JavaScript Snippet

React useFetch Hook with Cancellation

Difficulty: Hard

Building a useFetch from scratch teaches the pieces every data-fetching library has to solve: tracking loading and error state, cancelling in-flight requests when the URL changes, and ignoring stale responses after the component unmounts. This snippet covers the canonical AbortController-based hook, a generation-counter variant that protects against race conditions when AbortController is unavailable, and a mutate refetch helper for manual revalidation.