The term “smoke testing ” may have originated in the plumbing industry, and then it came to be widely used in the realm of hardware testing: it referred to the act of powering up a device to check for smoke (caused by bad wiring, for instance). These days, what we call the smoke testing process has also become an essential part of modern software development, serving as a valuable tool for software developers, QA engineers, and tech decision-makers. It saves both time and resources by helping them identify critical issues at an early stage.
In this post, we’ll give you an overview of smoke testing’s underlying principles, the various types of smoke testing, and each type’s benefits. On top of that, we aim to offer valuable insights into how smoke testing can be incorporated into your software development processes.
What Is Smoke Testing? Assessing the stability of a newly developed or modified software build is often the primary aim of smoke testing. It focuses on key functionalities so you can verify that they operate as intended. If essential features aren’t working — or if significant bugs remain unresolved — there’s likely no reason to continue with more comprehensive testing.
Smoke testing is a non-exhaustive testing approach — that is, it does not cover all possible use cases. Typically, a smoke test suite is executed using expected scenarios and valid data, in order to gain a somewhat reliable measure of the software's stability and readiness for further testing.
And it’s crucial to understand that “a somewhat reliable measure” is perfectly acceptable for smoke tests. The goal is to help you avoid wasting time on more comprehensive tests. For instance, you could smoke test a web app’s login functionality by:
Navigating to the login page. Entering a valid username and password. Clicking on the login button. Verifying that the user is redirected to the dashboard or home page. You can also think of smoke tests as “verification tests.”
In most scenarios, smoke testing is going to revolve around functional testing ; however, some tools also allow you to perform smoke tests — and other, related forms of testing — in the area of non-functional testing .
Smoke testing does have its limitations. For example, the heavy reliance on expected scenarios and valid data means that it may not catch all possible issues, especially those that arise from edge cases or that might be uncovered by negative testing. Additionally, smoke testing’s non-exhaustive nature means that it’s not a substitute for more thorough testing methods; rather, it’s a precursor to them.
Why Smoke Testing Is Crucial in Software Development The smoke testing process serves as a quality gate between different stages of the development pipeline, particularly after the generation of a new build. In DevOps, a smoke test suite is often the first set of automated tests that’s executed. Successfully completing smoke testing allows development and QA teams to proceed with confidence to more exhaustive testing and, eventually, production.
Consider a cloud storage service that has recently integrated a new file-sharing feature. A well-designed smoke test will swiftly verify that users can still upload, download, and share files without encountering errors, thereby enabling quicker iterations and more reliable deployments.
This not only ensures that critical functionalities are intact but also aids in the early identification of significant issues, thereby facilitating more efficient and effective development processes.
Understanding the Different Forms of Smoke Testing When diving into the world of smoke testing, it’s important to understand the different types you might want to implement.
Manual Smoke Testing Manual smoke testing allows testers to adapt to different testing conditions and requirements on-the-fly, which is particularly beneficial with projects where the requirements are not fully defined or where they’re subject to frequent changes.
This is on top of the nuanced evaluation capabilities that manual testing provides. Human testers can assess the functionality of an application as well as its usability and user experience. They can identify issues that automated tests might overlook, such as inconsistencies in the user interface or problems with the user flow that could affect the end-user experience.
Use-Case: Verifying a New Feature in a Mobile App
When a new feature is introduced in a mobile application, manual smoke testing can be used for initial validations. For example, if a mobile app introduces a new chat feature, manual testers can quickly ensure that it works as expected without disrupting other features like notifications or user settings.
Moreover, manual testing allows for a nuanced evaluation of the new feature's impact on the overall user experience, as testers can validate the feature's ease of use, its integration into the existing user interface, and even whether certain design elements follow the brand’s design principles exactly but somehow still look “off.” This ensures that the new feature not only works as intended but also aligns with the user experience goals of the application.
Use-Case: Checking Login Functionality After a Security Update
In the wake of a security update, manual smoke testing is essential for ensuring that core functionalities remain intact. For instance, if a security update aims to enhance password encryption, manual testers can verify that users are still able to log in using their existing credentials.
Testers can check for specific error messages, verify that two-factor authentication is functioning, and even simulate various login scenarios to ensure that no new vulnerabilities have been introduced. Of course, this may also be possible with some automated testing tools, but it’s important to consider how much time you spend automating something in relation to how often it’s being done.
Automated Smoke Testing When you do get to a point where manual testing is limiting you, automated smoke testing can be a highly efficient way of running multiple tests in parallel, thereby reducing the time required for the testing phase. This is particularly advantageous in larger projects or in environments that prioritize speed, such as DevOps and continuous integration (CI) frameworks.
