The Ultimate Guide to Smoke Testing

Identifying and eliminating software bugs while maximizing software quality are the primary objectives of software testing. Testers must perform various levels of testing before finalizing changes and releasing the product to the market.

Testing allows software teams to gain the client’s trust and confidence. That said, unless testing experts apply testing procedures strategically, detecting bugs in software can become extremely time-consuming and complex.

One way of identifying critical issues in software is to conduct a preliminary round of testing and find basic issues in software. Smoke testing is among the best measures to deal with software bugs initially and conduct testing strategically.

To help our readers, we have created the Ultimate Guide to Smoke Testing, where you’ll find out everything you need to learn about smoke testing.

Table of Contents

1. Smoke Testing: Definition and Features
2. When Should We Perform Smoke Testing?
3. Importance of Smoke Testing
4. Advantages of Smoke Testing
5. How to Perform Smoke Testing
6. Conclusion

Smoke Testing: Definition and Features

What Is Smoke Testing?

Smoke Testing is a subset of software testing that helps us verify whether a deployed software build is stable or not. It serves as a prerequisite to software testing and lets the QA team know if they can proceed with further testing.

What makes smoke tests unique is that it must be performed universally across every new build. In simple terms, carrying out smoke testing helps us verify whether the critical features in a particular build are working or not.

For context, you can imagine it as a mini and rapid regression test, conducted for major functionalities. It assists the team in avoiding wasting time and resources in useless test processes, thereby decreasing the project costs and maximizing profit.

After a software build is verified in a smoke test, it is ready for further formal testing. Every software build comprises of libraries, data files, engineered components, as well as reusable modules.

All these components are needed for the implementation of one or more product functions. To account for these functionalities, smoke tests are designed while ensuring conformance to requirements and system stability.

Features of Smoke Testing

Smoke testing includes several important features that make it different from other types of testing. Therefore, we need to understand these features to understand the fundamentals of smoke testing. Here are some of the key features of smoke testing:

• Smoke testing is often referred to as Build Verification Testing, where the build is verified by testing the important features of the application and then sent for next levels of testing based on test results
• It’s an integral part of the software development cycle where the build is verified by testing the important features of the application
• Smoke Tests can be executed manually or can be automated based on the test requirements
• It applies to different levels of software testing like integration testing, system testing, and acceptance testing.
• This is non-exhaustive testing with a very limited number of test cases. Usually, smoke testing is performed with positive scenarios and with valid data.

In simple terms, you can think of smoke testing as a normal health checkup of a build of an application. Rest of this ‘What is Smoke Testing?’ article, let’s check out some important questions related to smoke testing.

When Should We Perform Smoke Testing?

Smoke Testing is done whenever the new functionalities of the software are developed and integrated with an existing build that is deployed in a QA/staging environment. It ensures that all critical functionalities are working correctly.

In this testing method, the development team deploys the build in the QA. The subsets of test cases are identified, and then testers run test cases on the build. The QA team tests the application against the critical functionalities. These series of test cases are designed to expose errors that are in build. If these tests are passed, the QA team continues with Functional Testing.

Any failure indicates a need to handle the system back to the development team. Whenever there is a change in the build, we perform Smoke Testing to ensure stability.

Importance of Smoke Testing

Smoke testing plays an important role in software development as it ensures the correctness of the system in initial stages. By this, we can save test effort. As a result, smoke tests bring the system to a good state. Once we complete smoke testing then only we start functional testing.

• All the show stoppers in the build will get identified by performing smoke testing.
• Smoke testing is done after the build is released to QA. With the help of smoke testing, most of the defects are identified at the initial stages of software development life cycle.
• With smoke testing, we simplify the detection and correction of major defects.
• By smoke testing, the QA team can find defects in the application functionality that may have surfaced by the new code. 

Advantages of Smoke Testing

Detect show-stopping bugs much earlier

Customers report that they can uncover and fix as many as 80% of the bugs they discover simply by configuring and executing a solid smoke testing suite. This corresponds well with the Pareto principle of 80/20. For many teams, smoke tests might be covering only 20% or less of all test cases and yet catch 80% or more of the bugs. This alone makes it smoke testing efforts worth the time investment.

Improve the effectiveness of the QA team

If your QA process is potentially wasting effort and time by only running a larger test suite when many of the issues could be discovered with a smoke test, then you are probably wasting resources and foregoing time savings that you could use to perform other tests or maintain your automation toolset.

