Unexpected expansion of primitive types and built-in objects when used in a generic type parameter extends clause

[kieselai]

All of the values in these types are expanded to include the full prototype of the built in primitive or object, specifically when used in an extends clause of a generic type parameter.

export interface ExtendingPrimitives<
  TString extends string,
  TNumber extends number,
  TBigInt extends bigint,
  TSymbol extends symbol,
  TBoolean extends boolean,
>
{
  string_val: TString,
  number_val: TNumber,
  bigint_val: TBigInt,
  symbol_val: TSymbol,
  boolean_val: TBoolean
}

export interface ExtendingBuiltInObjects<
  TRegex extends RegExp,
  TDate extends Date,
  TSet extends Set<any>
>
{
  regex_val: TRegex,
  date_val: TDate
  set_val: TSet
}

[mylesmmurphy]

Hi @kieselai Sorry for the delay again! This one is tricky... As far as I know, the TS Language Server doesn't provide a way to know what properties on a type are inherited from an object's prototype, but I could be wrong. I will look into this and get back to you. The TS LS does provide flags and checks for if a type is a built in primitive, which is how the current check prevents displaying all these ugly types prototype props. I will look into this and get back to you!

[kieselai]

Alternatively, if there is some way to check the type in the left hand side of an "extends" clause, maybe the expansion could be prevented based on a hard coded list of standard built-in types? The types listed out in Mozilla's docs could be useful for such an implementation.