Add a deprecation when a Node uses echo/print

CHANGELOG

@@ -1,7 +1,8 @@
-# 3.9.0 (2023-XX-XX)
+# 3.9.0 (2024-XX-XX)
 
  * Add a new "yield" mode for output generation
-   The "use_yield" Environment option controls the strategy: use "false" for "echo", "true" for "yield"
+   The "use_yield" Environment option controls the output strategy: use "false" for "echo", "true" for "yield"
+   "yield" will be the only strategy supported in the next major version
  * Add return type for Symfony 7 compatibility
  * Fix premature loop exit in Security Policy lookup of allowed methods/properties
  * Deprecate all internal extension functions in favor of methods on the extension classes

extra/twig-extra-bundle/Tests/Fixture/Kernel.php

@@ -30,7 +30,7 @@ class Kernel extends BaseKernel
             'router' => ['utf8' => true],
             'http_method_override' => false,
         ];
-        if (Kernel::MAJOR_VERSION >= 6 &&  Kernel::MINOR_VERSION >= 2) {
+        if (6 === Kernel::MAJOR_VERSION) {
             $config['handle_all_throwables'] = true;
             $config['php_errors']['log'] = true;
         }

src/Compiler.php

@@ -27,10 +27,12 @@ class Compiler
     private $sourceOffset;
     private $sourceLine;
     private $varNameSalt = 0;
+    private $checkForOutput;
 
     public function __construct(Environment $env)
     {
         $this->env = $env;
+        $this->checkForOutput = $env->isDebug();
     }
 
     public function getEnvironment(): Environment
@@ -85,6 +87,16 @@ class Compiler
         return $this;
     }
 
+    /**
+     * @return $this
+     */
+    public function checkForOutput(bool $checkForOutput)
+    {
+        $this->checkForOutput = $checkForOutput ? $this->env->isDebug() : false;
+
+        return $this;
+    }
+
     /**
      * Adds a raw string to the compiled code.
      *
@@ -92,6 +104,9 @@ class Compiler
      */
     public function raw(string $string)
     {
+        if ($this->checkForOutput) {
+            $this->checkStringForOutput(trim($string));
+        }
         $this->source .= $string;
 
         return $this;
@@ -105,6 +120,10 @@ class Compiler
     public function write(...$strings)
     {
         foreach ($strings as $string) {
+            if ($this->checkForOutput) {
+                $this->checkStringForOutput(trim($string));
+            }
+
             $this->source .= str_repeat(' ', $this->indentation * 4).$string;
         }
 
@@ -220,4 +239,13 @@ class Compiler
     {
         return sprintf('__internal_compile_%d', $this->varNameSalt++);
     }
+
+    private function checkStringForOutput(string $string): void
+    {
+        if (str_starts_with($string, 'echo')) {
+            trigger_deprecation('twig/twig', '3.9.0', 'Using "echo" in a "Node::compile()" method is deprecated; use a "TextNode" or "PrintNode" instead or use "yield" when "use_yield" is "true" on the environment (triggered by "%s").', $string);
+        } elseif (str_starts_with($string, 'print')) {
+            trigger_deprecation('twig/twig', '3.9.0', 'Using "print" in a "Node::compile()" method is deprecated; use a "TextNode" or "PrintNode" instead or use "yield" when "use_yield" is "true" on the environment (triggered by "%s").', $string);
+        }
+    }
 }

src/Node/Expression/InlinePrint.php

@@ -33,7 +33,9 @@ final class InlinePrint extends AbstractExpression
             ;
         } else {
             $compiler
+                ->checkForOutput(false)
                 ->raw('print(')
+                ->checkForOutput(true)
                 ->subcompile($this->getNode('node'))
                 ->raw(')')
             ;

src/Node/PrintNode.php

@@ -34,7 +34,11 @@ class PrintNode extends Node implements NodeOutputInterface
         if ($compiler->getEnvironment()->useYield()) {
             $compiler->write('yield ');
         } else {
-            $compiler->write('echo ');
+            $compiler
+                ->checkForOutput(false)
+                ->write('echo ')
+                ->checkForOutput(true)
+            ;
         }
 
         $compiler

src/Node/TextNode.php

@@ -33,7 +33,11 @@ class TextNode extends Node implements NodeOutputInterface
         if ($compiler->getEnvironment()->useYield()) {
             $compiler->write('yield ');
         } else {
-            $compiler->write('echo ');
+            $compiler
+                ->checkForOutput(false)
+                ->write('echo ')
+                ->checkForOutput(true)
+            ;
         }
 
         $compiler