Fix availability WTF

Author: dvlpp

src/Book.php

@@ -64,11 +64,13 @@ public function canBeOrdered(): bool
             && ($this->hasStock() || $this->availability == BookAvailability::AvailableOnDemand);
     }
 
-    public function getAvailabilityLabelAttribute(): ?string
+    public function availabilityLabel(): Attribute
     {
-        return $this->hasStock() && $this->availability != BookAvailability::Forthcoming
-            ? null
-            : $this->availability->getLabel();
+        return Attribute::make(
+            get: fn () => $this->hasStock() && $this->availability != BookAvailability::Forthcoming
+                ? null
+                : $this->availability->getLabel()
+        );
     }
 
     public function visual(string $size): string
@@ -82,6 +84,15 @@ public function visual(string $size): string
         return $url;
     }
 
+    public function jsonSerialize(): array
+    {
+        return [
+            ...$this->toArray(),
+            'availability_label' => $this->availability_label,
+            'url' => $this->url,
+        ];
+    }
+
     public function resolveRouteBinding($value, $field = null)
     {
         if (is_array($value)) {