Avoid unnecessarily analyzing scope

Author: zodern

lib/assignment-visitor.js

@@ -79,14 +79,22 @@ function assignmentHelper(visitor, path, childName) {
   const child = path.getValue()[childName];
   const assignedNames = utils.getNamesFromPattern(child);
   const nameCount = assignedNames.length;
-  const scope = path.getScope();
+
+  let scope = null;
+  function inModuleScope(name) {
+    if (scope === null) {
+      scope = path.getScope();
+    }
+
+    return !scope || scope.find_owner(name).parent === null;
+  }
 
   // Wrap assignments to exported identifiers with `module.runSetters`.
   for (let i = 0; i < nameCount; ++i) {
     let name = assignedNames[i];
     if (
       visitor.exportedLocalNames[name] === true &&
-      (!scope || scope.find_owner(name).parent === null)
+      inModuleScope(name)
     ) {
       wrap(visitor, path);
       break;