use container instead of a singleton for UnitMockRegistry

src/Testing/MockMe.php

@@ -2,18 +2,23 @@
 
 namespace Lucid\Testing;
 
+use Mockery\Mock;
+
 trait MockMe
 {
     public static function mock(array $constructorExpectations = []): UnitMock
     {
         $unit = static::class;
 
-        if (UnitMockRegistry::has($unit)) {
-            $mock = UnitMockRegistry::get($unit);
+        /** @var UnitMockRegistry $registry */
+        $registry = app(UnitMockRegistry::class);
+
+        if ($registry->has($unit)) {
+            $mock = $registry->get($unit);
             $mock->setConstructorExpectations($constructorExpectations);
         } else {
             $mock = new UnitMock($unit, $constructorExpectations);
-            UnitMockRegistry::register($unit, $mock);
+            $registry->register($unit, $mock);
         }
 
         return $mock;

src/Testing/UnitMockRegistry.php

@@ -7,22 +7,36 @@ class UnitMockRegistry
     /**
      * @var array
      */
-    private static $mocks = [];
+    private $mocks = [];
 
-    public static function has(string $unit): bool
+    public function __construct()
     {
-        return isset(self::$mocks[$unit]);
+        // there should only be one instance of the registry,
+        // so we register ourselves onto the application to be reused.
+        // this is necessary in order to have a clean registry at the beginning of each test method run,
+        // otherwise, with a singleton mocks will be carried on across test runs within the same class.
+        app()->instance(static::class, $this);
     }
 
-    public static function get(string $unit): ?UnitMock
+    public function has(string $unit): bool
     {
-        if (!self::has($unit)) return null;
+        return isset($this->mocks[$unit]);
+    }
+
+    public function get(string $unit): ?UnitMock
+    {
+        if (!$this->has($unit)) return null;
 
-        return self::$mocks[$unit];
+        return $this->mocks[$unit];
+    }
+
+    public function register(string $unit, UnitMock $mock)
+    {
+        $this->mocks[$unit] = $mock;
     }
 
-    public static function register(string $unit, UnitMock $mock)
+    public function count()
     {
-        self::$mocks[$unit] = $mock;
+        return count($this->mocks);
     }
 }