TypeScript Definition Utilities

tsdef is a TypeScript utility library that provides a curated collection of common type definitions and aliases to simplify complex type patterns and enhance code readability in TypeScript projects. It aims to reduce boilerplate and improve type safety by offering widely applicable utility types such as `Nullable`, `NonNull`, `MaybePromise`, and various `Props` modifiers (e.g., `NonNullProps`, `WritableProps`). The current stable version is 0.0.14. As a pre-1.0 release, its release cadence is likely irregular, and breaking changes might occur more frequently than with a semantically versioned stable library. It differentiates itself by being a pure type-only library, meaning it introduces zero runtime overhead and focuses exclusively on type-system improvements, making it suitable for projects that prioritize strict type integrity without adding to the JavaScript bundle size.