Jest encountered an unexpected token inside ts-jest/node_modules/jest-util

[ben-obringer]

Hi all,

I'm trying run jest using ts-jest, but I'm running into the following 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:

    /Users/benjaminobringer/Development/icm/i-check-music/node_modules/ts-jest/node_modules/jest-util/build/requireOrImportModule.js:65
            const importedModule = await import(moduleUrl.href);
                                         ^^^^^^

    SyntaxError: Unexpected token import

      at Object.<anonymous> (node_modules/ts-jest/node_modules/jest-util/build/index.js:161:3)

For more context, I have the following setup:

• Meteor 1.8.2
• jest ^24.9.0
• ts-jest ^27.1.2

I've tried:

• Following the installation instructions https://kulshekhar.github.io/ts-jest/docs/getting-started/installation
• Running npx ts-jest config:init
  • I get the following error: yargs parser supports a minimum Node.js version of 10. Read our version support policy: https://github.com/yargs/yargs-parser#supported-nodejs-versions
• I tried this https://github.com/kulshekhar/ts-jest/blob/main/TROUBLESHOOTING.md#transform-node-module-explicitly by setting transformIgnorePatterns to /node_modules/(?!ts-jest/node_modules/jest-util)

Does anybody have any idea on what could be going on?

Thanks,
Ben

[ahnpnl]

I see you are using incompatible combination of Jest and ts-jest. Maybe downgrading ts-jest to 24 could help since you are using jest 24

[ben-obringer]

Thank you! I have ts-jest at ^23.1.4, and the error went away.

[ghost]

I'm having a similar problem, my package.json file (snippet) has:

    "@types/jest": "^27.0.1",
    "jest": "^27.0.6",
    "ts-jest": "^27.0.5",
    "jest-mock-extended": "^2.0.2-beta2",

This worked fine when the downloaded versions were jest: "27.2.4" & "ts-jest": "27.0.5", but since it's configured as ^ I removed yarn.lock to upgrade other dependencies and now it upgraded jest to 27.4.6 & ts-jest to 27.1.3 and I have an error similar to what OP posted.

The problem is that I cannot simply fix jest version by removing the ^ symbol in package.json because jest internally has dependencies marked with the caret, hence it ends up downloading 27.4.6

Any clue how to fix this?

[ghost]

Any clue as to how to fix that?
And why it worked before?

[ahnpnl]

I think it worked before could be due to Jest cache. Now removing lock file and reinstall the old cache is not reused anymore. The problem can exist for long but not pop up due to cache reusing, just a theory.

To ask Jest transform something explicitly you need https://jestjs.io/docs/configuration#transformignorepatterns-arraystring

Another theory is removing yarn lock and install deps again can pull unwanted versions which lead to this problem while lock file protects from that.

[ghost]

I'm using ES2019, it should understand optional chaining without issues, no?

[ahnpnl]

It depends on NodeJs version as well, Node 14 supports optional chaining. However, this is for Jest, ts-jest doesn’t handle logic “when should js be transpiled” or “is this syntax supported”

[wyseguyonline]

I am dealing with this issue as well.

node version is 14.18.1

From package.json
"jest": "^27.5.1",
"ts-jest": "^27.1.3",
"ts-node": "^10.7.0",
"typescript": "^4.5.4",

Contents of jest.config.js
/** @type {import('ts-jest/dist/types').InitialOptionsTsJest} /
module.exports = {
roots: ["", "/../"],
preset: "ts-jest",
testEnvironment: "node",
transform: {
"^.+\.ts?x?$": "ts-jest",
},
moduleFileExtensions: ["ts", "tsx", "js", "jsx", "json"],
testPathIgnorePatterns: ["/node_modules/", "/dist/"],
testMatch: ["/tests//.[jt]s?(x)", "**/?(*.)+(spec|test).[jt]s?(x)"],
collectCoverage: true,
coverageThreshold: {
global: {
branches: 50,
functions: 50,
lines: 50,
statements: 50,
},
},
};

For me, the syntax error is as follows:
SyntaxError: Cannot use import statement outside a module

I have tried adjusting my transformignorepatterns to mark the offending file as one to be ignored. I have tried mocking the module in question (the one being imported). Searching on this error yields a host of different solutions which to me suggests there is something much deeper going on than jest being misconfigured.