Merge pull request #7436 from loganfsmyth/less-upfront-work

Default to `ast:false` and do less work when loading core

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

@@ -3,7 +3,6 @@
 import path from "path";
 import * as context from "../index";
 import Plugin from "./plugin";
-import merge from "lodash/merge";
 import {
   buildRootChain,
   buildPresetChain,
@@ -13,10 +12,9 @@ import {
 } from "./config-chain";
 import type { UnloadedDescriptor } from "./config-descriptors";
 import traverse from "@babel/traverse";
-import clone from "lodash/clone";
 import { makeWeakCache, type CacheConfigurator } from "./caching";
 import { getEnv } from "./helpers/environment";
-import { validate } from "./validation/options";
+import { validate, type ValidatedOptions } from "./validation/options";
 import { validatePluginObject } from "./validation/plugins";
 
 type LoadedDescriptor = {
@@ -109,7 +107,7 @@ export default function loadConfig(inputOpts: mixed): ResolvedConfig | null {
           if (ignored) return true;
 
           preset.options.forEach(opts => {
-            merge(optionDefaults, opts);
+            mergeOptions(optionDefaults, opts);
           });
         }
       }
@@ -129,7 +127,7 @@ export default function loadConfig(inputOpts: mixed): ResolvedConfig | null {
     if (ignored) return null;
 
     configChain.options.forEach(opts => {
-      merge(options, opts);
+      mergeOptions(options, opts);
     });
   } catch (e) {
     // There are a few case where thrown errors will try to annotate themselves multiple times, so
@@ -141,7 +139,8 @@ export default function loadConfig(inputOpts: mixed): ResolvedConfig | null {
     throw e;
   }
 
-  const opts: Object = merge(optionDefaults, options);
+  const opts: Object = optionDefaults;
+  mergeOptions(opts, options);
 
   // Tack the passes onto the object itself so that, if this object is passed back to Babel a second time,
   // it will be in the right structure to not change behavior.
@@ -161,6 +160,33 @@ export default function loadConfig(inputOpts: mixed): ResolvedConfig | null {
   };
 }
 
+function mergeOptions(
+  target: ValidatedOptions,
+  source: ValidatedOptions,
+): void {
+  for (const k of Object.keys(source)) {
+    if (k === "parserOpts" && source.parserOpts) {
+      const parserOpts = source.parserOpts;
+      const targetObj = (target.parserOpts = target.parserOpts || {});
+      mergeDefaultFields(targetObj, parserOpts);
+    } else if (k === "generatorOpts" && source.generatorOpts) {
+      const generatorOpts = source.generatorOpts;
+      const targetObj = (target.generatorOpts = target.generatorOpts || {});
+      mergeDefaultFields(targetObj, generatorOpts);
+    } else {
+      const val = source[k];
+      if (val !== undefined) target[k] = (val: any);
+    }
+  }
+}
+
+function mergeDefaultFields<T: {}>(target: T, source: T) {
+  for (const k of Object.keys(source)) {
+    const val = source[k];
+    if (val !== undefined) target[k] = (val: any);
+  }
+}
+
 /**
  * Load a generic plugin/preset from the given descriptor loaded from the config object.
  */
@@ -238,7 +264,7 @@ const instantiatePlugin = makeWeakCache(
 
     const plugin = Object.assign({}, pluginObj);
     if (plugin.visitor) {
-      plugin.visitor = traverse.explode(clone(plugin.visitor));
+      plugin.visitor = traverse.explode(Object.assign({}, plugin.visitor));
     }
 
     if (plugin.inherits) {

packages/babel-core/src/tools/build-external-helpers.js

@@ -3,19 +3,22 @@ import generator from "@babel/generator";
 import template from "@babel/template";
 import * as t from "@babel/types";
 
