As we near the end of 2024, the early stage of quality assurance methods needs to be implemented as a continuous evolution in software development. Smoke testing is the primary level of testing that provides an assurance about the expected functionality working as intended after any update or integration of its core functionality.
This article talks about the importance of smoke testing, its practical applications, and examples, and best practices for effective early-stage testing.
What is Smoke Testing?
Smoke testing is a software testing that involves running a set of predefined tests on a build, usually after the major changes or additions to the software. The purpose of smoke testing is to quickly check if the program's most important functions work, not going into the finer details.
The term "smoke testing" comes from the hardware world where initially, the objective was that a device didn't "catch fire" when it was turned on. In software, this would translate to the application starting up and basic functionalities behaving as they should.
Smoke tests assess critical functionalities such as:
- Does the software launch successfully?
- Can users log in?
- Are the primary features accessible?
Why You Need Smoke Tests
Identifying defects early in the software development lifecycle is crucial. Bugs discovered in later stages are significantly more expensive and time-consuming to fix. Smoke testing helps address this issue by enabling early detection of defects, ultimately saving time, effort, and costs.
By running a predefined set of tests, smoke testing allows DevOps teams to identify and fix major issues before they impact end users. Acting as a first line of defense, smoke testing ensures that the software’s core functionality is stable and reliable.
Smoke Testing Examples
Smoke testing serves as an initial check to identify significant issues early in the development cycle, ensuring a build’s stability for further testing. Here’s an example:
Login Functionality Verification
Imagine testing a newly developed web application. One of the critical features is user authentication, which ensures that only registered users can log in with valid credentials.
In this scenario, a smoke test might include:
User Registration and Login: Verification that users can register and subsequently log in using their credentials.
Authentication Flow: It verifies whether the login is in the expected sequence, for example, entering a username and password and clicking the login button.
Error Handling: Checking if appropriate error messages appear for wrong credentials and any other incorrect login issues.
If these functionalities pass the smoke test, the application is stable enough to proceed with further testing.
Benefits of Smoke Tests in Software Testing
Catching Major Issues Early
Smoke testing lets us know about big problems early in the development lifecycle. Such early detection enables teams to avoid potential roadblocks before they turn into a more complex situation that would be hard to solve.
Preventing Wasted Effort
By focusing on major issues, smoke testing prevents wasted time on detailed testing of unstable builds. A failed smoke test indicates that the build requires fixes before further testing can proceed, ensuring that subsequent efforts are directed at a stable foundation.
Time and Cost Savings
Smoke testing saves time and reduces costs by catching critical defects early. Fixing defects in their early stages is more efficient since they are less likely to impact other system components. This streamlines the development process and minimizes unnecessary rework.
Confidence for Stakeholders
Smoke testing reassures stakeholders that the software is stable enough for further evaluation. A successful smoke test demonstrates that basic functionalities are operational, instilling confidence in the build’s quality and reliability. This assurance is especially important in agile environments, where frequent build releases require rapid validation.
Disadvantages of Smoke Tests
While smoke testing is an integral part of software testing, it’s essential to understand its limitations. Smoke tests are not designed to identify every defect, and there are certain drawbacks to consider:
Limited Coverage
Smoke testing focuses on validating the most critical functionalities of a system. While this approach effectively detects major issues early, it may fail to uncover less obvious bugs or defects in rarely used system areas.
Possibility of False Negatives
Smoke tests are broad and shallow, meaning they assess key features without diving into their intricacies. This approach can lead to false negatives, where the tests pass but other critical bugs remain undetected. A successful smoke test provides confidence in the build's stability but does not guarantee the software is bug-free.
Minor Issues May Go Undetected
Since smoke testing prioritizes identifying significant defects, minor issues may go unnoticed. While individually small, these issues can accumulate over time, potentially causing more substantial problems later in the development cycle.
Types of Smoke Testing
There are several types of smoke testing, each suited to specific needs and stages of the software development process:
Manual Testing
In manual smoke testing, human testers execute predefined tests without automation tools. This involves manually interacting with the software’s interface to ensure essential functionalities work as intended. Though widely used, manual testing is time-intensive and relies heavily on testers’ efforts.
