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From Union to Tuple

@RiccardoOdone•Suggest a tip•

Going from tuple to union is easy but sometimes you need the opposite.

type Screen = "Home" | "Login"
const allScreens: Screen[] = ["Home"] // ⛔️ Missing "Login"

type TuplifyUnion<U extends string, R extends any[] = []> = {
  [S in U]: // for each variant in the union
    Exclude<U, S> extends never // remove it and..
      ? [...R, S] // ..stop recursion if it was the last variant
      : TuplifyUnion<Exclude<U, S>, [...R, S]> // ..recur if not
}[U] // extract all values from the object

type Screen = "Home" | "Login"
type AllScreens = TuplifyUnion<Screen>
const allScreens: AllScreens = ["Home"] // ✅ 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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