Smoke Testing vs. Regression Testing: Key Differences and When to Use Each
Have you ever downloaded an application that crashes when trying to perform basic functions? Developers are the guardians against such frustrations, as they aim to constantly deliver reliable and glitch-free software. Testing is essential in the development lifecycle, ensuring the final product is high-quality, functions excellently, and meets the user's needs.
Data shows that only 52% of software projects pass the post-release quality assessment. Companies use different testing types to make the testing process thorough. By employing various methods, the team can guarantee reliability and software quality.
This article focuses on when to use smoke testing vs regression testing and their differences. Although teams employ both methods for quality checks, each serves a different purpose. Moreover, they are also used at various stages of software testing.
The key difference between the two methods is in their purpose. Smoke testing establishes the performance of the software's core functionality, while regression testing ensures the software is not negatively affected by recent changes. Development companies use smoke testing to assess the stability of each build and regression testing after making changes to the codebase.
What is Smoke Testing?
Smoke testing is a preliminary software testing type designed to quickly assess a software build's stability and critical functionality. Typically performed at the early stage of the development process, this method ensures that all the core features are working correctly. It is a quick assessment to identify major bugs early on.
This method prevents the team from wasting resources on flawed builds. Smoke testing helps determine if the software is stable enough for further testing. The goal is to discover major roadblocks before going into intricate details.
This test focuses on only the core features of a software build, ensuring the main workflows are not broken. Smoke testing covers the most important functionalities without going into in-depth verification. The development team uses this process to reject flawed builds and decide whether to proceed with additional tests.
Smoke testers carry out a set of test cases to cover the application's essential functionalities. Typical test scenarios might include:
- Verifying basic login and logout processes
- Data input and output functionality
- Navigating through the application
- Checking core integrations with other system modules
Smoke tests are usually carried out by developers or quality assurance (QA) engineers. They perform this high-level process before handing the software off for more in-depth testing. By catching the bugs early on, the team saves resources and time.
What is Regression Testing?
Regression testing is a comprehensive testing process that ensures changes made to the build have not negatively affected existing functionality. When the development team modifies or tweaks parts of the code, it can have unexpected consequences. This test ensures that recent modifications do not break the system's functions.
Regression testing aims to identify bugs that may have been introduced into the source code. It also ensures that previously fixed issues have not been impacted by adding new functionalities. By running regression testing, the team confirms that the application still works fine even as changes occur.
Unlike methodologies that focus on specific areas of the application, this test covers a broader scope. It aims to validate both new and existing features, ensuring proper functioning across the entire software after every iteration. With regression testing, the team can pick up potential issues and reduce the risk of unexpected behavior in the application.
Today, this type of test has become crucial as software releases occur frequently. The typical test scenario in regression testing involves:
- Retesting previously passed test cases
- Verifying integrations function as intended
- Checking edge cases that may occur outside of the typical user workflow
- Ensuring backward compatibility
QA engineers are primarily responsible for regression testing. Repeating a series of test cases each time the source code is updated can be time-consuming, so sometimes, QA engineers perform these tests with automated tools.
Key Differences Between Smoke Testing and Regression Testing
Speaking of smoke testing vs. regression testing, there are important differences to note. While they are both incredible tools, they differ in purpose, scope, and execution. Before picking a testing method, the development and testing teams need to understand its ins and outs.
Purpose
When it comes to smoke testing vs regression testing, they serve different purposes.
Smoke testing is used for a quick assessment of the build's stability. The team can quickly fix critical issues by conducting a smoke test before investing in more extensive test phases.
On the other hand, regression testing ensures stability after code changes. This method helps prevent the introduction of bugs after adding new functionalities or features. A regression test helps the team maintain stability even after modifying the source code.
Scope
Another difference when considering smoke testing vs regression testing is the coverage. While smoke testing is limited to core features, regression testing aims to cover a wider range of functionalities.
The team's primary aim when using smoke tests is to ascertain whether the critical features are working as expected. With smoke testing, the focus is on all the essential aspects of the application and verifying its overall stability. There is no need to go into in-depth verification of every feature.
Conversely, the primary feature of regression testing is its comprehensive coverage. With this method, the team conducts an extensive test to validate various functionalities and use cases. Its end-to-end coverage helps ensure there are no deviations in all aspects of the software, reducing the risk of failure.
Test case Depth
Another varying element in smoke testing vs regression testing is the amount of detail involved. While smoke testing is a shallow, high-level test, regression testing is a more detailed and deep test.
Smoke testing validates only the essential features as a preliminary test method. Regression testing is the best choice for granular verification, ensuring quality throughout the software.
Frequency
Smoke testing is performed after each build to determine its stability. This test is conducted after deployment before moving the project into a more exhaustive testing phase.
In contrast, regression testing is performed after changes or fixes are made to the codebase. It thoroughly verifies the functionality of the software following new features and enhancements.
Who Performs
The software developers or QA engineers can perform smoke testing. Since it is a surface-level test, it does not always require professional testers. Regression testing, on the other hand, is executed primarily by QA engineers.
