Does Jest support ES6 import/export?

Question

If I use import/export from ES6 then all my jest tests fail with error:

Unexpected reserved word

I convert my object under test to use old school IIFY syntax and suddenly my tests pass. Or, take an even simpler test case:

   var Validation = require('../src/components/validation/validation');//PASS
   //import * as Validation from '../src/components/validation/validation'//FAIL

Same error. Obviously there's a problem with import/export here. It's not practical for me to rewrite my code using ES5 syntax just to make my test framework happy.

I have babel-jest. I tried various suggestions from github issues. No go so far.

package.json

 "scripts": {
    "start": "webpack-dev-server",
    "test": "jest"
  },
      "jest": {
        "testPathDirs": [
          "__tests__"
        ],
        "testPathIgnorePatterns": [
          "/node_modules/"
        ],
        "testFileExtensions": ["es6", "js"],
        "moduleFileExtensions": ["js", "json", "es6"]
      },

babelrc

{
  "presets": ["es2015", "react"],
  "plugins": ["transform-decorators-legacy"]
}

Is there a fix for this?

Answer 1

From my answer on another question, this can be simpler:

---

The only requirement is to config your test environment to Babel, and add the es2015 transform plugin:

---

Step 1:

Add your test environment to .babelrc in the root of your project:

{
  "env": {
    "test": {
      "plugins": ["transform-es2015-modules-commonjs"]
    }
  }
}

Step 2:

Install the es2015 transform plugin:

npm install --save-dev babel-plugin-transform-es2015-modules-commonjs

---

And that's it. Jest will enable compilation from ES modules to CommonJS automatically, without having to inform additional options to your jest property inside package.json.

Answer 2

It's a matter of adding stage-0 to your .babelrc file. here is an example:

{
  "presets": ["es2015", "react", "stage-0"],
  "plugins": ["transform-decorators-legacy"]
}

Answer 3

In addition to installing babel-jest (which comes with jest by default now) be sure to install regenerator-runtime.

Answer 4

I solved it with .default.

Try var Validation = require('../src/components/validation/validation').default;