(fix) Class fields are set to undefined if there's no initializer

crates/swc/tests/fixture/issue-1160/output/entry.ts

@@ -16,11 +16,6 @@ function _applyDecoratedDescriptor(target, property, decorators, descriptor, con
         desc.value = desc.initializer ? desc.initializer.call(context) : void 0;
         desc.initializer = undefined;
     }
-    var own = Object.getOwnPropertyDescriptor(target, property);
-    if (own && (own.get || own.set)) {
-        delete desc.writable;
-        delete desc.initializer;
-    }
     if (desc.initializer === void 0) {
         Object.defineProperty(target, property, desc);
         desc = null;
@@ -53,7 +48,7 @@ let Xpto = ((_class = class Xpto {
     configurable: true,
     enumerable: true,
     writable: true,
-    initializer: void 0
+    initializer: null
 }), _class);
 function Decorator() {
     return function(...args) {};

crates/swc/tests/fixture/issue-1278/output/index.ts

@@ -16,11 +16,6 @@ function _applyDecoratedDescriptor(target, property, decorators, descriptor, con
         desc.value = desc.initializer ? desc.initializer.call(context) : void 0;
         desc.initializer = undefined;
     }
-    var own = Object.getOwnPropertyDescriptor(target, property);
-    if (own && (own.get || own.set)) {
-        delete desc.writable;
-        delete desc.initializer;
-    }
     if (desc.initializer === void 0) {
         Object.defineProperty(target, property, desc);
         desc = null;
@@ -54,6 +49,6 @@ let MyClass = ((_class = class MyClass {
     configurable: true,
     enumerable: true,
     writable: true,
-    initializer: void 0
+    initializer: null
 }), _class);
 console.log(new MyClass());

crates/swc/tests/fixture/issue-1345/output/index.ts

@@ -15,11 +15,6 @@ function _applyDecoratedDescriptor(target, property, decorators, descriptor, con
         desc.value = desc.initializer ? desc.initializer.call(context) : void 0;
         desc.initializer = undefined;
     }
-    var own = Object.getOwnPropertyDescriptor(target, property);
-    if (own && (own.get || own.set)) {
-        delete desc.writable;
-        delete desc.initializer;
-    }
     if (desc.initializer === void 0) {
         Object.defineProperty(target, property, desc);
         desc = null;
@@ -75,61 +70,61 @@ export var AccountMemberView = _class = _dec16((_class = function AccountMemberV
     configurable: true,
     enumerable: true,
     writable: true,
-    initializer: void 0
+    initializer: null
 }), _descriptor1 = _applyDecoratedDescriptor(_class.prototype, "mallId", [
     _dec2,
     _dec3
 ], {
     configurable: true,
     enumerable: true,
     writable: true,
-    initializer: void 0
+    initializer: null
 }), _descriptor2 = _applyDecoratedDescriptor(_class.prototype, "allowAccountCnt", [
     _dec4,
     _dec5
 ], {
     configurable: true,
     enumerable: true,
     writable: true,
-    initializer: void 0
+    initializer: null
 }), _descriptor3 = _applyDecoratedDescriptor(_class.prototype, "allowQuickAccountCnt", [
     _dec6,
     _dec7
 ], {
     configurable: true,
     enumerable: true,
     writable: true,
-    initializer: void 0
+    initializer: null
 }), _descriptor4 = _applyDecoratedDescriptor(_class.prototype, "accountEnddedAt", [
     _dec8,
     _dec9
 ], {
     configurable: true,
     enumerable: true,
     writable: true,
-    initializer: void 0
+    initializer: null
 }), _descriptor5 = _applyDecoratedDescriptor(_class.prototype, "accountQuickEnddedAt", [
     _dec10,
     _dec11
 ], {
     configurable: true,
     enumerable: true,
     writable: true,
-    initializer: void 0
+    initializer: null
 }), _descriptor6 = _applyDecoratedDescriptor(_class.prototype, "accountCnt", [
     _dec12,
     _dec13
 ], {
     configurable: true,
     enumerable: true,
     writable: true,
-    initializer: void 0
+    initializer: null
 }), _descriptor7 = _applyDecoratedDescriptor(_class.prototype, "accountQuickCnt", [
     _dec14,
     _dec15
 ], {
     configurable: true,
     enumerable: true,
     writable: true,
-    initializer: void 0
+    initializer: null
 }), _class)) || _class;

