fixes

app/Models/Shop/Unity.php

@@ -3,7 +3,10 @@
 namespace App\Models\Shop;
 
 use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Database\Eloquent\Relations\HasMany;
 use Illuminate\Database\Eloquent\SoftDeletes;
+use Znck\Eloquent\Relations\BelongsToThrough as RelationsBelongsToThrough;
 use Znck\Eloquent\Traits\BelongsToThrough;
 
 class Unity extends Model
@@ -14,19 +17,33 @@ class Unity extends Model
 
     protected $table = 'shop_unities';
 
-    public function package()
+    public function package(): BelongsTo
     {
         return $this->belongsTo(Package::class);
     }
 
-    public function article_family()
+    public function variations(): HasMany
     {
-        return $this->belongsToThrough(ArticleNature::class, Package::class, null, '', ['App\Models\Shop\ArticleNature' => 'article_family_id', 'App\Models\Shop\Package' => 'package_id']);
+        return $this->hasMany(Variation::class);
+    }
+
+    public function article_family(): RelationsBelongsToThrough
+    {
+        return $this->belongsToThrough(
+            ArticleNature::class,
+            Package::class,
+            null,
+            '',
+            [
+                'App\Models\Shop\ArticleNature' => 'article_family_id',
+                'App\Models\Shop\Package' => 'package_id'
+            ]
+        );
     }
 
     public function scopeByPackage($query, $id)
     {
-        return $query->where($this->table.'.package_id', $id);
+        return $query->where($this->table . '.package_id', $id);
     }
 
     public function scopeByArticleNature($query, $id)

app/Models/Shop/Variation.php

@@ -30,8 +30,13 @@ class Variation extends Model
         return $this->hasMany(Offer::class);
     }
 
-    public function scopeByPackage($query, $package_id)
+    public function scopeByPackage($query, $packageId)
     {
-        return $query->where($this->table.'.package_id', $package_id);
+        return $query->where($this->table . '.package_id', $packageId);
+    }
+
+    public function scopeByUnity($query, $unityId)
+    {
+        return $query->where($this->table . '.unity_id', $unityId);
     }
 }