Free AI Code Debugger

async function loadUserData(userId) {
  const response = fetch('/api/users/' + userId);
  const userData = response.json();
  
  console.log(userData.name);
  
  return userData;
}

// Usage
const user = loadUserData(123);
console.log('User email:', user.email);

async function loadUserData(userId) {
  // BUG FIX 1: Added await keyword before fetch
  // Issue: fetch returns Promise, not Response object
  const response = await fetch('/api/users/' + userId);
  
  // BUG FIX 2: Added await keyword before json()
  // Issue: response.json() returns Promise<any>, not direct object
  const userData = await response.json();
  
  // BUG FIX 3: Added HTTP error checking
  // Issue: fetch doesn't throw on HTTP errors (404, 500)
  if (!response.ok) {
    throw new Error(`HTTP error! status: ${response.status}`);
  }
  
  console.log(userData.name);
  
  return userData;
}

// BUG FIX 4: Added await to function call
// Issue: Calling async function without await returns Promise, not value
async function displayUser() {
  try {
    const user = await loadUserData(123);
    console.log('User email:', user.email);
  } catch (error) {
    console.error('Failed to load user:', error);
  }
}

displayUser();

// Alternative: Using .then() chain
loadUserData(123)
  .then(user => console.log('User email:', user.email))
  .catch(error => console.error('Failed to load user:', error));

def calculate_average(numbers):
    total = 0
    for num in numbers:
        total += num
    average = total / len(numbers)
    return round(average, 2)

# Usage
scores = [85, 92, 78, 90]
print('Average:', calculate_average(scores))

# Bug trigger
empty_list = []
print('Empty avg:', calculate_average(empty_list))

# Type bug
mixed_data = [10, '20', 30]
print('Mixed avg:', calculate_average(mixed_data))

def calculate_average(numbers: list[float | int]) -> float | None:
    """
    Calculate arithmetic mean of numbers with error handling.
    
    Args:
        numbers: List of numeric values (int or float)
        
    Returns:
        Average as float rounded to 2 decimals, or None if list is empty
        
    Raises:
        TypeError: If list contains non-numeric values
    """
    # BUG FIX 1: Check for empty list to prevent ZeroDivisionError
    # Issue: len(numbers) = 0 causes division by zero
    if not numbers:
        return None  # Or raise ValueError("Cannot calculate average of empty list")
    
    # BUG FIX 2: Type validation to prevent TypeError
    # Issue: Adding string to int raises "unsupported operand type(s) for +:"
    if not all(isinstance(num, (int, float)) for num in numbers):
        raise TypeError("All elements must be numeric (int or float)")
    
    total = 0
    for num in numbers:
        total += num
    
    average = total / len(numbers)
    return round(average, 2)

# Usage
scores = [85, 92, 78, 90]
print('Average:', calculate_average(scores))  # Output: 86.25

# Bug fix demonstration 1: Empty list
empty_list = []
result = calculate_average(empty_list)
print('Empty avg:', result if result is not None else 'No data')  # Output: No data

# Bug fix demonstration 2: Type error handling
mixed_data = [10, '20', 30]
try:
    print('Mixed avg:', calculate_average(mixed_data))
except TypeError as e:
    print(f'Error: {e}')  # Output: Error: All elements must be numeric

# Alternative: Convert strings to numbers if possible
def safe_average(numbers):
    """Version that attempts type conversion."""
    try:
        numeric_values = [float(n) for n in numbers]
        return calculate_average(numeric_values)
    except (ValueError, TypeError) as e:
        return None