-const buildUmdWrapper = template(`
+// Wrapped to avoid wasting time parsing this when almost no-one uses
-  (function (root, factory) {
+// build-external-helpers.
-    if (typeof define === "function" && define.amd) {
+const buildUmdWrapper = replacements =>
-      define(AMD_ARGUMENTS, factory);
+  template`
-    } else if (typeof exports === "object") {
+    (function (root, factory) {
-      factory(COMMON_ARGUMENTS);
+      if (typeof define === "function" && define.amd) {
-    } else {
+        define(AMD_ARGUMENTS, factory);
-      factory(BROWSER_ARGUMENTS);
+      } else if (typeof exports === "object") {
-    }
+        factory(COMMON_ARGUMENTS);
-  })(UMD_ROOT, function (FACTORY_PARAMETERS) {
+      } else {
-    FACTORY_BODY
+        factory(BROWSER_ARGUMENTS);
-  });
+      }
-`);
+    })(UMD_ROOT, function (FACTORY_PARAMETERS) {
+      FACTORY_BODY
+    });
+  `(replacements);
 
 function buildGlobal(whitelist) {
   const namespace = t.identifier("babelHelpers");

packages/babel-core/src/transformation/index.js

@@ -64,7 +64,7 @@ export function runSync(
   return {
     metadata: file.metadata,
     options: opts,
-    ast: opts.ast !== false ? file.ast : null,
+    ast: opts.ast === true ? file.ast : null,
     code: outputCode === undefined ? null : outputCode,
     map: outputMap === undefined ? null : outputMap,
   };

packages/babel-core/test/api.js

@@ -34,6 +34,7 @@ describe("parser and generator options", function() {
 
   function newTransform(string) {
     return babel.transform(string, {
+      ast: true,
       parserOpts: {
         parser: recast.parse,
         plugins: ["flow"],
@@ -47,7 +48,10 @@ describe("parser and generator options", function() {
 
   it("options", function() {
     const string = "original;";
-    assert.deepEqual(newTransform(string).ast, babel.transform(string).ast);
+    assert.deepEqual(
+      newTransform(string).ast,
+      babel.transform(string, { ast: true }).ast,
+    );
     assert.equal(newTransform(string).code, string);
   });
 
@@ -57,6 +61,7 @@ describe("parser and generator options", function() {
     assert.deepEqual(
       newTransform(experimental).ast,
       babel.transform(experimental, {
+        ast: true,
         parserOpts: {
           plugins: ["flow"],
         },
@@ -66,6 +71,7 @@ describe("parser and generator options", function() {
 
     function newTransformWithPlugins(string) {
       return babel.transform(string, {
+        ast: true,
         plugins: [__dirname + "/../../babel-plugin-syntax-flow"],
         parserOpts: {
           parser: recast.parse,
@@ -79,6 +85,7 @@ describe("parser and generator options", function() {
     assert.deepEqual(
       newTransformWithPlugins(experimental).ast,
       babel.transform(experimental, {
+        ast: true,
         parserOpts: {
           plugins: ["flow"],
         },
@@ -93,6 +100,7 @@ describe("parser and generator options", function() {
     assert.notEqual(
       newTransform(experimental).ast,
       babel.transform(experimental, {
+        ast: true,
         parserOpts: {
           allowImportExportEverywhere: true,
         },
@@ -401,6 +409,18 @@ describe("api", function() {
     });
   });
 
+  it("ast option true", function() {
+    return transformAsync("foo('bar');", { ast: true }).then(function(result) {
+      assert.ok(result.ast);
+    });
+  });
+
+  it("ast option default", function() {
+    return transformAsync("foo('bar');").then(function(result) {
+      assert.ok(!result.ast);
+    });
+  });
+
   it("auxiliaryComment option", function() {
     return transformAsync("class Foo {}", {
       auxiliaryCommentBefore: "before",

packages/babel-helpers/src/helpers.js

@@ -5,11 +5,7 @@ import template from "@babel/template";
 const helpers = {};
 export default helpers;
 
-// Helpers never include placeholders, so we disable placeholder pattern
+helpers.typeof = () => template.program.ast`
-// matching to allow us to use pattern-like variable names.
-const defineHelper = template.program({ placeholderPattern: false });
-
-helpers.typeof = defineHelper(`
   export default function _typeof(obj) {
     if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") {
       _typeof = function (obj) { return typeof obj; };
@@ -23,9 +19,9 @@ helpers.typeof = defineHelper(`
 
     return _typeof(obj);
   }
-`);
+`;
 
