SyntaxError: Unexpected token 'export' while running jest test cases

[vikaspuri-goswami]

SyntaxError: Unexpected token 'export' while running jest test cases.

bable.config.js

module.exports = {
  presets: [
    [
      "@babel/preset-env",
      {
        targets: {
          node: "current",
        },
      },
    ],
  ],
}

Jest configuration in package.json

"jest": {
    "transform": {
      "^.+\\.js$": "babel-jest",
      "^.+\\.svelte$": "svelte-jester"
    },
    "moduleFileExtensions": [
      "js",
      "svelte"
    ],
    "setupFilesAfterEnv": [
      "@testing-library/jest-dom/extend-expect"
    ],
    "testPathIgnorePatterns": [
      "dist"
    ]
  },

Screenshot attached

[jakobrosenberg]

Can you set script to ESM somehow?

[vikaspuri-goswami]

@jakobrosenberg You can find the import statement in the first screenshot import { goto } from "@roxi/routify". We are using jest src in the npm run test command in pckage.json. Please let me know if you need anything else?

[jakobrosenberg]

If I'm reading the screenshot correctly, you haven't configured Jest to handle ESM.

[tmaxmax]

Same error here, is this looked upon?

[jakobrosenberg]

Does this help? #349

[vikaspuri-goswami]

We would need to ignore transform patterns for ESM. Below are the sample code for the reference.

1. Create array of ESM which we would need to ignore while transforming
2. Add full path of those modules in transformIgnorePatterns.

const esModules = ["@roxi"].join("|")

module.exports = {
  transform: {
    "^.+\\.js$": "babel-jest",
    "^.+\\.svelte$": "svelte-jester",
  },
  moduleFileExtensions: ["js", "svelte"],
  setupFilesAfterEnv: ["@testing-library/jest-dom/extend-expect"],
  testPathIgnorePatterns: ["dist"],
  transformIgnorePatterns: [`/node_modules/(?!${esModules})`],
}

Let me know if any question, happy to help you.

[doylio]

Same issue here

[ghostdevv]

I think you need to configure Jest as Jake said to support esm. If you still having issues please reopen

[tobiasbueschel]

I think you need to configure Jest as Jake said to support esm. If you still having issues please reopen

Thanks for this @vikaspuri-goswami!

Unfortunately, neither the jest.config.ts configuration to ignore the routify module nor the ESM approach worked for me. I still get the same error:

Dependency versions used:

        "@roxi/routify": "^2.18.5",
        "@testing-library/jest-dom": "^5.16.2",
        "@testing-library/svelte": "^3.0.3",
        "@tsconfig/svelte": "^3.0.0",
        "jest": "^27.5.1",
        "svelte": "^3.46.4",
        "svelte-check": "^2.4.5",
        "svelte-jester": "^2.3.2",
        "svelte-preprocess": "^4.10.4",
        "ts-jest": "^27.1.3",
        "ts-node": "^10.7.0",
        "tslib": "^2.3.1",
        "typescript": "^4.6.2",

jest.config.ts

import type { Config } from '@jest/types';

const config: Config.InitialOptions = {
    preset: 'ts-jest',
    testEnvironment: 'jsdom',
    verbose: true,
    transform: {
        '^.+\\.svelte$': [
            'svelte-jester',
            {
                preprocess: true
            }
        ],
        '^.+\\.ts$': 'ts-jest',
        '^.+\\.js$': 'ts-jest',
        '.+\\.(css|styl|less|sass|scss)$': 'jest-css-modules-transform'
    },
    setupFilesAfterEnv: ['@testing-library/jest-dom/extend-expect'],
    moduleFileExtensions: ['js', 'ts', 'svelte'],
    transformIgnorePatterns: ['<rootDir>/node_modules/(?!@roxi)']
};

export default config;

I've also tried:

"test": "NODE_OPTIONS=--experimental-vm-modules jest src",

I'll share back if I find a fix - if someone else has any suggestions in the meantime, would greatly appreciate it 🙏

Thanks

cc @ghostdevv

[TimoReusch]

@tobiasbueschel I'm facing the same problem - have you found a solution meanwhile?

[ghostdevv]

I would recommend migrating to Vitest, for the most part it should be a drop in replacement for Jest as it supports the Jest mock syntax OOTB

[aarzootrehannagarro]

Any solution for this issue?