fix(es/minifier): Don't inline into nested scope (#6002)

**Related issue:**

- vercel/next.js#30237 (comment)

crates/swc/tests/tsc-references/privateNameClassExpressionLoop.2.minified.js

@@ -3,19 +3,20 @@ import _class_private_field_init from "@swc/helpers/src/_class_private_field_ini
 import _class_private_method_init from "@swc/helpers/src/_class_private_method_init.mjs";
 let array = [];
 for(let i = 0; i < 10; ++i){
+    var _myField, _method, _accessor;
     function get_accessor() {
         return 42;
     }
     function set_accessor(val) {}
-    array.push(class {
+    array.push((_myField = new WeakMap(), _method = new WeakSet(), _accessor = new WeakMap(), class {
         constructor(){
-            _class_private_method_init(this, new WeakSet()), _class_private_field_init(this, new WeakMap(), {
+            _class_private_method_init(this, _method), _class_private_field_init(this, _accessor, {
                 get: get_accessor,
                 set: set_accessor
-            }), _class_private_field_init(this, new WeakMap(), {
+            }), _class_private_field_init(this, _myField, {
                 writable: !0,
                 value: "hello"
             });
         }
-    });
+    }));
 }

crates/swc/tests/tsc-references/typeOfThisInStaticMembers12(target=es2015).2.minified.js

@@ -1,10 +1,10 @@
 //// [typeOfThisInStaticMembers12.ts]
 var _Inner;
-let _c;
+let _c, _c1;
 class C {
 }
-C.c = "foo", C.bar = (_c = C.c, (_Inner = class {
+C.c = "foo", C.bar = (_c = C.c, _c1 = C.c, (_Inner = class {
     constructor(){
-        this[C.c] = 123;
+        this[_c1] = 123;
     }
 })[_c] = 123, _Inner);

crates/swc/tests/tsc-references/typeOfThisInStaticMembers13(target=es2015).2.minified.js

@@ -1,11 +1,11 @@
 //// [typeOfThisInStaticMembers13.ts]
 var _Inner;
-let _c;
+let _c, _c1;
 import _define_property from "@swc/helpers/src/_define_property.mjs";
 class C {
 }
-_define_property(C, "c", "foo"), _define_property(C, "bar", (_c = C.c, _Inner = class {
+_define_property(C, "c", "foo"), _define_property(C, "bar", (_c = C.c, _c1 = C.c, _Inner = class {
     constructor(){
-        _define_property(this, C.c, 123);
+        _define_property(this, _c1, 123);
     }
 }, _define_property(_Inner, _c, 123), _Inner));

crates/swc_ecma_minifier/src/analyzer/mod.rs

@@ -425,6 +425,24 @@ where
         })
     }
 
+    #[cfg_attr(feature = "debug", tracing::instrument(skip_all))]
+    fn visit_constructor(&mut self, n: &Constructor) {
+        self.with_child(n.span.ctxt, ScopeKind::Fn, |child| {
+            {
+                let ctx = Ctx {
+                    in_pat_of_param: true,
+                    ..child.ctx
+                };
+                n.params.visit_with(&mut *child.with_ctx(ctx));
+            }
+
+            // Bypass visit_block_stmt
+            if let Some(body) = &n.body {
+                body.visit_with(child);
+            }
+        })
+    }
+
     #[cfg_attr(feature = "debug", tracing::instrument(skip(self, n)))]
     fn visit_assign_expr(&mut self, n: &AssignExpr) {
         let ctx = Ctx {

crates/swc_ecma_minifier/src/compress/optimize/sequences.rs

@@ -1308,6 +1308,10 @@ where
             )
         };
 
+        if b.is_class() || b.is_fn_expr() || b.is_arrow() {
+            return Ok(false);
+        }
+
         match a {
             Mergable::Var(..) => {}
             Mergable::Expr(a) => {

crates/swc_ecma_minifier/src/compress/util/mod.rs

@@ -347,20 +347,10 @@ pub(crate) fn negate_cost(
                         return cost(expr_ctx, last, in_bool_ctx, bin_op, is_ret_val_ignored);
                     }
 
-                    if is_ret_val_ignored {
-                        0
-                    } else {
-                        1
-                    }
+                    isize::from(!is_ret_val_ignored)
                 }
 
-                _ => {
-                    if is_ret_val_ignored {
-                        0
-                    } else {
-                        1
-                    }
-                }
+                _ => isize::from(!is_ret_val_ignored),
             }
         })();
 

crates/swc_ecma_minifier/src/util/size.rs

@@ -162,7 +162,7 @@ impl SizeWithCtxt for Expr {
                         _ => 2 + params.size(unresolved),
                     };
                     let a = if *is_async {
-                        5 + if params.len() == 1 { 0 } else { 1 }
+                        5 + usize::from(params.len() != 1)
                     } else {
                         0
                     };

crates/swc_ecma_minifier/tests/fixture/next/octokit/config.json

@@ -0,0 +1,4 @@
+{
+    "defaults": true,
+    "toplevel": true
+}