From cbe0e8239d35d2095864f5bb0f6efecfb51649f4 Mon Sep 17 00:00:00 2001
From: Boshen <1430279+Boshen@users.noreply.github.com>
Date: Sun, 26 Jan 2025 10:30:33 +0000
Subject: [PATCH] feat(minifier): minimize `foo(...[])` -> `foo()` (#8726)

---
 crates/oxc_minifier/src/peephole/mod.rs         |  8 ++++++++
 .../src/peephole/remove_dead_code.rs            | 17 +++++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/crates/oxc_minifier/src/peephole/mod.rs b/crates/oxc_minifier/src/peephole/mod.rs
index a8558c03f5353..87d319ce13178 100644
--- a/crates/oxc_minifier/src/peephole/mod.rs
+++ b/crates/oxc_minifier/src/peephole/mod.rs
@@ -306,6 +306,14 @@ impl<'a> Traverse<'a> for LatePeepholeOptimizations {
     fn exit_catch_clause(&mut self, catch: &mut CatchClause<'a>, ctx: &mut TraverseCtx<'a>) {
         self.substitute_catch_clause(catch, Ctx(ctx));
     }
+
+    fn exit_call_expression(&mut self, e: &mut CallExpression<'a>, _ctx: &mut TraverseCtx<'a>) {
+        Self::remove_empty_spread_arguments(&mut e.arguments);
+    }
+
+    fn exit_new_expression(&mut self, e: &mut NewExpression<'a>, _ctx: &mut TraverseCtx<'a>) {
+        Self::remove_empty_spread_arguments(&mut e.arguments);
+    }
 }
 
 pub struct DeadCodeElimination {
diff --git a/crates/oxc_minifier/src/peephole/remove_dead_code.rs b/crates/oxc_minifier/src/peephole/remove_dead_code.rs
index bd76163110170..b9a9e8941e163 100644
--- a/crates/oxc_minifier/src/peephole/remove_dead_code.rs
+++ b/crates/oxc_minifier/src/peephole/remove_dead_code.rs
@@ -620,6 +620,17 @@ impl<'a> LatePeepholeOptimizations {
     pub fn remove_dead_code_exit_class_body(body: &mut ClassBody<'a>, _ctx: Ctx<'a, '_>) {
         body.body.retain(|e| !matches!(e, ClassElement::StaticBlock(s) if s.body.is_empty()));
     }
+
+    pub fn remove_empty_spread_arguments(args: &mut Vec<'a, Argument<'a>>) {
+        if args.len() != 1 {
+            return;
+        }
+        let Argument::SpreadElement(e) = &args[0] else { return };
+        let Expression::ArrayExpression(e) = &e.argument else { return };
+        if e.elements.is_empty() {
+            args.drain(..);
+        }
+    }
 }
 
 /// <https://github.com/google/closure-compiler/blob/v20240609/test/com/google/javascript/jscomp/PeepholeRemoveDeadCodeTest.java>
@@ -898,4 +909,10 @@ mod test {
         test_same("throw foo; export let bar");
         test_same("throw foo; export default bar");
     }
+
+    #[test]
+    fn remove_empty_spread_arguments() {
+        test("foo(...[])", "foo()");
+        test("new Foo(...[])", "new Foo()");
+    }
 }