Level up from basic types to constructing expressive, type-safe frontend systems. Master conditional types, mapped types, template literals, type guards, and bulletproof React props & hooks typing.
Static Compilation vs Dynamic Runtime & Type Erasure
When to Annotate vs Let the Compiler Infer
Interface vs Type, Declaration Merging & Extensibility
Fixed-Length Arrays, Labeled Tuples & Zero-Cost Immutability
Parameters, void vs undefined vs never, and Callback Types
Union Operators, Intersection Contracts & Type Guards
Type Variables, Generic Constraints with `extends` & Defaults
Tagged Unions, State Machines & Exhaustive `never` Checks
Safely Indexing Objects, Lookup Types & Type-Safe Accessors
Type Predicates (`is`), Assertion Functions (`asserts`) & Validation
Partial, Required, Readonly, Pick, Omit, Record & Extract
ComponentProps, Generic Components, useRef & State Typing
T extends U ? X : Y, Distributive Unions & Pattern Matching
Key Remapping (`as`), Modifiers (`+`/`-`), and String Type Manipulation
Top Types (`unknown`, `any`), Bottom Types (`never`) & Soundness
Strict Mode, noUncheckedIndexedAccess, Bundler Resolution & Build Speed
DeepPartial, DeepReadonly, JSON Value Trees & AST Modeling
Nominal Typing, Preventing Primitive Obsession & Compile-Time Safety