Use Object Spread Syntax (babel#7777)

* Use Object Spread Syntax

* Nits

codemods/babel-plugin-codemod-object-assign-to-object-spread/.npmignore

@@ -0,0 +1,3 @@
+src
+test
+*.log

codemods/babel-plugin-codemod-object-assign-to-object-spread/README.md

@@ -0,0 +1,57 @@
+# @babel/plugin-codemod-object-assign-to-object-spread
+
+Transforms old code that uses `Object.assign` with an Object Literal as
+the first param to use Object Spread syntax.
+
+## Examples
+
+```js
+const obj = Object.assign({
+  test1: 1,
+}, other, {
+  test2: 2,
+}, other2);
+```
+
+Is transformed to:
+
+```js
+const obj = {
+  test1: 1,
+  ...other,
+  test2: 2,
+  ...other2,
+};
+```
+
+## Installation
+
+```sh
+npm install --save-dev @babel/plugin-codemod-object-assign-to-object-spread
+```
+
+## Usage
+
+### Via `.babelrc` (Recommended)
+
+**.babelrc**
+
+```json
+{
+  "plugins": ["@babel/plugin-codemod-object-assign-to-object-spread"]
+}
+```
+
+### Via CLI
+
+```sh
+babel --plugins @babel/plugin-codemod-object-assign-to-object-spread script.js
+```
+
+### Via Node API
+
+```javascript
+require("@babel/core").transform("code", {
+  plugins: ["@babel/plugin-codemod-object-assign-to-object-spread"]
+});
+```

codemods/babel-plugin-codemod-object-assign-to-object-spread/package.json

@@ -0,0 +1,22 @@
+{
+  "name": "@babel/plugin-codemod-object-assign-to-object-spread",
+  "version": "7.0.0-beta.44",
+  "description": "Transforms Object.assign into object spread syntax",
+  "repository": "https://github.com/babel/babel/tree/master/codemods/babel-plugin-codemod-object-assign-to-object-spread",
+  "license": "MIT",
+  "main": "lib/index.js",
+  "keywords": [
+    "@babel/codemod",
+    "@babel/plugin"
+  ],
+  "dependencies": {
+    "@babel/plugin-syntax-object-rest-spread": "7.0.0-beta.44"
+  },
+  "peerDependencies": {
+    "@babel/core": "7.0.0-beta.44"
+  },
+  "devDependencies": {
+    "@babel/core": "7.0.0-beta.44",
+    "@babel/helper-plugin-test-runner": "7.0.0-beta.44"
+  }
+}

codemods/babel-plugin-codemod-object-assign-to-object-spread/src/index.js

@@ -0,0 +1,35 @@
+import syntaxObjectRestSpread from "@babel/plugin-syntax-object-rest-spread";
+
+export default function({ types: t }) {
+  return {
+    inherits: syntaxObjectRestSpread,
+
+    visitor: {
+      CallExpression(path) {
+        if (!path.get("callee").matchesPattern("Object.assign")) return;
+
+        const args = path.get("arguments");
+        if (args.length === 0) return;
+
+        const [objPath] = args;
+        if (!objPath.isObjectExpression()) return;
+
+        const obj = objPath.node;
+        const { properties } = obj;
+
+        for (let i = 1; i < args.length; i++) {
+          const arg = args[i];
+          const { node } = arg;
+
+          if (arg.isObjectExpression()) {
+            properties.push(...node.properties);
+          } else {
+            properties.push(t.spreadElement(node));
+          }
+        }
+
+        path.replaceWith(obj);
+      },
+    },
+  };
+}

codemods/babel-plugin-codemod-object-assign-to-object-spread/test/fixtures/object-assign-to-object-spread/multiple-objects/input.js

@@ -0,0 +1 @@
+Object.assign({test: 1}, {test: 2});

codemods/babel-plugin-codemod-object-assign-to-object-spread/test/fixtures/object-assign-to-object-spread/multiple-objects/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["../../../../lib"]
+}

codemods/babel-plugin-codemod-object-assign-to-object-spread/test/fixtures/object-assign-to-object-spread/multiple-objects/output.js

@@ -0,0 +1,4 @@
+({
+  test: 1,
+  test: 2
+});

codemods/babel-plugin-codemod-object-assign-to-object-spread/test/fixtures/object-assign-to-object-spread/multiple/input.js

@@ -0,0 +1 @@
+Object.assign({test: 1}, test2, {test: 2}, test3);

codemods/babel-plugin-codemod-object-assign-to-object-spread/test/fixtures/object-assign-to-object-spread/multiple/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["../../../../lib"]
+}

codemods/babel-plugin-codemod-object-assign-to-object-spread/test/fixtures/object-assign-to-object-spread/multiple/output.js

