feat: adds plugin uses api

src/Plugin.php

@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Pest;
+
+use Pest\TestSuite;
+
+final class Plugin
+{
+    /**
+     * The lazy callables to be executed
+     * once the test suite boots.
+     *
+     * @var array<int, callable>
+     *
+     * @internal
+     */
+    public static $callables = [];
+
+    /**
+     * Lazy loads an `uses` call on the context of plugins.
+     */
+    public static function uses(...$traits): void
+    {
+        self::$callables[] = function () use ($traits) {
+            uses(...$traits)->in(TestSuite::getInstance()->rootPath . DIRECTORY_SEPARATOR . 'tests');
+        };
+    }
+}

src/TestSuite.php

@@ -106,7 +106,13 @@ final class TestSuite
     public static function getInstance(string $rootPath = null): TestSuite
     {
         if (is_string($rootPath)) {
-            return self::$instance ?? self::$instance = new TestSuite($rootPath);
+            self::$instance = new TestSuite($rootPath);
+
+            foreach (Plugin::$callables as $callable) {
+                $callable();
+            }
+
+            return self::$instance;
         }
 
         if (self::$instance === null) {