From e2a0997911aadc88bb5a24d53bd66a9538f9264f Mon Sep 17 00:00:00 2001
From: overlookmotel <557937+overlookmotel@users.noreply.github.com>
Date: Fri, 14 Nov 2025 12:55:21 +0000
Subject: [PATCH] perf(linter/plugins): recycle empty visitor object in ESLint
 compat mode (#15693)

Small perf optimization. In ESLint compat mode, `create` returns an empty visitor object when `before` hook returns `false`. Reuse the same object, instead of creating a new one each time.
---
 apps/oxlint/src-js/index.ts | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/apps/oxlint/src-js/index.ts b/apps/oxlint/src-js/index.ts
index b1feb57c5493d..ec03f26d83d04 100644
--- a/apps/oxlint/src-js/index.ts
+++ b/apps/oxlint/src-js/index.ts
@@ -51,6 +51,9 @@ const {
   assign: ObjectAssign,
 } = Object;
 
+// Empty visitor object, returned by `create` when `before` hook returns `false`.
+const EMPTY_VISITOR: Visitor = {};
+
 /**
  * Define a plugin.
  *
@@ -124,7 +127,7 @@ export function defineRule(rule: Rule): Rule {
     // If `before` hook returns `false`, skip traversal by returning an empty object as visitor
     if (beforeHook !== null) {
       const shouldRun = beforeHook();
-      if (shouldRun === false) return {};
+      if (shouldRun === false) return EMPTY_VISITOR;
     }
 
     // Return same visitor each time