// members N and M of types S and T have the same name, same accessibility, same optionality, and N is assignable M
// additional optional properties do not cause errors

class S implements S2 { foo: string; }
class T implements T2 { foo: string; }
var s: S;
var t: T;

interface S2 { foo: string; bar?: string }
interface T2 { foo: string; baz?: string }
var s2: S2;
var t2: T2;

var a: { foo: string; bar?: string }
var b: { foo: string; baz?: string }

var a2: S2 = { foo: '' };
var b2: T2 = { foo: '' };

s = t;
t = s;
s = s2;
s = a2;

s2 = t2;
t2 = s2;
s2 = t;
s2 = b;
s2 = a2;

a = b;
b = a;
a = s;
a = s2;
a = a2;

a2 = b2;
b2 = a2;
a2 = b;
a2 = t2;
a2 = t;