Jest not parsing es6: SyntaxError: Unexpected token import
You need to do two things:
Create a Babel config file (
babel.config.js
):This is necessary because
babel-jest
relies on a traditional Babel config file, not webpack. Since version 7 Babel has supported JS configs asbabel.config.js
.When using a JS Babel config (as opposed to a
.babelrc
, for example) Jest also compiles modules innode_modules
. AFAIK by convention this must be in the root of your project, alongside the jest configuration file.Here is a config based on the Babel options in your
webpack.config.js
file:// babel.config.js module.exports = { presets: [ '@babel/preset-env', '@babel/preset-react', '@babel/preset-flow', ], plugins: [ 'babel-plugin-styled-components', '@babel/plugin-proposal-class-properties', ] }
Install the
babel-core
bridge version:npm install [email protected] --save-dev
From github.com/babel/babel-bridge:
This repo holds what we're calling a "bridge" package that is meant to ease the transition for libraries that use "babel-core" as a peer dependency for Babel 6.
The issue with Babel 7's transition to scopes is that if a package depends on Babel 6, they may want to add support for Babel 7 alongside. Because Babel 7 will be released as @babel/core instead of babel-core, maintainers have no way to do that transition without making a breaking change. e.g.
I ran into a similar situation where I wanted to test a React component .js
file with jest, but it was failing because the component imported a .css
stylesheet. I was using Babel with Webpack.
As per the accepted answer @sdgluck, I had to add a babel.config.js
:
1.
module.exports = {
presets: ['@babel/preset-env', '@babel/preset-react']
};
2. I also installed babel-jest
as a dev-dependency
3. Then I read through the jest webpack guide
4. Which led me to adding a "jest" property to my package.json
which mocks files and stylesheets:
"jest": {
"moduleNameMapper": {
"\\.(jpg|jpeg|png|gif|eot|otf|webp|svg|ttf|woff|woff2|mp4|webm|wav|mp3|m4a|aac|oga)$": "<rootDir>/__mocks__/fileMock.js",
"\\.(css|less)$": "<rootDir>/__mocks__/styleMock.js"
}
}
5. Then I had to create the mocked files at the specified paths (you can use any path you want, those are just from their docs):
// __mocks__/styleMock.js
module.exports = {};
// __mocks__/fileMock.js
module.exports = 'test-file-stub';
Then it worked :)