expo start --web",
    "test": "jest"
  },
  "jest": {
    "preset": "jest-expo",
    "transformIgnorePatterns": [
      "/node_modules/(?!react-native)/.+"
    ],
    "transform": {
      "^.+\\.ts?$": "ts-jest",
      "^.+\\.tsx?$": "ts-jest"
    }
  }

...
}

babel.config.js

module.exports = function(api) {
  api.cache(true);
  return {
    presets: ['babel-preset-expo'],
  };
};

tsconfig.js

{
  "compilerOptions": {
    "jsx": "react",
    "allowJs": true
  },
  "extends": "expo/tsconfig.base"
}

Upvotes: 0

Thilina Chamika
Thilina Chamika

Reputation: 340

[Solved] Work for me Install below

npm install --save-dev @babel/core @babel/preset-env

after that create the "babel.config.js" file in the root and that content should be as below

module.exports = {
  presets: ['@babel/preset-env', '@babel/preset-react'],
  env: {
    test: {
      plugins: ["@babel/plugin-transform-runtime"]
    }
  }
};

Upvotes: 2

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