Convert isset and empty to modifiercomilers, and smooth the error handling to fix unit tests.

src/Compile/FunctionCallCompiler.php

@@ -55,23 +55,28 @@ class FunctionCallCompiler extends Base {
 		$_attr = $this->getAttributes($compiler, $args);
 		unset($_attr['nocache']);
 
-		if (!$functionHandler = $compiler->getSmarty()->getFunctionHandler($function)) {
-			throw new CompilerException("Cannot compile unknown function $function.");
-		}
-
-		// not cacheable?
-		$compiler->tag_nocache = $compiler->tag_nocache || !$functionHandler->isCacheable();
-
 		$_paramsArray = $this->formatParamsArray($_attr);
-
 		$_params = 'array(' . implode(',', $_paramsArray) . ')';
 
-		$output = "\$_smarty_tpl->getSmarty()->getFunctionHandler(" . var_export($function, true) . ")";
-		$output .= "->handle($_params, \$_smarty_tpl)";
+		try {
+			$value = array_shift($_attr);
+			$output = $compiler->compileModifier([array_merge([$function], $_attr)], $value);
+		} catch (\Smarty\CompilerException $e) {
+			if ($functionHandler = $compiler->getSmarty()->getFunctionHandler($function)) {
+
+				// not cacheable?
+				$compiler->tag_nocache = $compiler->tag_nocache || !$functionHandler->isCacheable();
+				$output = "\$_smarty_tpl->getSmarty()->getFunctionHandler(" . var_export($function, true) . ")";
+				$output .= "->handle($_params, \$_smarty_tpl)";
+			} else {
+				throw $e;
+			}
+		}
 
 		if (!empty($parameter['modifierlist'])) {
 			$output = $compiler->compileModifier($parameter['modifierlist'], $output);
 		}
+
 		return $output;
 	}
 }

src/Compile/Modifier/EmptyModifierCompiler.php

@@ -0,0 +1,19 @@
+<?php
+namespace Smarty\Compile\Modifier;
+use Smarty\CompilerException;
+
+/**
+ * Smarty empty modifier plugin
+ */
+class EmptyModifierCompiler extends Base {
+
+	public function compile($params, \Smarty\Compiler\Template $compiler) {
+
+		if (count($params) !== 1) {
+			throw new CompilerException("Invalid number of arguments for empty. empty expects exactly 1 parameter.");
+		}
+
+		return 'empty(' . $params[0] . ')';
+	}
+
+}

src/Compile/Modifier/IssetModifierCompiler.php

@@ -0,0 +1,25 @@
+<?php
+namespace Smarty\Compile\Modifier;
+use Smarty\CompilerException;
+
+/**
+ * Smarty isset modifier plugin
+ */
+class IssetModifierCompiler extends Base {
+
+	public function compile($params, \Smarty\Compiler\Template $compiler) {
+
+		$params = array_filter($params, function($v) { return !empty($v); });
+
+		if (count($params) < 1) {
+			throw new CompilerException("Invalid number of arguments for isset. isset expects at least one parameter.");
+		}
+
+		$tests = [];
+		foreach ($params as $param) {
+			$tests[] = 'null !== (' . $param . ' ?? null)';
+		}
+		return '(' . implode(' && ', $tests) . ')';
+	}
+
+}

src/Compile/ModifierCompiler.php

@@ -11,6 +11,8 @@
 namespace Smarty\Compile;
 
 use Smarty\Compile\Base;
+use Smarty\Compiler\Template;
+use Smarty\CompilerException;
 
 /**
  * Smarty Internal Plugin Compile Modifier Class
@@ -35,9 +37,8 @@ class ModifierCompiler extends Base {
 
 		$compiler->has_code = true;
 
