Smoke Testing vs Sanity Testing: All You Need To Know

Software testing is an integral part of the software development life cycle, ensuring that the final product meets the desired quality and functionality standards. Among the various testing strategies, Smoke Testing and Sanity Testing are two crucial techniques that play a pivotal role in ensuring the reliability and stability of software applications.

Let's dive into comparison of Smoke Testing vs Sanity Testing, best practices, and tools you can use.

Importance of Sanity Testing and Smoke Testing

Before diving into the specifics of Smoke and Sanity Testing, it's essential to understand their significance in the context of software quality assurance.

Sanity and Smoke Testing serve as the first line of defense in identifying critical defects early in the development process. By doing so, they help in saving time, effort, and resources, ultimately contributing to the successful delivery of high-quality software products.

What is Smoke Testing?

Smoke Testing, also known as Build Verification Testing (BVT), is a preliminary testing phase designed to check whether the most critical functions of a software application are working correctly.

Its primary objectives are to ensure that the software build is stable enough for further testing and to identify show-stopper defects that would prevent further testing.

Smoke testing serves as the inaugural phase in the software development life cycle, executed by developers to validate two critical aspects: the successful compilation of code modules and the proper functioning of the software's core features. The passage through smoke testing acts as a prerequisite for conducting any subsequent levels of testing.

Advantages of Smoke Testing:

• Early Defect Detection: Smoke tests catch critical issues at the outset, preventing them from propagating through the development cycle.
• Time and Cost Savings: Identifying major issues early reduces rework and development costs.
• Enhanced Collaboration: Teams can collaborate effectively when they know the basic functionalities are stable.

Disadvantages of Smoke Testing:

• Limited Coverage: Smoke tests only cover the most critical paths, leaving other functionalities untested.
• Potential False Negatives: Occasionally, minor issues might be overlooked, leading to false negatives.

Types of Smoke Testing

• Manual Smoke Testing: Manual smoke testing involves testing teams that meticulously perform the verification process. This manual approach encompasses the creation and maintenance of test cases, ensuring that they remain relevant and up-to-date. Additionally, test scripts, whether for new functionalities or existing features, are crafted manually by these testers, who use their expertise to execute the tests.

• Automated Smoke Testing: In automated smoke testing, specialized software tools take center stage to streamline the testing procedure. These smoke testing tools inject efficiency into the process by autonomously generating and executing relevant tests. This automation not only accelerates testing but also reduces the potential for human error, resulting in more precise assessments.

• Hybrid Smoke Testing: Hybrid smoke testing represents a fusion of manual and automated testing methodologies. Testers initially invest their skills in the creation of test cases, meticulously shaping the testing strategy. Subsequently, automation tools come into play, automating the predefined tests using these test cases. This combination harnesses the strengths of both manual and automated testing, providing the flexibility of human judgment and the efficiency of automation.

How to Run a Smoke Test?

Following the delivery of a new application build by the developers, Quality Assurance (QA) testers initiate the smoke testing phase. This pivotal assessment is conducted either manually by QA testers or automatically by employing pre-existing test scripts.

When the smoke test successfully verifies the integrity of the software, it advances to integration within the established QA and staging environment. Subsequently, the software build proceeds to endure a battery of more exhaustive evaluations, including unit and integration tests.

If the smoke test fails, it signifies the detection of a significant flaw that brings all subsequent testing activities to an immediate halt. In such cases, the QA teams promptly request developers to supply a rectified build to address the identified issues.

Smoke Test Case Scenario

Imagine you are tasked with performing Smoke Testing on an e-commerce website to ensure its basic functionality is working correctly after a new build has been deployed. The objective of this Smoke Test is to verify that critical functionalities of the e-commerce website are functioning as expected, allowing users to perform essential actions.

1. Website Loading:

   • Open a web browser and navigate to the e-commerce website.
   • Verify that the website loads without any errors or long delays.
   • Check for any browser console errors.

2. User Registration:

   • Click on the "Sign Up" or "Register" link.
   • Fill in the registration form with valid information.
   • Submit the form and verify that the user is successfully registered.