Automated tests can be easily scaled up to handle larger test suites, so they are ideal for projects that grow in complexity over time. Moreover, once the initial setup is complete, automated tests can be run with minimal human intervention, thereby reducing the likelihood of human error and ensuring consistent test results.
But as mentioned in the previous section, you should make sure that the time saved by implementing automated tests outweighs the effort required to configure them. Because of this, it’s crucial to use a tool that requires as little configuration as possible .
Use-Case: Continuous Integration in a DevOps Pipeline
Automated smoke testing tools can be integrated into a CI/CD pipeline to automatically identify bugs. For example, after every code merge, you can run a series of tests to ensure that the changes haven't introduced any regressions or broken existing functionalities.
The advantages of this automated approach are its speed and efficiency. Because these tests are automated, they can be run in parallel, thereby providing quick feedback to the development team. This is particularly beneficial in a DevOps setting where continuous integration and rapid deployments are the norm.
Use-Case: Validating Multiple Builds in Parallel
Automated smoke testing shines in scenarios where multiple builds need to be validated simultaneously. For instance, if a software company is working on different versions of an application for various platforms, automated tests can validate all these builds in parallel.
Tools like Meticulous further enhance this efficiency by focusing on catching UI bugs without requiring that development teams write or maintain UI tests. This drastically reduces time to market and allows development teams to concentrate on feature development rather than late-stage bug fixing.
Hybrid Smoke Testing Hybrid smoke testing offers the best of both manual testing and automated testing. It allows teams to leverage automated tests for repetitive, time-sensitive tasks, and manual tests for tasks that require human judgment and contextual understanding.
The versatility of hybrid testing is a significant advantage. It can be customized to fit a project’s specific needs and constraints. For instance, for a complex project involving multiple microservices, automated tests can validate the interactions between services, while manual tests can focus on end-to-end scenarios and user experience.
Use-Case: E-commerce Platforms
In the context of e-commerce platforms, a hybrid approach offers a balanced testing strategy. Automated tests can swiftly validate database interactions and server logic, ensuring that the backend is robust. For example, automated tests can quickly verify that a new payment gateway is integrated correctly with the existing system.
At the same time, manual tests can focus on the user experience and visual elements, which are critical for customer engagement and satisfaction. Testers can manually navigate through the checkout process to ensure that it is intuitive and that all visual elements, such as buttons and banners, display correctly.
Use-Case: Complex Applications Involving Multiple Microservices
For applications built on a microservices architecture, hybrid smoke testing is often the most effective approach. Automated tests can efficiently validate the interactions between different services. For instance, if a new microservice for user authentication is introduced, automated tests can ensure that it communicates correctly with the existing user database and other related services.
However, you may still want to get a human perspective on the user experience — in which case, testers can manually verify that a new user authentication microservice works seamlessly from the user's perspective.
A hybrid smoke test ensures that the login process is smooth and that all security protocols are followed.
Comparing Different Types of Smoke Testing Understanding the nuances between different types of smoke testing — manual, automated, and hybrid — will help you make informed decisions about your software testing strategy. This section serves as a decision-making guide, focusing on two key criteria: speed and accuracy.
Speed as a Decision Factor Imagine you're working against a tight deadline, and every minute counts. In a high-pressure scenario like this, the speed of your testing process is a critical factor. Let's explore how each type of smoke testing process fares when speed is of the essence.
Manual Testing: While manual testing allows for targeted, in-depth testing, it’s often time-consuming, especially for larger applications. Automated Testing (Meticulous): Automated tests, particularly those run by tools like Meticulous, are exceptionally fast, and multiple automated tests can be run at the same time. However, the initial setup time can be significant. Hybrid Testing: A hybrid approach offers a balance between speed and thoroughness: you can leverage automated tests for quick validations and manual tests for more complex scenarios. The challenge here is coordinating the two types, which can sometimes lead to delays. Accuracy as a Decision Factor Now picture a scenario where a minor bug could result in a significant security vulnerability. In a case like this, the accuracy of your testing process is non-negotiable. Here's how each testing method measures up in terms of accuracy.
Manual Testing: Manual testing offers a high level of accuracy for tests that require human judgment, but with repetitive tasks, human error will always be a factor. Manual testing is generally more time-consuming over the course of an application’s lifetime. Automated Testing: Automated testing is highly accurate for automatable tasks like catching UI bugs. However, it may miss issues that require human intuition or business context understanding. Hybrid Testing: A hybrid approach combines the accuracy of both automated and manual tests but requires careful management to avoid missing issues. Best Practices For Speed: If you're in a race against time, and quick feedback loops are your lifeline, then automated testing is your most reliable ally. For Accuracy: When the intricacies of human judgment come into play, and the stakes are high for even the smallest error, manual testing is the gold standard. For a Balance: For projects that require both speed and accuracy, a hybrid approach is often the most effective. It combines the rapidity of automated tests with the meticulous scrutiny of manual tests, offering a well-rounded testing strategy. Choosing the right type of smoke testing is a nuanced decision that should be based on the specific needs and constraints of your project. Whether you prioritize speed or accuracy, understanding the strengths and weaknesses of each type can guide you in optimizing your testing strategy.
