test_examples.py

#!/usr/bin/env python3
"""
Additional examples and tests for the StringWalker class.
"""

from string_walker import StringWalker

def test_basic_operations():
    """Test basic string walking operations."""
    print("=== Basic Operations Test ===")
    
    walker = StringWalker("Python Programming")
    print(f"String: '{walker.get_string()}'")
    print(f"Length: {walker.get_length()}")
    print(f"Current position: {walker.get_current_position()}")
    print(f"Current character: '{walker.get_current_character()}'")
    print()

def test_navigation():
    """Test navigation methods."""
    print("=== Navigation Test ===")
    
    walker = StringWalker("ABCDEFGHIJK")
    
    # Walk forward in steps
    print("Walking forward:")
    for i in range(5):
        walker.walk_forward()
        print(f"Position {walker.get_current_position()}: '{walker.get_current_character()}'")
    
    print("\nWalking backward:")
    for i in range(3):
        walker.walk_backward()
        print(f"Position {walker.get_current_position()}: '{walker.get_current_character()}'")
    
    # Jump to specific positions
    print("\nJumping to positions:")
    positions = [0, 5, 10, 7, 2]
    for pos in positions:
        if walker.go_to_position(pos):
            print(f"Position {pos}: '{walker.get_current_character()}'")
        else:
            print(f"Position {pos}: Invalid position")
    print()

def test_character_replacement():
    """Test character replacement functionality."""
    print("=== Character Replacement Test ===")
    
    walker = StringWalker("Hello World")
    print(f"Original: '{walker.get_string()}'")
    
    # Replace characters at specific positions
    replacements = [(0, 'J'), (6, 'P'), (10, '!')]
    for pos, char in replacements:
        if walker.replace_character_at(pos, char):
            print(f"Replaced position {pos} with '{char}': '{walker.get_string()}'")
        else:
            print(f"Failed to replace position {pos}")
    
    # Replace current character
    walker.go_to_position(4)
    print(f"Current position {walker.get_current_position()}: '{walker.get_current_character()}'")
    walker.replace_current_character('X')
    print(f"After replacing current: '{walker.get_string()}'")
    print()

def test_bounds_checking():
    """Test bounds checking and error handling."""
    print("=== Bounds Checking Test ===")
    
    walker = StringWalker("Short")
    print(f"String: '{walker.get_string()}' (length: {walker.get_length()})")
    
    # Test out-of-bounds access
    print("\nTesting out-of-bounds access:")
    invalid_positions = [-1, 5, 10, 100]
    for pos in invalid_positions:
        char = walker.get_character_at(pos)
        print(f"Position {pos}: {char}")
    
    # Test out-of-bounds navigation
    print("\nTesting out-of-bounds navigation:")
    walker.go_to_start()
    print(f"At start: position {walker.get_current_position()}")
    
    # Try to walk backward from start
    success = walker.walk_backward()
    print(f"Walk backward from start: {success}")
    
    # Try to walk forward beyond end
    walker.go_to_end()
    print(f"At end: position {walker.get_current_position()}")
    success = walker.walk_forward()
    print(f"Walk forward from end: {success}")
    
    # Test invalid replacement
    print("\nTesting invalid replacement:")
    success = walker.replace_character_at(10, 'X')  # Out of bounds
    print(f"Replace at position 10: {success}")
    
    success = walker.replace_character_at(0, 'AB')  # Multiple characters
    print(f"Replace with multiple chars: {success}")
    print()

def test_edge_cases():
    """Test edge cases and special scenarios."""
    print("=== Edge Cases Test ===")
    
    # Empty string
    print("Testing empty string:")
    empty_walker = StringWalker("")
    print(f"Empty string length: {empty_walker.get_length()}")
    print(f"Current character: {empty_walker.get_current_character()}")
    print(f"Can walk forward: {empty_walker.walk_forward()}")
    print()
    
    # Single character string
    print("Testing single character string:")
    single_walker = StringWalker("A")
    print(f"String: '{single_walker.get_string()}'")
    print(f"At start: {single_walker.is_at_start()}")
    print(f"At end: {single_walker.is_at_end()}")
    print(f"Can walk forward: {single_walker.walk_forward()}")
    print(f"Can walk backward: {single_walker.walk_backward()}")
    print()

def interactive_demo():
    """Interactive demonstration of StringWalker."""
    print("=== Interactive Demo ===")
    
    user_string = input("Enter a string to walk through: ")
    if not user_string:
        user_string = "Default String"
    
    walker = StringWalker(user_string)
    
    while True:
        print(f"\nCurrent state: {walker}")
        print("\nCommands:")
        print("f <steps> - walk forward")
        print("b <steps> - walk backward")
        print("g <position> - go to position")
        print("r <position> <char> - replace character at position")
        print("c <char> - replace current character")
        print("s - go to start")
        print("e - go to end")
        print("q - quit")
        
        command = input("\nEnter command: ").strip().lower()
        
        if command == 'q':
            break
        elif command.startswith('f '):
            try:
                steps = int(command.split()[1])
                success = walker.walk_forward(steps)
                print(f"Walked forward {steps} steps: {'Success' if success else 'Failed'}")
            except (IndexError, ValueError):
                print("Invalid format. Use: f <steps>")
        elif command.startswith('b '):
            try:
                steps = int(command.split()[1])
                success = walker.walk_backward(steps)
                print(f"Walked backward {steps} steps: {'Success' if success else 'Failed'}")
            except (IndexError, ValueError):
                print("Invalid format. Use: b <steps>")
        elif command.startswith('g '):
            try:
                position = int(command.split()[1])
                success = walker.go_to_position(position)
                print(f"Went to position {position}: {'Success' if success else 'Failed'}")
            except (IndexError, ValueError):
                print("Invalid format. Use: g <position>")
        elif command.startswith('r '):
            try:
                parts = command.split()
                position = int(parts[1])
                char = parts[2]
                success = walker.replace_character_at(position, char)
                print(f"Replaced at position {position}: {'Success' if success else 'Failed'}")
            except (IndexError, ValueError):
                print("Invalid format. Use: r <position> <char>")
        elif command.startswith('c '):
            try:
                char = command.split()[1]
                success = walker.replace_current_character(char)
                print(f"Replaced current character: {'Success' if success else 'Failed'}")
            except (IndexError, ValueError):
                print("Invalid format. Use: c <char>")
        elif command == 's':
            walker.go_to_start()
            print("Went to start")
        elif command == 'e':
            walker.go_to_end()
            print("Went to end")
        else:
            print("Unknown command")

if __name__ == "__main__":
    # Run all tests
    test_basic_operations()
    test_navigation()
    test_character_replacement()
    test_bounds_checking()
    test_edge_cases()
    
    # Uncomment the line below to run interactive demo
    # interactive_demo()