Add testing docs

Author: stevebauman

README.md

@@ -34,6 +34,7 @@ ActiveRedis provides you simple and efficient way to interact with Redis hashes
   - [Querying Models](#querying-models)
     - [Chunking](#chunking)
     - [Searching](#searching)
+  - [Testing](#testing)
 - [Credits](#credits)
 
 ## Requirements
@@ -680,6 +681,35 @@ $visit = Visit::create(['user_id' => 1]);
 $visit->update(['user_id' => 2]);
 ```
 
+## Testing
+
+To run your application tests without a real Redis server, you may swap the underlying repository to an array.
+
+This will allow you to test with your models without needing to interact with Redis:
+
+```php
+use DirectoryTree\ActiveRedis\Model;
+
+Model::setRepository('array');
+```
+
+Otherwise, you will need to run your tests with a Redis server running, and flush your Redis database after each test:
+
+```php
+use Illuminate\Support\Facades\Redis;
+
+// Pest
+beforeEach(fn () => Redis::flushdb());
+
+// PHPUnit
+protected function setUp(): void
+{
+    parent::setUp();
+
+    Redis::flushdb();
+}
+```
+
 ## Credits
 
 This package is directly inspired from <a href="https://laravel.com/docs/eloquent">Laravel's Eloquent</a>, and most features are direct ports to a Redis equivalent.