5
votes

I'm want to test a component in react app using jest enzyme with typescript, I follow instruction in jest but for some reason I get: SyntaxError: Unexpected token <

I can test test some functions there is no problem with that, but when I use component I get an error,

this is jest config in package.json

"jest": {
    "transform": {
      "^.+\\.tsx?$": "ts-jest"
    },
    "testMatch": ["**/__tests__/*.(ts|tsx)"],
    "snapshotSerializers": ["enzyme-to-json/serializer"],
    "setupFilesAfterEnv": ["<rootDir>/src/setupEnzyme.ts"],
    "unmockedModulePathPatterns": ["node_modules/react/", "node_modules/enzyme/"]
  }

enzyme config

import { configure } from 'enzyme';
import Adapter from 'enzyme-adapter-react-16';

configure({ adapter: new Adapter() });
export default class TesComponent extends Component { 
    render(){
        return (
            <div>test</div>
        )
    }
}
import { shallow } from 'enzyme'
import TestCompoenent from '../TestComponent'

test('component testing', () => {
    const component = shallow(<TestCompoenent />)
    expect(component.contains(<div>test</div>)).toBeTruthy()
})

this is the error

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://jestjs.io/docs/en/configuration.html

    Details:

    /home/user/Documents/local-platform/frontend/src/pages/__tests__/settigs.test.tsx:9
        var component = enzyme_1.shallow(<TestComponent_1.default />);
                                         ^

    SyntaxError: Unexpected token <

      at ScriptTransformer._transformAndBuildScript (node_modules/@jest/transform/build/ScriptTransformer.js:471:17)
      at ScriptTransformer.transform (node_modules/@jest/transform/build/ScriptTransformer.js:513:25)

i expect for test to pass because Test Component does include <div>test</div>

2
Post your TestCompoenent also.ravibagul91
i've edited postDavit Yeritsyan
Try jest --clearCacheravibagul91
got the same error:(Davit Yeritsyan
Any solutions for NextJs?Ronald Araújo

2 Answers

9
votes

Try changing tsconfig.json

"jsx": "preserve" -> "jsx": "react"

0
votes

It seems that you config does not process TSX properly. Here is part of my working configuration

"jest": {
    "transform": {
       "^.+\\.tsx?$": "ts-jest",
    },
    "moduleFileExtensions": [
       "ts",
       "tsx",
       "js",
       "json"
    ],
    "setupTestFrameworkScriptFile": "<rootDir>/src/setupSpecs.ts"
}

I have used setupTestFrameworkScriptFile instead of setupFilesAfterEnv