If you tell TypeScript what your range of data types is ("constrain your data type"), then TypeScript will let you use any functionality that's common to those data types. You implement constraints on ...

And, any existing JavaScript program is already valid TypeScript ... new type that’s a composite of existing types (an “intersection” type), use the & operator: runFn would accept a function ...

TypeScript allows you to use the features available in latest ... it won’t be able to detect the types of the function arguments and the type ‘any’ will be assigned to all the function ...

With TypeScript 5.8, when a function’s return type is a generic conditional type, TypeScript now will use control flow analysis for generic parameters whose types are used in the conditional ...