TypeScript essentials

What you'll learn

• The two worlds: types vs values
• Modeling domain with unions and discriminated unions
• Generics, used in moderation
• Narrowing, inference, and where to annotate
• Reading type errors quickly
• The strict-mode flags worth turning on

1. 01
   Types vs values

   The two worlds, and why mixing them up is the #1 confusion.
   13 min
2. 02
   Primitives and unions

   Building useful types out of the smallest pieces.
   14 min
3. 03
   Objects and interfaces

   Records, optionality, readonly, index signatures.
   15 min
4. 04
   Generics — gently

   Functions that keep their types. Start small.
   16 min
5. 05
   Narrowing

   How TypeScript reads your code to refine types.
   16 min
6. 06
   Discriminated unions

   The pattern that makes domain modeling pleasant.
   14 min
7. 07
   Utility types

   Partial, Pick, Omit, Record — and the day you write your own.
   14 min
8. 08
   Type vs interface

   Settling the argument with rules, not opinions.
   12 min
9. 09
   Inference and contracts

   Where to annotate, where to let TS figure it out.
   14 min
10. 10
    Common errors, decoded

    Reading the squiggle and what it's actually telling you.
    14 min
11. 11
    Strict mode tips

    The flags worth turning on today.
    14 min