NextJS cookbook

I slapped 'use client' on the whole page to fix one error, and now half my components ship extra JavaScript for nothing.

Jest's config for the App Router is a wall of transforms and mocks, so testing kept getting put off.

The value is right there in the .env file, and the browser still logs undefined.

A product page ships with a title, description and image, but every crawler still sees the homepage's.

The form submits, the database updates, and the button just sits there looking exactly like it did before anyone clicked it.

A deleted product's URL still loads. It just loads empty.

Someone deletes a todo. The database agrees it's gone. The list on screen does not.

The build output calls the route dynamic. Nothing in the code looks like it should be.

Three awaits, three round trips, one after another, for data that never depended on each other.

One middleware.ts file redirects every signed-out visitor away from the dashboard, so the page components themselves never check who's asking.

The test payment goes through every time. The Route Handler still answers back with a signature error.