typings cause compiler errors

[agnauck]

when I compile my code without the skipLibCheck option I get the following error:

66:5 Property '2' of type '"px" | "%" | undefined' is not assignable to numeric index type 'string | number'.
    64 |     0: number,
    65 |     1: number,
  > 66 |     2?: 'px' | '%'
       |     ^
    67 |   }
    68 | 
    69 | }

[Evertvdw]

Yes, I get this error also with Typescript 3.8.3