Smoke Testing: The Key to Faster, Flawless Development

Smoke tests are fast and targeted. They ensure that critical functions are working properly. They should be the start of the testing phase in any software development process. If your code passes the smoke test, the quality assurance team can continue with further and more complex testing.

Why Is It Called Smoke Testing?

If there is smoke, there is fire. 

If your code creates smoke, it’s not ready for the next testing phase. The smoke in this allegory is a code-related issue that may become a major problem in the future if it’s not dealt with.

The term “smoke testing” comes from hardware testing and there are two different approaches:

• Electrical Engineering: If you see smoke coming from a circuit board the first time you power it on, you know it’s not going to work.
• Plumbing Industry: When you blow smoke into a pipe, you can see if it’s leak-proof.

Smoke testing in hardware and software helps you avoid wasting time on detailed testing if your product isn’t stable. It doesn’t provide detailed validation for each feature or scenario – smoke test simply verifies your product’s overall stability.

How to Smoke Test?

As mentioned before, you can be testing your code as an electrician or a plumber. As a plumber, focus on system “leaks” and end-to-end flows. Test if key integrations (e.g., databases, APIs) and core user actions (e.g., login, transaction) work smoothly. As an electrician, perform a quick check to ensure basic functionality. Verify that the application starts, key pages load, and critical services are running.

Optimize your smoke-testing process:

• Scope
  Setting clear criteria for smoke tests helps ensure you’re consistently checking the right features. Focus on what matters most, no detailed documentation is required.

1. 1. • Document Core Features: List all the critical features that need testing, such as user authentication and basic API calls.
      • Script Simple Test Cases: Create straightforward test cases to avoid overcomplicating the process.
      • Clean Data: Remove any files that may interfere with the smoke test (for example, stop the server and empty your database). 

• Pick the Correct Type

1. 1. • The smoke test type depends on what you need to test (or even on your personal preference). There are three types:
        1. Manual
           The most common type. Test any new feature added to existing builds.
        2. Automated
           Ideal for saving time.
        3. Hybrid
           A mix of the manual and automated smoke tests. Enhance your testing performance.

• Automate Where Possible
  Automation speeds up smoke testing and makes it more reliable. Reduce manual effort and ensure consistency.

1. 1. • Automation Tools: Use tools like Selenium, Cypress, or Jenkins to run smoke tests automatically.
      • Continuous Integration (CI): Incorporate smoke testing into your CI pipeline to validate each new build.

• Test Regularly
  Perform the smoke tests regularly, for example:

1. • After every build
   • Before integration testing/major testing phases/manual testing
   • After environment changes
   • After deployment
   • Before reviews

Do the smoke test whenever you need to ensure that the system is working. The timing depends on your development process.

• Collaborate
  Good communication enhances the effectiveness of smoke testing.

1. • Knowledge Sharing: Discuss the testing process with your team to refine and improve it.
   • Feedback: Gather feedback to keep your smoke testing practices sharp.

The Impact of Smoke Testing

Incorporating smoke testing into your development process ensures that critical features are validated early, catching issues before they escalate. By focusing on core functionality, automating where possible, and testing regularly, you improve testing efficiency and product stability. While not a substitute for thorough testing, smoke testing helps teams quickly assess whether the system is stable enough to proceed with more detailed testing.

Author: Kristýna Supradnyan

Images:  https://leonardo.ai/

Sources and References:

https://www.techtarget.com/

https://medium.com/

https://www.globalapptesting.com/

https://www.thoughtworks.com/

https://blog.qasource.com/