Smoke testing, also known in the software development world as "build verification testing," serves as a frontline defense in the quality assurance process. It's comparable to a first impression---a quick, initial examination to ensure the fundamental aspects of a software build are functioning properly.
The term "smoke test" has its roots in electronics, where new hardware devices are powered up for the first time; if no smoke arises, it's a basic indication that the components won't burn out under normal usage. In software terms, a smoke test is designed to catch glaring issues that, if undetected, could cause major problems down the line.
When should you perform smoke testing?
Which approach is better: manual smoke tests or automated ones?
Learn how to automate your smoke test cases with our comprehensive guide.
What Is Smoke Testing?
At its core, smoke testing is a software testing method that involves the creation of a smoke test suite---a collection of basic tests covering the main functionality of an application.
Smoke testing is performed on new builds to verify that when the software is run for the first time, the core features operate correctly. Smoke testing is typically performed by either the testing team or by developers before the build is handed off for further testing.
It's a quick-fire way to give a software product a clean bill of health, or to send it back to development for a more thorough check-up if any "smoke" is detected.
Check also Smoke Testing vs Sanity Testing: All You Need To Know for more resources.
Types of Smoke Testing
Smoke testing, a crucial type of software testing, is a preliminary method used by testing teams to identify major flaws in software applications. There are different types of smoke testing, each serving a specific purpose in the testing cycle:
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Basic Smoke Testing: This is a fundamental approach where the testing is done on critical functionalities of the software to ensure they are working. It's a subset of regression testing and often the first set of tests run in a testing cycle.
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Automated Smoke Testing: Involving tools for automated smoke testing, this type allows teams to automate the tests, ensuring that they are run efficiently every time there is a new build. This is especially beneficial in continuous integration environments.
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Manual Smoke Testing: Here, testing is performed manually by a testing team. Manual smoke testing allows for more flexibility and human insight, which can be crucial for complex applications.
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Hybrid Smoke Testing: Combines both manual and automated testing methods. This kind of testing ensures thorough coverage and efficiency.
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Build Verification Testing (BVT): Often used interchangeably with smoke testing, BVT focuses on verifying the stability of a build, ensuring it's fit for further testing.
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Confidence Testing: A type of smoke testing aimed at building confidence that the core aspects of the software are functioning as expected. This is typically performed after each new build.
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Load Smoke Testing: This kind of testing involves checking the software's basic functionality under minimal load. It's a precursor to more intensive load testing.
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Smoke Test Suite: A collection of smoke tests often run together to assess the software's critical functionalities quickly.
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Smoke Testing in System Testing: Smoke testing is also an integral part of system testing, where it is used to validate the reliability of the entire system.
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Sanity Testing vs Smoke Testing: While both are subsets of regression testing, sanity testing is used after smoke testing to focus on specific functionalities, whereas smoke testing covers a broader range of the application.
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Smoke Testing in Hardware Testing: In the context of hardware testing, smoke testing can drastically reduce the risk of hardware failures by identifying critical issues early on.
The benefits of smoke testing include early detection of major issues, saving time and resources in the software development process. Automating your smoke testing can further enhance efficiency and reliability.
Effective smoke testing aims to ensure that the most critical parts of the application are stable before proceeding with further testing, making it an important part of the overall software testing strategy.
Benefits of Smoke Testing
The advantages of smoke testing are manifold. It is a time-saver; by quickly identifying any catastrophic issues early in the testing cycle, it prevents the wasting of resources on builds that are fundamentally flawed.
Smoke testing can act as a gatekeeper, preventing defective builds from moving down the production line. The immediate feedback it provides ensures that no major regressions have been introduced, allowing the development team to address issues promptly.
As such, smoke testing is an important part of maintaining continuous delivery and integration practices. By verifying that key areas of the application are unaffected by recent changes, smoke testing instills confidence that the software is ready for more detailed and exhaustive testing.
Smoke testing can be considered a form of lightweight regression testing as it checks whether the basic functions still operate after a new integration.
Smoke Testing Process
The process of smoke testing can be distilled into a series of methodical steps. Initially, a smoke test suite is constructed with the purpose of smoke testing in mind---to cover the application's main functionality with a broad stroke. These test cases are typically straightforward, and designed to verify basic behaviors and functionalities.
