How to compare Object.create()?

[fundon]

Using Object.create method to create object.
How to compare them for equality or deep equality?

Use Object.getPrototypeOf?

e.g.

var a = Object.create(null);
var b = Object.create({});
assert.deepEqual(a, b);

var a = Object.create({});
var b = Object.create({a:233});
assert.deepEqual(a, b);

[vkurchatkin]

see nodejs/node-v0.x-archive#4523
it's a bug in CommonJS: http://wiki.commonjs.org/wiki/Unit_Testing/1.0

7.4. For all other Object pairs, including Array objects, equivalence is determined by having the same number of owned properties (as verified with Object.prototype.hasOwnProperty.call), the same set of keys (although not necessarily the same order), equivalent values for every corresponding key, and an identical "prototype" property.

obviously, it had to be __proto__, [[Prototype]] or something like this
changing this behaviour breaks 3 tests

/cc @iojs/owners

[bnoordhuis]

I'm alright with fixing it. assert.deepEqual({}, []) doesn't throw. That's clearly a bug.

[fundon]

@vkurchatkin thanks, great work.

[vkurchatkin]

you can use deepStrictEqual introduced in 3f473ef, which compares prototypes using ===

[fundon]

Thanks, great.

[jokeyrhyme]

I just noticed that this does NOT throw:

assert.deepEqual(Object.create({tea:'chai'}), Object.create({tea:'black'}))

Weird.

[vkurchatkin]

@jokeyrhyme use deepStrictEqual