Error when using imagejpeg function in internal PHP class function

Question

I made a class to generate images:

class Thumbnail {

private static $allowedTypes = [IMAGETYPE_GIF, IMAGETYPE_JPEG, IMAGETYPE_PNG, IMAGETYPE_BMP];
private $JPEGQuality = 75;

public function makeTumb($src, $dest, $desired_width) {
    $aImage = $this->imageCreateFromAny($src);

    if (!$aImage) {
        return false;
    }

    $source_image = $aImage['image'];
    $type = $aImage['type'];
    $width  = imagesx($source_image);
    $height = imagesy($source_image);

    $desired_height = floor($height * ($desired_width / $width));

    $virtual_image = imagecreatetruecolor($desired_width, $desired_height);

    imagecopyresampled($virtual_image, $source_image, 0, 0, 0, 0, $desired_width, $desired_height, $width, $height);
    // usando assim funciona
    // imagejpeg($virtual_image, $dest);
    // usando em uma funçao o imagejpeg($virtual_image, $dest); salva o arquivo, mas quando tento abrir diz que não é um .jpeg válido
    $this->imageSave($virtual_image, $dest, $type);

    return true;
}

private function imageSave($virtual_image, $dest, $type) {
    switch ($type) {
        case IMAGETYPE_GIF :
            imagegif($virtual_image, $dest);
            break;
        case IMAGETYPE_JPEG :
            imagejpeg($virtual_image, $dest);
        case IMAGETYPE_PNG :
            imagepng($virtual_image, $dest);
            break;
        case IMAGETYPE_BMP :
            imagewbmp($virtual_image, $dest);
            break;
    }
}

private function imageCreateFromAny($src) {
    $type = exif_imagetype($src);
    if (!in_array($type, self::$allowedTypes)) {
        return false;
    }
    switch ($type) {
        case IMAGETYPE_GIF :
            $rImage = imageCreateFromGif($src);
            break;
        case IMAGETYPE_JPEG :
            $rImage = imageCreateFromJpeg($src);
            break;
        case IMAGETYPE_PNG :
            $rImage = imageCreateFromPng($src);
            break;
        case IMAGETYPE_BMP :
            $rImage = imageCreateFromBmp($src);
            break;
    }
    return ['image' => $rImage, 'type' => $type];
  }
}

$oThumb = new Thumbnail();

$src = __DIR__.'/imagem_1.jpg';
$dest = __DIR__.'/thumb/thumb_imagem_1.jpg';
$desired_width = 256;
$oThumb->makeTumb($src, $dest, $desired_width);

But save the image and when I try to open it says it is not a valid image file, unless you use function imagejpeg directly.