-helpers.jsx = defineHelper(`
+helpers.jsx = () => template.program.ast`
   var REACT_ELEMENT_TYPE;
 
   export default function _createRawReactElement(type, props, key, children) {
@@ -72,9 +68,9 @@ helpers.jsx = defineHelper(`
       _owner: null,
     };
   }
-`);
+`;
 
-helpers.asyncIterator = defineHelper(`
+helpers.asyncIterator = () => template.program.ast`
   export default function _asyncIterator(iterable) {
     if (typeof Symbol === "function") {
       if (Symbol.asyncIterator) {
@@ -87,15 +83,15 @@ helpers.asyncIterator = defineHelper(`
     }
     throw new TypeError("Object is not async iterable");
   }
-`);
+`;
 
-helpers.AwaitValue = defineHelper(`
+helpers.AwaitValue = () => template.program.ast`
   export default function _AwaitValue(value) {
     this.wrapped = value;
   }
-`);
+`;
 
-helpers.AsyncGenerator = defineHelper(`
+helpers.AsyncGenerator = () => template.program.ast`
   import AwaitValue from "AwaitValue";
 
   export default function AsyncGenerator(gen) {
@@ -177,9 +173,9 @@ helpers.AsyncGenerator = defineHelper(`
   AsyncGenerator.prototype.next = function (arg) { return this._invoke("next", arg); };
   AsyncGenerator.prototype.throw = function (arg) { return this._invoke("throw", arg); };
   AsyncGenerator.prototype.return = function (arg) { return this._invoke("return", arg); };
-`);
+`;
 
-helpers.wrapAsyncGenerator = defineHelper(`
+helpers.wrapAsyncGenerator = () => template.program.ast`
   import AsyncGenerator from "AsyncGenerator";
 
   export default function _wrapAsyncGenerator(fn) {
@@ -187,17 +183,17 @@ helpers.wrapAsyncGenerator = defineHelper(`
       return new AsyncGenerator(fn.apply(this, arguments));
     };
   }
-`);
+`;
 
-helpers.awaitAsyncGenerator = defineHelper(`
+helpers.awaitAsyncGenerator = () => template.program.ast`
   import AwaitValue from "AwaitValue";
 
   export default function _awaitAsyncGenerator(value) {
     return new AwaitValue(value);
   }
-`);
+`;
 
-helpers.asyncGeneratorDelegate = defineHelper(`
+helpers.asyncGeneratorDelegate = () => template.program.ast`
   export default function _asyncGeneratorDelegate(inner, awaitWrap) {
     var iter = {}, waiting = false;
 
@@ -237,9 +233,9 @@ helpers.asyncGeneratorDelegate = defineHelper(`
 
     return iter;
   }
-`);
+`;
 
-helpers.asyncToGenerator = defineHelper(`
+helpers.asyncToGenerator = () => template.program.ast`
   export default function _asyncToGenerator(fn) {
     return function () {
       var self = this, args = arguments;
@@ -267,17 +263,17 @@ helpers.asyncToGenerator = defineHelper(`
       });
     };
   }
-`);
+`;
 
-helpers.classCallCheck = defineHelper(`
+helpers.classCallCheck = () => template.program.ast`
   export default function _classCallCheck(instance, Constructor) {
     if (!(instance instanceof Constructor)) {
       throw new TypeError("Cannot call a class as a function");
     }
   }
-`);
+`;
 
-helpers.createClass = defineHelper(`
+helpers.createClass = () => template.program.ast`
   function _defineProperties(target, props) {
     for (var i = 0; i < props.length; i ++) {
       var descriptor = props[i];
@@ -293,9 +289,9 @@ helpers.createClass = defineHelper(`
     if (staticProps) _defineProperties(Constructor, staticProps);
     return Constructor;
   }
-`);
+`;
 
-helpers.defineEnumerableProperties = defineHelper(`
+helpers.defineEnumerableProperties = () => template.program.ast`
   export default function _defineEnumerableProperties(obj, descs) {
     for (var key in descs) {
       var desc = descs[key];
@@ -319,9 +315,9 @@ helpers.defineEnumerableProperties = defineHelper(`
     }
     return obj;
   }
-`);
+`;
 
