jest: Test suite failed to run, SyntaxError: Unexpected token import
ReactjsBabeljsJestjsReactjs Problem Overview
This is my jest configuration from the package.json file:
"jest": {
"automock": false,
"browser": true,
"moduleNameMapper": {
"\\.(jpg|jpeg|png|gif|eot|otf|webp|svg|ttf|woff|woff2|mp4|webm|wav|mp3|m4a|aac|oga)$": "./app/tests/mocks/FileMock.js",
"\\.(css|less)$": "identity-obj-proxy"
},
"moduleFileExtensions": [
"js",
"jsx"
],
"moduleDirectories": [
"node_modules"
],
"transform": {
"^.+\\.jsx?$": "./node_modules/babel-jest",
"\\.(jpg|jpeg|png|gif|eot|otf|webp|svg|ttf|woff|woff2|mp4|webm|wav|mp3|m4a|aac|oga)$": "./app/tests/mocks/FileTransformer.js"
},
"testEnvironment": "jsdom",
"testPathDirs": [
"./app/tests"
],
"testRegex": ".*.test.js",
"verbose": true
}
And the .babelrc file located in my root folder:
{
"plugins": ["syntax-dynamic-import", "transform-runtime"],
"presets": [
[
"es2015",
{
"modules": false
}
],
"react",
"stage-0"
],
"env": {
"start": {
"presets": [
"react-hmre"
]
}
}
}
According to the documentation found at the jest getting started page this is everything I need for babel to work it's magic.
Regardless, this test:
import React from 'react';
import {shallow} from 'enzyme';
import Landing from '../components/Landing.component';
describe('<Landing/>', () => {
it('should render a header to the page', () => {
const landing = shallow(<Landing/>);
expect(landing.find('h1').text()).toBe('This is the Landing component');
});
});
returns:
FAIL app/tests/Landing.component.test.js
● Test suite failed to run
/Users/shooshte/PersonalProjects/surviveJS/app/tests/Landing.component.test.js:1
({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,global,jest){import React from 'react';
^^^^^^
SyntaxError: Unexpected token import
at transformAndBuildScript (node_modules/jest-runtime/build/transform.js:320:12)
What am I doing wrong?
Reactjs Solutions
Solution 1 - Reactjs
Jest sets the env variable to test, so I had to add my presets to the env setting in .babelrc:
{
"plugins": ["syntax-dynamic-import", "transform-runtime"],
"presets": [
[
"es2015",
{
"modules": false
}
],
"react",
"stage-0"
],
"env": {
"start": {
"presets": [
"react-hmre"
]
},
"test": {
"presets": ["es2015", "react", "stage-0"]
}
}
}
Solution 2 - Reactjs
> Each yearly preset only compiles what was ratified in that year. babel-preset-env replaces es2015
, es2016
, es2017
, latest
Based on this, on latest configurations you must use/replace your Plugins/Preset of es2015
and any esX
to the new one: env
.
- You must install
babel-preset-env
withnpm install
. - In your
.babelrc
you should update accordingly:
{
"presets": [
"env",
"stage-0",
"react-native"
],
"plugins": ...
}
More information on Babel plugins official Documentation.
☝️ Remember the order of the plugins/preset in the array is important.
Solution 3 - Reactjs
In my case, I had the following .babelrc
config:
{
"presets": [
["env", { "modules": false }],
"react",
"stage-2"
],
"plugins": [
"transform-runtime",
"transform-class-properties",
"react-hot-loader/babel"
]
}
Even though babel-env
was specified I still got the error. To fix it I had to remove the "modules": false flag.
Solution 4 - Reactjs
Jest doesn't handle imports so it needs a transform plugin, and this is why I had to add the plugin:
> babel-plugin-dynamic-import-node
and update my babel settings to tell jest to use this plugin to transform the code properly:
"env": {
"test": {
"plugins" : ["dynamic-import-node"]
}
}
Solution 5 - Reactjs
You need to install babel-jest. I had the same problem.
Go to your app directory, yarn add babel-jest
Good luck!
Solution 6 - Reactjs
The following .babelrc works for me (without additions):
{
"presets": [["env", {
"debug": false,
"modules": false
}], "es2015", "stage-0", "react"],
"plugins": [
"react-hot-loader/babel",
"syntax-dynamic-import",
"dynamic-import-node",
"transform-class-properties",
"transform-decorators-legacy"
]
}
"devDependencies" section of package.json looks like this:
...
"devDependencies": {
"babel-cli": "latest",
"babel-core": "^6.26.3",
"babel-eslint": "^8.2.3",
"babel-jest": "^22.4.4",
"babel-loader": "latest",
"babel-plugin-dynamic-import-node": "^1.2.0",
"babel-plugin-lodash": "latest",
"babel-plugin-syntax-dynamic-import": "^6.18.0",
"babel-plugin-transform-class-properties": "^6.24.1",
"babel-plugin-transform-decorators-legacy": "latest",
"babel-plugin-transform-dynamic-import": "^2.0.0",
"babel-plugin-transform-flow-strip-types": "^6.22.0",
"babel-plugin-transform-object-rest-spread": "latest",
"babel-polyfill": "^6.26.0",
"babel-preset-env": "^1.7.0",
"babel-preset-flow": "^6.23.0",
"babel-preset-react": "^6.24.1",
"babel-preset-react-app-babel-7": "^4.0.1",
"babel-preset-stage-0": "^6.24.1",
...