-		// check and get attributes
-		$_attr = $this->getAttributes($compiler, $args);
 		$output = $parameter['value'];
+
 		// loop over list of modifiers
 		foreach ($parameter['modifierlist'] as $single_modifier) {
 			/* @var string $modifier */
@@ -74,4 +75,19 @@ class ModifierCompiler extends Base {
 		}
 		return $output;
 	}
+
+	/**
+	 * Wether this class will be able to compile the given modifier.
+	 * @param string $modifier
+	 * @param Template $compiler
+	 *
+	 * @return bool
+	 * @throws CompilerException
+	 */
+	public function canCompileForModifier(string $modifier, \Smarty\Compiler\Template $compiler): bool {
+		return $compiler->getModifierCompiler($modifier)
+			|| $compiler->getSmarty()->getModifierCallback($modifier)
+			|| $compiler->getPluginFromDefaultHandler($modifier, \Smarty\Smarty::PLUGIN_MODIFIERCOMPILER)
+			|| $compiler->getPluginFromDefaultHandler($modifier, \Smarty\Smarty::PLUGIN_MODIFIER);
+	}
 }

src/Extension/CallbackWrapper.php

@@ -0,0 +1,35 @@
+<?php
+
+namespace Smarty\Extension;
+
+use Smarty\Exception;
+
+class CallbackWrapper {
+
+	/**
+	 * @var callback
+	 */
+	private $callback;
+	/**
+	 * @var string
+	 */
+	private $modifierName;
+
+	/**
+	 * @param string $modifierName
+	 * @param callback $callback
+	 */
+	public function __construct(string $modifierName, $callback) {
+		$this->callback = $callback;
+		$this->modifierName = $modifierName;
+	}
+
+	public function handle(...$params) {
+		try {
+			return call_user_func_array($this->callback, $params);
+		} catch (\ArgumentCountError $e) {
+			throw new Exception("Invalid number of arguments to modifier " . $this->modifierName);
+		}
+	}
+
+}

src/Extension/DefaultExtension.php

@@ -23,9 +23,11 @@ class DefaultExtension extends Base {
 			case 'count_sentences': $this->modifiers[$modifier] = new \Smarty\Compile\Modifier\CountSentencesModifierCompiler(); break;
 			case 'count_words': $this->modifiers[$modifier] = new \Smarty\Compile\Modifier\CountWordsModifierCompiler(); break;
 			case 'default': $this->modifiers[$modifier] = new \Smarty\Compile\Modifier\DefaultModifierCompiler(); break;
+			case 'empty': $this->modifiers[$modifier] = new \Smarty\Compile\Modifier\EmptyModifierCompiler(); break;
 			case 'escape': $this->modifiers[$modifier] = new \Smarty\Compile\Modifier\EscapeModifierCompiler(); break;
 			case 'from_charset': $this->modifiers[$modifier] = new \Smarty\Compile\Modifier\FromCharsetModifierCompiler(); break;
 			case 'indent': $this->modifiers[$modifier] = new \Smarty\Compile\Modifier\IndentModifierCompiler(); break;
+			case 'isset': $this->modifiers[$modifier] = new \Smarty\Compile\Modifier\IssetModifierCompiler(); break;
 			case 'lower': $this->modifiers[$modifier] = new \Smarty\Compile\Modifier\LowerModifierCompiler(); break;
 			case 'nl2br': $this->modifiers[$modifier] = new \Smarty\Compile\Modifier\Nl2brModifierCompiler(); break;
 			case 'noprint': $this->modifiers[$modifier] = new \Smarty\Compile\Modifier\NoPrintModifierCompiler(); break;
@@ -72,7 +74,6 @@ class DefaultExtension extends Base {
 			case 'count': $this->functionHandlers[$functionName] = new \Smarty\FunctionHandler\Count(); break;
 			case 'counter': $this->functionHandlers[$functionName] = new \Smarty\FunctionHandler\Counter(); break;
 			case 'cycle': $this->functionHandlers[$functionName] = new \Smarty\FunctionHandler\Cycle(); break;
-			case 'empty': $this->functionHandlers[$functionName] = new \Smarty\FunctionHandler\EmptyHandler(); break;
 			case 'fetch': $this->functionHandlers[$functionName] = new \Smarty\FunctionHandler\Fetch(); break;
 			case 'html_checkboxes': $this->functionHandlers[$functionName] = new \Smarty\FunctionHandler\HtmlCheckboxes(); break;
 			case 'html_image': $this->functionHandlers[$functionName] = new \Smarty\FunctionHandler\HtmlImage(); break;
@@ -83,7 +84,6 @@ class DefaultExtension extends Base {
 			case 'html_table': $this->functionHandlers[$functionName] = new \Smarty\FunctionHandler\HtmlTable(); break;
 			case 'in_array': $this->functionHandlers[$functionName] = new \Smarty\FunctionHandler\InArray(); break;
 			case 'is_array': $this->functionHandlers[$functionName] = new \Smarty\FunctionHandler\IsArray(); break;
-			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;

