JSTests/test262/test/language/expressions/instanceof/prototype-getter-with-object-throws.js

// Copyright (C) 2015 André Bargull. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.

/*---
es6id: 12.9.3
description: >
  "prototype" property is retrieved when left-hand side expression in `instanceof` is object.
info: |
  12.9.3 Runtime Semantics: Evaluation
  RelationalExpression : RelationalExpression instanceof ShiftExpression
    ...
    7. Return InstanceofOperator(lval, rval).

    12.9.4 Runtime Semantics: InstanceofOperator(O, C)
    ...
    6. Return OrdinaryHasInstance(C, O).

    7.3.19 OrdinaryHasInstance
    ...
    3. If Type(O) is not Object, return false.
    4. Let P be Get(C, "prototype").
    5. ReturnIfAbrupt(P).
    ...
---*/

var getterCalled = false;

function DummyError() { }

// The "prototype" property for constructor functions is a non-configurable data-property,
// therefore we need to use a non-constructor function to install the getter.
Object.defineProperty(Function.prototype, "prototype", {
  get: function() {
    assert.sameValue(getterCalled, false, "'prototype' getter called once");
    getterCalled = true;
    throw new DummyError();
  }
});

assert.throws(DummyError, function() {
  [] instanceof Function.prototype;
});