Complete example of proxying an array for this article: https://itnext.io/meta-programming-in-javascript-with-proxies-64fa4898070e

Proxy.js

const db = [
    {
        name: 'John Doe',
        age: 28,
        lastModified: Date.now(),
        lastAccessed: Date.now()
    },
    {
        name: 'Jane Smith',
        age: 30,
        lastModified: Date.now(),
        lastAccessed: Date.now()
    },
        {
        name: 'Albert Einstein',
        age: 52,
        lastModified: Date.now(),
        lastAccessed: Date.now()
    }
];

const handler = {
    get(tgt, prop, rcvr) {
        const _prop = +prop;
        
        if (prop in tgt) tgt[prop].lastAccessed = Date.now();
      
        if (Number.isInteger(_prop) && _prop >= 0) 
            return tgt[_prop];
        
        if (Number.isInteger(_prop) && _prop < 0) {
            const posProp = tgt.length + _prop;
            if (posProp in tgt) tgt[posProp].lastAccessed = Date.now();
            return tgt[posProp];
        }
      
        if (prop === 'last') return rcvr[-1];
        
        return tgt[prop];
    },
  
    set(tgt, prop, val, rcvr) {
        if (prop === 'sort') {
            const { by, dir } = val;
            tgt.sort(
                (a, b) => dir === 'asc'
                    ? (a[by] < b[by] ? -1 : 1)
                    : (b[by] < a[by] ? -1 : 1)
            );
        }
        
        if (prop === 'new') {
            tgt.push({ ...val, lastModified: Date.now(), lastAccessed: Date.now() });
        }
        
        return true;
    },
  
    has(tgt, prop) {
        const obj = JSON.parse(prop);
        const criteria = Object.entries(obj);
        
        return tgt.some(obj =>
            criteria.every( ([key, val]) => obj[key] === val )
        );
    },
  
    ownKeys(tgt) {
        const keys = tgt.reduce(
            (keys, doc) => {
                const docKeys = Object.keys(doc);
                docKeys.forEach(key => {
                    keys.add(key);
                });
                
                return keys;
            },
            new Set()
        );
        
        return [ ...keys, 'length' ];
    },
  
    deleteProperty(tgt, prop) {
        const keys = this.ownKeys(tgt).slice(0, -1);
        
        if (keys.includes(prop)) {
            tgt.forEach(row => {
                delete row[prop];
            });
            
            return true;
        }
        
        return false;
    }
};

const dbProxy = new Proxy(db, handler);