hrms-shared/utils/circuitBreaker.js

HRMS shared code: models, middleware, utils

const CircuitBreaker = require('opossum');

/**
 * Create a reusable circuit breaker for any async function
 * @param {Function} actionFn - the function (e.g., API call) you want to wrap
 * @param {Object} options - breaker options
 * @param {Function} fallbackFn - optional fallback
 */

function createCircuitBreaker(actionFn, options = {}, fallbackFn = null) {
    const defaultOptions = {
        timeout: 5000,
        errorThresholdPercentage: 50,
        resetTimeout: 10000,
    };

    const breaker = new CircuitBreaker(actionFn, { ...defaultOptions, ...options });

    if (fallbackFn) {
        breaker.fallback(fallbackFn);
    }

    breaker.on('open', () => console.log('🚨 Circuit breaker OPEN - Service is unhealthy'));
    breaker.on('halfOpen', () => console.log('⚠️ Circuit breaker HALF-OPEN - Testing service...'));
    breaker.on('close', () => console.log('✅ Circuit breaker CLOSED - Service recovered'));

    return breaker;
}

module.exports = createCircuitBreaker;