tests/cases/compiler/returnValueInSetter.ts(2,9): error TS1056: Accessors are only available when targeting ECMAScript 5 and higher. tests/cases/compiler/returnValueInSetter.ts(3,16): error TS2408: Setters cannot return a value. ==== tests/cases/compiler/returnValueInSetter.ts (2 errors) ==== class f { set x(value) { ~ !!! error TS1056: Accessors are only available when targeting ECMAScript 5 and higher. return null; // Should be an error ~~~~ !!! error TS2408: Setters cannot return a value. } }