How to Write Effective Test Cases – Real-time Examples Included

In this post, I’ll guide you step-by-step on how to write clear, reusable, and practical test cases, along with real-time examples and templates.

---

📌 What Is a Test Case?

A test case is a set of actions executed to verify a particular feature or functionality of your software application. Each test case includes test steps, expected results, inputs, and actual results.

🎯 Why Are Effective Test Cases Important?

• ✅ Ensure coverage of all scenarios
• ✅ Help developers understand the issue clearly
• ✅ Speed up test execution and defect tracking
• ✅ Make regression testing easier
• ✅ Useful for training and future references

🧩 Components of a Good Test Case

Field	Description
Test Case ID	Unique identifier (e.g., TC_UI_001)
Test Case Title	Short, meaningful description
Pre-Conditions	Conditions that must be met before execution
Test Steps	Clear steps to perform the test
Test Data	Input data needed for the test
Expected Result	What should happen after execution
Actual Result	What actually happened
Status	Pass / Fail / In Progress
Remarks	Notes, screenshots, or references

📘 Real-Time Example: Login Functionality

Requirement: The User should be able to log in using a valid email and password. If credentials are invalid, show an error message.

✅ Test Case 1: Valid Login

• Test Case ID: TC_LOGIN_001
• Title: Login with valid credentials
• Pre-Condition: User already has a registered account
• Test Steps:
  1. Go to the Login page
  2. Enter a valid email
  3. Enter a valid password
  4. Click Login
• Test Data: Email: user@example.com | Password: 123456
• Expected Result: User should be redirected to the Dashboard
• Actual Result: (To be filled after testing)
• Status: Pass/Fail
• Remarks: Screenshot attached if it failed

❌ Test Case 2: Invalid Password

• Test Case ID: TC_LOGIN_002
• Title: Login with invalid password
• Pre-Condition: User already has a registered account
• Test Steps:
  1. Go to the Login page
  2. Enter a valid email
  3. Enter the wrong password
  4. Click Login
• Test Data: Email: user@example.com | Password: wrong123
• Expected Result: Error message: "Invalid credentials"
• Actual Result: (To be filled after testing)
• Status: Pass/Fail

🚫 Test Case 3: Blank Fields

• Test Case ID: TC_LOGIN_003
• Title: Login with blank email and password
• Pre-Condition: None
• Test Steps:
  1. Go to the Login page
  2. Leave email & password blank
  3. Click Login
• Expected Result: Validation error messages displayed
• Actual Result: (To be filled after testing)
• Status: Pass/Fail

✅ Tips for Writing Better Test Cases

• ✅ Keep test case steps simple and clear
• ✅ Use consistent naming conventions
• ✅ Focus on one functionality per test case
• ✅ Include positive & negative test scenarios
• ✅ Update your test cases regularly
• ✅ Add screenshots or references if needed
• ✅ Avoid repetition – use shared preconditions

🧪 Additional Scenarios to Cover (Same Login Module)

• Log in with an unregistered email
• Log in with SQL injection attempt
• The login button is disabled without input
• Login page responsiveness on mobile
• Session timeout after login

👋 Hi, I'm Suriya — QA Engineer with 4+ years of experience in manual, API & automation testing.

📬 Contact Me | LinkedIn | GitHub

📌 Follow for: Real-Time Test Cases, Bug Reports, Selenium Frameworks.

How to Use ChatGPT for Software Testing Effectively

 1. Test Case Generation

 Generate test cases based on requirements or user stories.
 Prompt: "Generate test cases for a login page with email and password validation."

2. Test Data Creation

 Generate sample test data for manual or automated testing.
 Prompt: "Provide sample test data for user registration with fields: Name, Email, Phone, and Password."

3. Automation Script Assistance

 Generate or debug Selenium, Python, or Java automation scripts.
 Prompt: "Write a Selenium script in Java to automate login functionality."

4. API Testing with Postman

 Generate API test cases and validate responses.
 Prompt: "Create test cases for a REST API with endpoints: /users, /users/{id}, and /login."
 

5. Bug Reporting Assistance

 Format bug reports with steps to reproduce, expected results, and actual results.
 Prompt: "Write a bug report for a login issue where an incorrect password does not show an error message."

