javascript / intermediate
Snippet
Dynamic Object Validation with Proxies
The Proxy object allows you to create a wrapper for another object, intercepting fundamental operations like property access and assignment. This is ideal for schema validation or logging without modifying the original object logic.
snippet.js
javascript
1
2
3
4
5
6
7
8
9
10
11
12
13
14
const validator = {set: (target, prop, value) => {if (prop === 'score') {if (!Number.isInteger(value)) throw new TypeError('Score must be an integer');if (value < 0) throw new RangeError('Score cannot be negative');}target[prop] = value;return true;}};const gameState = new Proxy({}, validator);gameState.score = 10; // Valid// gameState.score = -5; // Throws RangeError
nodejs
Breakdown
1
set: (target, prop, value) => { ... }
A trap for setting property values on the target object.
2
target[prop] = value;
Applies the validated value to the original object.
3
new Proxy({}, validator);
Creates the proxy with an empty target and the defined validation rules.