crates/swc/tests/fixture/issue-1362/case1/output/index.ts

@@ -23,11 +23,6 @@ function _applyDecoratedDescriptor(target, property, decorators, descriptor, con
         desc.value = desc.initializer ? desc.initializer.call(context) : void 0;
         desc.initializer = undefined;
     }
-    var own = Object.getOwnPropertyDescriptor(target, property);
-    if (own && (own.get || own.set)) {
-        delete desc.writable;
-        delete desc.initializer;
-    }
     if (desc.initializer === void 0) {
         Object.defineProperty(target, property, desc);
         desc = null;

crates/swc/tests/fixture/issue-1421/case1/output/index.ts

@@ -17,11 +17,6 @@ function _applyDecoratedDescriptor(target, property, decorators, descriptor, con
         desc.value = desc.initializer ? desc.initializer.call(context) : void 0;
         desc.initializer = undefined;
     }
-    var own = Object.getOwnPropertyDescriptor(target, property);
-    if (own && (own.get || own.set)) {
-        delete desc.writable;
-        delete desc.initializer;
-    }
     if (desc.initializer === void 0) {
         Object.defineProperty(target, property, desc);
         desc = null;
@@ -60,5 +55,5 @@ var User = ((_class = function User() {
     configurable: true,
     enumerable: true,
     writable: true,
-    initializer: void 0
+    initializer: null
 }), _class);

crates/swc/tests/fixture/issue-2428/1/output/index.ts

@@ -16,11 +16,6 @@ function _applyDecoratedDescriptor(target, property, decorators, descriptor, con
         desc.value = desc.initializer ? desc.initializer.call(context) : void 0;
         desc.initializer = undefined;
     }
-    var own = Object.getOwnPropertyDescriptor(target, property);
-    if (own && (own.get || own.set)) {
-        delete desc.writable;
-        delete desc.initializer;
-    }
     if (desc.initializer === void 0) {
         Object.defineProperty(target, property, desc);
         desc = null;

crates/swc/tests/fixture/issue-3337/output/input.ts

@@ -17,11 +17,6 @@ function _applyDecoratedDescriptor(target, property, decorators, descriptor, con
         desc.value = desc.initializer ? desc.initializer.call(context) : void 0;
         desc.initializer = undefined;
     }
-    var own = Object.getOwnPropertyDescriptor(target, property);
-    if (own && (own.get || own.set)) {
-        delete desc.writable;
-        delete desc.initializer;
-    }
     if (desc.initializer === void 0) {
         Object.defineProperty(target, property, desc);
         desc = null;
@@ -75,5 +70,5 @@ var Schema = ((_class = function Schema() {
     configurable: true,
     enumerable: true,
     writable: true,
-    initializer: void 0
+    initializer: null
 }), _class);

crates/swc_ecma_transforms/tests/decorators.rs

@@ -4467,42 +4467,42 @@ export let Product = _class = _dec6(((_class = class Product extends Timestamped
     configurable: true,
     enumerable: true,
     writable: true,
-    initializer: void 0,
+    initializer: null,
 }), _descriptor1 = _applyDecoratedDescriptor(_class.prototype, 'price', [
     _dec1
 ], {
     configurable: true,
     enumerable: true,
     writable: true,
-    initializer: void 0,
+    initializer: null,
 }), _descriptor2 = _applyDecoratedDescriptor(_class.prototype, 'type', [
     _dec2
 ], {
     configurable: true,
     enumerable: true,
     writable: true,
-    initializer: void 0,
+    initializer: null,
 }), _descriptor3 = _applyDecoratedDescriptor(_class.prototype, 'productEntityId', [
     _dec3
 ], {
     configurable: true,
     enumerable: true,
     writable: true,
-    initializer: void 0,
+    initializer: null,
 }), _descriptor4 = _applyDecoratedDescriptor(_class.prototype, 'orders', [
     _dec4
 ], {
     configurable: true,
     enumerable: true,
     writable: true,
-    initializer: void 0,
+    initializer: null,
 }), _descriptor5 = _applyDecoratedDescriptor(_class.prototype, 'discounts', [
     _dec5
 ], {
     configurable: true,
     enumerable: true,
     writable: true,
-    initializer: void 0
+    initializer: null
 }), _class)) || _class;
 "
 );
@@ -4532,7 +4532,7 @@ export class Product extends TimestampedEntity {
         configurable: true,
         enumerable: true,
         writable: true,
-        initializer: void 0
+        initializer: null
     }), _class)) || _class;
     "
 );
@@ -4789,15 +4789,15 @@ export let AppController = _class = _dec14(_class = _dec13(_class = _dec12(((_cl
     configurable: true,
     enumerable: true,
     writable: true,
-    initializer: void 0
+    initializer: null
 }), _descriptor1 = _applyDecoratedDescriptor(_class.prototype, "appService2", [
     _dec2,
     _dec3
 ], {
     configurable: true,
     enumerable: true,
     writable: true,
-    initializer: void 0
+    initializer: null
 }), _dec4 = Get(), _dec5 = typeof Reflect !== "undefined" && typeof Reflect.metadata === "function" && Reflect.metadata("design:type", Function), _dec6 = typeof Reflect !== "undefined" && typeof Reflect.metadata === "function" && Reflect.metadata("design:paramtypes", []), _applyDecoratedDescriptor(_class.prototype, "getHello", [
     _dec4,
     _dec5,
@@ -5124,7 +5124,7 @@ test!(
         configurable: true,
         enumerable: true,
         writable: true,
-        initializer: void 0
+        initializer: null
     }), _class);
     function Decorator() {
         return function(...args) {
@@ -5719,7 +5719,7 @@ test!(
         configurable: true,
         enumerable: true,
         writable: true,
-        initializer: void 0
+        initializer: null
     }), _class);
     "
 );
@@ -5858,7 +5858,7 @@ test!(
         configurable: true,
         enumerable: true,
         writable: true,
-        initializer: void 0
+        initializer: null
     }), _class);
     console.log(new MyClass());
     "
@@ -6029,7 +6029,7 @@ test!(
       configurable: true,
       enumerable: true,
       writable: true,
-      initializer: void 0
+      initializer: null
   }), _class);"
 );
 
