tests/cases/compiler/contextualTypingOfArrayLiterals1.ts(5,5): error TS2322: Type '(number | Date)[]' is not assignable to type 'I'. Index signatures are incompatible. Type 'number | Date' is not assignable to type 'Date'. Type 'number' is not assignable to type 'Date'. Property 'toDateString' is missing in type 'Number'. ==== tests/cases/compiler/contextualTypingOfArrayLiterals1.ts (1 errors) ==== interface I { [x: number]: Date; } var x3: I = [new Date(), 1]; ~~ !!! error TS2322: Type '(number | Date)[]' is not assignable to type 'I'. !!! error TS2322: Index signatures are incompatible. !!! error TS2322: Type 'number | Date' is not assignable to type 'Date'. !!! error TS2322: Type 'number' is not assignable to type 'Date'. !!! error TS2322: Property 'toDateString' is missing in type 'Number'. var r2 = x3[1]; r2.getDate();