const test = require('ava'); const { EventEmitter } = require('events'); const eventBus = new EventEmitter(); const { REQUEST_TIME } = require('./events'); const { startMonitoring } = require('./metrics'); const prometheusRegister = require('prom-client/lib/register'); test('should collect metrics for requests', t => { startMonitoring(true, eventBus); eventBus.emit(REQUEST_TIME, { path: 'somePath', method: 'GET', statusCode: 200, time: 1337 }); const metrics = prometheusRegister.metrics(); t.regex(metrics, /http_request_duration_milliseconds{quantile="0.99",status="200",method="GET",path="somePath"} 1337/) });