From 0400ff9ea5864bb7ce99e9a428ecf364c350971c Mon Sep 17 00:00:00 2001
From: overlookmotel <557937+overlookmotel@users.noreply.github.com>
Date: Tue, 1 Oct 2024 22:44:51 +0000
Subject: [PATCH] refactor(transformer): `VarDeclarations` common transform:
 check if at top level with `ctx.parent()` (#6231)

Micro-optimization. The stack of ancestors is now a `NonEmptyStack`, so `ctx.parent()` is now cheaper than `ctx.ancestors_depth()`.
---
 crates/oxc_transformer/src/common/var_declarations.rs | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/crates/oxc_transformer/src/common/var_declarations.rs b/crates/oxc_transformer/src/common/var_declarations.rs
index 24f5d9ab16b5c..3ae3bcf824ca1 100644
--- a/crates/oxc_transformer/src/common/var_declarations.rs
+++ b/crates/oxc_transformer/src/common/var_declarations.rs
@@ -19,7 +19,7 @@ use oxc_ast::{ast::*, NONE};
 use oxc_data_structures::stack::SparseStack;
 use oxc_span::SPAN;
 use oxc_syntax::symbol::SymbolId;
-use oxc_traverse::{Traverse, TraverseCtx};
+use oxc_traverse::{Ancestor, Traverse, TraverseCtx};
 
 use crate::TransformCtx;
 
@@ -59,9 +59,8 @@ impl<'a, 'ctx> Traverse<'a> for VarDeclarations<'a, 'ctx> {
     }
 
     fn exit_statements(&mut self, stmts: &mut Vec<'a, Statement<'a>>, ctx: &mut TraverseCtx<'a>) {
-        if ctx.ancestors_depth() == 2 {
-            // Top level. Handle in `exit_program` instead.
-            // (depth 1 = None, depth 2 = Program)
+        if matches!(ctx.parent(), Ancestor::ProgramBody(_)) {
+            // Handle in `exit_program` instead
             return;
         }