Merge pull request #13291 from mokhosh/current-panel-docs

Add docs for setting the current panel in tests

packages/panels/docs/14-testing.md

@@ -21,6 +21,18 @@ protected function setUp(): void
 }
 ```
 
+### Testing multiple panels
+
+If you have multiple panels and you would like to test a non-default panel, you will need to tell Filament which panel you are testing. This can be done in the `setUp()` method of the test case, or you can do it at the start of a particular test. Filament usually does this in a middleware when you access the panel through a request, so if you're not making a request in your test like when testing a Livewire component, you need to set the current panel manually:
+
+```php
+use Filament\Facades\Filament;
+
+Filament::setCurrentPanel(
+    Filament::getPanel('app'), // Where `app` is the ID of the panel you want to test
+);
+```
+
 ## Resources
 
 ### Pages