"IN" Operator Fails When Accessed via "VAR" Operator

[imanrahmani]

Problem Statement:

While trying to access a subset array from within a superset array using the "All" operator, I found that the "IN" operator does not function correctly when an array is accessed via the "VAR" operator.

Observed Behavior:
In the rule example below, the "IN" operator fails to correctly validate if all elements of the subset array are contained within the superset array:

Rule:

{ "all": [ {"var": "subset"}, {"in": [{"var": ""}, {"var": "superset"}]} ] }
Data

{ "subset": ["apple", "banana", "orange"], "superset": ["apple", "banana", "orange", "grape", "pear"] }

Expected Outcome:
The evaluation of this rule should yield True, as the subset array is fully included in the superset array.

Actual Outcome:
The rule incorrectly returns False.

Hint / Workaround:
When I specify the array directly within the rule instead of referencing it with the "VAR" operator, the "IN" operator behaves as expected:

Working Rule:
{ "all": [ {"var": "subset"}, {"in": [{"var": ""}, ["apple", "banana", "orange", "grape", "pear"]]} ] }

I suspect there might be a bug in the way the "IN" operator processes references to arrays. Your assistance in identifying and resolving the root cause of this behavior would be greatly appreciated.