[Bug]:

Version

27.1.1

Steps to reproduce

Trying to use the file-type module which is pure ESM in a TS project but my jest fails. I have set the ESM options as indicated here but still get a SyntaxError: Cannot use import statement outside a module error.

I have made a sandbox here.

Summary of my code:

import { fileTypeFromBuffer } from "file-type";

Jest config:

export default {
  testEnvironment: "jest-environment-node",
  globals: {
    extensionsToTreatAsEsm: [".ts"],
    "ts-jest": {
      useESM: true,
    },
  },
  transform: {
    "^.+\\.(ts|tsx|js|jsx)?$": "ts-jest",
    //"^.+\\.tsx?$": "ts-jest",
  },
  moduleNameMapper: {
    "^(\\.{1,2}/.*)\\.js$": "$1",
  },
  preset: "ts-jest",
  //preset: 'ts-jest/presets/default-esm' // or other ESM presets
};

TSConfig:

{
  "extends": "@tsconfig/node14/tsconfig.json",
  "compilerOptions": {
    "target": "ES2018",
    "module": "commonjs",
    "lib": ["es2018"],
    "declaration": true,
    "strict": true,
    "strictNullChecks": true,
    "alwaysStrict": true,
    //importsNotUsedAsValues
    // "noImplicitAny": false,
    "noImplicitReturns": false,
    "noImplicitThis": false,
    "noUnusedLocals": false,
    "noUnusedParameters": false,
    "noEmit": true,
    "noFallthroughCasesInSwitch": false,
    "inlineSourceMap": true,
    "inlineSources": true,
    "experimentalDecorators": true,
    "strictPropertyInitialization": false,
    // "typeRoots": ["./node_modules/@types"]
    "resolveJsonModule": true,
    "outDir": "dist",
    "baseUrl": ".",

    "skipLibCheck": true,
    "forceConsistentCasingInFileNames": true
  }
}

Any ideas?

Expected behavior

Expected to run without errors

Actual behavior

SyntaxError: Cannot use import statement outside a module

Debug log

https://gist.github.com/b5b24ed3e4fd2e9fb0298e01f1b41287

Additional context

No response

Environment

System:
    OS: macOS 12.0.1
    CPU: (8) x64 Intel(R) Core(TM) i7-1060NG7 CPU @ 1.20GHz
  Binaries:
    Node: 16.3.0 - /usr/local/bin/node
    Yarn: 1.22.10 - /usr/local/bin/yarn
    npm: 7.15.1 - /usr/local/bin/npm
  npmPackages:
    jest: ^27.4.4 => 27.4.4 

[ahnpnl]

Depending on which mode you want to run Jest: either CJS or ESM.

If you want to run in CJS mode, you would need to inform Jest to transform file-type to CJS via transformIgnoredPatterns

If you want to run in ESM mode, you would need to follow ts-jest ESM doc. It seems like you are trying to run Jest in ESM mode but you probably miss a few things:

• module in tsconfig must be ESM value like: ES2015 or ES2020 etc…
• use preset ts-jest/presets/defaults-esm

When I set these 2 on, the test will throw a different error, but it’s no longer Jest errors.

I hope this helps.

[marwej]

I’m having the same issue and would be happy to know about any ready solution to this (ts-jest-resolver didn’t do it).

Edit: https://www.npmjs.com/package/jest-node-exports-resolver fixed it.