Posts tagged “immutability”

Learn how TypeScript's ReadonlyMap and ReadonlySet prevent accidental mutations at compile time, when to use them over Record and Map, and how to build type-safe cache APIs and configuration systems that enforce immutability.

Most readonly bugs stem from shallow enforcement and type widening. Learn when TypeScript's readonly protects your arrays and tuples—and when it silently fails.

Most TypeScript type widening problems in generic functions stem from a single overlooked feature: const type parameters. Learn when they beat as const and how to combine them with satisfies for maximum type safety.