tests/cases/compiler/objectLitStructuralTypeMismatch.ts(2,5): error TS2322: Type '{ b: number; }' is not assignable to type '{ a: number; }'. Property 'a' is missing in type '{ b: number; }'. ==== tests/cases/compiler/objectLitStructuralTypeMismatch.ts (1 errors) ==== // Shouldn't compile var x: { a: number; } = { b: 5 }; ~ !!! error TS2322: Type '{ b: number; }' is not assignable to type '{ a: number; }'. !!! error TS2322: Property 'a' is missing in type '{ b: number; }'.