From dffcef785a16d8e2f32445632213322ccc868db6 Mon Sep 17 00:00:00 2001
From: Logan Smyth <loganfsmyth@gmail.com>
Date: Fri, 1 Dec 2017 17:11:11 -0800
Subject: [PATCH] Lazy-initialize helper templates.

---
 packages/babel-helpers/src/helpers.js | 180 +++++++++++++-------------
 1 file changed, 88 insertions(+), 92 deletions(-)

diff --git a/packages/babel-helpers/src/helpers.js b/packages/babel-helpers/src/helpers.js
index 8cfabc8f64..8b89f2e55d 100644
--- a/packages/babel-helpers/src/helpers.js
+++ b/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
-// matching to allow us to use pattern-like variable names.
-const defineHelper = template.program({ placeholderPattern: false });
-
-helpers.typeof = defineHelper(`
+helpers.typeof = () => template.program.ast`
   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;
     }
-`);
+`;