6. Performance Testing Support

 Guide on JMeter or LoadRunner for performance testing.
 Prompt: "How to create a JMeter test plan for a login API?"

7. SQL Query Assistance

 Write SQL queries to fetch test data or validate results.
 Prompt: "Write an SQL query to find all users who registered in the last 30 days."

8. CI/CD Pipeline Testing

 Help with GitHub Actions, Jenkins, or other CI/CD tools.
 Prompt: "How to write a GitHub Actions YAML file for running Selenium tests?"

9. Security Testing Help

 Provide security testing guidelines and common vulnerabilities.
 Prompt: "What are common OWASP security risks for a web application?"

10. Debugging Assistance

 Identify and fix issues in test scripts or applications.
 Prompt: "Why is my Selenium script failing to locate an element using XPath?"

👋 Hi, I'm Suriya — QA Engineer with 4+ years of experience in manual, API & automation testing.

📬 Contact Me | LinkedIn | GitHub

📌 Follow for: Real-Time Test Cases, Bug Reports, Selenium Frameworks.

Top 25 Mobile Testing Interview Questions and Answers (2025 Updated)

Top 25 Mobile Testing Interview Questions and Answers (2025 Updated)

Mobile app testing is one of the fastest-growing areas in the QA industry. With Android and iOS dominating the market, companies are looking for testers who understand mobile testing concepts, tools like Appium, and real device challenges. In this blog post, we’ll cover the most frequently asked mobile testing interview questions, suitable for both freshers and experienced testers.

📱 What Is Mobile Testing?

Mobile testing involves testing applications built for mobile devices (smartphones, tablets) to ensure proper functionality, usability, and performance. It includes native, hybrid, and web apps running on different operating systems like Android and iOS.

---

🔝 Top 25 Mobile Testing Interview Questions and Answers

1. What is mobile application testing?
   Testing of mobile apps to ensure their quality on real devices or emulators under different networks, screen sizes, and OS versions.
2. What are the types of mobile apps?
   Native Apps, Web Apps, Hybrid Apps
3. What is the difference between mobile app testing and web testing?
   Mobile app testing considers factors like battery usage, memory, gesture handling, network switching, etc., which are not major concerns in desktop web testing.
4. What are the types of mobile testing?
   Functional Testing, UI Testing, Compatibility Testing, Performance Testing, Security Testing, Interruption Testing, Installation Testing
5. What is Appium?
   Appium is an open-source automation tool for testing native, hybrid, and mobile web apps using the WebDriver protocol.
6. Can Appium be used for both Android and iOS?
   Yes, Appium supports automation on both Android and iOS platforms.
7. What is the difference between simulator and emulator?
   Simulator mimics iOS behavior; Emulator mimics Android. Simulators don’t replicate hardware, while emulators do.
8. What tools are used for mobile testing?
   Appium, Espresso, XCUITest, Robotium, Kobiton, BrowserStack, Firebase Test Lab
9. What is mobile device fragmentation?
   The challenge of testing across different OS versions, screen sizes, and hardware types.
10. How do you perform compatibility testing?
    Test the app on multiple devices, OS versions, resolutions, and hardware configurations.
11. What is interruption testing?
    Testing how the app behaves when interrupted by calls, messages, notifications, or low battery alerts.
12. What are the key challenges in mobile testing?
    Device fragmentation, network conditions, OS upgrades, touch gestures, battery usage, screen orientation.
13. How do you test an app in different network conditions?
    Use network simulation tools or manually switch between WiFi, 2G/3G/4G/5G, airplane mode, and no network.
14. What is gesture testing?
    Testing app response to user gestures like tap, swipe, pinch, zoom, drag, etc.
15. What are the common test cases for mobile apps?
    Installation, login/logout, screen orientation, push notifications, in-app purchases, data sync, etc.
16. What is responsive testing?
    Ensuring UI elements adjust properly to different screen sizes and orientations.
17. How do you handle app crashes during testing?
    Capture crash logs, report with steps to reproduce, attach screenshots or device logs using tools like Logcat or Xcode logs.
18. What is the difference between native and hybrid apps?
    Native: Built for a specific platform (e.g. Swift for iOS); Hybrid: Single codebase wrapped in WebView (e.g. Ionic, Cordova).
19. Which is better for testing – real device or emulator?
    Real devices are better for performance, battery, gestures. Emulators are faster for basic functional tests.
20. What is test automation strategy for mobile apps?
    Choose tools like Appium, plan parallel testing, use cloud devices (BrowserStack), and maintain modular test scripts.
21. How do you test push notifications?
    Trigger test notifications from backend/API and verify delivery, UI response, and app state (foreground/background).
22. What is deep linking in mobile apps?
    Deep linking allows users to navigate to a specific part of the app from external links.
23. What is mobile security testing?
    Validating app against data leakage, insecure storage, API security, and unauthorized access.
24. What is monkey testing in mobile?
    Random tapping, swiping, shaking, or performing unexpected actions to find crashes or bugs.
25. How do you perform localization testing?
    Test the app in different languages, regions, and timezones to verify proper translation and formatting.

