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Enumerating a union type

@RiccardoOdone•Suggest a tip•

Avoid enumerating all the values of a union type manually.

type Check = 'Avionics' | 'Recovery' | 'Navigation'
const checklist: Check[] =
  ['Avionics', 'Recovery'] // ⛔️ Forgot 'Navigation'

const checklist = // ✅ Single point of truth
  ['Avionics', 'Recovery', 'Navigation'] as const
type Checklist = (typeof checklist)
//   ^? type Checklist = readonly ['Avionics', 'Recovery', 'Navigation']
type Check = Checklist[number]
//   ^? type Check = 'Avionics' | 'Recovery' | 'Navigation'
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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