3. User Login:

   • Go to the website's login page.
   • Enter valid login credentials (username and password).
   • Click the "Login" button and ensure the user is logged in.

4. Product Search:

   • Use the search bar to look for a product (e.g., "smartphone").
   • Verify that search results are displayed correctly.
   • Click on a product and check if the product details page loads.

5. Add to Cart:

   • Select a product and click the "Add to Cart" button.
   • Confirm that the selected product is added to the shopping cart.
   • Verify the cart total is updated.

6. Checkout Process:

   • Proceed to the checkout process.
   • Enter valid shipping and payment information.
   • Confirm that the order is processed without errors.
   • Check for the order confirmation page.

If all the test cases pass without any critical errors, the Smoke Test is considered successful. However, if any of the essential functionalities fail (e.g., website doesn't load, registration fails, or login is not working), the Smoke Test is considered unsuccessful, and further testing is halted until the issues are resolved.

This example ensures that the core features of the e-commerce website, such as user registration, login, and basic product functionality, are functioning as expected before proceeding with more extensive testing phases.

What is Sanity Testing?

Sanity testing is a subset of regression testing. It is a level of testing that focuses on ensuring that specific areas of the software build are functioning correctly after modifications or enhancements have been made.

In contrast to smoke testing, which is done at the initial stages of the software development life cycle, sanity testing is performed once the software build has undergone rigorous testing. Smoke testing is done to ascertain the basic stability of the build, while sanity testing delves deeper into in-depth testing of particular functionalities.

In summary, sanity testing is a critical type of testing that occurs later in the software development life cycle. It performs in-depth checks on specific functionalities and is distinct from smoke testing, which focuses on the build's basic stability and is performed earlier in the development process.

Advantages & Disadvantages of Sanity Testing

Advantages of Sanity Testing:

• Focused Testing: Sanity tests concentrate on specific areas, making them efficient and targeted.
• Quick Validation: They swiftly confirm that specific issues have been addressed.

Disadvantages of Sanity Testing:

• Limited Scope: It may overlook potential issues in untested areas.
• Not Comprehensive: It doesn't replace full-fledged regression testing.

Process with Example

Imagine you are a QA tester responsible for conducting Sanity Testing on a mobile weather application after a new update has been implemented. The objective of this Sanity Test is to verify that the critical functionalities of the weather application are working as expected after the recent update, ensuring that users can access essential weather information.

1. Application Launch:

   • Launch the weather application.
   • Verify that the application opens without any errors or crashes.

2. Location-Based Weather:

   • Allow the application to access your current location.
   • Confirm that the app displays the weather information for your location accurately.

3. Search Functionality:

   • Use the search feature to look up weather information for a different location (e.g., a different city or zip code).
   • Ensure that the application correctly retrieves and displays weather data for the searched location.

4. Forecast Accuracy:

   • Check the daily and hourly weather forecasts for your location.
   • Compare the forecasted data with a trusted external source (e.g., a trusted weather website) to verify accuracy.

5. Notification Settings:

   • Access the notification settings within the app.
   • Verify that you can customize and enable weather-related notifications (e.g., severe weather alerts).

6. Maps and Radar:

   • Open the weather map or radar feature (if applicable).
   • Confirm that the maps or radar images load and display real-time weather conditions.

If all the test cases pass without any critical issues (e.g., application crashes, inaccurate weather data), the Sanity Test is considered successful. It indicates that the essential features of the weather application are working properly after the update. However, if any critical issues are identified, the Sanity Test is considered unsuccessful, and further testing is halted until the issues are resolved.

When to Perform Sanity Testing?

The timing of sanity testing is crucial, as it serves to quickly verify that specific areas of the software are functioning as expected. Here are common scenarios and points in time when sanity testing should be conducted:

• After Code Fixes or Enhancements: When developers have made changes to the code, such as bug fixes or enhancements, sanity testing is performed to ensure that the modifications did not introduce new issues or disrupt existing functionality. It helps validate that the targeted changes have been successfully implemented.

