From 6ea0f9c3635d3e20b9a6aa13d6745086c7c10a3b Mon Sep 17 00:00:00 2001
From: CPunisher <1343316114@qq.com>
Date: Mon, 15 Jul 2024 13:11:06 +0800
Subject: [PATCH 1/2] Remove opt of array pat

---
 .../src/simplify/branch/mod.rs                | 28 +------------------
 1 file changed, 1 insertion(+), 27 deletions(-)

diff --git a/crates/swc_ecma_transforms_optimization/src/simplify/branch/mod.rs b/crates/swc_ecma_transforms_optimization/src/simplify/branch/mod.rs
index 6c248ec58ec7..e6adb6013493 100644
--- a/crates/swc_ecma_transforms_optimization/src/simplify/branch/mod.rs
+++ b/crates/swc_ecma_transforms_optimization/src/simplify/branch/mod.rs
@@ -1,4 +1,4 @@
-use std::{borrow::Cow, cmp::min, iter::once, mem::take};
+use std::{borrow::Cow, iter::once, mem::take};
 
 use swc_common::{
     pass::{CompilerPass, Repeated},
@@ -75,32 +75,6 @@ impl Parallel for Remover {
 impl VisitMut for Remover {
     standard_only_visit_mut!();
 
-    fn visit_mut_array_pat(&mut self, p: &mut ArrayPat) {
-        p.visit_mut_children_with(self);
-
-        let mut preserved = None;
-        let len = p.elems.len();
-        for (i, p) in p.elems.iter().enumerate() {
-            let can_be_removed = match p {
-                Some(Pat::Array(ref p)) if p.elems.is_empty() => true,
-                Some(Pat::Object(ref p)) if p.props.is_empty() => true,
-                _ => false,
-            };
-
-            if !can_be_removed {
-                preserved = Some(min(i + 1, len))
-            }
-        }
-
-        if let Some(i) = preserved {
-            if cfg!(feature = "debug") {
-                debug!("Removing elements of an array pattern");
-            }
-
-            p.elems.drain(i..);
-        }
-    }
-
     fn visit_mut_expr(&mut self, e: &mut Expr) {
         e.visit_mut_children_with(self);
 

From 0d5c575d6ce6917acee1e0dcb7f1242c6fd7e0dc Mon Sep 17 00:00:00 2001
From: CPunisher <1343316114@qq.com>
Date: Mon, 15 Jul 2024 13:41:06 +0800
Subject: [PATCH 2/2] Remove testcase

---
 .../src/simplify/branch/tests.rs                       | 10 ----------
 1 file changed, 10 deletions(-)

diff --git a/crates/swc_ecma_transforms_optimization/src/simplify/branch/tests.rs b/crates/swc_ecma_transforms_optimization/src/simplify/branch/tests.rs
index e01c55468fa4..a403e15a2d10 100644
--- a/crates/swc_ecma_transforms_optimization/src/simplify/branch/tests.rs
+++ b/crates/swc_ecma_transforms_optimization/src/simplify/branch/tests.rs
@@ -1432,16 +1432,6 @@ fn test_empty_pattern_in_for_of_loop_not_removed() {
     test_same("for ({} of foo());");
 }
 
-#[test]
-fn test_empty_slot_in_array_pattern_removed() {
-    test("[,,] = foo();", "foo()");
-    test("[a,b,,] = foo();", "[a,b] = foo();");
-    test("[a,[],b,[],[]] = foo();", "[a,[],b] = foo();");
-    test("[a,{},b,{},{}] = foo();", "[a,{},b] = foo();");
-    test("function f([,,,]) {}", "function f([]) {}");
-    test_same("[[], [], [], ...rest] = foo()");
-}
-
 #[test]
 #[ignore]
 fn test_empty_slot_in_array_pattern_with_default_value_maybe_removed_1() {