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A setInterval that has to be torn down on unmount. The contrast is in how each framework expresses "do this on mount, undo it on unmount".

Capture a DOM element from the template so the prev/next buttons can call scrollBy() on it.

Fetch on mount, render a loading/error/list state machine, and derive a filtered view from a search query.

Each button reads the same nanostore to know how many of this product are already in the cart, and writes to it on click.

The smallest possible store consumer. Subscribes to a computed total and renders it.

Bind an input to a store value, with deferred commit on blur/Enter so backspacing through the number does not delete the cart row.

Iterates over the cart items and embeds the same-framework QuantityStepper for each row.

Image gallery with selected-index local state, plus a reviews list with star ratings. The reviews loop is a small showcase of nested data rendering, and the star widget is reused both for the product rating and per-review rating.

Seven fields including a phone number and a shipping radio group, all validated. Live order summary derives subtotal from the cart store, looks up the selected shipping option, and surfaces a free-shipping threshold. Submit is gated until everything is valid; success replaces the form inline.

A heart-shaped toggle on each product card that persists across sessions. The button reads "is this in the wishlist?" from a derived value and toggles the entry on click — same shape as the cart, but the store is a Set-of-ids and the state read is a boolean.

Cart subtotal lookup is needed in both CartView and CheckoutForm. Each framework has its own pattern for extracting reactive logic into a reusable function — different name, same idea. The three live in src/hooks, src/composables, and src/lib so they read like real-world code rather than demo files.

A reusable Toast wrapper that takes arbitrary content. The Toaster fires one for every add-to-cart and wishlist toggle. The interesting comparison is how each framework lets a parent pass markup into a child slot.