Initialize descriptor without always setting 'writable'.

Author: loganfsmyth

src/index.js

@@ -45,17 +45,14 @@ const buildInitializerDefineProperty = template(`
 
 const buildApplyDecoratedDescriptor = template(`
     function NAME(target, property, decorators, descriptor, context){
-        var desc = {
-            enumerable: !!descriptor.enumerable,
-            configurable: !!descriptor.configurable,
-        };
-        if ('value' in descriptor || 'initializer' in descriptor){
+        var desc = {};
+        Object.keys(descriptor).forEach(function(key){
+            desc[key] = descriptor[key];
+        });
+        desc.enumerable = !!desc.enumerable;
+        desc.configurable = !!desc.configurable;
+        if ('value' in desc || desc.initializer){
             desc.writable = true;
-            desc.initializer = descriptor.initializer;
-            desc.value = descriptor.value;
-        } else {
-            desc.get = descriptor.get;
-            desc.set = descriptor.set;
         }
 
         desc = decorators.slice().reverse().reduce(function(desc, decorator){

test/index.js

@@ -33,7 +33,7 @@ describe('decorators', function(){
                 expect(calls).to.eql([1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
             });
 
-            it('should call descriptors in reverse order per-method', function(){
+            it('should call decorators in reverse order per-method', function(){
                 const calls = [];
                 function dec(id){
                     return function(){
@@ -639,6 +639,36 @@ describe('decorators', function(){
                 expect(inst.prop).to.be.undefined;
             });
 
+            it('should support mutating an initialzer into an accessor', function(){
+                function dec(target, name, descriptor){
+                    expect(target).to.be.ok;
+                    expect(name).to.eql("prop");
+                    expect(descriptor).to.be.an('object');
+
+                    let {initializer} = descriptor;
+                    delete descriptor.initializer;
+                    delete descriptor.writable;
+
+                    let value;
+                    descriptor.get = function(){
+                        if (initializer){
+                            value = '__' + initializer.call(this) + '__';
+                            initializer = null;
+                        }
+                        return value;
+                    };
+                }
+
+                class Example {
+                    @dec
+                    prop = 3;
+                }
+
+                let inst = new Example();
+
+                expect(inst.prop).to.eql('__3__');
+            });
+
             it('should allow returning a descriptor', function(){
                 function dec(target, name, descriptor){
                     expect(target).to.be.ok;
@@ -854,6 +884,34 @@ describe('decorators', function(){
                 expect(Example.prop).to.be.undefined;
             });
 
+            it('should support mutating an initialzer into an accessor', function(){
+                function dec(target, name, descriptor){
+                    expect(target).to.be.ok;
+                    expect(name).to.eql("prop");
+                    expect(descriptor).to.be.an('object');
+
+                    let {initializer} = descriptor;
+                    delete descriptor.initializer;
+                    delete descriptor.writable;
+
+                    let value;
+                    descriptor.get = function(){
+                        if (initializer){
+                            value = '__' + initializer.call(this) + '__';
+                            initializer = null;
+                        }
+                        return value;
+                    };
+                }
+
+                class Example {
+                    @dec
+                    static prop = 3;
+                }
+
+                expect(Example.prop).to.eql('__3__');
+            });
+
             it('should allow returning a descriptor', function(){
                 function dec(target, name, descriptor){
                     expect(target).to.be.ok;
@@ -1405,6 +1463,34 @@ describe('decorators', function(){
                 };
             });
 
+            it('should support mutating an initialzer into an accessor', function(){
+                function dec(target, name, descriptor){
+                    expect(target).to.be.ok;
+                    expect(name).to.eql("prop");
+                    expect(descriptor).to.be.an('object');
+
+                    let {initializer} = descriptor;
+                    delete descriptor.initializer;
+                    delete descriptor.writable;
+
+                    let value;
+                    descriptor.get = function(){
+                        if (initializer){
+                            value = '__' + initializer.call(this) + '__';
+                            initializer = null;
+                        }
+                        return value;
+                    };
+                }
+
+                let inst = {
+                    @dec
+                    prop: 3
+                };
+
+                expect(inst.prop).to.eql('__3__');
+            });
+
             it('should allow returning a descriptor', function(){
                 function dec(target, name, descriptor){
                     expect(target).to.be.ok;