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 count. count expects 2 or 3 parameters.");
+			throw new Exception("Invalid number of arguments for count. count expects 1 or 2 parameters.");
 		}
 
 		$value = $params[0];

src/FunctionHandler/EmptyHandler.php

@@ -1,27 +0,0 @@
-<?php
-
-namespace Smarty\FunctionHandler;
-
-use Smarty\Exception;
-use Smarty\Template;
-
-/**
- * empty(mixed $var): bool
- *
- * Returns true if var does not exist or has a value that is empty or equal to zero, aka falsey, see conversion to
- * boolean. Otherwise returns false.
- *
- * No warning is generated if the variable does not exist. That means empty() is essentially the concise equivalent
- * to !isset($var) || $var == false.
- */
-class EmptyHandler extends Base {
-
-	public function handle($params, Template $template) {
-
-		if (count($params) !== 1) {
-			throw new Exception("Invalid number of arguments for empty. empty expects exactly 1 parameter.");
-		}
-		return empty(reset($params));
-	}
-
-}

src/FunctionHandler/IssetHandler.php

@@ -1,30 +0,0 @@
-<?php
-
-namespace Smarty\FunctionHandler;
-
-use Smarty\Exception;
-use Smarty\Template;
-
-/**
- * Determines if a variable is declared and is different than null
- * `isset(mixed $var, mixed ...$vars): bool`
- *
- * Returns true if var exists and has any value other than null. false otherwise.
- */
-class IssetHandler extends Base {
-
-	public function handle($params, Template $template) {
-
-		if (count($params) === 0) {
-			throw new Exception("Invalid number of arguments for isset. isset expects at least 1 parameter.");
-		}
-
-		foreach ($params as $param) {
-			if (!isset($param)) {
-				return false;
-			}
-		}
-		return true;
-	}
-
-}

src/Smarty.php

@@ -7,6 +7,7 @@ use RecursiveIteratorIterator;
 use Smarty\Cacheresource\File;
 use Smarty\Extension\Base;
 use Smarty\Extension\BCPluginsAdapter;
+use Smarty\Extension\CallbackWrapper;
 use Smarty\Extension\CoreExtension;
 use Smarty\Extension\DefaultExtension;
 use Smarty\Extension\ExtensionInterface;
@@ -1672,7 +1673,7 @@ class Smarty extends \Smarty\TemplateBase
 	public function getModifierCallback(string $modifierName) {
 		foreach ($this->getExtensions() as $extension) {
 			if ($callback = $extension->getModifierCallback($modifierName)) {
-				return $callback;
+				return [new CallbackWrapper($modifierName, $callback), 'handle'];
 			}
 		}
 		return null;

tests/UnitTests/SecurityTests/FunctionTest.php

@@ -32,7 +32,7 @@ class FunctionTest extends PHPUnit_Smarty
     {
         $this->smarty->enableSecurity();
         $this->expectException(\Smarty\CompilerException::class);
-        $this->expectExceptionMessage('Cannot compile unknown function unknown');
+        $this->expectExceptionMessage('unknown modifier');
         $this->smarty->fetch('eval:{unknown()}');
     }
 }

tests/UnitTests/TemplateSource/TagTests/PluginFunction/EmptyTest.php

@@ -36,7 +36,7 @@ class EmptyTest extends \PHPUnit_Smarty {
 	}
 
 	public function testInvalidParameters() {
-		$this->expectException(\Smarty\Exception::class);
+		$this->expectException(\Smarty\CompilerException::class);
 		$this->expectExceptionMessage('Invalid number of arguments');
 		$this->assertEquals("", $this->smarty->fetch("string:{empty(3, 'foo')}"));
 	}

