The deep equality algorithm does not work properly for complex objects

[justinenht]

• library version : 8.0.2
• Environment : Node 20
• Example URL :
• Other libraries you are using:

What did you expect to happen?

deepEqual should return false for different complex objects.

What actually happens

It returns true for two different complex objects. After some investigation, it is because the Object.keys() or Object.getOwnPropertySymbols return empty arrays:

samsam/lib/deep-equal.js

Line 132 in 1b141a7

var actualKeys = keys(actualObj);

How to reproduce

Clone the samsam repository, add in the following test in the ``deep-equal.test.js` file:

it("check URL", function () {
  var checkDeep = samsam.deepEqual(new URL('http://mock'), new URL('http://aaaaa'));
  assert.isTrue(checkDeep);
});

Run all the tests with npm run test and see that the test is passed, whereas it should have failed:

I have seen that the other fixes for the other deepEqual issues have been fixed with some special handling. Maybe it would be better to have a fail-safe mechanism to make the deepEqual return false when it is not possible to extract keys.properties from a complex object, instead of considering it as true ?