Instead of writing text from source file use text property to write text of synthesized node

Fixes #4364

Author: sheetalkamat

src/compiler/emitter.ts

@@ -1519,7 +1519,13 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
                         return;
                     }
                 }
-                writeTextOfNode(currentSourceFile, node);
+
+                if (nodeIsSynthesized(node)) {
+                    write(node.text);
+                }
+                else {
+                    writeTextOfNode(currentSourceFile, node);
+                }
             }
 
             function isNameOfNestedRedeclaration(node: Identifier) {

tests/baselines/reference/decoratorMetadataWithConstructorType.js

@@ -0,0 +1,39 @@
+//// [decoratorMetadataWithConstructorType.ts]
+
+declare var console: {
+    log(msg: string): void;
+};
+
+class A {
+    constructor() { console.log('new A'); }
+}
+
+function decorator(target: Object, propertyKey: string) {
+}
+
+export class B {
+    @decorator
+    x: A = new A();
+}
+
+
+//// [decoratorMetadataWithConstructorType.js]
+var A = (function () {
+    function A() {
+        console.log('new A');
+    }
+    return A;
+})();
+function decorator(target, propertyKey) {
+}
+var B = (function () {
+    function B() {
+        this.x = new A();
+    }
+    __decorate([
+        decorator, 
+        __metadata('design:type', A)
+    ], B.prototype, "x");
+    return B;
+})();
+exports.B = B;

tests/baselines/reference/decoratorMetadataWithConstructorType.symbols

@@ -0,0 +1,39 @@
+=== tests/cases/compiler/decoratorMetadataWithConstructorType.ts ===
+
+declare var console: {
+>console : Symbol(console, Decl(decoratorMetadataWithConstructorType.ts, 1, 11))
+
+    log(msg: string): void;
+>log : Symbol(log, Decl(decoratorMetadataWithConstructorType.ts, 1, 22))
+>msg : Symbol(msg, Decl(decoratorMetadataWithConstructorType.ts, 2, 8))
+
+};
+
+class A {
+>A : Symbol(A, Decl(decoratorMetadataWithConstructorType.ts, 3, 2))
+
+    constructor() { console.log('new A'); }
+>console.log : Symbol(log, Decl(decoratorMetadataWithConstructorType.ts, 1, 22))
+>console : Symbol(console, Decl(decoratorMetadataWithConstructorType.ts, 1, 11))
+>log : Symbol(log, Decl(decoratorMetadataWithConstructorType.ts, 1, 22))
+}
+
+function decorator(target: Object, propertyKey: string) {
+>decorator : Symbol(decorator, Decl(decoratorMetadataWithConstructorType.ts, 7, 1))
+>target : Symbol(target, Decl(decoratorMetadataWithConstructorType.ts, 9, 19))
+>Object : Symbol(Object, Decl(lib.d.ts, 92, 1), Decl(lib.d.ts, 223, 11))
+>propertyKey : Symbol(propertyKey, Decl(decoratorMetadataWithConstructorType.ts, 9, 34))
+}
+
+export class B {
+>B : Symbol(B, Decl(decoratorMetadataWithConstructorType.ts, 10, 1))
+
+    @decorator
+>decorator : Symbol(decorator, Decl(decoratorMetadataWithConstructorType.ts, 7, 1))
+
+    x: A = new A();
+>x : Symbol(x, Decl(decoratorMetadataWithConstructorType.ts, 12, 16))
+>A : Symbol(A, Decl(decoratorMetadataWithConstructorType.ts, 3, 2))
+>A : Symbol(A, Decl(decoratorMetadataWithConstructorType.ts, 3, 2))
+}
+

tests/baselines/reference/decoratorMetadataWithConstructorType.types

@@ -0,0 +1,42 @@
+=== tests/cases/compiler/decoratorMetadataWithConstructorType.ts ===
+
+declare var console: {
+>console : { log(msg: string): void; }
+
+    log(msg: string): void;
+>log : (msg: string) => void
+>msg : string
+
+};
+
+class A {
+>A : A
+
+    constructor() { console.log('new A'); }
+>console.log('new A') : void
+>console.log : (msg: string) => void
+>console : { log(msg: string): void; }
+>log : (msg: string) => void
+>'new A' : string
+}
+
+function decorator(target: Object, propertyKey: string) {
+>decorator : (target: Object, propertyKey: string) => void
+>target : Object
+>Object : Object
+>propertyKey : string
+}
+
+export class B {
+>B : B
+
+    @decorator
+>decorator : (target: Object, propertyKey: string) => void
+
+    x: A = new A();
+>x : A
+>A : A
+>new A() : A
+>A : typeof A
+}
+

tests/cases/compiler/decoratorMetadataWithConstructorType.ts

@@ -0,0 +1,21 @@
+// @noemithelpers: true
+// @experimentaldecorators: true
+// @emitdecoratormetadata: true
+// @target: es5
+// @module: commonjs
+
+declare var console: {
+    log(msg: string): void;
+};
+
+class A {
+    constructor() { console.log('new A'); }
+}
+
+function decorator(target: Object, propertyKey: string) {
+}
+
+export class B {
+    @decorator
+    x: A = new A();
+}