Added strlen function, fixing some unit tests

src/Extension/DefaultExtension.php

@@ -86,6 +86,7 @@ class DefaultExtension extends Base {
 			case 'isset': $this->functionHandlers[$functionName] = new \Smarty\FunctionHandler\IssetHandler(); break;
 			case 'mailto': $this->functionHandlers[$functionName] = new \Smarty\FunctionHandler\Mailto(); break;
 			case 'math': $this->functionHandlers[$functionName] = new \Smarty\FunctionHandler\Math(); break;
+			case 'strlen': $this->functionHandlers[$functionName] = new \Smarty\FunctionHandler\Strlen(); break;
 			case 'time': $this->functionHandlers[$functionName] = new \Smarty\FunctionHandler\Time(); break;
 		}
 

src/FunctionHandler/Count.php

@@ -20,7 +20,7 @@ class Count extends Base {
 		$params = array_values($params ?? []);
 
 		if (count($params) < 1 || count($params) > 2) {
-			throw new Exception("Invalid number of arguments for in_array. in_arrays expects 2 or 3 parameters.");
+			throw new Exception("Invalid number of arguments for count. count expects 2 or 3 parameters.");
 		}
 
 		$value = $params[0];

src/FunctionHandler/Strlen.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace Smarty\FunctionHandler;
+
+use Smarty\Exception;
+use Smarty\Template;
+
+/**
+ * Get string length
+ *
+ *  strlen(string $string): int
+ *
+ * Returns length of the string on success, and 0 if the string is empty.
+ */
+class Strlen extends Base {
+
+	public function handle($params, Template $template) {
+
+		$params = array_values($params ?? []);
+
+		if (count($params) !== 1) {
+			throw new Exception("Invalid number of arguments for strlen. strlen expects exactly 1 parameter.");
+		}
+
+		return strlen((string) $params[0]);
+	}
+
+}