Mapping JSON parsed object instances

arr.json

[
    {
        "name": "John",
        "age": 20
    },
    {
        "name": "Jack",
        "age": 28
    }
]

job1234.json

{
    "id": 1234,
    "assignee": {
        "name": "Jack",
        "age": 28
    },
    "comments": [
        {
            "text": "A comment.",
            "author": {
                "name": "Jack",
                "age": 28
            }
        },
        {
            "text": "Another comment.",
            "author": {
                "name": "John",
                "age": 20
            }
        }
    ]
}

test.js

var fs = require('fs');

var map = new Map();

var reviver = function(k, v) {
    if (v === null || Array.isArray(v)) return v;
    if (typeof v !== 'object') return v;
    var key = JSON.stringify(v);
    if (map.has(key)) {
        return map.get(key);
    }
    map.set(key, v);
    return v;
};

var arr = JSON.parse(fs.readFileSync("arr.json"), reviver);

var job = JSON.parse(fs.readFileSync("job1234.json"), reviver);

console.log(arr.indexOf(job.assignee)); // 1 => correct!
console.log(Object.is(job.assignee, job.comments[0].author)); // true => correct!