After adding a new package (date-holidays), when running tests with Jest, the following error appears:
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
Details:
/Users/username/system/.yarn/cache/astronomia-npm-4.1.1-364d12a189-ec80faf6e0.zip/node_modules/astronomia/data/vsop87Bearth.js:2611
export default m;
^^^^^^
SyntaxError: Unexpected token 'export'
at Runtime.createScriptFromCode (../.yarn/cache/jest-runtime-npm-27.4.6-d1229253b6-64d833c7d7.zip/node_modules/jest-runtime/build/index.js:1728:14)
at Object.<anonymous> (../.yarn/cache/date-holidays-parser-npm-3.4.3-ff1621004b-c5c8f51b62.zip/node_modules/date-holidays-parser/lib/vsop87Bearth.cjs:5:21)
I am using yarn with node modules in cache, so from my understanding, the path to the astronomia package would be like:
<rootPath>/.yarn/cache/astronomia-npm-4.1.1-364d12a189-ec80faf6e0.zip/node_modules/astronomia
After researching this issue for a while, adding the transformIgnorePatterns looks the most promising to me, so I updated my jest.config.js file to this:
module.exports = {
preset: "ts-jest",
testEnvironment: "node",
projects: ["<rootDir>/inventory", "<rootDir>/backoffice/api"],
transformIgnorePatterns: [
"<rootDir>/.yarn/cache/astronomia-npm-4.1.1-364d12a189-ec80faf6e0.zip/node_modules/(?!astronomia)",
],
};
But no matter what I changed the path to, the test still fails. Does anyone have an idea what a better approach would be?