When Should You Perform Smoke Testing? The timing of smoke testing can substantially impact its efficacy. This section explores the optimal timing for creating and executing smoke test cases. It’s segmented by the nature of the project: web development, mobile development, and DevOps environments. Although many more types exist, these three cover most scenarios that developers will experience.
Web Development In the fast-paced world of web development, smoke testing is an indispensable asset. It serves as an immediate validation checkpoint, confirming that new code integrations haven't adversely affected existing functionalities. This is especially vital in agile frameworks, where the ability to pivot quickly is a requirement.
Mobile Development For mobile application development, the timing of smoke testing is equally crucial. It's generally advisable to conduct smoke tests immediately after each new build, to quickly validate essential features such as navigation, login, and data retrieval. This proactive approach ensures that the application remains both functional and user-friendly.
DevOps Environments Within DevOps ecosystems, particularly those that emphasize continuous integration, the frequency of smoke testing should be synchronized with the rate of new code commits and integrations. This alignment guarantees that emerging issues are promptly identified and addressed, thereby preserving the integrity and fluidity of the development pipeline.
The timing for conducting smoke tests is not a universal standard; it depends on the specific project type and the development methodology being used. But figuring out the ideal timing for smoke testing is essential. Timing plays a significant role in optimizing the test's effectiveness and, consequently, contributes to the overall success of your project.
Smoke Testing vs. Other Types of Testing Understanding the nuanced differences between smoke testing and other forms of testing — namely sanity testing and regression testing — is pivotal for crafting an effective testing strategy. This section aims to explain these differences by offering a criteria-based comparison, so you can make informed decisions tailored to your project's unique requirements and challenges.
Objective: More Than Just Semantics Each type of testing serves a unique objective. Smoke testing serves as a gatekeeper, ensuring that a new build is stable and functional enough to merit more detailed testing. Sanity testing is akin to a surgical strike, focusing exclusively on specific functionalities or components that have recently been modified, while still not moving into full regression testing. Regression testing serves as a comprehensive safety net, ensuring that new code changes have not inadvertently affected existing functionalities.
Testing
Objective
Smoke Testing
Validates that new builds are stable and functional enough for further testing
Sanity Testing
Focuses on specific functionalities or components that have undergone recent changes
Regression Testing
Ensures that new code changes haven't disrupted existing functionalities
Scope: The Breadth of Examination Smoke testing is a broad sweep, designed to test essential functionalities and ensure an application's basic stability. Sanity testing narrows its focus to specific functionalities or components that have been altered. Regression testing is the most exhaustive; it scrutinizes all areas of an application to ensure that even untouched segments remain unaffected by new changes.
Testing
Scope
Smoke Testing
Broad, covering essential functionalities
Sanity Testing
Narrow, focusing on recently changed functionalities or components
Regression Testing
Comprehensive, scrutinizing all areas of the application
Timing: When to Test? Smoke testing is typically the first line of defense, performed immediately after a new build or major release. Sanity testing is more situational; it comes into play after specific changes or bug fixes. Regression testing is a constant companion throughout the development cycle, especially following any code changes or updates.
Testing
Timing
Smoke Testing
Immediately after a new build or major release
Sanity Testing
After specific changes or bug fixes
Regression Testing
Constantly, especially after any code changes or updates
Depth: A Matter of Complexity Smoke testing is quick and shallow, designed for early identification of high-level issues. Sanity testing, while also quick, delves deeper into specific functionalities to ensure that they are working as intended. Regression testing is the most thorough; it meticulously examines an application for unintended side effects due to new code changes.
Testing
Depth
Smoke Testing
Quick and shallow
Sanity Testing
Quick but deep into specific functionalities
Regression Testing
Thorough and meticulous
Automating Smoke Testing: A Smart Move In the ever-evolving landscape of software development, the need for efficient and reliable testing methods is high. Automated smoke testing has emerged as an indispensable tool, especially in environments that prioritize DevOps and continuous integration. But what sets it apart from manual methods?
A biased comparison of automated and manual testing can end up producing a table like this:
Criteria
Manual Testing
Automated Testing
Speed
Thorough but time-consuming.
