Advent of Svelte 2025 - Day 21: createContext #javascript #sveltejs #webdevelopment

Description

Previously, sharing values through component trees required importing getContext and setContext, creating a Symbol to avoid string collisions, and exporting typed wrapper functions. With createContext, you simply call it with your type and get back a typed [get, set] tuple — no symbols, no strings, no boilerplate. In this example, Santa's naughty-and-nice list app uses createContext to share a notification function across deeply nested components. Read the docs: https://svelte.dev/docs/svelte/context#Type-safe-context