Source code
Revision control
Copy as Markdown
Other Tools
load(libdir + 'asserts.js');
function getObjects() {
function func(){}
return [func,
new func(),
{x: 5},
/regexp/,
[1, 2, 3],
new Date(),
new Number(1),
new Boolean(true),
new String('str'),
Object.create(null)];
}
var coercibleValues = [1,
true,
'string'];
var nonCoercibleValues = [undefined,
null];
var valuesWithoutNull = coercibleValues.concat(undefined);
function TestSetPrototypeOf(object, proto) {
assertEq(Object.setPrototypeOf(object, proto), object);
assertEq(Object.getPrototypeOf(object), proto);
}
// check if Object.setPrototypeOf works with coercible values
for(var value of coercibleValues) {
assertEq(Object.setPrototypeOf(value, {}), value);
}
// check if Object.setPrototypeOf fails on non-coercible values
for (var value of nonCoercibleValues) {
assertThrowsInstanceOf(() => Object.setPrototypeOf(value, {}),
TypeError, "Object.setPrototypeOf shouldn't work on non-coercible values");
}
// check if Object.setPrototypeOf works when prototype is set to non-objects
var objects = getObjects();
for (var object of objects) {
for (var proto of valuesWithoutNull) {
assertThrowsInstanceOf(() => Object.setPrototypeOf(object, proto),
TypeError, "Object.setPrototypeOf fails when the prototype is set to non-objects");
}
}
// check if Object.setPrototypeOf works when prototype is set to objects
var objects1 = getObjects();
var objects2 = getObjects();
for (var object1 of objects1) {
for (var object2 of objects2) {
TestSetPrototypeOf(object1, object2);
}
}
// check if Object.setPrototypeOf works when prototype is set to null
objects = getObjects();
for (var object of objects) {
TestSetPrototypeOf(object, null);
}
// check if Object.setPrototypeOf fails when object is not extensible
var objects = getObjects();
var proto = {};
for (var object of objects) {
Object.preventExtensions(object);
assertThrowsInstanceOf(() => Object.setPrototypeOf(object, proto),
TypeError, "Object.setPrototypeOf should fail when the object is not extensible");
}
// check if Object.setPrototypeof(A, B) succeeds on not extensible object A if
// prototype of A == B already
var objectProto = {};
var nonExtensibleObject = Object.create(objectProto);
Object.preventExtensions(nonExtensibleObject);
assertEq(Object.setPrototypeOf(nonExtensibleObject, objectProto), nonExtensibleObject);
// check if Object.setPrototypeOf works with prototype lookup
var object = {};
assertEq('x' in object, false);
assertEq('y' in object, false);
var oldProto = {
x: 'old x',
y: 'old y'
};
Object.setPrototypeOf(object, oldProto);
assertEq(object.x, 'old x');
assertEq(object.y, 'old y');
var newProto = {
x: 'new x'
};
Object.setPrototypeOf(object, newProto);
assertEq(object.x, 'new x');
assertEq('y' in object, false);
// check if Object.setPrototypeOf throws TypeError on fewer arguments
assertThrowsInstanceOf(() => Object.setPrototypeOf(),
TypeError, "Object.setPrototypeOf throws TypeError when called without any parameters");
assertThrowsInstanceOf(() => Object.setPrototypeOf({}),
TypeError, "Object.setPrototypeOf throws TypeError when called with 1 parameter");