Add sample codemod for renaming old-style constructors

samples/class_constructor_rename.php

@@ -0,0 +1,48 @@
+<?php
+
+use \Codeshift\AbstractCodemod;
+use \PhpParser\{Node, NodeVisitorAbstract};
+
+
+// Visitor, which renames old-style constructors of PHP <= 4 to the new style.
+// Practically speaking, it searches for class methods named like their class.
+class ConstructorRenamingVisitor extends NodeVisitorAbstract {
+    private $currClassName = '';
+
+    public function enterNode(Node $node) {
+        if ($node instanceof Node\Stmt\Class_) {
+            $identifier = $node->name;
+            $this->currClassName = $identifier->name;  // Remember class name
+        }
+    }
+
+    public function leaveNode(Node $node) {
+        if ($node instanceof Node\Stmt\ClassMethod) {
+            $identifier = $node->name;
+
+            // Replace method name, if it matches class name
+            if ($identifier == $this->currClassName AND $identifier != '') {
+                $node->name = new Node\Identifier('__construct');
+            }
+        }
+    }
+}
+
+
+// Codemod definition class
+class ConstructorRenamingCodemod extends AbstractCodemod {
+
+    // @override
+    public function init() {
+        // Init the renaming visitor
+        $visitor = new ConstructorRenamingVisitor();
+
+        // Schedule a traversal run on the code that uses the visitor
+        $this->addTraversalTransform($visitor);
+    }
+
+};
+
+
+// Important: Export the codemod class
+return ConstructorRenamingCodemod;

samples/foobar_codemod.php

@@ -15,6 +15,7 @@ public function leaveNode(Node $node) {
 }
 
 
+// Codemod definition class
 class FoobarCodemod extends AbstractCodemod {
 
     // Example: Traverse with visitor "FooReplaceVisitor"