fix(es/minifier): Fix minifier (#2564)

swc_ecma_minifier:
 - Don't change depth of function while negating if statements. (#2558)

swc_ecma_transforms_optimization:
 - `dead_branch_remover`: Preserve `this`. (#2465, #2466)

swc:
 - Make `toplevel` default to true if `module` is true. (#2254)

Author: kdy1

Cargo.lock

@@ -21,7 +21,7 @@ include = ["Cargo.toml", "src/**/*.rs"]
 license = "Apache-2.0/MIT"
 name = "swc"
 repository = "https://github.com/swc-project/swc.git"
-version = "0.79.1"
+version = "0.79.2"
 
 [lib]
 name = "swc"

Cargo.toml

@@ -7,7 +7,7 @@ include = ["Cargo.toml", "src/**/*.rs", "src/lists/*.json"]
 license = "Apache-2.0/MIT"
 name = "swc_ecma_minifier"
 repository = "https://github.com/swc-project/swc.git"
-version = "0.46.5"
+version = "0.46.6"
 
 [features]
 debug = ["backtrace"]

ecmascript/minifier/Cargo.toml

@@ -75,8 +75,19 @@ impl<M> Pure<'_, M> {
         );
 
         let mut new = vec![];
+        let mut fn_decls = vec![];
         new.extend(stmts.drain(..pos_of_if));
-        let cons = stmts.drain(1..).collect::<Vec<_>>();
+        let cons = stmts
+            .drain(1..)
+            .filter_map(|stmt| {
+                if matches!(stmt, Stmt::Decl(Decl::Fn(..))) {
+                    fn_decls.push(stmt);
+                    return None;
+                }
+
+                Some(stmt)
+            })
+            .collect::<Vec<_>>();
 
         let if_stmt = stmts.take().into_iter().next().unwrap();
         match if_stmt {
@@ -101,6 +112,8 @@ impl<M> Pure<'_, M> {
             }
         }
 
+        new.extend(fn_decls);
+
         *stmts = new;
     }
 }

ecmascript/minifier/src/compress/pure/if_return.rs

@@ -7,35 +7,30 @@ function _defineProperties(target, props) {
         descriptor.enumerable = descriptor.enumerable || !1, descriptor.configurable = !0, "value" in descriptor && (descriptor.writable = !0), Object.defineProperty(target, descriptor.key, descriptor);
     }
 }
-function _createClass(Constructor, protoProps, staticProps) {
-    return protoProps && _defineProperties(Constructor.prototype, protoProps), staticProps && _defineProperties(Constructor, staticProps), Constructor;
-}
-function _defineProperty(obj, key, value) {
-    return key in obj ? Object.defineProperty(obj, key, {
-        value: value,
-        enumerable: !0,
-        configurable: !0,
-        writable: !0
-    }) : obj[key] = value, obj;
-}
 var ClassA1 = function ClassA() {
     "use strict";
     _classCallCheck(this, ClassA);
 };
 module.exports = (function() {
-    var ClassB1 = function() {
+    var obj, value, ClassB1 = function() {
         "use strict";
+        var Constructor, protoProps, staticProps;
         function ClassB() {
             _classCallCheck(this, ClassB);
         }
-        return _createClass(ClassB, [
+        return Constructor = ClassB, protoProps = [
             {
                 key: "it",
                 value: function() {
                     this.bb = new ClassB.MyA();
                 }
             }
-        ]), ClassB;
+        ], _defineProperties(Constructor.prototype, protoProps), staticProps && _defineProperties(Constructor, staticProps), ClassB;
     }();
-    return _defineProperty(ClassB1, "MyA", ClassA1), ClassB1;
+    return obj = ClassB1, value = ClassA1, "MyA" in obj ? Object.defineProperty(obj, "MyA", {
+        value: value,
+        enumerable: !0,
+        configurable: !0,
+        writable: !0
+    }) : obj.MyA = value, ClassB1;
 })();

ecmascript/minifier/tests/compress/fixture/issues/2011/actual/output.js

@@ -1,7 +1,6 @@
-class ClassA {
-}
 module.exports = class ClassB {
-    static MyA = ClassA;
+    static MyA = class {
+    };
     it() {
         this.bb = new ClassB.MyA();
     }

ecmascript/minifier/tests/compress/fixture/issues/2011/reduced/output.js

@@ -1,7 +1,3 @@
-function isSymbol(s) {
-    return null != s;
-}
-function isKey(value, object) {
-    return !!(null == value || isSymbol(value));
-}
-module.exports = isKey;
+module.exports = function(value, object) {
+    return null == value || null != value;
+};

ecmascript/minifier/tests/compress/fixture/issues/2028/output.js

@@ -1,10 +1,6 @@
 function createCommonjsModule(fn) {
     return fn();
 }
-const isFile = (config)=>!0
-, pkgBrowserslist = {
-}, config = {
-};
 createCommonjsModule(function(module, exports) {
     Object.defineProperty(exports, "__esModule", {
         value: !0
@@ -32,11 +28,9 @@ createCommonjsModule(function(module, exports) {
     exports.default = null, module.exports = exports.default;
 }), createCommonjsModule(function(module, exports) {
     exports.default = void 0;
-});
-var namespace$1 = createCommonjsModule(function(module, exports) {
+}), createCommonjsModule(function(module, exports) {
     exports.default = void 0, module.exports = exports.default;
-});
-createCommonjsModule(function(module, exports) {
+}), createCommonjsModule(function(module, exports) {
     exports.default = void 0, module.exports = exports.default;
 }), createCommonjsModule(function(module, exports) {
     exports.default = void 0, exports.default = String;

ecmascript/minifier/tests/compress/fixture/issues/2044/full/output.js

@@ -1,8 +0,0 @@
-function cost(oldItem, newItem) {
-    if (newItem.val === oldItem.val) return 0;
-    if ("object" == typeof oldItem.val && "object" == typeof newItem.val) {
-        if (void 0 === oldItem.key || void 0 === newItem.key) return 1;
-        if (oldItem.key === newItem.key) return 0;
-    }
-    return 1;
-}

ecmascript/minifier/tests/compress/fixture/issues/2072/1/output.js

@@ -1,7 +0,0 @@
-function f(a, b) {
-    if (a) {
-        if (b) return;
-        foo();
-    }
-    bar();
-}