@@ -0,0 +1,6 @@
+({
+  test: 1,
+  ...test2,
+  test: 2,
+  ...test3
+});

codemods/babel-plugin-codemod-object-assign-to-object-spread/test/fixtures/object-assign-to-object-spread/single-non-object/input.js

@@ -0,0 +1 @@
+Object.assign(test);

codemods/babel-plugin-codemod-object-assign-to-object-spread/test/fixtures/object-assign-to-object-spread/single-non-object/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["../../../../lib"]
+}

codemods/babel-plugin-codemod-object-assign-to-object-spread/test/fixtures/object-assign-to-object-spread/single-non-object/output.js

@@ -0,0 +1 @@
+Object.assign(test);

codemods/babel-plugin-codemod-object-assign-to-object-spread/test/fixtures/object-assign-to-object-spread/single/input.js

@@ -0,0 +1 @@
+Object.assign({test: 1});

codemods/babel-plugin-codemod-object-assign-to-object-spread/test/fixtures/object-assign-to-object-spread/single/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["../../../../lib"]
+}

codemods/babel-plugin-codemod-object-assign-to-object-spread/test/fixtures/object-assign-to-object-spread/single/output.js

@@ -0,0 +1,3 @@
+({
+  test: 1
+});

codemods/babel-plugin-codemod-object-assign-to-object-spread/test/index.js

@@ -0,0 +1,3 @@
+import runner from "@babel/helper-plugin-test-runner";
+
+runner(__dirname);

codemods/babel-plugin-codemod-optional-catch-binding/package.json

@@ -2,10 +2,11 @@
   "name": "@babel/plugin-codemod-optional-catch-binding",
   "version": "7.0.0-beta.46",
   "description": "Remove unused catch bindings",
-  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-transform-remove-unused-catch-binding",
+  "repository": "https://github.com/babel/babel/tree/master/codemods/babel-plugin-codemod-remove-unused-catch-binding",
   "license": "MIT",
   "main": "lib/index.js",
   "keywords": [
+    "@babel/codemod",
     "@babel/plugin"
   ],
   "dependencies": {

codemods/babel-plugin-codemod-optional-catch-binding/src/index.js

@@ -1,7 +1,6 @@
 import syntaxOptionalCatchBinding from "@babel/plugin-syntax-optional-catch-binding";
-import { types as t } from "@babel/core";
 
-export default function() {
+export default function({ types: t }) {
   return {
     inherits: syntaxOptionalCatchBinding,
 

packages/babel-cli/src/babel/util.js

@@ -51,9 +51,10 @@ export function log(msg, force) {
 }
 
 export function transform(filename, code, opts, callback) {
-  opts = Object.assign({}, opts, {
+  opts = {
+    ...opts,
     filename,
-  });
+  };
 
   babel.transform(code, opts, callback);
 }

packages/babel-code-frame/src/index.js

@@ -38,12 +38,15 @@ function getMarkerLines(
   source: Array<string>,
   opts: Object,
 ): { start: number, end: number, markerLines: Object } {
-  const startLoc: Location = Object.assign(
-    {},
-    { column: 0, line: -1 },
-    loc.start,
-  );
-  const endLoc: Location = Object.assign({}, startLoc, loc.end);
+  const startLoc: Location = {
+    column: 0,
+    line: -1,
+    ...loc.start,
+  };
+  const endLoc: Location = {
+    ...startLoc,
+    ...loc.end,
+  };
   const { linesAbove = 2, linesBelow = 3 } = opts || {};
   const startLine = startLoc.line;
   const startColumn = startLoc.column;

packages/babel-core/src/config/config-chain.js

@@ -480,7 +480,9 @@ function emptyChain(): ConfigChain {
 }
 
 function normalizeOptions(opts: ValidatedOptions): ValidatedOptions {
-  const options = Object.assign({}, opts);
+  const options = {
+    ...opts,
+  };
   delete options.extends;
   delete options.env;
   delete options.plugins;

packages/babel-core/src/config/full.js

@@ -174,7 +174,10 @@ const loadDescriptor = makeWeakCache(
 
     let item = value;
     if (typeof value === "function") {
-      const api = Object.assign({}, context, makeAPI(cache));
+      const api = {
+        ...context,
+        ...makeAPI(cache),
+      };
       try {
         item = value(api, options, dirname);
       } catch (e) {
@@ -229,9 +232,13 @@ const instantiatePlugin = makeWeakCache(
   ): Plugin => {
     const pluginObj = validatePluginObject(value);
 