---

📄 Bonus: Sample Manual Test Cases for a Mobile Login Page

Test Case ID	Scenario	Expected Result
TC001	Valid username and password	User should be logged in
TC002	Invalid password	Error message shown
TC003	Switch orientation during login	Form should remain stable
TC004	Interruption by call	App should resume login screen

---

🧠 Interview Tips

• Learn both Android and iOS differences
• Practice Appium scripts for login, swipe, drag-drop
• Focus on real device testing scenarios

👋 Hi, I'm Suriya — QA Engineer with 4+ years of experience in manual, API & automation testing.

📬 Contact Me | LinkedIn | GitHub

📌 Follow for: Real-Time Test Cases, Bug Reports, Selenium Frameworks.

Top API Testing Interview Questions and Answers – Part 1 (With Postman & Real-Time Scenarios)

 1. API

  API is an application programming interface that acts as an intermediate between two applications. API is a collection of functions and procedures.

2. API Methods:

  GET - GET requests are used to retrieve the information from the given URL.

  POST - To send the new data to an api.

  PUT - This method is used to update the existing data.

  DELETE - This is used to remove or delete the existing.

  PATCH - Partially updated resource.

3. What is the difference between the 201 and 204 Status codes?

• 201 - The request was successful, and a new resource was created.
• 204 - The request was successful, but there is no response body. When an update or delete operation is successful.

4. What is the difference between 401 and 403 Status Code?

• 401 - Unauthorized. without logging in or with invalid credentials.
• 403 - Forbidden. When a logged-in user tries to access a restricted area without the required permissions.

5. What is the difference between Query Parameters and Path Parameters?

• Both Query Parameters and Path Parameters are used to send data in API requests.

6. How does an API Work?

• Client request -> Server Processing -> Response - Client Handling

7. Main types of API?

• Public API
• Private API
• Partner API
• Comboste API

8. What must be checked when performing API testing?

• Accuracy of data
• HTTP status codes
• Data type, validations, order, and completeness
• Authorization checks
• Implementation of response timeout
• Error codes in case the API returns, and

9. How do you handle dynamic data in API testing?

• Data Parameterization: Using data-driven tests where input values are generated dynamically from a data source (e.g., database, files).

10. What are the major challenges faced in API testing?

• Output verification and validation.

11. Difference b/w RESTful API and SOAP API?

• RESTful API and SOAP API lie in their architectural styles and message formats.

12. API Endpoint - Refers to a specific URL or URI

13. Purpose of authentication:

• Verify the requester's identity before granting access to protected resources.

14. Authentication methods used in API Testing:

• Token-based authentication - A token to the client after successful authentication.
• Basic authentication - sending the username and password 

👋 Hi, I'm Suriya — QA Engineer with 4+ years of experience in manual, API & automation testing.

📬 Contact Me | LinkedIn | GitHub

📌 Follow for: Real-Time Test Cases, Bug Reports, Selenium Frameworks.

Top Manual Testing Interview Questions and Answers – Part 1 (2025 Updated)

1. Authentication and authorization?

• Authentication (Auth): Verifies the user's identity.
• Authorization: Determines the user's permissions.Defines what actions the user can perform.

   
2. Retesting and Regression testing?

• Retesting involves testing a specific bug or issue after it has been fixed by the developer.
•  Regression testing involves testing the fixed bug and the surrounding areas that may have been affected by the fix. verify that the software works as expected after changes?

  Retesting - Testing only the affected area.
  Regression Testing - Testing the affected as well as the unaffected areas.
  
