| // Copyright (C) 2016 the V8 project authors. All rights reserved. |
| // This code is governed by the BSD license found in the LICENSE file. |
| /*--- |
| esid: sec-object.prototype.__proto__ |
| es6id: B.2.2.1 |
| description: Cycle detection |
| info: | |
| [...] |
| 4. Let status be ? O.[[SetPrototypeOf]](proto). |
| 5. If status is false, throw a TypeError exception. |
| |
| 9.1.2.1 OrdinarySetPrototypeOf |
| |
| [...] |
| 6. Let p be V. |
| 7. Let done be false. |
| 8. Repeat while done is false, |
| a. If p is null, let done be true. |
| b. Else if SameValue(p, O) is true, return false. |
| c. Else, |
| i. If the [[GetPrototypeOf]] internal method of p is not the ordinary |
| object internal method defined in 9.1.1, let done be true. |
| ii. Else, let p be the value of p's [[Prototype]] internal slot. |
| ---*/ |
| |
| var root = {}; |
| var intermediary = Object.create(root); |
| var leaf = Object.create(intermediary); |
| |
| assert.throws(TypeError, function() { |
| root.__proto__ = leaf; |
| }); |
| |
| assert.sameValue(Object.getPrototypeOf(root), Object.prototype); |