// demonstrate objects prototype chain

// https://developer.mozilla.org/en/JavaScript/Guide/Inheritance_and_the_prototype_chain

module("About Prototype Chain (topics/about_prototype_chain.js)");

var father = {

b: 3,

c: 4

};

var child = Object.create(father);

child.a = 1;

child.b = 2;

/*

* ---------------------- ---- ---- ----

* [a] [b] [c]

* ---------------------- ---- ---- ----

* [child] 1 2

* ---------------------- ---- ---- ----

* [father] 3 4

* ---------------------- ---- ---- ----

* [Object.prototype]

* ---------------------- ---- ---- ----

* [null]

* ---------------------- ---- ---- ----

* */

test("Is there an 'a' and 'b' own property on childObj?", function () {

equals(child.a, __, 'what is \'a\' value?');

equals(child.b, __, 'what is \'b\' value?');

});

test("If 'b' was removed, whats b value?", function () {

delete child.b;

equals(child.b, __, 'what is \'b\' value now?');

});

// Is there a 'c' own property on childObj? No, check its prototype

// Is there a 'c' own property on childObj.[[Prototype]]? Yes, its value is...

test("Is there a 'c' own property on childObj.[[Prototype]]?", function () {

equals(child.hasOwnProperty('c'), __, 'childObj.hasOwnProperty(\'c\')?');

});

test("Is there a 'c' own property on childObj.[[Prototype]]?", function () {

equals(child.c, __, 'childObj.c?');

});

// Is there a 'd' own property on childObj? No, check its prototype

// Is there a 'd' own property on childObj.[[Prototype]]? No, check it prototype

// childObj.[[Prototype]].[[Prototype]] is null, stop searching, no property found, return...

test("Is there an 'd' own property on childObj?", function () {

equals(child.d, __, 'what is the value of childObj.d?');

});