fix module binding resolution - fixes #762

lib/6to5/traversal/scope.js

@@ -141,7 +141,7 @@ Scope.prototype.checkBlockScopedCollisions = function (kind, name, id) {
   if (kind === "param") return;
   if (kind === "hoisted" && local.kind === "let") return;
 
-  if (local.kind === "let" || local.kind === "const") {
+  if (local.kind === "let" || local.kind === "const" || local.kind === "module") {
     throw this.file.errorWithNode(id, messages.get("scopeDuplicateDeclaration", name), TypeError);
   }
 };

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

@@ -22,6 +22,9 @@
   "FunctionDeclaration":     ["Statement", "Declaration", "Scopable", "Function"],
   "FunctionExpression":      ["Scopable", "Function", "Expression"],
 
+  "ImportSpecifier": ["ModuleSpecifier"],
+  "ExportSpecifier": ["ModuleSpecifier"],
+
   "BlockStatement": ["Statement", "Scopable"],
   "Program":        ["Scopable"],
   "CatchClause":    ["Scopable"],

lib/6to5/types/index.js

@@ -590,6 +590,8 @@ t.getBindingIdentifiers = function (node) {
 
     if (t.isIdentifier(id)) {
       ids[id.name] = id;
+    } else if (t.isModuleSpecifier(id)) {
+      search.push(id.name || id.id);
     } else if (t.isExportDeclaration(id)) {
       if (t.isDeclaration(node.declaration)) {
         search.push(node.declaration);
@@ -608,8 +610,6 @@ t.getBindingIdentifiers = function (node) {
 t.getBindingIdentifiers.keys = {
   AssignmentExpression: ["left"],
   ImportBatchSpecifier: ["name"],
-  ImportSpecifier: ["name", "id"],
-  ExportSpecifier: ["name", "id"],
   VariableDeclarator: ["id"],
   FunctionDeclaration: ["id"],
   ClassDeclaration: ["id"],