feat(es/minifier): Ignore closure in initializer from sequential inli…

…ner (#5702)

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

@@ -6,10 +6,6 @@ var Private = function Private() {
     "use strict";
     for(var _len = arguments.length, args = Array(_len), _key = 0; _key < _len; _key++)args[_key] = arguments[_key];
     _class_call_check(this, Private);
-}, Private2 = function Private2() {
-    "use strict";
-    for(var _len = arguments.length, args = Array(_len), _key = 0; _key < _len; _key++)args[_key] = arguments[_key];
-    _class_call_check(this, Private2);
 }, Protected = function Protected() {
     "use strict";
     for(var _len = arguments.length, args = Array(_len), _key = 0; _key < _len; _key++)args[_key] = arguments[_key];
@@ -27,7 +23,11 @@ var Private = function Private() {
     for(var _len = arguments.length, args = Array(_len), _key = 0; _key < _len; _key++)args[_key] = arguments[_key];
     _class_call_check(this, Public2);
 };
-Mix(Private, Private2), Mix(Private, Protected), Mix(Private, Public);
+Mix(Private, function Private2() {
+    "use strict";
+    for(var _len = arguments.length, args = Array(_len), _key = 0; _key < _len; _key++)args[_key] = arguments[_key];
+    _class_call_check(this, Private2);
+}), Mix(Private, Protected), Mix(Private, Public);
 var C4 = function(_superClass) {
     "use strict";
     _inherits(C4, _superClass);

crates/swc/tests/tsc-references/typeOfThisInStaticMembers11(target=es5).2.minified.js

@@ -7,10 +7,10 @@ import _get_prototype_of from "@swc/helpers/src/_get_prototype_of.mjs";
 import _inherits from "@swc/helpers/src/_inherits.mjs";
 import _create_super from "@swc/helpers/src/_create_super.mjs";
 import _ts_decorate from "@swc/helpers/src/_ts_decorate.mjs";
-var _C, _D, C = (_C = function C() {
+var _C, _D, C = (_define_property(_C = function C() {
     "use strict";
     _class_call_check(this, C);
-}, _define_property(_C, "a", 1), _define_property(_C, "b", _C.a + 1), _C), D = (_D = function(C) {
+}, "a", 1), _define_property(_C, "b", _C.a + 1), _C), D = (_D = function(C) {
     "use strict";
     _inherits(D, C);
     var _super = _create_super(D);

crates/swc_ecma_minifier/src/alias/mod.rs

@@ -12,15 +12,50 @@ use crate::marks::Marks;
 
 mod ctx;
 
+#[derive(Default)]
 pub(crate) struct AliasConfig {
     pub marks: Option<Marks>,
+    pub ignore_nested: bool,
+}
+
+pub(crate) trait InfectableNode {
+    fn is_fn_or_arrow_expr(&self) -> bool;
+}
+
+impl InfectableNode for Function {
+    fn is_fn_or_arrow_expr(&self) -> bool {
+        false
+    }
+}
+
+impl InfectableNode for Expr {
+    fn is_fn_or_arrow_expr(&self) -> bool {
+        match self {
+            Expr::Arrow(..) | Expr::Fn(..) => true,
+            _ => false,
+        }
+    }
+}
+
+impl<T> InfectableNode for Box<T>
+where
+    T: InfectableNode,
+{
+    fn is_fn_or_arrow_expr(&self) -> bool {
+        (**self).is_fn_or_arrow_expr()
+    }
 }
 
 pub(crate) fn collect_infects_from<N>(node: &N, config: AliasConfig) -> FxHashSet<Id>
 where
-    N: for<'aa> VisitWith<InfectionCollector<'aa>>,
-    N: VisitWith<BindingCollector<Id>>,
+    N: InfectableNode
+        + VisitWith<BindingCollector<Id>>
+        + for<'aa> VisitWith<InfectionCollector<'aa>>,
 {
+    if config.ignore_nested && node.is_fn_or_arrow_expr() {
+        return Default::default();
+    }
+
     let unresolved_ctxt = config
         .marks
         .map(|m| SyntaxContext::empty().apply_mark(m.unresolved_mark));

crates/swc_ecma_minifier/src/analyzer/mod.rs

@@ -722,7 +722,13 @@ where
         self.used_recursively.remove(&id);
 
         {
-            for id in collect_infects_from(&n.function, AliasConfig { marks: self.marks }) {
+            for id in collect_infects_from(
+                &n.function,
+                AliasConfig {
+                    marks: self.marks,
+                    ..Default::default()
+                },
+            ) {
                 self.data
                     .var_or_default(n.ident.to_id())
                     .add_infects_to(id.clone());
@@ -740,7 +746,13 @@ where
                 .mark_declared_as_fn_expr();
 
             {
-                for id in collect_infects_from(&n.function, AliasConfig { marks: self.marks }) {
+                for id in collect_infects_from(
+                    &n.function,
+                    AliasConfig {
+                        marks: self.marks,
+                        ..Default::default()
+                    },
+                ) {
                     self.data
                         .var_or_default(n_id.to_id())
                         .add_infects_to(id.to_id());
@@ -1100,7 +1112,13 @@ where
 
         for decl in &n.decls {
             if let (Pat::Ident(var), Some(init)) = (&decl.name, decl.init.as_deref()) {
-                for id in collect_infects_from(init, AliasConfig { marks: self.marks }) {
+                for id in collect_infects_from(
+                    init,
+                    AliasConfig {
+                        marks: self.marks,
+                        ..Default::default()
+                    },
+                ) {
                     self.data
                         .var_or_default(var.to_id())
                         .add_infects_to(id.clone());

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

@@ -977,6 +977,7 @@ where
                                 init,
                                 AliasConfig {
                                     marks: Some(self.marks),
+                                    ignore_nested: true,
                                 },
                             )
                         }),
@@ -992,6 +993,7 @@ where
                                         right,
                                         AliasConfig {
                                             marks: Some(self.marks),
+                                            ignore_nested: true,
                                         },
                                     ))
                                 } else {

crates/swc_ecma_minifier/tests/fixture/issues/2257/full/output.js

@@ -7795,7 +7795,7 @@
                     has(AllSymbols, key) && (!IS_OBJECT_PROTOTYPE || has(ObjectPrototype, key)) && result.push(AllSymbols[key]);
                 }), result;
             };
-            if (NATIVE_SYMBOL || ($Symbol = function() {
+            if (NATIVE_SYMBOL || (redefine(($Symbol = function() {
                 if (this instanceof $Symbol) throw TypeError("Symbol is not a constructor");
                 var description = arguments.length && void 0 !== arguments[0] ? $toString(arguments[0]) : void 0, tag = uid(description), setter = function(value) {
                     this === ObjectPrototype && setter.call(ObjectPrototypeSymbols, value), has(this, HIDDEN) && has(this[HIDDEN], tag) && (this[HIDDEN][tag] = !1), setSymbolDescriptor(this, tag, createPropertyDescriptor(1, value));
@@ -7804,7 +7804,7 @@
                     configurable: !0,
                     set: setter
                 }), wrap(tag, description);
-            }, redefine($Symbol[PROTOTYPE], "toString", function() {
+            })[PROTOTYPE], "toString", function() {
                 return getInternalState(this).tag;
             }), redefine($Symbol, "withoutSetter", function(description) {
                 return wrap(uid(description), description);