Question: Error when trying to use the module in jest #68
Description
Expected Behavior
"@planetscale/database" should be able to import in Jest tests.
Current Behavior
An error occurs and jest is not able to run.
FAIL ./test.test.ts
● 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:
/foo/node_modules/@planetscale/database/dist/index.js:1
({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,jest){import { format } from './sanitization.js';
^^^^^^
SyntaxError: Cannot use import statement outside a module
What I've tried
I'm not sure what the root cause is but it seems Jest cannot transform the ESM(?) file included in @planetscale/database/dist/index.js.
I assumed this error is a well-known jest misconfiguration and tried some of these solutions:
- support esm in
ts-node - tried the same settings as this repository(planetscale/database-js)
The same error occurred each time.
Steps to Reproduce
I've created a minimum code base as follows:
https://github.com/kenfdev/planetscale-jest-poc
You can reproduce it with npm test.
I might totally be missing something from the beginning but am pretty much stuck right now. Any advice would be highly appreciated!
Thank you in advance!