add BindingIdentifier virtual type

src/babel/transformation/helpers/name-method.js

@@ -20,11 +20,8 @@ var visitor = {
     visitIdentifier(this, node, scope, state);
   },
 
-  AssignmentExpression(node, parent, scope, state) {
+  BindingIdentifier(node, parent, scope, state) {
-    var ids = this.getBindingIdentifiers();
+    visitIdentifier(this, node, scope, state);
-    for (var name in ids) {
-      visitIdentifier(this, ids[name], scope, state);
-    }
   }
 };
 

src/babel/traversal/path/lib/virtual-types.js

@@ -18,6 +18,13 @@ export var ReferencedIdentifier = {
   }
 };
 
+export var BindingIdentifier = {
+  types: ["Identifier"],
+  checkPath({ node, parent }, opts) {
+    return t.isBinding(node, parent);
+  }
+};
+
 export var Expression = {
   types: ["Expression"],
   checkPath(path) {

src/babel/types/validators.js

@@ -1,6 +1,20 @@
+import { getBindingIdentifiers } from "./retrievers";
 import esutils from "esutils";
 import * as t from "./index";
 
+/**
+ *
+ */
+
+export function isBinding(node: Object, parent: Object): boolean {
+  var bindingKey = getBindingIdentifiers.keys[parent.type];
+  if (bindingKey) {
+    return parent[bindingKey] === node;
+  } else {
+    return false;
+  }
+}
+
 /**
  * Check if the input `node` is a reference to a bound variable.
  */