Laravel: Password Requirements Rule

_usage.php

<?php
...
use App\Rules\PasswordRequirementRule;

class SaveUserRequest extends FormRequest
{
...
  public function rules() {
    ...
    $rules['password'] = [
      'required',
      'confirmed',
      (new PasswordRequirementRule)
    ];
    ...
  }
...
}

PasswordRequirementsRule.php

<?php

namespace App\Rules;

use Illuminate\Contracts\Validation\Rule;

class PasswordRequirementsRule implements Rule
{
	// @var string
	//private $regex;

	// @var int
	private $minLength = 8;

	// @var bool
	private $needsNumber = true;

	// @var bool
	private $needsLowercaseLetter = true;

	// @var bool
	private $needsUppercaseLetter = true;

	// @var bool
	private $needsSpecialCharacter = true;

	// @var bool (faith in humanity)
	private $isValid = true;

	// @var array
	private $errors = [];

	/**
	 * Create a new rule instance.
	 *
	 * @return void
	 */
	public function __construct()
	{
		//$this->regex = "/^(?=.*?[A-Z])(?=.*?[a-z])(?=.*?[0-9])(?=.*?[#?!@$%^&*-]).{6,}$/";
	}

	/**
	 * Check the value against the rule's minimum length.
	 *
	 * @param  $string  $value
	 * @return bool
	 */
	private function checkLength(string $value): bool
	{
		return strlen($value) >= $this->minLength;
	}

	/**
	 * Check the value for a number.
	 *
	 * @param  $string  $value
	 * @return bool
	 */
	private function checkNumber(string $value)
	{
		return (bool) preg_match('/[0-9]{1,}/', $value);
	}
	
	/**
	 * Check the value for a lowercase letter.
	 *
	 * @param  $string  $value
	 * @return bool
	 */
	private function checkLowercaseLetter(string $value): bool
	{
		return (bool) preg_match('/[a-z]{1,}/', $value);
	}
	
	/**
	 * Check the value for a uppercase letter.
	 *
	 * @param  $string  $value
	 * @return bool
	 */
	private function checkUppercaseLetter(string $value): bool
	{
		return (bool) preg_match('/[A-Z]{1,}/', $value);
	}

	/**
	 * Check the value for a special character.
	 *
	 * @param  $string  $value
	 * @return bool
	 */
	private function checkSpecialCharacter(string $value): bool
	{
		$chars = '/[\`\~\!\@\#\$\%\^\&\*\(\)\_\+\-\=\{\}\|\[\]\\\:\"\;\'\<\>\?\,\.\/]{1,}/';
		return (bool) preg_match($chars, $value);
	}
	
	/**
	 * Determine if the validation rule passes.
	 *
	 * @see \Illuminate\Contracts\Validation\Rule
	 * @param  string  $attribute
	 * @param  mixed  $value
	 * @return bool
	 */
	public function passes($attribute, $value)
	{
		if ($this->minLength > 0 && !$this->checkLength($value))
			$this->errors[] = "a minimum of {$this->minLength} characters";

		if ($this->needsNumber && !$this->checkNumber($value))
			$this->errors[] = "at least one number";

		if ($this->needsLowercaseLetter && !$this->checkLowercaseLetter($value))
			$this->errors[] = "at least one lowercase character";

		if ($this->needsUppercaseLetter && !$this->checkUppercaseLetter($value))
			$this->errors[] = "at least one uppercase character";

		if ($this->needsSpecialCharacter && !$this->checkSpecialCharacter($value))
			$this->errors[] = "at least one special character";

		return count($this->errors) === 0;
	}

	/**
	 * Get the validation error message.
	 *
	 * @see \Illuminate\Contracts\Validation\Rule
	 * @return string
	 */
	public function message()
	{
		switch (count($this->errors)):
			case 1:
				$missing = $this->errors[0];
				break;

			case 2:
				$missing = "{$this->errors[0]} and {$this->errors[1]}";
				break;

			default:
				$last = array_pop($this->errors);
				$this->errors[] = "and {$last}";
				$missing = implode(", ", $this->errors);

		endswitch; // count errors

		return "Password must include {$missing}.";
	}
}