tests/UnitTests/TemplateSource/TagTests/PluginFunction/IssetTest.php

@@ -37,9 +37,9 @@ class IssetTest extends \PHPUnit_Smarty {
 	}
 
 	public function testInvalidParameters() {
-		$this->expectException(\Smarty\Exception::class);
+		$this->expectException(\Smarty\CompilerException::class);
 		$this->expectExceptionMessage('Invalid number of arguments');
-		$this->assertEquals("", $this->smarty->fetch("string:{empty(3, 'foo')}"));
+		$this->assertEquals("", $this->smarty->fetch("string:{if isset()}blurp{/if}"));
 	}
 
 }

tests/UnitTests/TemplateSource/ValueTests/PHPfunctions/PhpFunctionTest.php

@@ -57,6 +57,7 @@ class PhpFunctionTest extends PHPUnit_Smarty
     public function testEmpty2()
     {
         $this->smarty->disableSecurity();
+        $this->getSmarty()->registerPlugin(\Smarty\Smarty::PLUGIN_MODIFIER, 'pass', function ($v) { return $v; });
         $this->smarty->assign('var', array(null,
                                            false,
                                            (int) 0,
@@ -78,6 +79,7 @@ class PhpFunctionTest extends PHPUnit_Smarty
     public function testEmpty3()
     {
         $this->smarty->disableSecurity();
+        $this->getSmarty()->registerPlugin(\Smarty\Smarty::PLUGIN_FUNCTION, 'pass', function ($v) { return $v; });
         $this->smarty->assign('var', array(true,
                                            (int) 1,
                                            (float) 0.1,
@@ -97,6 +99,7 @@ class PhpFunctionTest extends PHPUnit_Smarty
     public function testEmpty4()
     {
         $this->smarty->disableSecurity();
+        $this->getSmarty()->registerPlugin(\Smarty\Smarty::PLUGIN_FUNCTION, 'pass', function ($v) { return $v; });
         $this->smarty->assign('var', new TestIsset());
         $expected = ' true , false , false , true , true , true , false ';
         $this->assertEquals($expected, $this->smarty->fetch('string:{strip}{if empty($var->isNull)} true {else} false {/IF}
@@ -114,6 +117,7 @@ class PhpFunctionTest extends PHPUnit_Smarty
     public function testIsset1()
     {
         $this->smarty->disableSecurity();
+        $this->getSmarty()->registerPlugin(\Smarty\Smarty::PLUGIN_MODIFIER, 'pass', function ($v) { return $v; });
         $this->smarty->assign('isNull', null);
         $this->smarty->assign('isSet', 1);
         $this->smarty->assign('arr', array('isNull' => null, 'isSet' => 1));
@@ -135,6 +139,7 @@ class PhpFunctionTest extends PHPUnit_Smarty
     {
         $this->smarty->disableSecurity();
         $this->smarty->assign('var', new TestIsset());
+        $this->smarty->registerPlugin(\Smarty\Smarty::PLUGIN_MODIFIER, 'pass', function ($v) { return $v; });
         $expected = ' false , true , true , false , false , false , true ';
         $this->assertEquals($expected, $this->smarty->fetch('string:{strip}{if isset($var->isNull)} true {else} false {/IF}
         ,{if isset($var->isSet)} true {else} false {/IF}
@@ -155,6 +160,7 @@ class PhpFunctionTest extends PHPUnit_Smarty
     public function testIsset3($strTemplate, $result)
     {
         $this->smarty->disableSecurity();
+        $this->smarty->registerPlugin(\Smarty\Smarty::PLUGIN_MODIFIER, 'intval', 'intval');
 
         $this->smarty->assign('varobject', new TestIsset());
         $this->smarty->assign('vararray', $vararray = array(
@@ -198,15 +204,6 @@ class PhpFunctionTest extends PHPUnit_Smarty
     }
 }
 
-/**
- * @param mixed $v
- *
- * @return mixed
- */
-function pass($v) {
-    return $v;
-}
-
 /**
  * Class TestIsset
  */