src/Taggable.php
public function hasTag($tag): bool
    {
        if ($tag instanceof Tag) {
            $normalized = $tag->getAttribute('normalized');
        } else {
            $normalized = app(TagService::class)->normalize($tag);
        }

        return in_array($normalized, $this->getTagArrayNormalizedAttribute(), true);
    }
public function hasTag($tag): bool
    {
        if ($tag instanceof Tag) {
            $normalized = $tag->getAttribute('normalized');
        } else {
            $normalized = app(TagService::class)->normalize($tag);
        }

        return in_array($normalized, $this->getTagArrayNormalizedAttribute(), true);
    }
Determine if a given tag is attached to the model.

@param Tag|string $tag

@return bool