use standard loops and array.push for performance

sebastian-fredriksson-bernholtz · brettz9 · commit bf0acfe5c048 · 2025-03-17T17:11:54.000+08:00
realised that performance matter a lot for eslint, and functional map, recursive calls and converting forth and back between set and creating new arrays would not be very performant, so changed implementation to old style loops and working with a single SET
diff --git a/src/rules/noUndefinedTypes.js b/src/rules/noUndefinedTypes.js
@@ -227,12 +227,14 @@ export default iterateJsdoc(({
    * @returns {Set<string>}
    */
   const getValidRuntimeIdentifiers = (scope) => {
-    return scope
-      ? new Set([
-          ...new Set(scope.variables.map(({ name }) => name)),
-          ...getValidRuntimeIdentifiers(scope.upper),
-        ])
-      : new Set();
+    const result = new Set()
+    while (scope) {
+      for (const {name} of scope.variables) {
+        result.add(name)
+      }
+      scope = scope.upper
+    }
+    return result
   };
 
   const allDefinedTypes = new Set(globalScope.variables.map(({