Can run in parallel, significantly reducing the time needed for testing.
Accuracy
Susceptible to human error.
Offers a higher degree of reliability, ensuring that the tests are performed the same way every time.
Reliability
Limited by human fatigue and subject to inconsistency.
Can be run as frequently as needed without fatigue, ensuring consistent results. Crucial for continuous integration pipelines.
It’s important to note again that manual testing has its place in some organizations. However, with more and more tools becoming available with a focus on easing test automation, it’s becoming tougher and tougher to justify manual testing.
Also, automation in smoke testing is not just a technical upgrade; it's a business enabler.
Technical Advantages
Business Benefits
Speed: Tests can run in parallel, reducing the overall testing time.
Cost-Efficiency: Automated tests, once set up, can run without additional costs, making them cost-effective in the long run.
Reusability: Test scripts can be reused, ensuring consistency across different stages.
Faster Time-to-Market: With quicker testing cycles, products can be released to the market more rapidly.
Accuracy: Eliminates human error, increasing the test's reliability.
Meticulous as a Benchmark for Automated Smoke Testing Meticulous stands out as a popular tool for automated smoke testing, particularly for UI bug detection. It integrates seamlessly into CI/CD pipelines and offers unique features like replaying user traffic to catch UI bugs. Below is a sample configuration for integrating Meticulous into your CI/CD pipeline:
# Sample Configuration for Meticulous in a CI/CD pipeline
steps:
- name: Run Meticulous Smoke Tests
uses: meticulous-action@v1
with:
api_key: ${{ secrets.METICULOUS_API_KEY }}
The decision to automate smoke testing is not merely a technical one; it's a strategic choice that has far-reaching implications for both the quality and business aspects of a project. By understanding the comparative advantages and integrating tools like Meticulous, organizations can significantly enhance their testing efficiency and overall software quality.
Final Thoughts Smoke testing is a cornerstone of software quality assurance — it serves multiple roles, from gatekeeper to early-warning system. Its versatility is evident in its adaptability to various forms of testing — manual, automated, and hybrid — each with its unique set of advantages and limitations. Choosing a type of smoke test is a nuanced process. Your decision should be tailored to the specific requirements and constraints of your project.
The timing of smoke tests is another pivotal factor that varies depending on the nature of the project and the development methodology in use. Whether you’re engaged in web development, mobile application creation, or operating within a DevOps framework, the timing of these tests can significantly influence their effectiveness.
Moreover, understanding the differences between smoke testing and other types of testing — such as sanity and regression testing — is indispensable for crafting a comprehensive and effective testing strategy. Each serves a unique purpose and has its own scope and depth, and understanding these can guide you in optimizing your overall testing approach.
Automated smoke tests, especially in fast-paced DevOps and CI/CD environments, is not only a technical decision but also a strategic one. Tools like Meticulous offer a streamlined approach to automated testing, saving time and reducing human error — thereby acting as significant business enablers. The initial investment in setting up automated tests is quickly offset by the gains in speed, reliability, and overall efficiency.
Final Recommendations Assess Your Needs: Before implementing any form of smoke testing, conduct a thorough assessment of your project’s specific needs, constraints, and objectives. This will guide you in choosing the most appropriate form of testing — manual, automated, or hybrid. Prioritize Timing: Align the timing of your smoke tests with your development cycle. Immediate testing after new builds or major releases can provide quick feedback, enabling timely corrections. Choose the Right Tools: If you opt for automated or hybrid testing, invest in reliable and user-friendly tools that require minimal setup but offer maximum efficiency. This not only speeds up the testing process but also ensures more accurate results. Continual Review: Given the dynamic nature of software development, it's crucial to continually review and update your testing strategies to adapt to new challenges and requirements. Integrate into CI/CD: If you are operating in a DevOps environment, integrate your automated smoke tests into your CI/CD pipeline for seamless and automated quality checks. By implementing smoke testing in your software development processes, you not only ensure the quality and reliability of your product but also contribute to more efficient and effective development cycles. It is an investment in quality that pays rich dividends in both the short and long term.
Meticulous Meticulous creates and maintains an exhaustive suite of e2e ui tests with zero developer effort.
This quote from the CTO of Traba sums the product up best: "Meticulous has fundamentally changed the way we approach frontend testing in our web applications, fully eliminating the need to write any frontend tests. The software gives us confidence that every change will be completely regression tested, allowing us to ship more quickly with significantly fewer bugs in our code. The platform is easy to use and reduces the barrier to entry for backend-focused devs to contribute to our frontend codebase."
This post from our CTO (formerly lead of Palantir's main engineering group) sets out the context of why exhaustive testing can double engineering velocity. Learn more about the product here.
