script.js

import http from 'k6/http'
import { sleep, check } from 'k6'
import { Rate, Trend } from 'k6/metrics'

// Custom defined metrics
const lowerThan2sRate = new Rate('lower_than_2s')
const durationInSeconds = new Trend('duration_in_seconds')

// This BASE_URL won't work if you're using Docker.
// You'll need to know the IP address of the host.
// Then replace localhost with the IP address.
const BASE_URL = 'http://localhost:3000'

export const options = {
    vus: 1000,          // 1000 users will be simulated
    duration: '1m',     // the test will run for 1 minute
    thresholds: {       // you can define threshold here. all criteria of a successful test
        lower_than_2s: [{               // custom defined metrics
            threshold: 'rate>0.75',     // the result rate should be above 75 percents 
            abortOnFail: true,          // if the criteria wasn't met, then the test is aborted
        }],
    }
}

export default function(data) {
    // We need this to pass the authorization and authentication middleware
    const params = {
        headers: {
            'Content-Type': 'application/json',
            Authorization: `Bearer ${data.token}`
        }
    }


    data.incomeExpenseTypes.forEach(t => {
        const payload = {
            value: 10000,
            description: 'Test',
            income_expense_type_id: t.id,
            is_income: false
        }
        const res = http.post(`${BASE_URL}/income-expense`, JSON.stringify(payload), params)
        
        // this check function will run at each iteration
        // making sure that the checks criteria is met
        check(res, {
            'is success': (r) => r.json().success,
            'duration below 2s': r => r.timings.duration < 2000
        })
        
        // lowerThan2sRate is added by one if the duration is below 2s
        lowerThan2sRate.add(res.timings.duration < 2000)
        
        // we know that the duration is in millisecond
        // but for demonstartion purposes, we convert it to second
        durationInSeconds.add(res.timings.duration / 1000)
    })
    
    // sleep for one second at each iteration
    sleep(1)
}