Differentiate object spread and non-spread properties (#9341)

* add isSpread field

* use argument

* t.booleanLiteral

* fix typo

* push empty-argument object

* .object

* .value

* object field should be an expression

* lint

* update outputs

* isSpread for the second argument is redundant

* add test

* alternating spread

packages/babel-helpers/src/helpers.js

@@ -389,16 +389,20 @@ helpers.objectSpread = helper("7.0.0-beta.0")`
 
   export default function _objectSpread(target) {
     for (var i = 1; i < arguments.length; i++) {
-      var source = (arguments[i] != null) ? arguments[i] : {};
-      var ownKeys = Object.keys(source);
-      if (typeof Object.getOwnPropertySymbols === 'function') {
-        ownKeys = ownKeys.concat(Object.getOwnPropertySymbols(source).filter(function(sym) {
-          return Object.getOwnPropertyDescriptor(source, sym).enumerable;
-        }));
+      if (i % 2) {
+        var source = (arguments[i] != null) ? arguments[i] : {};
+        var ownKeys = Object.keys(source);
+        if (typeof Object.getOwnPropertySymbols === 'function') {
+          ownKeys = ownKeys.concat(Object.getOwnPropertySymbols(source).filter(function(sym) {
+            return Object.getOwnPropertyDescriptor(source, sym).enumerable;
+          }));
+        }
+        ownKeys.forEach(function(key) {
+          defineProperty(target, key, source[key]);
+        });
+      } else {
+        Object.defineProperties(target, Object.getOwnPropertyDescriptors(arguments[i]));
       }
-      ownKeys.forEach(function(key) {
-        defineProperty(target, key, source[key]);
-      });
     }
     return target;
   }

packages/babel-plugin-proposal-object-rest-spread/src/index.js

@@ -412,15 +412,10 @@ export default declare((api, opts) => {
         let props = [];
 
         function push() {
-          if (!props.length) return;
           args.push(t.objectExpression(props));
           props = [];
         }
 
-        if (t.isSpreadElement(path.node.properties[0])) {
-          args.push(t.objectExpression([]));
-        }
-
         for (const prop of (path.node.properties: Array)) {
           if (t.isSpreadElement(prop)) {
             push();
@@ -430,7 +425,9 @@ export default declare((api, opts) => {
           }
         }
 
-        push();
+        if (props.length) {
+          push();
+        }
 
         let helper;
         if (loose) {

packages/babel-plugin-proposal-object-rest-spread/test/fixtures/object-spread/assignment/output.js

@@ -1,4 +1,4 @@
-function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i] != null ? arguments[i] : {}; var ownKeys = Object.keys(source); if (typeof Object.getOwnPropertySymbols === 'function') { ownKeys = ownKeys.concat(Object.getOwnPropertySymbols(source).filter(function (sym) { return Object.getOwnPropertyDescriptor(source, sym).enumerable; })); } ownKeys.forEach(function (key) { _defineProperty(target, key, source[key]); }); } return target; }
+function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { if (i % 2) { var source = arguments[i] != null ? arguments[i] : {}; var ownKeys = Object.keys(source); if (typeof Object.getOwnPropertySymbols === 'function') { ownKeys = ownKeys.concat(Object.getOwnPropertySymbols(source).filter(function (sym) { return Object.getOwnPropertyDescriptor(source, sym).enumerable; })); } ownKeys.forEach(function (key) { _defineProperty(target, key, source[key]); }); } else { Object.defineProperties(target, Object.getOwnPropertyDescriptors(arguments[i])); } } return target; }
 
 function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
 

packages/babel-plugin-proposal-object-rest-spread/test/fixtures/object-spread/expression/exec.js

@@ -0,0 +1,8 @@
+var log = [];
+
+var a = {
+  ...{ get foo() { log.push(1); } },
+  get bar() { log.push(2); }
+};
+
+expect(log).toEqual([1]);

packages/babel-plugin-proposal-object-rest-spread/test/fixtures/object-spread/expression/input.js

@@ -4,4 +4,6 @@
 
 ({ ...{ foo: 'bar' } });
 
+({ ...{ foo: 'bar' }, ...{ bar: 'baz' } });
+
 ({ ...{ get foo () { return 'foo' } } });

packages/babel-plugin-proposal-object-rest-spread/test/fixtures/object-spread/expression/output.js