-helpers.defaults = defineHelper(`
+helpers.defaults = () => template.program.ast`
   export default function _defaults(obj, defaults) {
     var keys = Object.getOwnPropertyNames(defaults);
     for (var i = 0; i < keys.length; i++) {
@@ -333,9 +329,9 @@ helpers.defaults = defineHelper(`
     }
     return obj;
   }
-`);
+`;
 
-helpers.defineProperty = defineHelper(`
+helpers.defineProperty = () => template.program.ast`
   export default function _defineProperty(obj, key, value) {
     // Shortcircuit the slow defineProperty path when possible.
     // We are trying to avoid issues where setters defined on the
@@ -354,9 +350,9 @@ helpers.defineProperty = defineHelper(`
     }
     return obj;
   }
-`);
+`;
 
-helpers.extends = defineHelper(`
+helpers.extends = () => template.program.ast`
   export default function _extends() {
     _extends = Object.assign || function (target) {
       for (var i = 1; i < arguments.length; i++) {
@@ -372,9 +368,9 @@ helpers.extends = defineHelper(`
 
     return _extends.apply(this, arguments);
   }
-`);
+`;
 
-helpers.objectSpread = defineHelper(`
+helpers.objectSpread = () => template.program.ast`
   import defineProperty from "defineProperty";
 
   export default function _objectSpread(target) {
@@ -392,9 +388,9 @@ helpers.objectSpread = defineHelper(`
     }
     return target;
   }
-`);
+`;
 
-helpers.get = defineHelper(`
+helpers.get = () => template.program.ast`
   export default function _get(object, property, receiver) {
     if (object === null) object = Function.prototype;
 
@@ -420,9 +416,9 @@ helpers.get = defineHelper(`
       return getter.call(receiver);
     }
   }
-`);
+`;
 
-helpers.inherits = defineHelper(`
+helpers.inherits = () => template.program.ast`
   export default function _inherits(subClass, superClass) {
     if (typeof superClass !== "function" && superClass !== null) {
       throw new TypeError("Super expression must either be null or a function");
@@ -437,18 +433,18 @@ helpers.inherits = defineHelper(`
     });
     if (superClass) Object.setPrototypeOf ? Object.setPrototypeOf(subClass, superClass) : subClass.__proto__ = superClass;
   }
-`);
+`;
 
-helpers.inheritsLoose = defineHelper(`
+helpers.inheritsLoose = () => template.program.ast`
   export default function _inheritsLoose(subClass, superClass) {
     subClass.prototype = Object.create(superClass.prototype);
     subClass.prototype.constructor = subClass;
     subClass.__proto__ = superClass;
   }
-`);
+`;
 
 // Based on https://github.com/WebReflection/babel-plugin-transform-builtin-classes
-helpers.wrapNativeSuper = defineHelper(`
+helpers.wrapNativeSuper = () => template.program.ast`
   var _gPO = Object.getPrototypeOf || function _gPO(o) { return o.__proto__ };
   var _sPO = Object.setPrototypeOf || function _sPO(o, p) { o.__proto__ = p; return o };
   var _construct = (typeof Reflect === "object" && Reflect.construct) ||
@@ -490,9 +486,9 @@ helpers.wrapNativeSuper = defineHelper(`
       )
     );
   }
-`);
+`;
 
-helpers.instanceof = defineHelper(`
+helpers.instanceof = () => template.program.ast`
   export default function _instanceof(left, right) {
     if (right != null && typeof Symbol !== "undefined" && right[Symbol.hasInstance]) {
       return right[Symbol.hasInstance](left);
@@ -500,15 +496,15 @@ helpers.instanceof = defineHelper(`
       return left instanceof right;
     }
   }
-`);
+`;
 
-helpers.interopRequireDefault = defineHelper(`
+helpers.interopRequireDefault = () => template.program.ast`
   export default function _interopRequireDefault(obj) {
     return obj && obj.__esModule ? obj : { default: obj };
   }
-`);
+`;
 
-helpers.interopRequireWildcard = defineHelper(`
+helpers.interopRequireWildcard = () => template.program.ast`
   export default function _interopRequireWildcard(obj) {
     if (obj && obj.__esModule) {
       return obj;
@@ -532,23 +528,23 @@ helpers.interopRequireWildcard = defineHelper(`
       return newObj;
     }
   }
-`);
+`;
 
