Calculator Multi-Issues Repository

A calculator library with multiple bugs for educational purposes. Students should clone this repository and fix all the issues.

Issues to Fix

Issue 1: Negative Number Addition

• File: calculator.py - add() function
• Problem: The add() function incorrectly handles negative numbers by using absolute values
• Expected: add(-2, 3) should return 1, not 5
• Test: test_negative_numbers in TestAdd class

Issue 2: Inefficient Multiplication

• File: calculator.py - multiply() function
• Problem: Uses slow iterative approach for large numbers
• Expected: Should use direct multiplication operator *
• Test: test_large_numbers in TestMultiply class

Issue 3: Division by Zero Handling

• File: calculator.py - divide() function
• Problem: Returns inf instead of raising an exception for division by zero
• Expected: Should raise ValueError with message "Cannot divide by zero"
• Test: test_division_by_zero in TestDivide class

Issue 4: Negative Exponents in Power

• File: calculator.py - power() function
• Problem: Recursive call with negative exponent causes infinite recursion
• Expected: Should handle negative exponents correctly
• Test: test_negative_exponent in TestPower class

Issue 5: Factorial with Negative Input

• File: calculator.py - factorial() function
• Problem: Returns -1 for negative inputs instead of raising exception
• Expected: Should raise ValueError for negative inputs
• Test: test_negative_numbers in TestFactorial class

Issue 6: Prime Number Detection

• File: calculator.py - is_prime() function
• Problem: Inefficient and may have logical errors
• Expected: Should correctly identify prime numbers
• Tests: All tests in TestIsPrime class

Setup Instructions

1. Clone the repository:

git clone <repository-url>
cd calculator-multi-issues