Duration
Timelines are another varying feature in smoke testing compared to regression testing. Smoke tests are designed to be short and quick, while regression tests are lengthy.
The team's primary goal when conducting smoke tests is to detect major issues quickly. If a software project does not pass the smoke tests, then there is no need for extensive testing.
Regression testing, however, can take a long time, depending on the project's complexity. These tests are usually time-consuming since the teams run many test cases. Although regression testing can be lengthy, it's essential to the testing process before releasing products to end users.
Automation
Another varying element in smoke testing vs. regression testing is automation. Smoke testing can be automated, but it is usually conducted manually.
In contrast, regression tests are often automated. Automation is necessary to save time and resources due to the need for continuous testing.
When to Use Smoke Testing vs Regression Testing
As software developers and QA engineers, understanding when to use each method is crucial. This will help the team leverage the right testing type for an efficient, high-quality software release.
Smoke Testing
The testing team can use this method in the following scenarios:
1. After a New Build
Smoke tests are executed for immediate feedback when the development team deploys a new build. They occur after creating a new build for the project and before moving to production. Smoke testing is conducted as part of the early verification process in the software development lifecycle.
2. When Integrating Code Changes
A smoke test is also necessary each time the developers change the code. When the new build is delivered, it goes through a smoke testing phase, which verifies all the core functionalities.
3. Before Major Testing Cycles
Every new build undergoes smoke testing as a preliminary test phase. If it fails the test, it is handed back to the development team.
The team executes another set of smoke tests. If it passes, the build moves to a more detailed test cycle. The software goes through smoke testing before more rigorous tests like functional and integration testing.
Regression Testing
The team can use this method in the following scenarios:
1. After Bug Fixes or Patches
After developers fix any bugs or defects in the build, regression testing is performed. When the software fails due to errors, developers debug the source code. After identifying the bugs, appropriate changes are made. Since these modifications may cause unexpected behaviors, regression testing is essential.
2. After New Features
A shift in the business strategy may cause the development team to revise the existing functionality. Adding new features, making enhancements, and modifying the software require regression testing. A new functionality is one of the most common reasons for this test type. There is always a risk of compatibility with an existing build after modifying or adding new features. Moreover, interference with the software may introduce new defects.
3. Before Major Releases
A regression test is performed during the last system integration before rolling out a major release. It ensures the new update does not impact existing features.
4. During Maintenance Phases
Development teams regularly perform routine maintenance tasks, such as updating frameworks and libraries. After these activities, regression testing helps ensure these updates do not compromise the software's performance.
Best Practices and Tools
Planning and designing effective test cases ensures the tests target the right functionalities. They help the development and testing teams meet the requirements laid out for the software project.
Effective test cases are designed to focus on essential parts of the software and prevent redundancy. For both smoke testing and regression testing, the team should consider these key aspects:
Establish Objectives
Before generating test cases for the project, the team should clearly define the testing purpose. This helps guide the scope of testing and guarantees all the crucial aspects are covered.
Prioritize Test Cases
This is essential when testing, especially to address constraints in time and budget. Test case prioritization involves ranking them based on their importance and impact on the project. By doing so, the team executes high-priority cases first, and the testing process is handled efficiently.
Regularly Review Test Cases
Frequently refining test cases ensures they remain relevant and reflect any changes made to requirements or software. Having a regular review is crucial, as it helps the team maintain the effectiveness of each testing phase.
Automating Regression Tests
In the concept of smoke testing vs regression testing, one of the differences is that regression tests are often automated. There are various tools and frameworks that help the testing team automate regression tests.
Automating the process is effective in saving time and resources. Some of the most common tools and frameworks for regression tests include:
1. Selenium
Pros:
- Free and open-source testing tool
- Supports testing across major browsers and operating systems
- Integrates seamlessly with continuous integration and deployment (CI/CD) platforms
- Allows users to run test cases concurrently
- Does not restrict integration with third-party tools
Cons:
- Cannot generate reports; testers have to use third-party tools
- Supports only web-based applications
Price: Selenium is free and open-source
2. Appium
Pros:
- Cross-platform compatibility, including Android, iOS, and Windows
- Supports multiple programming languages
- Integrates easily with other testing frameworks
- Users enjoy support from an active community of fellow testers and developers
Cons:
- Test execution may be slower compared to other frameworks
- Knowledge of essential programming languages is needed
Price: Appium is a free and open-source automation framework
3. Ranorex
Pros:
- Offers comprehensive testing tools for desktop, mobile, and web apps
- Integrates excellently with Jira, Jenkins, and multiple development tools to accelerate software release
- Creates a detailed summary at the end of every test run
- User-friendly interface that makes it easy for beginners to get started
Cons:
- Requires a license, which may be expensive for small teams on a budget
Price:
- A free trial is available
- Customers can request a quote on the pricing page
4. TestComplete
https://smartbear.com/product/testcomplete/
Pros:
