Unexpected token import es6 class

[bredah]

🐛 Bug Report

When I run JEST, the execution failed and show the message:

> [email protected] test C:\Users\bredah\git\lab_js\es6                                                                    
> jest                                                                                                                                      
                                                                                                                                            
 FAIL  src/example/calculator.spec.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:                                                                                                                 
     • 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://facebook.github.io/jest/docs/en/configuration.html                                                                              
                                                                                                                                            
    Details:                                                                                                                                
                                                                                                                                            
    C:\Users\bredah\git\lab_js\es6\src\example\calculator.spec.js:1                                                                 
    ({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,global,jest){import { Calculator } from './calculator';     
                                                                                             ^^^^^^                                         
                                                                                                                                            
    SyntaxError: Unexpected token import                                                                                                    
                                                                                                                                            
      at ScriptTransformer._transformAndBuildScript (node_modules/jest-runtime/build/script_transformer.js:402:17)                          
                                                                                                                                            
Test Suites: 1 failed, 1 total                                                                                                              
Tests:       0 total                                                                                                                        
Snapshots:   0 total                                                                                                                        
Time:        5.468s                                                                                                                         
Ran all test suites.                                                                                                                        
npm ERR! code ELIFECYCLE                                                                                                                    
npm ERR! errno 1                                                                                                                            
npm ERR! [email protected] test: `jest`                                                                                            
npm ERR! Exit status 1                                                                                                                      
npm ERR!                                                                                                                                    
npm ERR! Failed at the [email protected] test script.                                                                              
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.                                          
                                                                                                                                            
npm ERR! A complete log of this run can be found in:                                                                                        
npm ERR!     C:\Users\bredah\AppData\Roaming\npm-cache\_logs\2018-06-06T12_27_15_540Z-debug.log                                     

To Reproduce

Execute the command:

λ npm run test

Expected behavior

Executing all test without any error.

Code

.
│   .jshintrc
│   package-lock.json
│   package.json
├───src
│   └───example
│           calculator.js
│           calculator.spec.js

File packages.json

{
  "name": "example_js_unit_test",
  "version": "1.0.0",
  "description": "Example: How to use develop unit test with JS",
  "main": "",
  "scripts": {
    "test": "jest"
  },
  "author": "bredah",
  "license": "ISC",
  "devDependencies": {
    "jest": "^23.1.0"
  }
}

File: calculator.js

class Calculator {

    constructor(){
    }

    result(varA, varB, equation) {
        if (equation == null) {
            throw new Error('Not exist equation with NUL value');
        }
        var value = 0;
        switch (equation.toLowerCase()) {
            case 'add':
                value = varA + varB;
                break;
            case 'subtract':
                value = varA - varB;
                break;
            case 'multiply':
                value = varA * varB;
                break;
            case 'divide':
                value = varA / varB;
                break;
            default:
                value = 0;
                break;
        }
        return value;
    }
}

export { Calculator };

File: calculator.spec.js

import { Calculator } from './calculator';

let calc = null;

beforeEach(() => {
  calc = new Calculator();
});

afterEach(() => {
});

test('Add', () => {
  var result = calc.result(4, 2, 'add');
  expect(result).toBe(6);
});

test('Subtract', () => {
  var result = calc.result(4, 2, 'subtract');
  expect(result).toBe(2);
});

test('Multiply', () => {
  var result = calc.result(4, 2, 'multiply');
  expect(result).toBe(8);
});

test('Divide', () => {
  var result = calc.result(4, 2, 'divide');
  expect(result).toBe(2);
});

test('Equation not exist', () => {
  var result = calc.result(4, 2, 'x');
  expect(result).toBe(0);
});

test('Equation void', () => {
  var result = calc.result(4, 2, '');
  expect(result).toBe(0);
});

test('Equation null', () => {
  expect(calc.result(4, 2, null)).toThrow(Error);
});

Run npx envinfo --preset jest

λ npx envinfo --preset jest
npx: installed 1 in 6.787s
Path must be a string. Received undefined
npx: installed 1 in 4.451s
C:\Users\bredah\AppData\Roaming\npm-cache\_npx\148484\node_modules\envinfo\dist\cli.js

  System:
    OS: Windows 10
    CPU: x64 Intel(R) Core(TM) i7-7820HQ CPU @ 2.90GHz
  Binaries:
    Yarn: 1.6.0 - ~\AppData\Roaming\npm\yarn.CMD
    npm: 6.1.0 - C:\Program Files\nodejs\npm.CMD

[thymikee]

This is not a bug. You need to configure Babel properly to use ES6 modules with Jest. Please read our documentation, or have a better search on this issue tracker or Stack Overflow.

[Nantris]

Seems like there's a possible bug here.

Example 1 - Trying to import a non-existent path

import { expectSaga } from 'redux-saga-test-plan';
import database from '../wrongPath/database';

This fails because it can't find database, NOT because Unexpected token import

Example 2 - Trying to import a from the correct path

import { expectSaga } from 'redux-saga-test-plan';
import database from '../rightPath/database';

Fails on the first import with Unexpected token import

---

I would expect an improper babel configuration would result in Unexpected token import in both examples, but I'm only seeing it when I ask for an existent path.

The import that is failing is the first line of example 2, not an import within another file.

[github-actions]

This issue has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.
Please note this issue tracker is not a help forum. We recommend using StackOverflow or our discord channel for questions.