3. Black Box, White Box, Gray Box Testing:

•  Black box: Focuses on external behaviour and user interactions. No knowledge of internal code or structure required. Typically performed by testers, QA engineers, or end-users. Examples: Functional testing, User Acceptance Testing (UAT), Exploratory testing.
• White Box: Focuses on internal code structure and logic. Requires knowledge of programming languages and code. Typically performed by developers. Examples: Unit testing, Integration testing, Code reviews.
• Gray Box: Combines elements of black box and white box testing. Requires some knowledge of programming and code. Typically performed by testers with programming skills or developers. Examples: API testing, Database testing, Security testing.

  
4. Severity: Refers to the impact or effect of a defect on the application's functionality. Measures the defect's damage or risk
     Priority: How soon will the defect be fixed?
  
5. Test scenarios focus on what to test, while test cases focus on how to test. Test scenarios define end-to-end functions to be tested, while test cases provide instructions on how to test specific features.

6. Alpha, Beta, Gamma Testing:
  Alpha: Conducted by the in-house testing team. Focus on functionality.
  Beta: Conducted by external customers, end-users, or a select group. Focus on real-world usage.
  Gamma: Conducted by end-users and customers. For the final validation, focus on business requirements and user expectations.
  
7. Equivalence Partitioning:

• Equivalence partitioning is a black-box testing technique that divides input data into partitions.
• Test cases that cover all possible input scenarios reduce the number of test cases.

 Example:  Age (1-100)
   Valid ages: 1-100
   Invalid Ages:
       Below 1 (e.g., 0, -1)
       Above 100 (e.g., 101, 150)
       Non-numeric input (e.g., "abc")

8. Smoke and Sanity testing

• Smoke testing - Focusing on Major functionalities in the software through positive test cases.
• Sanity testing - Focusing on Major functionalities in the software through positive and negative test cases.

9. Usability testing - Easy to use.

10. BUG - Caused by a programming error.
      ERROR - Mismatch between expected and actual output.
      DEFECT - When the actual output differs from customer expectations, it is considered a defect.
      MISTAKE - An error made by the user.

11. Adhoc/Monkey testing - testing an application randomly without following the requirements. Here we check negative scenarios.

12. Compatibility testing - testing an application with different hardware and software.

13. Globalisation testing - testing an application which is developed for different languages.

14. Reliability testing - testing the functionality of an application for a long duration of time.

15. Accessibility testing - testing the application which is developed for physically challenged people.

16. Acceptance testing - testing the business scenarios of an application, which is done by the customer.

17. Aesthetic testing - Testing the beauty of the application. checking colour combination, font style, font size and attractiveness of an application.

18. Functional, integration and system testing are mandatory for every testing application.

19. Smoke, sanity, exploratory and ad-hoc testing are situation-based testing.

20. Recovery testing - Later, close the application and open it again, and see whether all the previous data is still available or not.

21. SDLC - It is the Software Development Life Cycle

 It has different stages:

• Requirement Analysis
• Designing
• Coding
• Testing
• Deployment
• Maintenance

22. Agile Model - When a customer wants an application very fast, with less time, we go for this model.

23. STLC - Software Testing Life Cycle

  It has different stages:

• Requirement Analysis
• Test Planing
• Test Designing
• Test Environment Setup
• Test execution
• Test Cycle Closure

24. Scrum terminology

Scrum is a version of agile.

• Epic - It is a complete set of requirements given by the customer.
• Sprint - It is the duration of time taken to work on 1 or more user stories. Each sprint can be either 2/3/4 weeks, depending on the customer's decision.
• Sprint planning meeting - It is a meeting which is conducted before the sprint starts.
• Sprint backlog - It is a user story which is not completed in that particular sprint and is carried into the next sprint.
• Sprint review meeting - In this meeting, the scrum master will check whether all the user stories are completely developed and tested, and it is ready to be released to the customer or not.

25. Requirement Traceability Matrix:

• It is a document which is prepared to check whether every requirement has at least one test case or not. RTM maps all the requirements with the test cases.

👋 Hi, I'm Suriya — QA Engineer with 4+ years of experience in manual, API & automation testing.

📬 Contact Me | LinkedIn | GitHub

📌 Follow for: Real-Time Test Cases, Bug Reports, Selenium Frameworks.