Password Strength Checker JavaScript

```javascript
function checkPasswordStrength(password) {
  // Password must be at least 8 characters long
  if (password.length < 8) {
    return "Weak: Password must be at least 8 characters long.";
  }

  // Password must contain at least one uppercase letter
  if (!/[A-Z]/.test(password)) {
    return "Weak: Password must contain at least one uppercase letter.";
  }

  // Password must contain at least one lowercase letter
  if (!/[a-z]/.test(password)) {
    return "Weak: Password must contain at least one lowercase letter.";
  }

  // Password must contain at least one number
  if (!/[0-9]/.test(password)) {
    return "Weak: Password must contain at least one number.";
  }

  // Password must contain at least one special character
  if (!/[^a-zA-Z0-9\s]/.test(password)) {
    return "Weak: Password must contain at least one special character.";
  }

  // If all criteria are met, the password is strong
  return "Strong: Password meets all requirements.";
}

// Example usage:
function testPassword(password) {
    const strength = checkPasswordStrength(password);
    console.log(`Password: ${password}, Strength: ${strength}`);
}


testPassword("P@ssword1"); //Strong
testPassword("Password"); //Weak
testPassword("password1"); //Weak
testPassword("PASSWORD1"); //Weak
testPassword("Passwor"); //Weak
testPassword("P@sswor"); //Weak
testPassword("P@ssword"); //Weak
testPassword("P@sswordd"); //Strong

//For a simple command-line usage
// const readline = require('readline').createInterface({
//   input: process.stdin,
//   output: process.stdout,
// });

// readline.question('Enter a password: ', password => {
//   const strength = checkPasswordStrength(password);
//   console.log(strength);
//   readline.close();
// });
```