v7.3.2

* Use a GitHub Action to generate the changelog

* Update main.workflow [skip ci]

.github/actions/trigger-github-release/Dockerfile

@@ -0,0 +1,18 @@
+FROM node:10
+
+LABEL "name" = "trigger-github-release"
+LABEL "version" = "0.0.1"
+
+LABEL "com.github.actions.name" = "Trigger GitHub release"
+LABEL "com.github.actions.description" = "Trigger a new GitHub release and generate the changelog using lerna-changelog."
+LABEL "com.github.actions.icon" = "tag"
+LABEL "com.github.actions.color" = "yellow"
+
+ADD entrypoint.sh /action/entrypoint.sh
+ADD package.json /action/package.json
+ADD package-lock.json /action/package-lock.json
+ADD release.js /action/release.js
+
+RUN chmod +x /action/entrypoint.sh
+
+ENTRYPOINT ["/action/entrypoint.sh"]

.github/actions/trigger-github-release/entrypoint.sh

@@ -0,0 +1,29 @@
+#!/bin/sh
+
+set -e
+
+echo "INFO: Installing action dependencies..."
+(cd /action; npm ci)
+
+echo "INFO: Checking out current tag..."
+git -c advice.detachedHead=false checkout $GITHUB_REF
+
+echo "INFO: Getting tag info..."
+current_tag=$(git describe --abbrev=0 --tags)
+last_tag=$(git describe --abbrev=0 --tags HEAD^)
+echo "INFO: New version is $current_tag; last version is $last_tag."
+
+echo "INFO: Generating the changelog..."
+
+# lerna-changelog expects the token to be provided as GITHUB_AUTH,
+# but GitHub actions don't allow to predefine custom env vars prefixed with
+# GITHUB_. We need to define it here.
+changelog=$(
+  GITHUB_AUTH="$GITHUB_TOKEN" \
+  node /action/node_modules/.bin/lerna-changelog --tag-from $last_tag --tag-to $current_tag
+)
+
+echo "INFO: Publishing the new GitHub release..."
+echo "$changelog" | node /action/release $current_tag
+
+echo "INFO: Done! Don't forget to thank new contributors :)"

.github/actions/trigger-github-release/package.json

@@ -0,0 +1,12 @@
+{
+    "private": true,
+    "name": "@internal/trigger-github-release",
+    "version": "0.0.1",
+    "author": "Nicolò Ribaudo <nicolo.ribaudo@gmail.com>",
+    "license": "MIT",
+    "dependencies": {
+        "@octokit/rest": "^16.3.0",
+        "get-stdin": "^6.0.0",
+        "lerna-changelog": "^0.8.2"
+    }
+}

.github/actions/trigger-github-release/release.js

@@ -0,0 +1,25 @@
+"use strict";
+
+const [ /* node */, /* file */, tag ] = process.argv;
+
+const getStdin = require("get-stdin");
+const octokit = require("@octokit/rest")();
+
+octokit.authenticate({
+  type: "token",
+  token: process.env.GITHUB_TOKEN
+});
+
+const [ repoOwner, repoName ] = process.env.GITHUB_REPOSITORY.split("/");
+
+getStdin()
+  .then(changelog => octokit.repos.createRelease({
+    owner: repoOwner,
+    repo: repoName,
+    tag_name: tag,
+    body: changelog,
+  }))
+  .catch(err => {
+    console.error(err);
+    process.exit(1);
+  });

.github/main.workflow

@@ -0,0 +1,26 @@
+workflow "Release" {
+  on = "push"
+  resolves = ["Trigger GitHub release"]
+}
+
+action "Trigger GitHub release" {
+  uses = "./.github/actions/trigger-github-release/"
+  secrets = ["GITHUB_TOKEN"]
+
+  # When GitHub Actions will support the "release" event for public
+  # repositories, we won't need these checks anymore.
+  needs = [
+    "Is version tag",
+    "On master branch",
+  ]
+}
+
+action "Is version tag" {
+  uses = "actions/bin/filter@master"
+  args = "tag v*"
+}
+
+action "On master branch" {
+  uses = "actions/bin/filter@master"
+  args = "branch master"
+}

.gitignore

@@ -1,5 +1,6 @@
 .DS_Store
 /node_modules
+/.github/actions/*/node_modules
 /packages/*/node_modules
 /packages/*/LICENSE
 !/packages/babel-parser/LICENSE
@@ -15,6 +16,7 @@ coverage
 dist
 /.package.json
 package-lock.json
+!/.github/actions/*/package-lock.json
 
 /packages/babel-runtime/helpers/*.js
 !/packages/babel-runtime/helpers/toArray.js

