jestjs - Jest gives an error: "SyntaxError: Unexpected token export"

Question

I'm using Jest to test my React app.

Recently, I added DeckGL to my app. My tests fail with this error:

Test suite failed to run

/my_project/node_modules/deck.gl/src/react/index.js:21
export {default as DeckGL} from './deckgl';
^^^^^^

SyntaxError: Unexpected token export

  at ScriptTransformer._transformAndBuildScript (node_modules/jest-runtime/build/script_transformer.js:318:17)
  at Object.<anonymous> (node_modules/deck.gl/dist/react/deckgl.js:9:14)
  at Object.<anonymous> (node_modules/deck.gl/dist/react/index.js:7:15)

This looks like an issue with Jest transforming a node module before running it's tests.

Here is my .babelrc:

{
  "presets": ["react", "es2015", "stage-1"]
}

Here is my jest setup:

"jest": {
    "testURL": "http://localhost",
    "setupFiles": [
      "./test/jestsetup.js"
    ],
    "snapshotSerializers": [
      "<rootDir>/node_modules/enzyme-to-json/serializer"
    ],
    "moduleDirectories": [
      "node_modules",
      "/src"
    ],
    "moduleNameMapper": {
      "\.(css|scss)$": "<rootDir>/test/EmptyModule.js"
    }
  },

I seem to have the correct things necessary to transform export {default as DeckGL }. So any ideas whats going wrong?

Answer 1

This means, that a file is not transformed through TypeScript compiler, e.g. because it is a JS file with TS syntax, or it is published to npm as uncompiled source files. Here's what you can do.

Adjust your transformIgnorePatterns allowed list:

{
  "jest": {
    "transformIgnorePatterns": [
      "node_modules/(?!@ngrx|(?!deck.gl)|ng-dynamic)"
    ]
  }
}