custom return value

src/Fsm.php

@@ -75,9 +75,9 @@ public function getCurrentState() : string
      *
      * @param  string|Transition $action
      * @param  mixed $payload
-     * @return string
+     * @return mixed
      */
-    public function process(string|Transition $action, $payload = null) : string
+    public function process(string|Transition $action, $payload = null) : mixed
     {
         $action = is_string($action) ? $action : $action->action;
 
@@ -90,11 +90,13 @@ public function process(string|Transition $action, $payload = null) : string
         $transition = $this->transitions[$this->state][$action];
 
         if (is_callable($transition)) {
-            $transition($this->stateful_object, $payload);
+            $returnValue = $transition($this->stateful_object, $payload);
         } else {
             $this->stateful_object->setState($transition->to_state);
         }
 
-        return $this->state = $transition->to_state;
+        $this->state = $transition->to_state;
+
+        return $returnValue ?? $this->state;
     }
 }

tests/FsmTest.php

@@ -43,6 +43,14 @@ public function it_transitions_machine_between_object_states()
         $this->assertEquals('idle', $this->fsm->getCurrentState());
     }
 
+    /** @test */
+    public function it_returns_custom_transition_value()
+    {
+        $this->assertEquals('off', $this->fsm->getCurrentState());
+        $this->assertEquals(['custom' => 'return'], $this->fsm->process(CustomTransition::make('off', 'custom_start', 'idle')));
+        $this->assertEquals('idle', $this->fsm->getCurrentState());
+    }
+
     /** @test */
     public function it_puts_machine_object_in_proper_state()
     {
@@ -101,5 +109,7 @@ public function __invoke($stateful_object, $payload)
     {
         $stateful_object->prop = $payload['prop'];
         $stateful_object->setState($this->to_state);
+
+        return ['custom' => 'return'];
     }
 }