When a new build is ready, these smoke tests are run to check the stability and basic health of the application. If the smoke test fails, it's a clear signal that there are fundamental flaws that need immediate attention.
Conversely, a successful smoke test indicates that developers and testers can confidently proceed with further testing, safe in the knowledge that the application is structurally sound.
How To Use Smoke Testing?
Step 1: Identify Critical Functions
Before running a smoke test, identify the critical functionalities of the application that must be working for it to operate at the most basic level. This typically includes functions like logging in, data retrieval, main navigation, and basic transaction processing.
Step 2: Create or Select Test Cases
Develop a suite of test cases that cover these critical functions. These should be high-level tests that do not delve into detailed functionality but ensure that the application can handle basic operations. The suite should be concise enough to be run quickly but comprehensive enough to cover all major areas of the application.
Step 3: Prepare the Test Environment
Set up a stable test environment that mimics the production environment as closely as possible. Ensure that any required data, services, and resources are available and configured correctly for the test.
Step 4: Execute the Test Cases
Run the test cases either manually or using automated test scripts. Automated smoke tests are common in continuous integration environments, where they are triggered automatically when a new build is integrated. After smoke testing verifies that the basic functionalities of the application are working in isolation, integration testing takes over to ensure that these components work together as expected.
Step 5: Record the Results
Document the outcomes of each test case. If you are using an automated testing tool, it may record results for you. Otherwise, keep track of which tests pass and which fail.
Step 6: Analyze Failures
If any test cases fail, analyze the results to determine what went wrong. Failures in smoke testing typically indicate significant issues with the build that need to be resolved before any further testing can be meaningful.
Step 7: Communicate with the Team
Share the results of the smoke test with the development team and other stakeholders. If the test was successful, the build can move on to more exhaustive testing phases. If the smoke test reveals problems, the build should be rejected, and the development team should be notified to fix the issues.
Step 8: Make a Go/No-Go Decision
Based on the results of the smoke test, make a decision on whether to proceed with further testing or to send the build back for further development. A successful smoke test means you can go ahead with detailed testing, while a failed smoke test means a no-go until the critical issues are fixed.
Step 9: Iterate
After issues identified in the smoke test are resolved, a new build will be created. Repeat the smoke testing process for each new build to ensure that the critical functionalities are always in a working state.
Smoke testing should be simple, quick, and repeatable, providing a consistent preliminary check for every new build. It's a critical step in a robust software development and quality assurance process, acting as an early indicator of the health of a software application.
Smoke testing is an important type of testing that can drastically improve the quality of software by catching major issues early. It is a subset of both functional test and regression testing and aims to provide a preliminary assessment of the build's stability.
By using tools for automated smoke testing, teams can ensure that smoke tests are run efficiently and consistently, which is vital for automating your smoke testing process and maintaining an effective testing cycle.
When You Should Do Smoke Testing?
Smoke testing is a versatile tool and should be employed at several key points within the software development lifecycle. It's particularly critical after a new build is compiled, serving as a checkpoint that determines whether the build is stable enough for further testing.
Additionally, smoke testing is invaluable after any significant integration to ensure that existing functionality has not been adversely affected. Before any major testing efforts, such as system testing or user acceptance testing, smoke testing can be used to verify that the fundamental aspects of the application are functioning, thus avoiding wasted effort on a defective build.
Can You Automate Smoke Testing?
The short answer is a resounding yes.
Automating smoke testing can transform it from a routine checkpoint into a strategic asset. By automating, you eliminate the variability that comes with manual testing and ensure that each test is performed with precision every single time.
Automated smoke testing becomes part of the continuous integration (CI) process, where each new build automatically undergoes a series of tests. This integration ensures that any new integration or feature does not disrupt the key functions of the software.
With automation, smoke testing scales from being a simple health check to an integral part of the delivery pipeline, providing consistent, reliable, and immediate feedback on the build's quality.
Final Thoughts
In summary, smoke testing is an essential kind of testing used to ensure that the basic functionalities of a software application are working before it undergoes further, more granular testing. The automation of smoke testing is a step towards increasing efficiency, reducing manual errors, and speeding up the delivery process in the software development lifecycle.
Whether manual or automated, smoke testing serves as a critical filter, ensuring that only stable builds proceed through the testing pipeline, thereby upholding the integrity and reliability of the software development process.
Happy (automated) testing!