Gulpfile.js

@@ -6,7 +6,7 @@ const chalk = require("chalk");
 const newer = require("gulp-newer");
 const babel = require("gulp-babel");
 const gulpWatch = require("gulp-watch");
-const gutil = require("gulp-util");
+const fancyLog = require("fancy-log");
 const filter = require("gulp-filter");
 const gulp = require("gulp");
 const path = require("path");
@@ -38,7 +38,7 @@ function getIndexFromPackage(name) {
 
 function compilationLogger(rollup) {
   return through.obj(function(file, enc, callback) {
-    gutil.log(
+    fancyLog(
       `Compiling '${chalk.cyan(file.relative)}'${
         rollup ? " with rollup " : ""
       }...`
@@ -50,7 +50,7 @@ function compilationLogger(rollup) {
 function errorsLogger() {
   return plumber({
     errorHandler(err) {
-      gutil.log(err.stack);
+      fancyLog(err.stack);
     },
   });
 }

lerna.json

@@ -1,5 +1,5 @@
 {
-  "version": "7.3.0",
+  "version": "7.3.2",
   "changelog": {
     "repo": "babel/babel",
     "cacheDir": ".changelog",

package.json

@@ -9,55 +9,54 @@
     "test": "make test"
   },
   "devDependencies": {
-    "@babel/cli": "^7.2.0",
-    "@babel/core": "^7.2.0",
+    "@babel/cli": "^7.2.3",
+    "@babel/core": "^7.2.2",
     "@babel/eslint-plugin-development": "^1.0.1",
-    "@babel/plugin-proposal-class-properties": "^7.2.1",
+    "@babel/plugin-proposal-class-properties": "^7.3.0",
     "@babel/plugin-proposal-export-namespace-from": "^7.2.0",
     "@babel/plugin-proposal-numeric-separator": "^7.2.0",
     "@babel/plugin-transform-modules-commonjs": "^7.2.0",
     "@babel/plugin-transform-runtime": "^7.2.0",
-    "@babel/preset-env": "^7.2.0",
+    "@babel/preset-env": "^7.3.1",
     "@babel/preset-flow": "^7.0.0",
     "@babel/register": "^7.0.0",
-    "@babel/runtime": "^7.2.0",
-    "babel-core": "^7.0.0-0",
-    "babel-eslint": "^10.0.1",
-    "babel-jest": "^23.6.0",
-    "babel-loader": "^8.0.4",
-    "babel-plugin-transform-charcodes": "^0.1.1",
-    "browserify": "^16.2.2",
+    "@babel/runtime": "^7.3.1",
+    "babel-eslint": "^11.0.0-beta.0",
+    "babel-jest": "^24.0.0",
+    "babel-loader": "^8.0.5",
+    "babel-plugin-transform-charcodes": "^0.2.0",
+    "browserify": "^16.2.3",
     "bundle-collapser": "^1.2.1",
     "chalk": "^2.3.2",
-    "charcodes": "^0.1.1",
+    "charcodes": "^0.2.0",
     "derequire": "^2.0.2",
     "enhanced-resolve": "^3.0.0",
-    "eslint": "^5.9.0",
+    "eslint": "^5.12.1",
     "eslint-config-babel": "^8.0.2",
-    "eslint-plugin-flowtype": "^3.2.0",
-    "eslint-plugin-prettier": "^3.0.0",
+    "eslint-plugin-flowtype": "^3.2.1",
+    "eslint-plugin-prettier": "^3.0.1",
+    "fancy-log": "^1.3.3",
     "flow-bin": "^0.87.0",
-    "graceful-fs": "^4.1.11",
+    "graceful-fs": "^4.1.15",
     "gulp": "^4.0.0",
     "gulp-babel": "^8.0.0",
     "gulp-filter": "^5.1.0",
     "gulp-newer": "^1.0.0",
-    "gulp-plumber": "^1.2.0",
+    "gulp-plumber": "^1.2.1",
     "gulp-rename": "^1.4.0",
     "gulp-uglify": "^3.0.1",
-    "gulp-util": "^3.0.7",
     "gulp-watch": "^5.0.1",
-    "husky": "^1.2.0",
-    "jest": "^23.6.0",
+    "husky": "^1.3.1",
+    "jest": "^24.0.0",
     "lerna": "^3.6.0",
     "lerna-changelog": "^0.5.0",
     "lint-staged": "^8.1.0",
-    "lodash": "^4.17.10",
+    "lodash": "^4.17.11",
     "merge-stream": "^1.0.1",
     "output-file-sync": "^2.0.0",
-    "prettier": "^1.15.2",
+    "prettier": "^1.16.1",
     "pump": "^3.0.0",
-    "rimraf": "^2.4.3",
+    "rimraf": "^2.6.3",
     "rollup-plugin-babel": "^4.0.0-beta.0",
     "rollup-plugin-node-resolve": "^3.0.2",
     "rollup-stream": "^1.24.1",
@@ -108,7 +107,9 @@
       "_browser\\.js"
     ],
     "testEnvironment": "node",
-    "setupTestFrameworkScriptFile": "<rootDir>/test/testSetupFile.js",
+    "setupFilesAfterEnv": [
+      "<rootDir>/test/testSetupFile.js"
+    ],
     "transformIgnorePatterns": [
       "/node_modules/",
       "<rootDir>/packages/babel-standalone/babel(\\.min)?\\.js",
@@ -131,5 +132,6 @@
     "moduleNameMapper": {
       "^@babel/([a-zA-Z0-9_-]+)$": "<rootDir>/packages/babel-$1/"
     }
-  }
+  },
+  "dependencies": {}
 }