• After Integration Testing: Once various modules or components of the software have been integrated, sanity testing is carried out to verify that the integrated parts work harmoniously together. It ensures that the core functionalities are intact post-integration.

• After Regression Testing: In regression testing, comprehensive tests are executed to identify any unintended side effects of code changes. After regression testing, sanity testing can be performed to confirm that the most critical features remain unaffected and that the software still meets its basic requirements.

• Before or After Build Deployment: In the context of continuous integration and continuous deployment (CI/CD) pipelines, sanity testing may be conducted both before and after a new build is deployed. Before deployment, it ensures that the build is stable enough for deployment. After deployment, it verifies that the software operates correctly in the production or staging environment.

Sanity Testing vs Smoke Testing

The key difference between smoke testing and sanity testing lies in their scope and objectives. Smoke testing is broader and is used to determine if the software build is suitable for further testing, whereas sanity testing is more targeted and verifies specific functionalities.

Sanity testing is also a subset of acceptance testing, ensuring that the software meets the acceptance criteria for specific features or enhancements. It is often used to save time and resources by avoiding exhaustive testing of the entire software build.

Automation tests can be employed for both smoke and sanity testing, depending on the testing team's preference and project requirements. However, manual testing is also commonly used for sanity testing, especially when in-depth examination is necessary.

Let's compare Smoke and Sanity Testing in a table for a quick reference:

Criteria	Smoke Testing	Sanity Testing
Objective	Verify overall software stability.	Confirm specific changes or fixes.
Scope	Broad, covering critical functionalities.	Narrow, focusing on recent changes.
Frequency	After every build or significant change.	After minor changes or bug fixes.
Automation	Often automated for critical paths.	Partial automation for efficiency.
Coverage	Limited but ensures core functionality.	Targeted, checks specific areas.
Advantages	Early defect detection, cost savings.	Focused and efficient testing.
Disadvantages	Limited coverage, potential false negatives.	May miss issues in untested areas.

Best Practices for Sanity and Smoke Testing

Tips for Effective Testing

1. Clear Test Strategy Define clear objectives and criteria for both Smoke and Sanity Testing.

2. Automation Selection Choose the right automation tools and frameworks based on project requirements.

3. Regular Updates Keep test cases up-to-date to reflect changes in the application.

4. Documentation Maintain comprehensive test documentation for traceability.

Pitfalls to Avoid

1. Skipping Testing Never skip Smoke or Sanity Testing, as it can lead to critical issues in the final product.

2. Over-Automation Don't automate everything; focus on critical areas for efficiency.

3. Ignoring Regression Testing Remember that Sanity Testing is not a replacement for full regression testing.

Tools for Sanity and Smoke Testing

BugBug

BugBug is one of the most user-friendly test automation tools in the market. It offers a completely codeless interface, which can be used without extensive programming background. Its Freemium plan features unlimited tests, unlimited local test runs, unlimited users, and 7-day test history.

Selenium

Selenium is a widely popular open-source automation testing framework primarily used for web applications. It allows you to create automated test scripts in various programming languages (e.g., Java, Python) and supports multiple web browsers. Selenium is a powerful choice for automating repetitive smoke tests for web-based applications.

Jenkins

Jenkins is a popular open-source automation server that can be used to automate various stages of the software development and testing process, including Smoke Testing. You can configure Jenkins to trigger smoke tests automatically whenever a new build is deployed, providing quick feedback on the build's stability.

TestNG

TestNG is a testing framework for Java that is often used for both unit testing and automated testing, including Smoke Testing. It provides features like test parallelization, grouping, and reporting, making it suitable for managing and executing smoke test suites.

Cucumber

Cucumber is a behavior-driven development (BDD) tool that allows you to write test cases in plain language using the Gherkin syntax. It's well-suited for creating human-readable test scenarios, and it can be integrated with automation frameworks like Selenium for Smoke Testing.

Travis CI

Travis CI is a cloud-based continuous integration service that can automate the build and test process. It's particularly useful for projects hosted on GitHub. You can set up Travis CI to run your smoke tests whenever there are changes to your codebase.

