Sanity Testing Vs. Smoke Testing: What Are The Differences?

Sanity Testing vs. Smoke Testing: Core Differences

Both smoke testing and sanity testing act as initial quality checks for new software builds. However, they differ in their scope, goals and execution. Here's a breakdown of sanity testing vs. smoke testing:

Focus:

• Smoke Testing:

  The focus is on verifying the absolute basics — Can users log in? Do core functionalities like data entry and saving work as expected? The goal is to identify any major roadblocks that would prevent further testing altogether.

• Sanity Testing:

  Sanity testing delves a bit deeper while still prioritising core functionalities. Its aim is to ensure not only basic functionality but also the stability of key user flows and core features after code changes. It is a more in-depth health check compared to the basic smoke test.

Scope:

• Smoke Testing:

  Smoke testing has a narrower scope. It typically involves a small set of pre-defined tests designed to catch showstopper bugs. The idea is to quickly identify major issues before investing time and resources in further testing.

• Sanity Testing: 

  Sanity testing has a slightly broader scope than smoke testing. It involves additional checks beyond the core functionalities, ensuring basic user journeys and interactions function as intended. This provides a more complete picture of the build's stability.

Execution:

• Smoke Testing: 

  Smoke testing is designed for speed and efficiency. It involves testers or developers running a pre-defined set of automated tests to quickly assess the build's basic functionality.

• Sanity Testing: 

  Sanity testing is more flexible in its execution. While some level of automation might be employed, testers often design test cases based on their knowledge of the recent code changes and the application's core functionalities.

Smoke testing acts as the initial hurdle, ensuring the build is minimally functional before further testing commences. Sanity testing builds upon this foundation by providing a more in-depth check of core functionalities and user flows.

Development teams can use both techniques for a more efficient and effective testing strategy, ultimately leading to the delivery of high-quality software by understanding the core differences in sanity testing vs. smoke testing.

Smoke and Sanity Testing

Both smoke and sanity testing play important roles in software development, but their applications to specific things differ. Here's a closer look at examples illustrating the key distinctions between them:

1. Smoke Testing Example:

Imagine a new build for a social media application is released. Here's how smoke testing might be implemented:

• Test Case 1:

  
  

  User Login: 

  The smoke test would verify if users can log in successfully using their existing credentials. A failed login could indicate issues with user authentication or database connectivity, thus preventing further testing.

• Test Case 2:

  
  

  Creating a New Post: The main function of the application is creating new posts. The smoke test would check if users can successfully create a new post with text and an image. Failure here could signify problems with data entry, content storage or image upload functionality which ultimately requires further investigation before proceeding.

• Test Case 3:

  
  

  Basic Navigation: Smoke testing would involve verifying if users can navigate through the main sections of the application, such as the home feed, profile page and messaging section. Inability to navigate smoothly could indicate issues with the user interface or underlying routing mechanisms.

These smoke tests are designed to be quick and automated whenever possible. If any of these basic functionalities fail, the build would be considered "unsmokable" and returned to developers for bug fixing before further testing commences.

2. Sanity Testing Example:

Let's consider the same social media application after a code change that has focused on improving the newsfeed algorithm. Here's how sanity testing might be applied:

• Test Case 1:

• Login and Feed Display: Sanity testing would include a basic login check, similar to smoke testing. Then, it would verify if the user's newsfeed displays content after logging in, thus ensuring core functionality is not broken.

• Test Case 2:

  
  

  Newsfeed Content Relevance: Since the code change focused on the newsfeed algorithm, sanity testing would delve deeper. It usually would involve checking if the content displayed in the newsfeed is somewhat relevant to the user's interests or past interactions (a basic test of the new algorithm). This ensures the main functionality of the newsfeed has not been entirely broken by the code changes.

• Test Case 3:

  
  

  Basic User Interactions: Sanity testing might involve checking if users can still perform basic actions like liking posts, commenting and sharing content within the newsfeed. This ensures that core user interactions have not been unintentionally impacted by the algorithm update.

