That just proves that "contains" is the correct name for the language feature.
Implement it correctly, without regard to any silly things that 3rd parties were doing. 5 years from now, nobody will remember that library.
Do it the way they're doing, and 5, 15, 50 years from now people will still be asking why this stupid language used a non-standard method name for Array.contains.
Extra points for encouraging all the other poorly implemented javascript libraries to fix their things before they break for similar reasons.
Implement it correctly, without regard to any silly things that 3rd parties were doing. 5 years from now, nobody will remember that library.
Do it the way they're doing, and 5, 15, 50 years from now people will still be asking why this stupid language used a non-standard method name for Array.contains.
Extra points for encouraging all the other poorly implemented javascript libraries to fix their things before they break for similar reasons.