@@ -1,4 +1,4 @@
-function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i] != null ? arguments[i] : {}; var ownKeys = Object.keys(source); if (typeof Object.getOwnPropertySymbols === 'function') { ownKeys = ownKeys.concat(Object.getOwnPropertySymbols(source).filter(function (sym) { return Object.getOwnPropertyDescriptor(source, sym).enumerable; })); } ownKeys.forEach(function (key) { _defineProperty(target, key, source[key]); }); } return target; }
+function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { if (i % 2) { var source = arguments[i] != null ? arguments[i] : {}; var ownKeys = Object.keys(source); if (typeof Object.getOwnPropertySymbols === 'function') { ownKeys = ownKeys.concat(Object.getOwnPropertySymbols(source).filter(function (sym) { return Object.getOwnPropertyDescriptor(source, sym).enumerable; })); } ownKeys.forEach(function (key) { _defineProperty(target, key, source[key]); }); } else { Object.defineProperties(target, Object.getOwnPropertyDescriptors(arguments[i])); } } return target; }
 
 function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
 
@@ -16,6 +16,12 @@ _objectSpread({}, {
   foo: 'bar'
 });
 
+_objectSpread({}, {
+  foo: 'bar'
+}, {}, {
+  bar: 'baz'
+});
+
 _objectSpread({}, {
   get foo() {
     return 'foo';

packages/babel-preset-env/test/fixtures/preset-options/shippedProposals-use-builtins-entry/output.js

@@ -1,4 +1,4 @@
-function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i] != null ? arguments[i] : {}; var ownKeys = Object.keys(source); if (typeof Object.getOwnPropertySymbols === 'function') { ownKeys = ownKeys.concat(Object.getOwnPropertySymbols(source).filter(function (sym) { return Object.getOwnPropertyDescriptor(source, sym).enumerable; })); } ownKeys.forEach(function (key) { _defineProperty(target, key, source[key]); }); } return target; }
+function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { if (i % 2) { var source = arguments[i] != null ? arguments[i] : {}; var ownKeys = Object.keys(source); if (typeof Object.getOwnPropertySymbols === 'function') { ownKeys = ownKeys.concat(Object.getOwnPropertySymbols(source).filter(function (sym) { return Object.getOwnPropertyDescriptor(source, sym).enumerable; })); } ownKeys.forEach(function (key) { _defineProperty(target, key, source[key]); }); } else { Object.defineProperties(target, Object.getOwnPropertyDescriptors(arguments[i])); } } return target; }
 
 function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
 

packages/babel-preset-env/test/fixtures/preset-options/shippedProposals-use-builtins-usage/output.js

@@ -1,5 +1,9 @@
 "use strict";
 
+require("core-js/modules/es7.object.get-own-property-descriptors");
+
+require("core-js/modules/es6.object.define-properties");
+
 require("core-js/modules/es6.array.for-each");
 
 require("core-js/modules/es6.array.filter");
@@ -22,7 +26,7 @@ require("core-js/modules/es6.symbol");
 
 require("core-js/modules/es6.promise");
 
-function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i] != null ? arguments[i] : {}; var ownKeys = Object.keys(source); if (typeof Object.getOwnPropertySymbols === 'function') { ownKeys = ownKeys.concat(Object.getOwnPropertySymbols(source).filter(function (sym) { return Object.getOwnPropertyDescriptor(source, sym).enumerable; })); } ownKeys.forEach(function (key) { _defineProperty(target, key, source[key]); }); } return target; }
+function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { if (i % 2) { var source = arguments[i] != null ? arguments[i] : {}; var ownKeys = Object.keys(source); if (typeof Object.getOwnPropertySymbols === 'function') { ownKeys = ownKeys.concat(Object.getOwnPropertySymbols(source).filter(function (sym) { return Object.getOwnPropertyDescriptor(source, sym).enumerable; })); } ownKeys.forEach(function (key) { _defineProperty(target, key, source[key]); }); } else { Object.defineProperties(target, Object.getOwnPropertyDescriptors(arguments[i])); } } return target; }
 
 function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
 

packages/babel-preset-env/test/fixtures/preset-options/shippedProposals/output.js

@@ -1,4 +1,4 @@
-function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i] != null ? arguments[i] : {}; var ownKeys = Object.keys(source); if (typeof Object.getOwnPropertySymbols === 'function') { ownKeys = ownKeys.concat(Object.getOwnPropertySymbols(source).filter(function (sym) { return Object.getOwnPropertyDescriptor(source, sym).enumerable; })); } ownKeys.forEach(function (key) { _defineProperty(target, key, source[key]); }); } return target; }
+function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { if (i % 2) { var source = arguments[i] != null ? arguments[i] : {}; var ownKeys = Object.keys(source); if (typeof Object.getOwnPropertySymbols === 'function') { ownKeys = ownKeys.concat(Object.getOwnPropertySymbols(source).filter(function (sym) { return Object.getOwnPropertyDescriptor(source, sym).enumerable; })); } ownKeys.forEach(function (key) { _defineProperty(target, key, source[key]); }); } else { Object.defineProperties(target, Object.getOwnPropertyDescriptors(arguments[i])); } } return target; }
 
 function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }