Types of Software Testing

# CHAPTER 3

Types of Software Testing #

1. Introduction #

2. Learning Objectives #

• Distinguish between Functional and Non-Functional Testing.

• Understand the critical role of Regression Testing in agile environments.

• Differentiate between Smoke Testing and Sanity Testing.

• Identify when to apply White-Box vs. Black-Box testing methodologies.

• Categorize tests based on the SDLC phase (Unit, Integration, System, UAT).

3. The Big Divide: Functional vs. Non-Functional #

• Functional Testing (What it does): Validates the software against business requirements. If the user clicks "Add to Cart", does the item appear in the cart? This includes Unit testing, Integration testing, and UI testing.

• Non-Functional Testing (How well it does it): Validates the performance, usability, and security of the application. The cart works, but does it take 15 seconds to load? Does it crash under heavy load? Can a hacker manipulate the cart price?

4. Regression Testing #

• Regression Testing: Re-running previously executed test cases on a new build to ensure that recent code changes have not introduced new bugs into existing, working functionality.

• *Note:* Because this requires running hundreds of tests repeatedly, Regression Testing is the primary target for Automation.

5. Smoke Testing vs. Sanity Testing #

• Smoke Testing (Build Verification): A shallow, broad test. Does the app start? Can I log in? Can I access the main dashboard? If the app crashes on the login screen, QA rejects the build immediately without further testing. It checks the *critical path*.

• Sanity Testing: A deep, narrow test. If a developer specifically fixed the "PDF Export" feature, QA performs a Sanity Test *only* on the PDF export feature to verify the bug is actually fixed before running the full suite.

6. Black-Box vs. White-Box Testing #

• Black-Box Testing: The tester knows nothing about the internal code. They test the application entirely through the User Interface or API inputs/outputs. (Focus: User Perspective).

• White-Box Testing: The tester has access to the source code and database architecture. They write tests based on the internal logic and code paths. (Focus: Developer/Architecture Perspective, mostly Unit Testing).

7. Visual Learning: Testing Hierarchy #

[ SOFTWARE TESTING ]
       |
       +--- [ Functional ]
       |       |-- Unit Testing
       |       |-- Integration Testing
       |       |-- System Testing
       |       |-- User Acceptance Testing (UAT)
       |
       +--- [ Non-Functional ]
               |-- Performance / Load Testing
               |-- Security Testing
               |-- Usability Testing

8. Best Practices #

• Automate Regression: Manual regression testing is soul-crushing and prone to human error. If a test must be run every single time the code changes, it must be automated using tools like Selenium or Cypress.

9. Common Mistakes #

• Ignoring Non-Functional Testing: Many teams launch products that pass all Functional tests, only to have the product crash on launch day because they never performed Load Testing. "It works on my machine" does not mean it works for 10,000 concurrent users.

10. Mini Project: Categorize the Test #

1. 1. Verifying that a password must contain a special character. *(Answer: Functional)*

1. 2. Verifying that the login page loads in under 2 seconds. *(Answer: Non-Functional - Performance)*

1. 3. Verifying that a user cannot access the database via SQL Injection. *(Answer: Non-Functional - Security)*

1. 4. Verifying that the "Forgot Password" email contains a valid reset link. *(Answer: Functional)*

11. Practice Exercises #

1. 1. Explain the "Smoke Test". Why is it called a "Build Verification Test", and why does QA run it before any other test?

1. 2. Differentiate between Black-Box and White-Box testing methodologies.

12. MCQs with Answers #

13. Interview Questions #

• Q: Explain the difference between Smoke Testing and Sanity Testing. When would you execute a Sanity Test instead of a Smoke Test?

• Q: "We have 100% functional test coverage, so our application is ready for production." Challenge this statement. What critical testing types are being ignored?

• Q: Why is Regression Testing the ideal candidate for Test Automation? What happens if a team relies entirely on manual Regression Testing?

14. FAQs #

15. Summary #

16. Next Chapter Recommendation #