Jest encountered an unexpected token

[eliot-akira]

After the recent update to dependencies, running npm install then npm run jest results in a parse error.

Apparently the issue is related to Jest not supporting ES Modules out of the box, and requires Babel to transform it.

• Meta: Native support for ES Modules jestjs/jest#9430
• Jest - Docs: ECMAScript Modules

From the extensive error message below, it looks like the Babel config file (tests/jest/babel.config.cjs) is not being loaded.

---

● Test suite failed to run

Jest encountered an unexpected token

Jest failed to parse a file. This happens e.g. when your code or its dependencies use non-standard JavaScript syntax, or when Jest is not configured to support such syntax.

Out of the box Jest supports Babel, which will be used to transform your files into valid JS based on your Babel configuration.

By default "node_modules" folder is ignored by transformers.

Here's what you can do:
• If you are trying to use ECMAScript Modules, see https://jestjs.io/docs/ecmascript-modules for how to enable it.
• If you are trying to use TypeScript, see https://jestjs.io/docs/getting-started#using-typescript
• 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/configuration
For information about custom transformations, see:
https://jestjs.io/docs/code-transformation

...

Add @babel/preset-react (https://github.com/babel/babel/tree/main/packages/babel-preset-react) to the 'presets' section of your Babel config to enable transformation.

If you want to leave it as-is, add @babel/plugin-syntax-jsx (https://github.com/babel/babel/tree/main/packages/babel-plugin-syntax-jsx) to the 'plugins' section to enable parsing.

If you already added the plugin for this syntax to your config, it's possible that your config isn't being loaded.

[eliot-akira]

Aah, never mind, I was running jest directly instead of the NPM task jest:test. The latter loads the config file (Jest and Babel) from tests/jest.