Automated Testing
In automated testing, the testing is performed using software tools. Much faster than manual testing, once tests are developed, they can be executed with the click of a button. The results are provided in minutes, hence very apt for repetitive tasks and frequent testing cycles.
Fused Software Testing
Fused software testing integrates automated and manual testing, particularly within CI/CD pipelines, feature flags, or other systems. Automated tests are triggered as build criteria are met, and signals are sent to manual testers when necessary. This method ensures a comprehensive and efficient testing process.
Additional Smoke Testing Types
Daily Smoke Testing: Conducted daily in projects with frequent builds and continuous integration to ensure that each build meets minimal quality standards.
Acceptance Smoke Testing: Performed to verify whether the software meets stakeholders’ or end users’ requirements. These tests are typically conducted after development is complete and before release.
UI Smoke Testing: Focuses specifically on validating the user interface, ensuring that fundamental UI components and interactions function as expected.
Smoke Test Cycle
The smoke testing process begins when the development team delivers a build to the QA team. Key steps in the cycle include:
- Initial Testing: QA performs an initial smoke test on the build.
- Prioritizing Test Cases: A list of test cases for core features is created and prioritized.
- Execution: The software is tested against these cases to validate critical functionalities.
What Happens If a Smoke Test Fails?
When a smoke test fails, it signifies that the newly developed or updated software has critical issues requiring immediate attention. In such cases, the testing team halts further testing and may generate an interim report to highlight the problems for resolution. They may also request additional developer testing in the next cycle to ensure these issues are thoroughly addressed. Sharing the smoke test cases with the development team helps provide clarity and facilitates a deeper understanding of the underlying issues. By discovering major problems early in the development phase, smoke testing prevents wasting of time and resources on an unstable build. Therefore, a failed smoke test should not be a discouragement but rather a positive feedback mechanism driving the development toward a more robust and reliable software product.
How To Perform Smoke Testing
Smoke testing plays a vital role in ensuring the quality of software development. Here’s a detailed overview of the steps involved in performing smoke testing:
Step 1: Identify the Scope
The first step is to define the scope of the testing. This involves pinpointing the software’s most critical functionalities that need verification. For example, in a banking application, essential features might include login, account balance inquiries, and fund transfers.
Step 2: Create Test Cases
Once the scope is established, test cases are created to evaluate the identified functionalities. These test cases should be simple and specific. For instance, in the banking application example, a test case might be: “Verify that a user can successfully log in with valid credentials.”
Step 3: Execute Smoke Tests
Test cases prepared; the next step is the execution. It could be manual or through automated tools, depending on project requirements. The aim is to ensure whether the critical functionalities are working as expected or not.
Step 4: Analyze Results
The results of smoke tests are analyzed to identify which test passed or failed. This gives the implications of the results, showing the critical problems that need to be addressed.
Step 5: Report and Communicate
Finally, the results are documented and communicated to relevant parties, including developers, project managers, and quality assurance teams. Such information assists in informed decisions on whether to go ahead with further testing or to resolve issues identified during smoke testing.
Automated Smoke Tests
Automated smoke testing offers several advantages, making it an integral part of the software testing process:
- Increased Speed: Automated tests run quickly and provide immediate feedback, enabling developers to identify and resolve issues early.
- Improved Accuracy: Automation ensures consistent execution, eliminating human error and producing reliable results.
- Enhanced Repeatability: Automated tests can be executed repeatedly, making them ideal for agile environments with frequent changes.
- Integration with CI/CD Pipelines: Automated smoke tests can be seamlessly integrated into CI/CD pipelines, running automatically whenever new code is pushed to the repository. This provides instant feedback to the development team.
Conclusion
Smoke testing represents the first line of defense in software quality assurance and provides fast feedback about a build's stability. Manual, automated, or hybrid, smoke testing ensures the verification of critical functionalities.
With regular smoke testing, development teams avoid wasting resources and time on unstable builds, hence keeping the development cycle stable and productive. For teams seeking to fine-tune their smoke testing strategy and deliver quality software, working with a trusted partner like QA Genesis will be very instrumental. We provide specialized quality assurance services that are tailored to bring in optimal results with high-quality outcomes.