Jest won't transform the module - SyntaxError: Cannot use import statement outside a module

Even though I have tried them separately, I haven't tried them together (transform and transformIgnorePatterns). So this jest configuration solved my issue:

  "jest": {    "preset": "ts-jest",    "testEnvironment": "node",    "transform": {      "node_modules/variables/.+\\.(j|t)sx?$": "ts-jest"    },    "transformIgnorePatterns": [      "node_modules/(?!variables/.*)"    ]  },

My mistakes were:

1. Not using transform and transformIgnorePatterns together.
2. And defining babel-jest as the transformer instead of ts-jest (I guess that is a problem when the preset of jest is defined as ts-jest. Because if I change it to be babel-jest it throws the same error again.):

--- "node_modules/variables/.+\\.(j|t)sx?$": "babel-jest"+++ "node_modules/variables/.+\\.(j|t)sx?$": "ts-jest"

Since jest is not working with esmodules well, you need to add these configurations in jest.config.js to tell Jest to use commonJS builds instead

moduleNameMapper : {        '^variables$': 'variables/dist/cjs',        '^[NAME OF MODULE YOU WANT TO IMPORT]$': '[NAME OF MODULE YOU WANT TO IMPORT]/dist/cjs'}

I got stuck in the same situation. Due to I had a private untranspiled package which is based on TypeScript, and all my source files and test files were all applied with ECMA ( import syntax ), I encountered the following error as well.

SyntaxError: Cannot use import statement outside a module

The solutions I have tried.

• The above answers, such as use transform, transformIgnorePatterns, moduleNameMapper in jest.config.ts.
• Followed JEST official document, Configuration Jest#transformignorepatterns-arraystring, I used exactly the same method and even referred to the use case from React Native Guide.
• Removed all node_modules, including cache, and reinstalled them.
• Used react-scripts and downgrade jest and babel-jest to 26 from 27. There was another issue that occurred.

After all, I found ECMAScript Modules from the JEST official document, the four steps perfectly solved my problem. I pasted their instructions here, however, you should take a look at the document itself.

1. Ensure you either disable code transforms by passing transform: {} or otherwise configure your transformer to emit ESM rather than the default CommonJS (CJS).
2. Execute node with --experimental-vm-modules, e.g. node --experimental-vm-modules node_modules/.bin/jest or NODE_OPTIONS=--experimental-vm-modules npx jest etc.. On Windows, you can use cross-env to be able to set environment variables.
3. Beyond that, we attempt to follow node's logic for activating "ESM mode" (such as looking at type in package.json or mjs files), see their docs for details.
4. If you want to treat other file extensions (such as ts) as ESM, please use the extensionsToTreatAsEsm option.