While not as comprehensive as full regression testing, sanity testing provides a more in-depth check compared to smoke testing. It focuses on core functionalities and user flows likely to be affected by the recent code changes, allowing for early detection of regressions or unintended side effects.

Advantages of Smoke Testing and Sanity Testing

Advantages of Smoke Testing:

• Early Bug Detection: 

  Smoke testing is the first line of defense, identifying showstopper bugs early in the software development cycle. This prevents wasted time and resources on further testing an unstable build. This also helps save associated costs. If users cannot even log in, further testing becomes irrelevant.

• Improved Efficiency: 

  Smoke testing prioritizes a streamlined approach. It typically involves a pre-defined set of automated tests designed to assess basic functionalities quickly. This allows for rapid feedback on a build's stability, enabling developers to address issues promptly and testers to focus their efforts on more in-depth testing procedures for builds that pass the smoke test.

• Reduced Risk of Regression: 

  Even though it is not a substitute for regression testing, smoke testing often includes basic checks for functionalities to ensure they have not regressed (reintroduced bugs) due to recent code changes. This helps catch regressions early, preventing them from slipping through the cracks and causing problems later in the development process.

Advantages of Sanity Testing:

• Deeper Focus on Core Functionalities: 

  While smoke testing verifies the absolute basics, sanity testing delves a bit deeper. It ensures not only basic functionality but also the stability of key user flows and core features after code changes. This provides a more complete picture of the build's health, identifying issues that might have slipped through smoke testing.

• Faster Development Cycles: 

  By identifying critical issues early through both smoke and sanity testing, development teams can address them promptly and prevent wasted effort on testing unstable builds. This streamlined approach ultimately contributes to faster development cycles, allowing teams to iterate, fix issues and deliver software features at a more rapid pace.

• Reduced Release Risks: 

  Software releases riddled with bugs can damage user experience and brand reputation. Smoke and sanity testing work together to minimize the risk of major issues reaching production. These testing techniques provide a vital layer of confidence before deploying software to a wider audience by ensuring core functionalities and basic user flows remain operational after code changes.

Disadvantages of Smoke Testing and Sanity Testing

Disadvantages of Smoke Testing:

• Limited Scope: 

  Smoke testing focuses on verifying the absolute essentials. This is its strength for rapid feedback, but also its weakness. Complex functionalities, edge cases and non-core features might be overlooked, thereby leading to regressions or bugs in these areas remaining undetected.

• False Sense of Security: 

  A successful smoke test does not guarantee a bug-free application. Its limited scope can create a false sense of security, leading to overlooking issues that might surface during later testing stages. Testers and developers tend to have a sense of accomplishment after a successful smoke test, neglecting the need for thorough follow-up testing.

• Reliance on Pre-defined Tests: 

  Smoke testing often relies on pre-defined sets of automated tests. These tests usually do not adapt well to changes in the user interface or application behavior, missing newly introduced bugs. Maintaining a set of smoke tests can be time-consuming and require ongoing updates as the software evolves.

Disadvantages of Sanity Testing:

• Subjectivity and Bias: 

  Sanity testing often involves testers designing test cases on the fly based on their knowledge of the application and recent code changes. This flexibility can be advantageous, but it also introduces subjectivity and bias. Testers prioritize functionalities they are more familiar with, overlooking less prominent areas or edge cases.

• Limited Regression Coverage: 

  Sanity testing is not a replacement for regression testing. Its focus on core functions ensures stability after code changes, but it does not guarantee the regression of functionalities that are not specifically tested. Additional regression testing procedures are imperative to ensure the overall quality and stability of the software.

• Documentation Overhead: 

  Maintaining clear documentation of functionalities tested during sanity checks is necessary even though it is not as extensive as formal test scripts. This ensures consistency and facilitates knowledge sharing among testers, but it adds an overhead compared to entirely unscripted testing approaches. Finding the right balance between documentation and efficiency is key.

Conclusion

Smoke testing and sanity testing serve distinct yet complementary roles in the software development process. While smoke testing acts as a swift gatekeeper, sanity testing delves deeper into core functionalities.

Understanding these differences allows teams to use both techniques for a more efficient and effective testing strategy.