load("test-common.js"); try { assert(Reflect.preventExtensions.length === 1); [null, undefined, "foo", 123, NaN, Infinity].forEach(value => { assertThrowsError(() => { Reflect.preventExtensions(value); }, { error: TypeError, message: "First argument of Reflect.preventExtensions() must be an object" }); }); var o = {}; assert(Reflect.isExtensible(o) === true); assert(Reflect.preventExtensions(o) === true); assert(Reflect.isExtensible(o) === false); console.log("PASS"); } catch (e) { console.log("FAIL: " + e); }