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Model with different types (2)

@RiccardoOdone•Suggest a tip•

By using different types you can make the compiler check you are passing the right things to the right functions.

type User = { id?: number, name: string }

const createUser = (user: User) => {}
const updateUser = (user: User) => {}

createUser(persistedUser) // ⛔️
updateUser(newUser) // ⛔️

type User<Id> = {
  id: Id,
  email: string,
}
type NewUser = User<null>
type PersistedUser = User<number>

const createUser = (user: NewUser) => {}
const updateUser = (user: PersistedUser) => {}

createUser(persistedUser) // ✅ Does not compile
updateUser(newUser) // ✅ Does not compile
Type-safe carouselDo not throwFilter using a type assertionUse precise typesType-safe string templatingEnumerating a union typeNumbers with unitsZero nullEnumerating statusesAnd typesAvoiding window as anyUse descriptive valuesCheck authorization with typesExtract union types from record typesKeep in sync with conditional typesType-safe pickPass arguments by namePick instead of duplicatingPrevent mutationsType aliasesModel with different typesPrefer static types over testsPush conditionals downType-level functionsCheck Authorization With Types (again)From Union to TupleLimit typesLaser-focused typesCallable typesPartial considered harmfulSatisfy typesWTH?!Parse, don't castNarrow typesFetch footgunModel with different types (2)Polymorphic typesParse, don't cast (again)Type-safe envObject vs Recordconst Type ParametersDigType checksExpand intellisenseNumbers with units (2)Unchecked indexed accessExtract instead of duplicating

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