added tests for smarty and worked around a small bug

composer.json

@@ -79,7 +79,8 @@
 	},
 	"require-dev": {
 		"phpunit/phpunit": "3.7.*",
-		"twig/twig": "*"
+		"twig/twig": "*",
+		"smarty/smarty": "*"
 	},
 	"suggest": {
 		"phpdocumentor/reflection": "required by yii2-apidoc extension",
@@ -92,6 +93,7 @@
 		"imagine/imagine": "required by yii2-imagine extension",
 		"smarty/smarty": "required by yii2-smarty extension",
 		"swiftmailer/swiftmailer": "required by yii2-swiftmailer extension",
+		"twig/twig": "required by yii2-twig extension",
 		"yiisoft/yii2-coding-standards": "you can use this package to check for code style issues when contributing to yii"
 	},
 	"autoload": {

extensions/smarty/ViewRenderer.php

@@ -88,7 +88,7 @@ class ViewRenderer extends BaseViewRenderer
 	public function render($view, $file, $params)
 	{
 		/** @var \Smarty_Internal_Template $template */
-		$template = $this->smarty->createTemplate($file, null, null, $params, true);
+		$template = $this->smarty->createTemplate($file, null, null, empty($params) ? null : $params, true);
 
 		$template->assign('app', \Yii::$app);
 		$template->assign('this', $view);

tests/unit/extensions/smarty/ViewRendererTest.php

+<?php
+/**
+ * 
+ * 
+ * @author Carsten Brandt <mail@cebe.cc>
+ */
+
+namespace yiiunit\extensions\smarty;
+
+use yii\web\AssetManager;
+use yii\web\JqueryAsset;
+use yii\web\View;
+use Yii;
+use yiiunit\TestCase;
+
+/**
+ * @group smarty
+ */
+class ViewRendererTest extends TestCase
+{
+	protected function setUp()
+	{
+		$this->mockApplication();
+	}
+
+	/**
+	 * https://github.com/yiisoft/yii2/issues/2265
+	 */
+	public function testNoParams()
+	{
+		$view = $this->mockView();
+		$content = $view->renderFile('@yiiunit/extensions/smarty/views/simple.tpl');
+
+		$this->assertEquals('simple view without parameters.', $content);
+	}
+
+	public function testRender()
+	{
+		$view = $this->mockView();
+		$content = $view->renderFile('@yiiunit/extensions/smarty/views/view.tpl', ['param' => 'Hello World!']);
+
+		$this->assertEquals('test view Hello World!.', $content);
+	}
+
+	/**
+	 * @return View
+	 */
+	protected function mockView()
+	{
+		return new View([
+			'renderers' => [
+				'tpl' => [
+					'class' => 'yii\smarty\ViewRenderer',
+				],
+			],
+			'assetManager' => $this->mockAssetManager(),
+		]);
+	}
+
+	protected function mockAssetManager()
+	{
+		$assetDir = Yii::getAlias('@runtime/assets');
+		if (!is_dir($assetDir)) {
+			mkdir($assetDir, 0777, true);
+		}
+		return new AssetManager([
+			'basePath' => $assetDir,
+			'baseUrl' => '/assets',
+		]);
+	}
+} 
\ No newline at end of file

tests/unit/extensions/smarty/views/simple.tpl

+simple view without parameters.
\ No newline at end of file

tests/unit/extensions/smarty/views/view.tpl

+test view {$param}.
\ No newline at end of file