tests/cases/conformance/es6/Symbols/symbolProperty21.ts(10,5): error TS2345: Argument of type '{ [Symbol.isConcatSpreadable]: string; [Symbol.toPrimitive]: number; [Symbol.unscopables]: boolean; }' is not assignable to parameter of type 'I<boolean, string>'.
  Object literal may only specify known properties, and '[Symbol.toPrimitive]' does not exist in type 'I<boolean, string>'.


==== tests/cases/conformance/es6/Symbols/symbolProperty21.ts (1 errors) ====
    interface I<T, U> {
        [Symbol.unscopables]: T;
        [Symbol.isConcatSpreadable]: U;
    }
    
    declare function foo<T, U>(p: I<T, U>): { t: T; u: U };
    
    foo({
        [Symbol.isConcatSpreadable]: "",
        [Symbol.toPrimitive]: 0,
        ~~~~~~~~~~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '{ [Symbol.isConcatSpreadable]: string; [Symbol.toPrimitive]: number; [Symbol.unscopables]: boolean; }' is not assignable to parameter of type 'I<boolean, string>'.
!!! error TS2345:   Object literal may only specify known properties, and '[Symbol.toPrimitive]' does not exist in type 'I<boolean, string>'.
        [Symbol.unscopables]: true
    });