feat(traverse.js): ✨Add parent node to visitor function

Author: vivaxy

lib/traverse.js

@@ -8,50 +8,50 @@ const astTypes = require('../helpers/ast-types.js');
 const traverseTypes = {
   [astTypes.PROGRAM](ast, visitor) {
     ast.body.forEach((child) => {
-      traverse(child, visitor);
+      traverse(child, visitor, ast);
     });
   },
   [astTypes.EXPRESSION_STATEMENT](ast, visitor) {
-    traverse(ast.expression, visitor);
+    traverse(ast.expression, visitor, ast);
   },
   [astTypes.LITERAL](ast, visitor) {},
   [astTypes.BINARY_EXPRESSION](ast, visitor) {
-    traverse(ast.left, visitor);
-    traverse(ast.right, visitor);
+    traverse(ast.left, visitor, ast);
+    traverse(ast.right, visitor, ast);
   },
   [astTypes.UNARY_EXPRESSION](ast, visitor) {
-    traverse(ast.argument, visitor);
+    traverse(ast.argument, visitor, ast);
   },
   [astTypes.LOGICAL_EXPRESSION](ast, visitor) {
-    traverse(ast.left, visitor);
-    traverse(ast.right, visitor);
+    traverse(ast.left, visitor, ast);
+    traverse(ast.right, visitor, ast);
   },
   [astTypes.IDENTIFIER](ast, visitor) {},
   [astTypes.SEQUENCE_EXPRESSION](ast, visitor) {
     ast.expressions.forEach((child) => {
-      traverse(child, visitor);
+      traverse(child, visitor, ast);
     });
   },
   [astTypes.CONDITIONAL_EXPRESSION](ast, visitor) {
-    traverse(ast.test, visitor);
-    traverse(ast.consequent, visitor);
-    traverse(ast.alternate, visitor);
+    traverse(ast.test, visitor, ast);
+    traverse(ast.consequent, visitor, ast);
+    traverse(ast.alternate, visitor, ast);
   },
   [astTypes.MEMBER_EXPRESSION](ast, visitor) {
-    traverse(ast.object, visitor);
-    traverse(ast.property, visitor);
+    traverse(ast.object, visitor, ast);
+    traverse(ast.property, visitor, ast);
   },
   [astTypes.UPDATE_EXPRESSION](ast, visitor) {
-    traverse(ast.argument, visitor);
+    traverse(ast.argument, visitor, ast);
   },
 };
 
-function traverse(ast, visitor) {
-  visitor(ast);
+function traverse(ast, visitor, parent = null) {
+  visitor(ast, parent);
   if (!traverseTypes[ast.type]) {
     throw new Error('Unexpected ast.type: ' + ast.type);
   }
-  return traverseTypes[ast.type](ast, visitor);
+  return traverseTypes[ast.type](ast, visitor, parent);
 }
 
 module.exports = traverse;