accept array format for exponential backoff (#926)

src/ProvisioningPlan.php

@@ -172,6 +172,7 @@ protected function convert($supervisor, $options)
             $key = $key === 'tries' ? 'max_tries' : $key;
             $key = $key === 'processes' ? 'max_processes' : $key;
             $value = $key === 'queue' && is_array($value) ? implode(',', $value) : $value;
+            $value = $key === 'backoff' && is_array($value) ? implode(',', $value) : $value;
 
             return [Str::camel($key) => $value];
         })->all();

src/SupervisorOptions.php

@@ -91,7 +91,7 @@ class SupervisorOptions
     /**
      * The number of seconds to wait before retrying a job that encountered an uncaught exception.
      *
-     * @var int
+     * @var string
      */
     public $backoff;
 

tests/Feature/ProvisioningPlanTest.php

@@ -98,4 +98,21 @@ public function test_plan_is_converted_into_array_of_supervisor_options()
 
         $this->assertSame(20, $results['local']['supervisor-2']->maxProcesses);
     }
+
+    public function test_backoff_is_translated_to_string_form()
+    {
+        $plan = [
+            'local' => [
+                'supervisor-2' => [
+                    'connection' => 'redis',
+                    'queue' => 'local-supervisor-2-queue',
+                    'backoff' => [30, 60],
+                ],
+            ],
+        ];
+
+        $results = (new ProvisioningPlan(MasterSupervisor::name(), $plan))->toSupervisorOptions();
+
+        $this->assertSame('30,60', $results['local']['supervisor-2']->backoff);
+    }
 }