Postman

Postman is a popular tool for testing APIs. If your application relies heavily on APIs, you can use Postman to create automated API Smoke Tests to ensure that critical API endpoints are functioning correctly.

Definition and Objectives

Custom Scripts

In some cases, sanity testing may involve custom scripts or test harnesses developed in-house to automate specific functionalities. These scripts can be tailored to the unique requirements of the application.

The choice of tool for sanity testing depends on factors such as the nature of the application, the technology stack, the testing team's expertise, and the specific functionalities that need to be validated. Each tool has its strengths and is suited to different testing scenarios, so selecting the right tool is essential for effective sanity testing.

Conclusion

In conclusion, Smoke and Sanity Testing are invaluable components of a robust software quality assurance process. They act as gatekeepers, ensuring that software builds meet the minimum criteria for stability and correctness.

While Smoke Testing provides a broad overview of critical functionality, Sanity Testing focuses on specific changes or bug fixes. Automation tools and frameworks enhance the efficiency of these testing methods, but manual oversight remains essential for certain scenarios.

By implementing these testing strategies, development teams can catch defects early, reduce development costs, and deliver high-quality software products that meet customer expectations.

Happy (automated) testing!

FAQ

Is smoke testing done before sanity testing?

Yes, smoke testing is typically done before sanity testing. Smoke testing serves as a preliminary test to verify the basic functionality and stability of a software build, ensuring that it is suitable for further testing. If the software build passes the smoke test, sanity testing, which focuses on specific functionalities, can be performed.

What is an example of a smoke test?

An example of a smoke test for a web application could be verifying that the application's homepage loads successfully, checking if the login functionality works, and ensuring that key navigation features, such as moving between pages, are functional.

What is sanity testing and example?

Sanity testing is a focused and narrowly scoped form of regression testing that checks specific areas of an application after changes or enhancements. For example, after a bug fix related to user authentication in a software application, sanity testing would include verifying login functionality, checking password recovery, and confirming user roles and permissions.

What is QA sanity testing?

QA sanity testing is a testing process conducted by quality assurance (QA) professionals to ensure that specific areas of an application remain functional and unaffected after code changes, enhancements, or bug fixes. It is a subset of regression testing and aims to quickly validate critical functionalities.

Can QA perform smoke testing manually?

Yes, QA professionals can perform smoke testing manually by executing predefined test cases or scenarios that verify basic functionality. Manual smoke testing involves human interaction with the software to validate its stability and core features.

Who performs sanity testing?

Sanity testing is typically performed by QA testers or quality assurance professionals. Their role is to verify specific functionalities or areas of the software after changes have been made to ensure that they continue to work as expected.

Who performs smoke testing?

Smoke testing can be performed by QA testers, developers, or automated scripts, depending on the testing strategy and the stage of development. It is often an initial test to ensure the build's basic stability.

Do we write test cases for smoke testing?

Yes, test cases are written for smoke testing. These test cases are designed to cover the most critical and fundamental functionalities of the software, ensuring that they can be quickly and effectively verified.

What comes after sanity testing?

After sanity testing, the software typically proceeds to more comprehensive testing phases, such as regression testing, functional testing, integration testing, and user acceptance testing (UAT), depending on the project's requirements and testing strategy.

Is sanity testing white box testing?

No, sanity testing is generally not considered white box testing. It is a form of black box testing that focuses on the application's functionality from the user's perspective rather than examining the internal code structure.

Is smoke testing part of UAT? Smoke testing is not part of user acceptance testing (UAT). Smoke testing is performed earlier in the testing process to ensure basic stability, while UAT is conducted by end-users or stakeholders to validate that the software meets their specific requirements and is ready for production use.

Can we automate smoke testing?

Yes, smoke testing can be automated. Automation tools and scripts can be used to quickly verify the basic functionality of a software build, making it efficient and repeatable. Automated smoke testing is especially beneficial for continuous integration and continuous deployment (CI/CD) pipelines.