Merge pull request #40 from kbond/double-register-event

Add failing test demonstrating double registering of events
tighten · Mar 18, 2019 · bb7d1bc · bb7d1bc
2 parents 6d3a955 + 607235e
commit bb7d1bc
Show file tree

Hide file tree

Showing 3 changed files with 51 additions and 2 deletions.
diff --git a/src/HasChildren.php b/src/HasChildren.php
@@ -6,19 +6,49 @@
 
 trait HasChildren
 {
+    protected static $parentBootMethods;
+
     protected $hasChildren = true;
 
     protected static function registerModelEvent($event, $callback)
     {
         parent::registerModelEvent($event, $callback);
 
         if (static::class === self::class && property_exists(self::class, 'childTypes')) {
-            foreach ((new self)->childTypes as $childClass) {
-                $childClass::registerModelEvent($event, $callback);
+            // We don't want to register the callbacks that happen in the boot method of the parent, as they'll be called
+            // from the child's boot method as well.
+            if (! self::parentIsBooting()) {
+                foreach ((new self)->childTypes as $childClass) {
+                    $childClass::registerModelEvent($event, $callback);
+                }
             }
         }
     }
 
+    protected static function parentIsBooting()
+    {
+        if (! isset(self::$parentBootMethods)) {
+            self::$parentBootMethods[] = 'boot';
+
+            foreach (class_uses_recursive(self::class) as $trait) {
+                self::$parentBootMethods[] = 'boot'.class_basename($trait);
+            }
+
+            self::$parentBootMethods = array_flip(self::$parentBootMethods);
+        }
+
+        foreach (debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS) as $trace) {
+            $class = isset($trace['class']) ? $trace['class'] : null;
+            $function = isset($trace['function']) ? $trace['function'] : '';
+
+            if ($class === self::class && isset(self::$parentBootMethods[$function])) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
     public function newInstance($attributes = [], $exists = false)
     {
         $model = isset($attributes[$this->getInheritanceColumn()])

diff --git a/tests/Features/ParentsObserveChildrenTest.php b/tests/Features/ParentsObserveChildrenTest.php
@@ -83,4 +83,14 @@ public function registering_events_on_child_doesnt_affect_parent()
         $train = Train::create();
         $this->assertNull($train->driver_id);
     }
+
+    /** @test */
+    public function registering_events_in_parent_boot_only_triggers_once()
+    {
+        $vehicle = Vehicle::create();
+        $this->assertEquals(1, $vehicle->boot_count);
+
+        $car = Car::create();
+        $this->assertEquals(1, $car->boot_count);
+    }
 }
diff --git a/tests/Models/Vehicle.php b/tests/Models/Vehicle.php
@@ -19,6 +19,15 @@ class Vehicle extends Model
 
     protected $guarded = [];
 
+    protected static function boot()
+    {
+        parent::boot();
+
+        static::created(function ($model) {
+            $model->boot_count = $model->boot_count ? $model->boot_count + 1 : 1;
+        });
+    }
+
     public function driver()
     {
         return $this->belongsTo(Driver::class);