-helpers.newArrowCheck = defineHelper(`
+helpers.newArrowCheck = () => template.program.ast`
   export default function _newArrowCheck(innerThis, boundThis) {
     if (innerThis !== boundThis) {
       throw new TypeError("Cannot instantiate an arrow function");
     }
   }
-`);
+`;
 
-helpers.objectDestructuringEmpty = defineHelper(`
+helpers.objectDestructuringEmpty = () => template.program.ast`
   export default function _objectDestructuringEmpty(obj) {
     if (obj == null) throw new TypeError("Cannot destructure undefined");
   }
-`);
+`;
 
-helpers.objectWithoutProperties = defineHelper(`
+helpers.objectWithoutProperties = () => template.program.ast`
   export default function _objectWithoutProperties(source, excluded) {
     if (source == null) return {};
 
@@ -574,18 +570,18 @@ helpers.objectWithoutProperties = defineHelper(`
 
     return target;
   }
-`);
+`;
 
-helpers.assertThisInitialized = defineHelper(`
+helpers.assertThisInitialized = () => template.program.ast`
   export default function _assertThisInitialized(self) {
     if (self === void 0) {
       throw new ReferenceError("this hasn't been initialised - super() hasn't been called");
     }
     return self;
   }
-`);
+`;
 
-helpers.possibleConstructorReturn = defineHelper(`
+helpers.possibleConstructorReturn = () => template.program.ast`
   export default function _possibleConstructorReturn(self, call) {
     if (call && (typeof call === "object" || typeof call === "function")) {
       return call;
@@ -598,9 +594,9 @@ helpers.possibleConstructorReturn = defineHelper(`
     }
     return self;
   }
-`);
+`;
 
-helpers.set = defineHelper(`
+helpers.set = () => template.program.ast`
   export default function _set(object, property, value, receiver) {
     var desc = Object.getOwnPropertyDescriptor(object, property);
 
@@ -622,9 +618,9 @@ helpers.set = defineHelper(`
 
     return value;
   }
-`);
+`;
 
-helpers.slicedToArray = defineHelper(`
+helpers.slicedToArray = () => template.program.ast`
   // Broken out into a separate function to avoid deoptimizations due to the try/catch for the
   // array iterator case.
   function _sliceIterator(arr, i) {
@@ -669,9 +665,9 @@ helpers.slicedToArray = defineHelper(`
       throw new TypeError("Invalid attempt to destructure non-iterable instance");
     }
   }
-`);
+`;
 
-helpers.slicedToArrayLoose = defineHelper(`
+helpers.slicedToArrayLoose = () => template.program.ast`
   export default function _slicedToArrayLoose(arr, i) {
     if (Array.isArray(arr)) {
       return arr;
@@ -686,26 +682,26 @@ helpers.slicedToArrayLoose = defineHelper(`
       throw new TypeError("Invalid attempt to destructure non-iterable instance");
     }
   }
-`);
+`;
 
-helpers.taggedTemplateLiteral = defineHelper(`
+helpers.taggedTemplateLiteral = () => template.program.ast`
   export default function _taggedTemplateLiteral(strings, raw) {
     if (!raw) { raw = strings.slice(0); }
     return Object.freeze(Object.defineProperties(strings, {
         raw: { value: Object.freeze(raw) }
     }));
   }
-`);
+`;
 
-helpers.taggedTemplateLiteralLoose = defineHelper(`
+helpers.taggedTemplateLiteralLoose = () => template.program.ast`
   export default function _taggedTemplateLiteralLoose(strings, raw) {
     if (!raw) { raw = strings.slice(0); }
     strings.raw = raw;
     return strings;
   }
-`);
+`;
 
-helpers.temporalRef = defineHelper(`
+helpers.temporalRef = () => template.program.ast`
   import undef from "temporalUndefined";
 
   export default function _temporalRef(val, name) {
@@ -715,31 +711,31 @@ helpers.temporalRef = defineHelper(`
       return val;
     }
   }
-`);
+`;
 
