tests/cases/compiler/classImplementsClass6.ts(20,3): error TS2339: Property 'bar' does not exist on type 'C'. tests/cases/compiler/classImplementsClass6.ts(21,4): error TS2339: Property 'bar' does not exist on type 'C2'. ==== tests/cases/compiler/classImplementsClass6.ts (2 errors) ==== class A { static bar(): string { return ""; } foo(): number { return 1; } } class C implements A { foo() { return 1; } } class C2 extends A {} var c: C; var c2: C2; c = c2; c2 = c; c.bar(); // error ~~~ !!! error TS2339: Property 'bar' does not exist on type 'C'. c2.bar(); // should error ~~~ !!! error TS2339: Property 'bar' does not exist on type 'C2'.