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Limit types

@RiccardoOdone•Suggest a tip•

Avoid branching by limiting the number of types that flow in the program

type PostCode = string | number

const shipTo = (postCode: PostCode) => {
  if (typeof postCode === "string") {
    // format string
  } else { // ⛔️ Need to branch
    // format number
  }
}

type PostCode = string

const shipTo = (postCode: PostCode) => {
  // ✅ Only need to format string
}
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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