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I like the tricks :) – Kasia

WTH?!

@RiccardoOdone•Suggest a tip•

From time to time, I get stuck into the following error. With this tip, I'm making sure the next time I google for it, I'll see my own explanation.

const identityBool = <T extends boolean>(x: T = false): T => x // ⛔️
// Type 'boolean' is not assignable to type 'T'.
//   'boolean' is assignable to the constraint of type 'T',
//    but 'T' could be instantiated with a different subtype
//    of constraint 'boolean'.

const identityTrue: <T extends true>(x: T) => T = identityBool
// This is what the error above refers to.
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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