Command getConfig should return "null" if no config key is found.

src/Commands/Command.php

@@ -178,7 +178,7 @@ abstract class Command
     /**
      * Get command config
      *
-     * Look for config $name if found return it, if not return empty array.
+     * Look for config $name if found return it, if not return null.
      * If $name is not set return all set config.
      *
      * @param string|null $name
@@ -193,7 +193,7 @@ abstract class Command
         if (isset($this->config[$name])) {
             return $this->config[$name];
         }
-        return [];
+        return null;
     }
 
     /**

tests/Unit/Commands/CommandTest.php

@@ -191,6 +191,6 @@ class CommandTest extends TestCase
         $this->assertEquals(['config_key' => 'config_value'], $this->command_stub_with_config->getConfig(null));
         $this->assertEquals(['config_key' => 'config_value'], $this->command_stub_with_config->getConfig());
         $this->assertEquals('config_value', $this->command_stub_with_config->getConfig('config_key'));
-        $this->assertEquals([], $this->command_stub_with_config->getConfig('not_config_key'));
+        $this->assertEquals(null, $this->command_stub_with_config->getConfig('not_config_key'));
     }
 }