Software Testing Fundamentals

Introduction to Software Testing

• Software testing is a process of evaluating a system or its components to determine if it meets specified requirements.
• It aims to identify defects and improve the overall quality of the product.
• Testing is crucial for ensuring a product is defect-free and meets user needs.
• A good system needs testing to ensure it works correctly.
• The goal is to produce a more robust and resilient system to prevent failures.

Why Developers Don't Test

• "I know it works!" – Developers may not test because they feel confident their code is functional.
• "I don't write broken code" – A developer often believes that the code is fault-free.
• "I have no time" – Testing may be seen as an unproductive activity that takes time when time is already considered limited.

Four Levels of Software Testing

• Unit Testing: The first level of functional testing, performed by the developer and testing individual components.
• Integration Testing: Evaluates how modules operate together, to test the interaction.
• System Testing: The complete and integrated application is tested. It involves verifying its overall behavior and functionality.
• Acceptance Testing: Performed by end-users or stakeholders to ensure that the system meets their needs and criteria.

Unit Testing Example

• Unit testing uses tests for a component or a single unit in software testing.
• Performed by the developer.
• The smallest testable part of a system or application.
• Ensures correct fulfillment of requirements and functionality.

Test Coverage

• Test coverage is the percentage of lines of code that are executed during tests.
• High coverage indicates high confidence in the code.
• Test coverage reports highlight areas of code not tested during testing.

Integration Testing

• Modules are logically integrated and tested as a complete system.
• It focuses on the interaction between software modules.
• This testing emphasizes on the data communication between modules.
• It's known as Integration and Testing.

Types of Integration Testing

• Big Bang Approach: All modules are combined and tested at once.
• Incremental Approach: Modules are integrated gradually.
  • Top Down
  • Bottom Up
  • Sandwich

Integration Test Example

• Example test cases for an e-commerce website may include ensuring that items transfer correctly, billing and shipping details are accurate, and payments are processed correctly.

System Testing

• System testing checks the overall system behavior.
• It verifies that the system as a whole meets specified requirements.
• It looks at its overall functionality and compliance with standards.

System Testing Process

• The testing includes preparing the test setting, creating test cases, generating test data, running test cases, eliminating errors, regression testing, and defect reporting.

Test Case Creation

• Test cases should consider happy, sad, and edge cases – positive & negative results.
• Include the steps needed to simulate the scenario, expected results, and pass/fail criteria to validate the program testing.

Test Examples

• Include examples of test cases, which involve specific scenarios such as searching for products, adding products to the cart, proceeding to checkout with invalid payment methods, placing orders, and verifying the success conditions.

Variations and Edge Cases

• Testing different product conditions, validating user types, testing promo codes, and including the maximum quantity in a cart as elements to comprehensively test the program.

How to Report a Defect

• A defect report should include steps to reproduce, environmental status, preconditions, expected and actual results, screenshots, logs, times, and a version number, with examples.

Some Defect Reporting Tools

• Jira
• HP ALM

Test Report

• A test report summarizes the completion of test activities and provides supporting documents.
• It contains information about the testing process, test cases, results, and other necessary data.
• The report is prepared by the testing team, approved by the test manager, and provided to stakeholders.

User Acceptance Testing(UAT)

• The final phase of software testing.
• End-users perform the testing in a real-world environment to validate whether the system meets their needs.
• Purpose of UAT is to ensure software functionality from user perspective.
• UAT will ideally also identify any issues missed during earlier testing.
• Before initiating UAT, review the current requirements and validate that UAT will cover the needs.

Example Scenario for UAT

• An e-commerce use case scenario could include validating how users search products, add them to a cart, and complete a payment successfully.
• The acceptance criteria would include details such as the accuracy of product search results, correct display of product details in the cart, successful payment processing via the gateway, and verification that the order confirmation emails are sent.

Other Types of Testing

• Exploratory Testing: Actively exploring the software without predefined scripts.
• Regression Testing: Verifying new changes don't negatively affect existing functionality.
• Re-Testing: Ensuring previously identified defects are fixed.
• Smoke Testing: Checks if major functionalities work after a build or fix.
• Sanity Testing: Narrow test to validate specific fixes or new features.
• Penetration Testing: Simulates attacks to identify security vulnerabilities.
• A/B Testing: Comparing two versions of the software to determine which performs better.
• Alpha Testing: Internal testing by the development.
• Beta Testing: Further testing with external users.
• Gamma Testing: Validation before the full release focusing on stability.
• Non-Functional Testing: Evaluating the performance, reliability, and usability of a system, which includes Load, Stress, Spike and Scalability testing and Usability testing.
• Automated Testing: Using scripts to automate testing tasks.

Automated Testing

• Used primarily for regression testing, performance, load and stress testing.
• Saves cost over time in repetitive tasks.
• Improves accuracy.

Some Testing Tools (Functional and API Testing)

• Selenium
• Appium
• TestComplete

When to Use Manual vs. Automated Testing

• Manual testing is best suited for exploratory, usability, and short-term projects for smaller applications.
• Automated testing is better for repetitive tasks like regression, performance testing, and when scaling for longer, larger projects.

Stages of Software Testing

• A sequential process for the various stages of software development and the specific tests associated with those stages.

White Box vs. Black Box Testing

• White Box testing is based on the internal structure of the application and Black Box is based on its external characteristics.

BDD & TDD

• BDD (Behavior Driven Development) and TDD (Test Driven Development) highlight aspects of the testing process as it relates to software development methodologies.

TDD Cycle

• The TDD methodology uses a cyclical process in the code writing process focusing on red, refactor, and green cycles in which new tests are created, code for the tests is implemented, and the code is then reviewed to make sure the tests still work.