ISTQB FOUNDATION 4.0 | Tutorial 35 | Branch Testing & Branch Coverage | Test Case Techniques | CTFL

Summary

This tutorial delves into white box testing techniques, specifically focusing on Branch Testing for ISTQB Foundation level certification. It explains the concept of Branch Testing, which aims to cover all possible branches in code with the minimum number of test cases, and contrasts it with Statement Testing. The video clarifies that 100% Branch coverage ensures 100% Statement coverage but not the reverse. It also covers how to calculate and measure Branch and Statement coverage, emphasizing their importance in achieving thorough code analysis, especially in safety-critical environments.

Takeaways

• 📘 The tutorial is focused on chapter 4 of the ISTQB Foundation Level certification, specifically on white box test techniques and branch testing.
• 🔍 Branch testing is a technique used to test all possible branches within a code fragment, aiming to find the minimum number of test cases required for coverage.
• 📊 Branch coverage is measured by the percentage of branches executed by the test cases, and it's represented graphically through a coverage diagram.
• 🚀 Branch testing is particularly important in safety-critical, mission-critical, or high-integrity environments for achieving thorough code coverage.
• 💡 Branch testing is considered a stronger technique than statement testing because 100% branch coverage guarantees 100% statement coverage, but not the other way around.
• 📝 The script explains the difference between statement testing (covering all executable statements) and branch testing (covering all decision paths in the code).
• 📐 The tutorial uses flowcharts to illustrate the components of code testing, including nodes (statements) and branches (decisions made from conditions).
• 🔑 The minimum number of test cases needed for branch testing can vary depending on the complexity of the code and the number of decisions made.
• 📉 The script provides an example to calculate the decision coverage percentage by dividing the number of executed branches by the total number of branches and multiplying by 100.
• 📚 The tutorial emphasizes the importance of understanding the definitions and differences between statement and branch coverage for theoretical questions in the ISTQB exam.
• 🔑 The script also discusses how to measure coverage without using specific techniques, by simply executing test cases and analyzing the coverage achieved.
• 🎓 The tutorial concludes with advice to keep learning and exploring, emphasizing the importance of understanding the context for effective software testing.

Q & A

What is the main focus of chapter 4, section 4.3 in the ISTQB Foundation Level certification tutorial?

The main focus is on white box test techniques, specifically Branch Testing and Branch coverage.

What is Branch Testing in the context of software testing?

Branch Testing is a white box testing technique aimed at testing all possible branches within a given fragment of code by finding the minimum number of test cases.

What does Branch coverage measure?

Branch coverage measures the coverage achieved by the written test cases in terms of the branches within the code that have been executed during testing.

Why are Branch Testing techniques used in regression testing?

Branch Testing techniques are used in regression testing for safety critical, mission critical, or high integrity environments to achieve more thorough code coverage.

How does Branch Testing differ from Statement Testing?

Branch Testing focuses on covering all decisions or branches in the code, whereas Statement Testing focuses on executing all statements or nodes. Branch Testing is considered a stronger technique because 100% Branch coverage guarantees 100% Statement coverage, but not vice versa.

What is the minimum number of test cases required to achieve 100% Branch coverage for a simple if-else statement?

For a simple if-else statement, a minimum of two test cases is required: one to cover the true condition and another to cover the false condition.

In the provided examples, why is the number of test cases different for achieving 100% Branch coverage compared to Statement coverage?

The number of test cases differs because Branch Testing requires covering all possible decision paths, which might involve multiple conditions and outcomes, whereas Statement Testing only requires executing each statement at least once.

How can one measure the coverage achieved by a set of test cases without using specific Branch Testing techniques?

One can measure the coverage by comparing the executed paths and decisions in a flowchart with the total number of branches or statements and calculating the percentage of coverage achieved.

What is the formula for calculating Branch coverage?

The formula for calculating Branch coverage is (Number of branches executed by the test / Total number of branches in the code) * 100.

What is the significance of the statement '100% Branch coverage guarantees 100% Statement coverage'?

This statement signifies that if all branches or decisions in the code are covered by tests, then all statements or nodes must also be covered, ensuring a more comprehensive test coverage.

How can the understanding of Branch Testing and Branch coverage be applied in practical software testing scenarios?

Understanding Branch Testing and Branch coverage can help testers design more effective test cases, ensure thorough testing of the code, and identify potential defects in decision-making logic within the software.