@@ -6048,11 +6048,11 @@ fn fixture(input: PathBuf) {
 
             chain!(
                 resolver_with_mark(top_level_mark),
-                strip(top_level_mark),
                 decorators(Config {
                     legacy: true,
                     emit_metadata: true,
-                })
+                }),
+                strip(top_level_mark),
             )
         },
         &code,

crates/swc_ecma_transforms/tests/fixture/decorator/issue-2117/1/exec.ts

@@ -0,0 +1,10 @@
+class TestClass2 {
+    @deco public testProperty?: string;
+}
+
+function deco(target: any, key: string) {
+    console.log(target, key);
+}
+
+const instance = new TestClass2();
+expect(instance.hasOwnProperty("testProperty")).toBe(true);

crates/swc_ecma_transforms/tests/fixture/decorator/issue-2127/2/exec.ts

@@ -1,6 +1,6 @@
 const returnValue = "asdasd"
 class TestClass2 {
-    @deco public testProperty: Date;
+    @deco public declare testProperty: Date;
 }
 function deco(target: any, key: string) {
     console.log(target, key);

crates/swc_ecma_transforms/tests/fixture/decorator/issue-2127/3/exec.ts

@@ -1,6 +1,6 @@
 const returnValue = "asdasd"
 class TestClass2 {
-    @deco public testProperty: Date;
+    @deco public declare testProperty: Date;
 }
 function deco(target: any, key: string) {
     console.log(target, key);

crates/swc_ecma_transforms_base/src/helpers/_apply_decorated_descriptor.js

@@ -16,14 +16,6 @@ function _applyDecoratedDescriptor(target, property, decorators, descriptor, con
     desc.value = desc.initializer ? desc.initializer.call(context) : void 0;
     desc.initializer = undefined;
   }
-
-  var own = Object.getOwnPropertyDescriptor(target, property);
-  if (own && (own.get || own.set)) {
-    // Prevent overriding
-    delete desc.writable;
-    delete desc.initializer;
-  }
-
   if (desc.initializer === void 0) {
     Object.defineProperty(target, property, desc);
     desc = null;

crates/swc_ecma_transforms_proposal/src/decorators/legacy/mod.rs

@@ -582,9 +582,7 @@ impl Legacy {
                                     },
                                 }))
                             } else {
-                                undefined(DUMMY_SP)
-                                // Box::new(Expr::Lit(Lit::Null(Null { span:
-                                // DUMMY_SP })))
+                                Box::new(Expr::Lit(Lit::Null(Null { span: DUMMY_SP })))
                             },
                         }))),
                     ],
@@ -675,7 +673,7 @@ impl Legacy {
                     extra_exprs.push(call_expr);
                 }
 
-                if !p.is_static {
+                if !p.is_static && !p.declare {
                     constructor_stmts.push(
                         CallExpr {
                             span: DUMMY_SP,

crates/swc_ecma_transforms_typescript/tests/strip.rs

@@ -966,7 +966,7 @@ test!(
         configurable: true,
         enumerable: true,
         writable: true,
-        initializer: void 0
+        initializer: null
     }), _class);
     "#,
     ok_if_code_eq
@@ -994,7 +994,7 @@ test_exec!(
     }
 
     class Child extends Base {
-      @DefineAction() action: number
+      @DefineAction() declare action: number
 
       callApi() {
         console.log(this.action) // undefined