- Supports automatic testing for mobile, desktop, and web
- Integrates tightly with third-party tools like Jira, Git, Jenkins, and Azure DevOps
- Provides a recording feature to save users lots of time
- The barrier to entry is low, allowing beginners to execute tests successfully
- Detailed test reports and analysis, including screenshots of actions performed
- Allows keyword-driven testing, making it easy for less technical team members
Cons:
- The documentation is not exhaustive in many areas, particularly scripting and the use of plugins
- Name mapping may become unstable and lead to occasional crashes
Price:
- Free 14-day trial
- TestComplete Base: Ranges from $3,923 to $7,839, depending on the number of users and devices
- TestComplete Pro: $3,015 for a single user on physical machines. $6,029 for multiple users on physical and virtual machines
- TestComplete Advanced: Custom pricing
5. Test Studio by Telerik
https://www.telerik.com/teststudio
Pros:
- Supports cross-platform automation testing
- Intuitive user interface and an easy-to-learn tool
- In many cases, test execution does not require coding skills
- Simplifies the testing process for beginners
Cons:
- It is not a free testing tool. Users have to pay a license fee
- Customization options are available but can be time-consuming to setup
Price:
- A free trial is available
- Licensing costs start at $2,499
6. Katalon Studio
Pros:
- Allows teams to perform end-to-end API testing without extra integrations
- All-in-one automation tool for web, mobile, and desktop testing
- Permits a wide range of integration with leading industry platforms, such as CircleCI, Jenkins, TestRail, and JIRA
- Rich graphics and a user-friendly interface
- Allows test analysis based on recorded scenarios
- Supports various tests, including data-driven and keyword testing
- Easy testing tool for non-technical users
Cons:
- Documentation is less extensive compared to other automation tools
- Supports a few scripting languages
Price:
- Functional free version for individuals and small teams
- Premium: $175 per month
7. WATIR (Web Application Testing in Ruby)
Pros:
- Provides support for multiple operating systems
- Open source Ruby library
- Can automate the testing for any web application that runs in a browser
- Contains in-built libraries for testing alerts, page performance, and many more
Cons:
- Requires extensive Ruby knowledge to use advanced features
- Supports only web applications
Price: WATIR is a free and open-source automation tool
8. Sahi Pro
Pros:
- Supports web, desktop, and mobile testing
- Beginner-friendly automation tool; no need for special training
- Automatic logging and reporting of script execution
- Compatible with different web technologies, including AJAX.
- Provides a great recorder and object spy for identifying web elements
Cons:
- Limited community support when it comes to troubleshooting and online resources
- Requires a paid license
- Fewer integration options
Price:
- 30-day free trial
- Prices start at $835 per year for each user license
9. testRigor
Pros:
- Non-technical team members can build and execute test automation
- Provides support for parallel testing, allowing the tester to use many browsers and devices concurrently
- Analyses test results and identifies error patterns using intelligent algorithms
Cons:
- Compared to other automation tools, testRigor has fewer pre-built integrations
Price:
- Free plan: All tests and results are public
- Private: $900 per month
- Custom: Contact support for personalized enterprise offers
Benefits of CI/CD Pipelines
Continuous integration and continuous delivery (CI/CD) pipelines are vital for efficient test execution. They allow teams to integrate the source code into a single repository, streamlining the development process. Here are some benefits of CI/CD pipelines for efficient testing.
1. Rapid Feedback Loops
CI/CD pipelines encourage fast feedback loops by automating the build, test, and deployment processes. This significantly reduces the time between code modifications and feedback. The team can see the immediate effect of their code changes and make necessary adjustments.
2. Smaller Modifications
An advantage of CI/CD pipelines is that they allow the team to make small code changes at a time. These modifications are easier to handle than larger blocks of code.
3. Faster Software Release
Incorporating CI/CD pipelines into the test plan leads to increased release rates. Teams can automatically deliver software features repeatedly and reliably. With smooth CI/CD workflows, it is easy to move to production after extensive testing.
4. Increased Test Coverage and Reliability
Test reliability and coverage increase with the introduction of a CI/CD pipeline, as it minimizes manual efforts. By using CI/CD pipelines, teams allow for more accurate tests to be performed.
5. Enhanced Team Collaboration
CI/CD increases collaboration among team members as they work from a centralized repository. This central environment fosters regular communication. Additionally, every member is aware of the latest changes, increasing transparency.
Conclusion
The smoke testing vs regression testing comparison helps teams understand their differences and when to use each. The key difference between these methodologies lies in their scope, objectives, and depth. However, they are both essential to achieving reliable and high-quality software.
Smoke testing prioritizes the build's core functionalities, ensuring they are stable for further testing. On the other hand, regression testing covers a broader range of features and focuses on validating both new and existing functionalities.
Smoke tests are shallow, high-level assessments that identify critical issues. Conversely, teams employ regression tests for deeper and more detailed assessments, exploring every possible test case. While smoke tests are performed after a new build, regression testing occurs whenever there is a change in the code.
Developers and QA engineers can achieve optimal results by adopting both testing methods. Smoke testing can be integrated into the software development cycle for short and quick tests before investing resources into in-depth quality checks. Regression tests are applied after every code change for stability and long-term reliability.
A balanced testing strategy incorporates both smoke testing and regression testing. Leveraging the strengths of both methodologies ensures that the testing teams deliver high-quality software that meets users' expectations.
