Deep dive handbook

Reliability and performance tests

Smoke test

Intro

The term comes from hardware testing, where engineers powered on a device and checked if smoke came out — if it did, testing stopped immediately.

Scheme

Key characteristics

• Shallow and broad: Focuses on covering major features, not detailed behavior.
• Quick execution: Designed to run quickly to validate build stability.
• Gatekeeper: Acts as a gate before proceeding to deeper testing.
• Automated or manual: Can be automated but is often a simple checklist when manual.
• Frequent execution: Typically run on every new build to catch show-stopper issues early.

Practical examples

• Is API returning response?
• Does main page loads?
• Can user login?

Users and time

• Number of virtual users:

  Smoke testing is not about concurrency or load — typically performed with 1 user or simulated user session.

• Execution time:

  Smoke tests should be fast - ideal duration is a few minutes (e.g., 5–15 min max), depending on project complexity, to quickly give feedback on build health.

Examples with tool k6

Simple example

script.js

import http from 'k6/http';
import { check } from 'k6';

export const options = {
  vus: 1,
  iterations: 5,
};

export default function () {
  const response = http.get('https://api.example.com/health');

  check(response, {
    'status is 200': (res) => res.status === 200,
    'body is not empty': (res) => res.body.length > 0,
  });
}

Runnable example

Resources

• What is Smoke Testing? | Definition from TechTarget