Part of the Full-Stack TypeScript track · course 2 of 7
TypeScript Deep Dive
Move past basic annotations into the parts of TypeScript that make large apps safe to change: discriminated unions and narrowing, generic functions with constraints, and the utility types you reach for every day. Every concept comes with runnable code.
3 lessons · ~1.5 hours
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Narrowing & discriminated unions. The rest of the course unlocks with a free account.
1. Types in Motion
Narrowing & discriminated unions
Teach the compiler to follow your logic so a value's type sharpens as you check it.
Generics & constraints
Write one function that stays type-safe across many types — and constrain it when you need a guarantee.
Utility types
Derive new types from existing ones with Partial, Pick, Omit, and Record instead of repeating yourself.