tests/cases/compiler/memberOverride.ts(4,5): error TS2300: Duplicate identifier 'a'. tests/cases/compiler/memberOverride.ts(5,5): error TS2300: Duplicate identifier 'a'. ==== tests/cases/compiler/memberOverride.ts (2 errors) ==== // An object initialiser accepts the first definition for the same property with a different type signature // Should compile, since the second declaration of a overrides the first var x = { a: "", ~ !!! error TS2300: Duplicate identifier 'a'. a: 5 ~ !!! error TS2300: Duplicate identifier 'a'. } var n: number = x.a;