javascript / expert
Snippet
Custom Reflect Proxy Trapping for Reactive Array Mutation Guards
Guarding reactive state arrays against unauthorized inline mutative method invocation requires proxy trapping method lookups on the target array prototype and evaluating condition guards before execution.
snippet.js
javascript
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
const MUTATING_METHODS = new Set(['push', 'pop', 'shift', 'unshift', 'splice']);export function createGuardedReactiveArray(initialItems, isFrozenCondition) {return new Proxy(initialItems, {get(target, prop, receiver) {if (typeof prop === 'string' && MUTATING_METHODS.has(prop)) {return function (...args) {if (isFrozenCondition()) {throw new Error(`Array mutation '${prop}' blocked by state guard.`);}return Reflect.get(target, prop, receiver).apply(target, args);};}return Reflect.get(target, prop, receiver);}});}
vue
Breakdown
1
const MUTATING_METHODS = new Set(['push', 'pop', 'shift', 'unshift', 'splice']);
Defines a high-performance Set containing array prototype methods that mutate arrays in place.
2
return new Proxy(initialItems, {
Creates an intercepting Proxy wrapper around array access operations.
3
if (isFrozenCondition()) {
Evaluates state predicate before allowing array modification methods to proceed.
4
return Reflect.get(target, prop, receiver).apply(target, args);
Applies original array prototype method via Reflect when guard condition succeeds.