From dea41dc132da8d4990d7eca5dd42e32f3a54b761 Mon Sep 17 00:00:00 2001
From: sapphi-red <49056869+sapphi-red@users.noreply.github.com>
Date: Fri, 15 Aug 2025 11:26:25 +0000
Subject: [PATCH] feat(minifier): compress `Object(expr)(args)` to `(0,
 expr)(args)` (#13092)

Compress `Object(expr)(args)` to `(0, expr)(args)`.

This can be done because
- the function call throws an error if the callee is not a function.
- `Object(expr)` would output a function if and only if `expr` is a function.

---

**References**

- [spec of `Object()`](https://tc39.es/ecma262/2025/multipage/fundamental-objects.html#sec-object-value)
---
 .../peephole/substitute_alternate_syntax.rs   | 54 +++++++++++++++++++
 tasks/minsize/minsize.snap                    |  4 +-
 2 files changed, 56 insertions(+), 2 deletions(-)

diff --git a/crates/oxc_minifier/src/peephole/substitute_alternate_syntax.rs b/crates/oxc_minifier/src/peephole/substitute_alternate_syntax.rs
index 40f16b059cd99..867787660fc77 100644
--- a/crates/oxc_minifier/src/peephole/substitute_alternate_syntax.rs
+++ b/crates/oxc_minifier/src/peephole/substitute_alternate_syntax.rs
@@ -131,6 +131,7 @@ impl<'a> PeepholeOptimizations {
 
     pub fn substitute_call_expression(expr: &mut CallExpression<'a>, ctx: &mut Ctx<'a, '_>) {
         Self::try_flatten_arguments(&mut expr.arguments, ctx);
+        Self::try_rewrite_object_callee_indirect_call(expr, ctx);
     }
 
     pub fn substitute_new_expression(expr: &mut NewExpression<'a>, ctx: &mut Ctx<'a, '_>) {
@@ -885,6 +886,49 @@ impl<'a> PeepholeOptimizations {
         ctx.state.changed = true;
     }
 
+    /// `Object(expr)(args)` -> `(0, expr)(args)`
+    ///
+    /// If `expr` is `null` or `undefined`, both before and after throws an TypeError ("something is not a function").
+    /// It is because `Object(expr)` returns `{}`.
+    ///
+    /// If `expr` is other primitive values, both before and after throws an TypeError ("something is not a function").
+    /// It is because `Object(expr)` returns the Object wrapped values (e.g. `new Boolean()`).
+    ///
+    /// If `expr` is an object / function, `Object(expr)` returns `expr` as-is.
+    /// Note that we need to wrap `expr` as `(0, expr)` so that the `this` value is preserved.
+    ///
+    /// <https://tc39.es/ecma262/2025/multipage/fundamental-objects.html#sec-object-value>
+    fn try_rewrite_object_callee_indirect_call(
+        expr: &mut CallExpression<'a>,
+        ctx: &mut Ctx<'a, '_>,
+    ) {
+        let Expression::CallExpression(inner_call) = &mut expr.callee else { return };
+        if inner_call.optional || inner_call.arguments.len() != 1 {
+            return;
+        }
+        let Expression::Identifier(callee) = &inner_call.callee else {
+            return;
+        };
+        if callee.name != "Object" || !ctx.is_global_reference(callee) {
+            return;
+        }
+
+        let span = inner_call.span;
+        let Some(arg_expr) = inner_call.arguments[0].as_expression_mut() else {
+            return;
+        };
+
+        let new_callee = ctx.ast.expression_sequence(
+            span,
+            ctx.ast.vec_from_array([
+                ctx.ast.expression_numeric_literal(span, 0.0, None, NumberBase::Decimal),
+                arg_expr.take_in(ctx.ast),
+            ]),
+        );
+        expr.callee = new_callee;
+        ctx.state.changed = true;
+    }
+
     /// Remove name from function expressions if it is not used.
     ///
     /// e.g. `var a = function f() {}` -> `var a = function () {}`
@@ -1832,4 +1876,14 @@ mod test {
         test("var {y: z, 'z': y} = x", "var {y: z, z: y} = x");
         test("var {y: y, 'z': z} = x", "var {y, z} = x");
     }
+
+    #[test]
+    fn test_object_callee_indirect_call() {
+        test("Object(f)(1,2)", "f(1, 2)");
+        test("(Object(g))(a)", "g(a)");
+        test("Object(a.b)(x)", "(0, a.b)(x)");
+        test_same("Object?.(f)(1)");
+        test_same("function Object(x){return x} Object(f)(1)");
+        test_same("Object(...a)(1)");
+    }
 }
diff --git a/tasks/minsize/minsize.snap b/tasks/minsize/minsize.snap
index 988c5f036e56e..1be9605400185 100644
--- a/tasks/minsize/minsize.snap
+++ b/tasks/minsize/minsize.snap
@@ -17,11 +17,11 @@ Original   | minified   | minified   | gzip       | gzip       | Iterations | Fi
 
 1.25 MB    | 646.98 kB  | 646.76 kB  | 160.27 kB  | 163.73 kB  |          2 | three.js   
 
-2.14 MB    | 717.51 kB  | 724.14 kB  | 161.88 kB  | 181.07 kB  |          2 | victory.js 
+2.14 MB    | 715.66 kB  | 724.14 kB  | 161.78 kB  | 181.07 kB  |          2 | victory.js 
 
 3.20 MB    | 1.01 MB    | 1.01 MB    | 324.08 kB  | 331.56 kB  |          2 | echarts.js 
 
-6.69 MB    | 2.25 MB    | 2.31 MB    | 463.12 kB  | 488.28 kB  |          3 | antd.js    
+6.69 MB    | 2.23 MB    | 2.31 MB    | 462.26 kB  | 488.28 kB  |          3 | antd.js    
 
 10.95 MB   | 3.35 MB    | 3.49 MB    | 860.97 kB  | 915.50 kB  |          2 | typescript.js