Implement Robust Prime Number Checker Function

src/prime_checker.py

@@ -0,0 +1,28 @@
+def is_prime(number):
+    """
+    Check if a given number is prime.
+
+    Args:
+        number (int): The number to check for primality.
+
+    Returns:
+        bool: True if the number is prime, False otherwise.
+
+    Raises:
+        TypeError: If the input is not an integer.
+    """
+    # Check for invalid input types
+    if not isinstance(number, int):
+        raise TypeError("Input must be an integer")
+
+    # Handle special cases
+    if number <= 1:
+        return False
+
+    # Check for primality using trial division
+    # Only need to check up to the square root of the number
+    for i in range(2, int(number**0.5) + 1):
+        if number % i == 0:
+            return False
+
+    return True

tests/test_prime_checker.py

@@ -0,0 +1,35 @@
+import pytest
+from src.prime_checker import is_prime
+
+def test_prime_numbers():
+    """Test known prime numbers"""
+    prime_numbers = [2, 3, 5, 7, 11, 13, 17, 19, 23, 29]
+    for num in prime_numbers:
+        assert is_prime(num) is True, f"{num} should be prime"
+
+def test_non_prime_numbers():
+    """Test known non-prime numbers"""
+    non_prime_numbers = [0, 1, 4, 6, 8, 9, 10, 12, 14, 15]
+    for num in non_prime_numbers:
+        assert is_prime(num) is False, f"{num} should not be prime"
+
+def test_large_prime():
+    """Test a large prime number"""
+    assert is_prime(104729) is True, "104729 is a prime number"
+
+def test_large_non_prime():
+    """Test a large non-prime number"""
+    assert is_prime(104730) is False, "104730 is not a prime number"
+
+def test_negative_numbers():
+    """Test negative numbers are not prime"""
+    negative_numbers = [-1, -2, -3, -5, -7]
+    for num in negative_numbers:
+        assert is_prime(num) is False, f"{num} should not be prime"
+
+def test_invalid_input_types():
+    """Test invalid input types raise TypeError"""
+    invalid_inputs = [3.14, "7", [2], {2}, None]
+    for invalid_input in invalid_inputs:
+        with pytest.raises(TypeError, match="Input must be an integer"):
+            is_prime(invalid_input)