javascript / expert
Snippet
Higher-Order Function Guards via Reflect.apply and Proxy Trap Interception
Metaprogramming techniques allow developers to wrap critical execution units with defensive assertions. Using Proxy traps for the 'apply' handler combined with Reflect.apply guarantees preserved binding contexts while enforcing strict parameter integrity dynamically.
snippet.js
javascript
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export function createGuardedFunction(fn, validator) {return new Proxy(fn, {apply(target, thisArg, argList) {if (!validator(...argList)) {throw new TypeError('Argument validation failed');}return Reflect.apply(target, thisArg, argList);}});}
nodejs
Breakdown
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return new Proxy(fn, {
Wraps the input target function within a proxy transparent interceptor.
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apply(target, thisArg, argList) {
Intercepts function invocation traps with target, receiver context, and arguments.
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if (!validator(...argList)) {
Executes runtime guard assertions prior to delegating function execution.
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return Reflect.apply(target, thisArg, argList);
Invokes the underlying function using Reflect semantics for safe evaluation.