Faster troubleshooting of new and regression bugs

If any are found in smoke testing, the development team can get to work much earlier on troubleshooting and performing root cause analysis—instead of waiting until after the results of the full test suite. This is due to the high coverage, shallow depth nature of smoke testing suites. Think of this test suite as a sketch-mapping of the quality of the application. If the build is somewhat viable, then more efficiency can be gained if QA continues with (partial) regression testing on that build while developers fix any smoke-test bugs. After fixing those bugs, the developers can then turn to fix any bugs that QA has found in the regression testing.

Cultivate a happier, high-productivity QA team

QA teams will be more productive and have higher job satisfaction when they can have more confidence about higher-viability builds that successfully pass through the smoke test suite.

How to Perform Smoke Testing

The process to implement an automated smoke test will vary depending on your application and the configuration of your build tool. But the basic steps of smoke testing should remain the same.

Manual Tests 

A common first step for companies who want to build a suite of smoke tests is to first start with manual QA. This is relatively easy to start with and, particularly in younger companies, people who aren’t engineers or QA testers will frequently get pulled into performing smoke tests.

As teams mature, they may choose to hire a QA manager or a manual tester. This is a good first step, even you plan to automate in the future because we will show you how to turn those manual QA testers into automation engineers as quickly as possible. There are two major benefits to starting with a manual process:

1. Non-engineers can own the testing process, freeing up engineers to build a product
2. The people who define manual smoke tests are the best people to create automated tests, provided they have the right tools

The main point of a smoke test suite is to let teams know whether or not they should continue testing their entire application. It’s also important to understand what level of testing should be included.

There are many types of QA testing but to keep things simple, let’s look at Unit Testing vs. Functional UI testing.

Unit Testing is a best practice among agile software development teams and is something that we won’t cover in great detail in this article. Unit tests are automated tests that happen at the source code level in a project and should be executed even before the smoke suite is run.

The best fit for smoke testing is at the Functional UI layer. Functional testing is all about testing the user interface (UI) to uncover new bugs (exploratory functional testing) or ensure that previously known bugs have not found their way back into the application (functional regression testing).

You want a smoke suite to be an easily manageable number of tests that can be executed quickly, regardless of whether the smoke suite has been automated. The recommended number of test cases is generally 20 on the low end to around 50 on the high end. Any less than this and you’re probably not getting enough relevant coverage, and any more than this and you’re probably trying to cover too much ground at this stage.

Automation

Once you have your suite of smoke tests defined, you’re going to want to think about automation. Given that the point of smoke testing is to determine quickly the state of the release and its readiness for full QA, you don’t want your suite to take more than a few minutes to execute. If you’re running 50 tests, and it takes half a day (or more) to run these tests, then your testing cycle is going to be too slow. This is why you want to automate.

Easier said than done for many teams. The process of automation typically involves yet another software engineering project. The most popular tools for building new testing automation focus on browser automation. The most popular browser automation framework today is Selenium, which is an open-source project that enables developers to automate browsers. This is important because you have to emulate user behavior to properly test modern web applications today. The tricky part about this is that when users interact with an application in the browser, there are lots of hidden things happening, such as JavaScript events firing, asynchronous calls being made to APIs, real-time font-renderings, CSS-based animations and much, much more. A proper automation framework will enable teams to both emulate user behavior and get visibility into all of these non-visible phenomena.

Tips by Experts for Smoke Testing

Once you have your suite created and an automation framework selected, you’ll want to think about a couple of key areas to keep your tests running healthy and providing valuable feedback:

1. Test creation and maintenance
2. Continuous Integration tools such as Jenkins and CircleCI
3. Daily execution
4. Create a penalty on developers whose contributions don’t pass

Conclusion

In conclusion, smoke testing needs to be executed on every build as it assists software testers in identifying defects in the early stages. It offers a simple, straightforward yet supremely effective option to speed up finding bugs. Developers and others alike can use smoke tests in software projects, and can dramatically improve code quality.

PFLB is a testing service dedicated to ensuring the best software quality for our clients. We have served over 500 companies across a wide variety of domains that range from finance and healthcare to retail and technology. 

With years of experience at our disposal, our testers have learned how to employ smoke testing strategically. Our in-depth knowledge of various testing procedures helps us find hidden issues in different components of the software and deliver the best solution for your business. To learn more about our company, feel free to visit our website.