Webmozart\Console\Util\StringUtil::parseBoolean PHP Method

    public static function parseBoolean($value, $nullable = true)
    {
        if ($nullable && (null === $value || 'null' === $value)) {
            return null;
        }
        if (is_bool($value)) {
            return $value;
        }
        if (is_string($value) || is_int($value)) {
            switch ((string) $value) {
                case '':
                case 'false':
                case '0':
                case 'no':
                case 'off':
                    return false;
                case 'true':
                case '1':
                case 'yes':
                case 'on':
                    return true;
            }
        }
        throw new InvalidValueException(sprintf('The value "%s" cannot be parsed as boolean.', $value));
    }

 /**
  * @dataProvider getInvalidParseBooleanTests
  * @expectedException \Webmozart\Console\Api\Args\Format\InvalidValueException
  */
 public function testParseBooleanFailsIfInvalid($input, $nullable = true)
 {
     StringUtil::parseBoolean($input, $nullable);
 }