White Box Testing on a Python Function.pptx
- 1. White Box Testing on a Python Function By Gevita Chinnaiah
- 2. • You are given a Python function that calculates the factorial of a number using recursion. • Perform White Box Testing to analyze its control flow, loops, and data flow. – Identify all execution paths in the function. – Write test cases to ensure 100% statement and branch coverage. – Implement the test cases in Python using unittest. Lab Question: White Box Testing on a Python Function
- 3. Python Function (To Be Tested)
- 4. • Step 1: Identify Execution Paths – The function has three main paths: • If n < 0, return "Invalid input". • If n == 0 or n == 1, return 1. • If n > 1, recursively compute n * factorial(n - 1). • We need to create test cases covering all these paths. Solution: White Box Testing Approach
- 5. • Using Python’s unittest module: Step 2: Write Test Cases
- 6. • Statement Coverage: – Every line of code is executed at least once. • Branch Coverage: – Each condition (if, elif, else) is tested with different inputs. • Loop Coverage: – The recursive function calls itself until n == 1, ensuring all iterations are tested. Step 3: Validate Coverage
- 8. • Step 1: Introduce an Error in the Code • What is Wrong? – Instead of decrementing n (n - 1), the function increments n (n + 1). – This results in infinite recursion, causing a RecursionError Simulating an Error in the Factorial Function and Fixing It
- 9. • Expected Output (with the error) • E means an error occurred. • RecursionError shows that the function never stops calling itself, leading to a crash. Step 2: Run the Test Cases and Observe the Error
- 10. • We correct the recursion step by changing (n + 1) back to (n - 1): Step 3: Fix the Error
- 11. • Expected Output (after the fix) Step 4: Re-run the Test Cases
- 12. Thank You