Summary

This fixes #9089
This bug is introduced by this PR #8687
So basically, there is a flaw on the circular reference logic within a function called subsetEquality.
The logic is that, to avoid circular reference, it stores the references of nodes that it has been through within one singleton variable seenReferences. Whenever we have seen the same node (using the reference), we skip the subset equality checking (which is done recursively) and do deep equality checking instead.
The implication is that nodes within the same level of tree will use the same reference seenReferences. It's a problem because then it will cause an invalid handling on this case :

const referencedObj = {abc: 'def'};
const object = {
  a: {abc: 'def'},
  b: {abc: 'def', zzz: 'zzz'},
};
const thisIsNotCircular = {
  a: referencedObj,
  b: referencedObj,
};
expect(subsetEquality(object, thisIsNotCircular)).toBeTruthy(); // this test fails while it should succeed

On current logic, above case is considered circular referenced which isn't supposed to be. It will result in incorrect handling because circular reference does not check for subset equality and only check for plain equality instead. It makes sense for circular referenced object but not for normal object.

What we should do is to keep the seenReferences only for parent node and its children. The solution is quite simple, we only need to remove the reference immediately after the recursive function is done called for all of a node's children.

Test plan

I have added one test case using example above which would fail previously.
After the fix, now it succeeds.