-    const plugin = Object.assign({}, pluginObj);
+    const plugin = {
+      ...pluginObj,
+    };
     if (plugin.visitor) {
-      plugin.visitor = traverse.explode(Object.assign({}, plugin.visitor));
+      plugin.visitor = traverse.explode({
+        ...plugin.visitor,
+      });
     }
 
     if (plugin.inherits) {

packages/babel-core/src/transform-file-sync.js

@@ -12,7 +12,10 @@ export default function transformFileSync(
   if (opts == null) {
     options = { filename };
   } else if (opts && typeof opts === "object") {
-    options = Object.assign({}, opts, { filename });
+    options = {
+      ...opts,
+      filename,
+    };
   }
 
   const config = loadConfig(options);

packages/babel-core/src/transform-file.js

@@ -19,7 +19,10 @@ export default ((function transformFile(filename, opts, callback) {
   if (opts == null) {
     options = { filename };
   } else if (opts && typeof opts === "object") {
-    options = Object.assign({}, opts, { filename });
+    options = {
+      ...opts,
+      filename,
+    };
   }
 
   process.nextTick(() => {

packages/babel-core/src/transformation/normalize-opts.js

@@ -22,36 +22,38 @@ export default function normalizeOptions(config: ResolvedConfig): {} {
 
   const opts = config.options;
 
-  const options = Object.assign({}, opts, {
-    parserOpts: Object.assign(
-      {
-        sourceType:
-          path.extname(filenameRelative) === ".mjs" ? "module" : sourceType,
-        sourceFileName: filename,
-        plugins: [],
-      },
-      opts.parserOpts,
-    ),
-    generatorOpts: Object.assign(
-      {
-        // General generator flags.
-        filename,
-        auxiliaryCommentBefore: opts.auxiliaryCommentBefore,
-        auxiliaryCommentAfter: opts.auxiliaryCommentAfter,
-        retainLines: opts.retainLines,
-        comments,
-        shouldPrintComment: opts.shouldPrintComment,
-        compact,
-        minified: opts.minified,
+  const options = {
+    ...opts,
 
-        // Source-map generation flags.
-        sourceMaps,
-        sourceRoot,
-        sourceFileName,
-      },
-      opts.generatorOpts,
-    ),
-  });
+    parserOpts: {
+      sourceType:
+        path.extname(filenameRelative) === ".mjs" ? "module" : sourceType,
+
+      sourceFileName: filename,
+      plugins: [],
+      ...opts.parserOpts,
+    },
+
+    generatorOpts: {
+      // General generator flags.
+      filename,
+
+      auxiliaryCommentBefore: opts.auxiliaryCommentBefore,
+      auxiliaryCommentAfter: opts.auxiliaryCommentAfter,
+      retainLines: opts.retainLines,
+      comments,
+      shouldPrintComment: opts.shouldPrintComment,
+      compact,
+      minified: opts.minified,
+
+      // Source-map generation flags.
+      sourceMaps,
+
+      sourceRoot,
+      sourceFileName,
+      ...opts.generatorOpts,
+    },
+  };
 
   for (const plugins of config.passes) {
     for (const plugin of plugins) {

packages/babel-helper-member-expression-to-functions/src/index.js

@@ -82,5 +82,8 @@ const handle = {
 // Optionally, a memoize method may be defined on the state, which will be
 // called when the member is a self-referential update.
 export default function memberExpressionToFunctions(path, visitor, state) {
-  path.traverse(visitor, Object.assign({}, state, handle));
+  path.traverse(visitor, {
+    ...state,
+    ...handle,
+  });
 }

packages/babel-helper-module-imports/src/import-injector.js

@@ -170,7 +170,9 @@ export default class ImportInjector {
       optsList.push(importedSource);
     }
 
-    const newOpts = Object.assign({}, this._defaultOpts);
+    const newOpts = {
+      ...this._defaultOpts,
+    };
     for (const opts of optsList) {
       if (!opts) continue;
       Object.keys(newOpts).forEach(key => {

packages/babel-helper-plugin-utils/src/index.js

@@ -34,7 +34,10 @@ function copyApiObject(api) {
     }
   }
 
-  return Object.assign({}, proto, api);
+  return {
+    ...proto,
+    ...api,
+  };
 }
 
 function has(obj, key) {

packages/babel-preset-env/src/index.js

@@ -95,7 +95,9 @@ export const isPluginRequired = (
 };
 
 const getBuiltInTargets = targets => {
-  const builtInTargets = Object.assign({}, targets);
+  const builtInTargets = {
+    ...targets,
+  };
   if (builtInTargets.uglify != null) {
     delete builtInTargets.uglify;
   }