-helpers.readOnlyError = defineHelper(`
+helpers.readOnlyError = () => template.program.ast`
   export default function _readOnlyError(name) {
     throw new Error("\\"" + name + "\\" is read-only");
   }
-`);
+`;
 
-helpers.classNameTDZError = defineHelper(`
+helpers.classNameTDZError = () => template.program.ast`
   export default function _classNameTDZError(name) {
     throw new Error("Class \\"" + name + "\\" cannot be referenced in computed property keys.");
   }
-`);
+`;
 
-helpers.temporalUndefined = defineHelper(`
+helpers.temporalUndefined = () => template.program.ast`
   export default {};
-`);
+`;
 
-helpers.toArray = defineHelper(`
+helpers.toArray = () => template.program.ast`
   export default function _toArray(arr) {
     return Array.isArray(arr) ? arr : Array.from(arr);
   }
-`);
+`;
 
-helpers.toConsumableArray = defineHelper(`
+helpers.toConsumableArray = () => template.program.ast`
   export default function _toConsumableArray(arr) {
     if (Array.isArray(arr)) {
       for (var i = 0, arr2 = new Array(arr.length); i < arr.length; i++) arr2[i] = arr[i];
@@ -748,9 +744,9 @@ helpers.toConsumableArray = defineHelper(`
       return Array.from(arr);
     }
   }
-`);
+`;
 
-helpers.skipFirstGeneratorNext = defineHelper(`
+helpers.skipFirstGeneratorNext = () => template.program.ast`
   export default function _skipFirstGeneratorNext(fn) {
     return function () {
       var it = fn.apply(this, arguments);
@@ -758,9 +754,9 @@ helpers.skipFirstGeneratorNext = defineHelper(`
       return it;
     }
   }
-`);
+`;
 
-helpers.toPropertyKey = defineHelper(`
+helpers.toPropertyKey = () => template.program.ast`
   export default function _toPropertyKey(key) {
     if (typeof key === "symbol") {
       return key;
@@ -768,13 +764,13 @@ helpers.toPropertyKey = defineHelper(`
       return String(key);
     }
   }
-`);
+`;
 
 /**
  * Add a helper that will throw a useful error if the transform fails to detect the class
  * property assignment, so users know something failed.
  */
-helpers.initializerWarningHelper = defineHelper(`
+helpers.initializerWarningHelper = () => template.program.ast`
     export default function _initializerWarningHelper(descriptor, context){
         throw new Error(
           'Decorating class property failed. Please ensure that ' +
@@ -783,12 +779,12 @@ helpers.initializerWarningHelper = defineHelper(`
           'the next major version of decorators in stage 2.'
         );
     }
-`);
+`;
 
 /**
  * Add a helper to call as a replacement for class property definition.
  */
-helpers.initializerDefineProperty = defineHelper(`
+helpers.initializerDefineProperty = () => template.program.ast`
     export default function _initializerDefineProperty(target, property, descriptor, context){
         if (!descriptor) return;
 
@@ -799,13 +795,13 @@ helpers.initializerDefineProperty = defineHelper(`
             value: descriptor.initializer ? descriptor.initializer.call(context) : void 0,
         });
     }
-`);
+`;
 
 /**
  * Add a helper to take an initial descriptor, apply some decorators to it, and optionally
  * define the property.
  */
-helpers.applyDecoratedDescriptor = defineHelper(`
+helpers.applyDecoratedDescriptor = () => template.program.ast`
     export default function _applyDecoratedDescriptor(target, property, decorators, descriptor, context){
         var desc = {};
         Object['ke' + 'ys'](descriptor).forEach(function(key){
@@ -835,4 +831,4 @@ helpers.applyDecoratedDescriptor = defineHelper(`
 
         return desc;
     }
-`);
+`;

packages/babel-plugin-transform-modules-commonjs/test/copied-nodes.js

@@ -5,6 +5,7 @@ test("Doesn't use the same object for two different nodes in the AST", function(
   const code = 'import Foo from "bar"; Foo; Foo;';
 
   const ast = babel.transform(code, {
+    ast: true,
     plugins: [[require("../"), { loose: true }]],
   }).ast;