Source code
Revision control
Copy as Markdown
Other Tools
function testPrimitive() {
for (var i = 0; i < 100; ++i) {
// Null and undefined.
assertEq(Object.prototype.isPrototypeOf(null), false);
assertEq(Object.prototype.isPrototypeOf(void 0), false);
// Primitive wrappers.
assertEq(String.prototype.isPrototypeOf(""), false);
assertEq(Number.prototype.isPrototypeOf(0), false);
assertEq(Boolean.prototype.isPrototypeOf(true), false);
assertEq(BigInt.prototype.isPrototypeOf(0n), false);
assertEq(Symbol.prototype.isPrototypeOf(Symbol.hasInstance), false);
}
}
testPrimitive();
function testObject() {
for (var i = 0; i < 100; ++i) {
assertEq(Object.prototype.isPrototypeOf({}), true);
assertEq(Object.prototype.isPrototypeOf([]), true);
assertEq(Array.prototype.isPrototypeOf({}), false);
assertEq(Array.prototype.isPrototypeOf([]), true);
}
}
testObject();
function testProxy() {
var proxy = new Proxy({}, new Proxy({}, {
get(t, pk, r) {
assertEq(pk, "getPrototypeOf");
return Reflect.get(t, pk, r);
}
}));
for (var i = 0; i < 100; ++i) {
assertEq(Object.prototype.isPrototypeOf(proxy), true);
assertEq(Array.prototype.isPrototypeOf(proxy), false);
}
}
testProxy();