Add tests, enhanced functionality to account for hasOne relationships

As a `hasOne` returns the instance of the model and not a collection,
handle calls to delete it correctly.

Ensure that we only attempt to delete models if a call to the
relationship doesn't return null.

Closes #10, closes #11

Author: michaeldyrynda

src/CascadeSoftDeletes.php

@@ -2,6 +2,7 @@
 
 namespace Iatstuti\Database\Support;
 
+use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\Relation;
 use LogicException;
 
@@ -35,9 +36,13 @@ protected static function bootCascadeSoftDeletes()
 
             $delete = $model->forceDeleting ? 'forceDelete' : 'delete';
 
-            foreach ($model->getCascadingDeletes() as $relationship) {
-                foreach ($model->{$relationship} as $child) {
-                    $child->{$delete}();
+            foreach ($model->getActiveCascadingDeletes() as $relationship) {
+                if ($model->{$relationship} instanceof Model) {
+                    $model->{$relationship}->{$delete}();
+                } else {
+                    foreach ($model->{$relationship} as $child) {
+                        $child->{$delete}();
+                    }
                 }
             }
         });
@@ -80,4 +85,17 @@ protected function getCascadingDeletes()
     {
         return isset($this->cascadeDeletes) ? (array) $this->cascadeDeletes : [];
     }
+
+
+    /**
+     * For the cascading deletes defined on the model, return only those that are not null.
+     *
+     * @return array
+     */
+    private function getActiveCascadingDeletes()
+    {
+        return array_filter($this->getCascadingDeletes(), function ($relationship) {
+            return ! is_null($this->{$relationship});
+        });
+    }
 }

tests/CascadeSoftDeletesIntegrationTest.php

@@ -212,7 +212,7 @@ public function it_handles_grandchildren()
     public function it_cascades_a_has_one_relationship()
     {
         $post = Tests\Entities\Post::create([
-            'title' => 'Cascae a has one relationship',
+            'title' => 'Cascade a has one relationship',
             'body'  => 'This is how you cascade a has one relationship',
         ]);
 
@@ -221,7 +221,7 @@ public function it_cascades_a_has_one_relationship()
         $post->postType()->save($type);
 
         $post->delete();
-        $this->assertCount(0, Tests\Entities\Author::withTrashed()->where('id', $type->id)->get());
+        $this->assertCount(0, Tests\Entities\PostType::where('id', $type->id)->get());
     }
 
     /**

tests/Entities/Post.php

@@ -23,6 +23,6 @@ public function comments()
 
     public function postType()
     {
-        return $this->hasOne('Tests\Entities\PostType');
+        return $this->hasOne('Tests\Entities\PostType', 'post_id');
     }
 }