more reliable scope construction

lib/6to5/transformation/transformers/es6/constants.js

@@ -31,13 +31,13 @@ var visitor = {
 
         throw state.file.errorWithNode(id, name + " is read-only");
       }
-    } else if (t.isScope(node)) {
+    } else if (t.isScope(node, parent)) {
       this.skip();
     }
   }
 };
 
-exports.Scope = function (node, parent, scope, file) {
+exports.Scopable = function (node, parent, scope, file) {
   scope.traverse(node, visitor, {
     constants: scope.getAllBindingsOfKind("const"),
     file:      file

lib/6to5/traversal/path.js

@@ -49,7 +49,7 @@ TraversalPath.getScope = function (node, parent, scope) {
   var ourScope = scope;
 
   // we're entering a new scope so let's construct it!
-  if (t.isScope(node)) {
+  if (t.isScope(node, parent)) {
     ourScope = new Scope(node, parent, scope);
   }
 

lib/6to5/traversal/scope.js

@@ -163,8 +163,8 @@ Scope.prototype.rename = function (oldName, newName) {
     enter: function (node, parent, scope) {
       if (t.isReferencedIdentifier(node, parent) && node.name === oldName) {
         node.name = newName;
-      } else if (t.isScope(node)) {
-        if (scope.bindingIdentifierEquals(oldName, binding)) {
+      } else if (t.isScope(node, parent)) {
+        if (!scope.bindingIdentifierEquals(oldName, binding)) {
           this.skip();
         }
       }
@@ -310,7 +310,7 @@ var blockVariableVisitor = {
   enter: function (node, parent, scope, state) {
     if (t.isFunctionDeclaration(node) || t.isBlockScoped(node)) {
       state.registerDeclaration(node);
-    } else if (t.isScope(node)) {
+    } else if (t.isScope(node, parent)) {
       this.skip();
     }
   }
@@ -336,15 +336,6 @@ Scope.prototype.crawl = function () {
 
   extend(this, info);
 
-  //
-
-  if (parent && t.isBlockStatement(block)) {
-    if (t.isLoop(parent.block, { body: block }) ||
-        t.isFunction(parent.block, { body: block })) {
-      return;
-    }
-  }
-
   // ForStatement - left, init
 
   if (t.isLoop(block)) {

lib/6to5/types/alias-keys.json

@@ -3,13 +3,13 @@
   "BreakStatement":      ["Statement"],
   "ContinueStatement":   ["Statement"],
   "DebuggerStatement":   ["Statement"],
-  "DoWhileStatement":    ["Statement", "Loop", "While", "Scope"],
+  "DoWhileStatement":    ["Statement", "Loop", "While", "Scopable"],
   "IfStatement":         ["Statement"],
   "ReturnStatement":     ["Statement"],
   "SwitchStatement":     ["Statement"],
   "ThrowStatement":      ["Statement"],
   "TryStatement":        ["Statement"],
-  "WhileStatement":      ["Statement", "Loop", "While", "Scope"],
+  "WhileStatement":      ["Statement", "Loop", "While", "Scopable"],
   "WithStatement":       ["Statement"],
   "EmptyStatement":      ["Statement"],
   "LabeledStatement":    ["Statement"],
@@ -18,13 +18,13 @@
   "ImportDeclaration":   ["Statement", "Declaration"],
   "PrivateDeclaration":  ["Statement", "Declaration"],
 
-  "ArrowFunctionExpression": ["Scope", "Function", "Expression"],
-  "FunctionDeclaration":     ["Statement", "Declaration", "Scope", "Function"],
-  "FunctionExpression":      ["Scope", "Function", "Expression"],
+  "ArrowFunctionExpression": ["Scopable", "Function", "Expression"],
+  "FunctionDeclaration":     ["Statement", "Declaration", "Scopable", "Function"],
+  "FunctionExpression":      ["Scopable", "Function", "Expression"],
 
-  "BlockStatement": ["Statement", "Scope"],
-  "Program":        ["Scope"],
-  "CatchClause":    ["Scope"],
+  "BlockStatement": ["Statement", "Scopable"],
+  "Program":        ["Scopable"],
+  "CatchClause":    ["Scopable"],
 
   "LogicalExpression": ["Binary", "Expression"],
   "BinaryExpression":  ["Binary", "Expression"],
@@ -36,9 +36,9 @@
   "ClassDeclaration": ["Statement", "Declaration", "Class"],
   "ClassExpression":  ["Class", "Expression"],
 
-  "ForOfStatement": ["Statement", "For", "Scope", "Loop"],
-  "ForInStatement": ["Statement", "For", "Scope", "Loop"],
-  "ForStatement":   ["Statement", "For", "Scope", "Loop"],
+  "ForOfStatement": ["Statement", "For", "Scopable", "Loop"],
+  "ForInStatement": ["Statement", "For", "Scopable", "Loop"],
+  "ForStatement":   ["Statement", "For", "Scopable", "Loop"],
 
   "ObjectPattern":     ["Pattern"],
   "ArrayPattern":      ["Pattern"],
@@ -53,7 +53,7 @@
   "BindFunctionExpression":    ["Expression"],
   "BindMemberExpression":      ["Expression"],
   "CallExpression":            ["Expression"],
-  "ComprehensionExpression":   ["Expression", "Scope"],
+  "ComprehensionExpression":   ["Expression", "Scopable"],
   "ConditionalExpression":     ["Expression"],
   "Identifier":                ["Expression"],
   "Literal":                   ["Expression"],

lib/6to5/types/index.js

@@ -780,5 +780,27 @@ t.isSpecifierDefault = function (specifier) {
   return specifier.default || t.isIdentifier(specifier.id) && specifier.id.name === "default";
 };
 
+/**
+ * Description
+ *
+ * @param {Node} node
+ * @param {Node} parent
+ * @returns {Boolean}
+ */
+
+t.isScope = function (node, parent) {
+  if (t.isBlockStatement(node)) {
+    if (t.isLoop(parent.block, { body: node })) {
+      return false;
+    }
+
+    if (t.isFunction(parent.block, { body: node })) {
+      return false;
+    }
+  }
+
+  return t.isScopable(node);
+};
+
 toFastProperties(t);
 toFastProperties(t.VISITOR_KEYS);