packages/babel-generator/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@babel/generator",
-  "version": "7.3.0",
+  "version": "7.3.2",
   "description": "Turns an AST into code.",
   "author": "Sebastian McKenzie <sebmck@gmail.com>",
   "homepage": "https://babeljs.io/",
@@ -14,7 +14,7 @@
     "lib"
   ],
   "dependencies": {
-    "@babel/types": "^7.3.0",
+    "@babel/types": "^7.3.2",
     "jsesc": "^2.5.1",
     "lodash": "^4.17.10",
     "source-map": "^0.5.0",
@@ -22,6 +22,6 @@
   },
   "devDependencies": {
     "@babel/helper-fixtures": "^7.2.0",
-    "@babel/parser": "^7.3.0"
+    "@babel/parser": "^7.3.2"
   }
 }

packages/babel-generator/test/fixtures/flow/interface-types/input.js

@@ -1,3 +1,4 @@
 type A = interface { p: string };
 type B = interface extends X { p: string };
 type C = interface extends X, Y { p: string };
+type D = interface extends X.Y<Z> { p: string };

packages/babel-generator/test/fixtures/flow/interface-types/output.js

@@ -6,4 +6,7 @@ type B = interface extends X {
 };
 type C = interface extends X, Y {
   p: string
-};
+};
+type D = interface extends X.Y<Z> {
+  p: string
+};

packages/babel-generator/test/fixtures/flow/type-alias/input.js

@@ -14,3 +14,5 @@ type overloads =
 ;
 
 type func = string => string;
+
+type D = X.Y<Z>;

packages/babel-generator/test/fixtures/flow/type-alias/output.js

@@ -9,3 +9,4 @@ type union = {
 };
 type overloads = (x: string) => number & (x: number) => string;
 type func = (string) => string;
+type D = X.Y<Z>;

packages/babel-helper-create-class-features-plugin/README.md

@@ -1,19 +1,19 @@
-# @babel/plugin-class-features
+# @babel/helper-create-class-features-plugin
 
 > Compile class public and private fields, private methods and decorators to ES6
 
-See our website [@babel/plugin-class-features](https://babeljs.io/docs/en/next/babel-plugin-class-features.html) for more information.
+See our website [@babel/helper-create-class-features-plugin](https://babeljs.io/docs/en/next/babel-helper-create-class-features-plugin.html) for more information.
 
 ## Install
 
 Using npm:
 
 ```sh
-npm install --save-dev @babel/plugin-class-features
+npm install --save-dev @babel/helper-create-class-features-plugin
 ```
 
 or using yarn:
 
 ```sh
-yarn add @babel/plugin-class-features --dev
+yarn add @babel/helper-create-class-features-plugin --dev
 ```

packages/babel-helper-create-class-features-plugin/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@babel/helper-create-class-features-plugin",
-  "version": "7.3.0",
+  "version": "7.3.2",
   "author": "The Babel Team (https://babeljs.io/team)",
   "license": "MIT",
   "description": "Compile class public and private fields, private methods and decorators to ES6",

packages/babel-helper-create-class-features-plugin/src/fields.js

@@ -410,8 +410,14 @@ function buildPrivateInstanceMethodDeclaration(prop, privateNamesMap) {
     getterDeclared,
     setterDeclared,
   } = privateName;
-  const { params, body } = prop.node;
-  const methodValue = t.functionExpression(methodId, params, body);
+  const { params, body, generator, async } = prop.node;
+  const methodValue = t.functionExpression(
+    methodId,
+    params,
+    body,
+    generator,
+    async,
+  );
   const isGetter = getId && !getterDeclared && params.length === 0;
   const isSetter = setId && !setterDeclared && params.length > 0;
 

packages/babel-helper-create-class-features-plugin/test/fixtures/plugin-proposal-class-properties/recursive-class-property-type-challenge/options.json

@@ -1,8 +1,4 @@
 {
-  "presets": [
-    "flow"
-  ],
-  "plugins": [
-    "proposal-class-properties"
-  ]
+  "presets": ["flow"],
+  "plugins": ["proposal-class-properties"]
 }

packages/babel-helper-create-class-features-plugin/test/fixtures/plugin-proposal-class-properties/recursive-class-property-type/options.json

@@ -1,8 +1,4 @@
 {
-  "presets": [
-    "flow"
-  ],
-  "plugins": [
-    "proposal-class-properties"
-  ]
+  "presets": ["flow"],
+  "plugins": ["proposal-class-properties"]
 }

packages/babel-helpers/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@babel/helpers",
-  "version": "7.3.0",
+  "version": "7.3.1",
   "description": "Collection of helper functions used by Babel transforms.",
   "author": "Sebastian McKenzie <sebmck@gmail.com>",
   "homepage": "https://babeljs.io/",

packages/babel-helpers/src/helpers.js

@@ -389,20 +389,16 @@ helpers.objectSpread = helper("7.0.0-beta.0")`
 
   export default 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]));
+      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;
   }

packages/babel-parser/README.md

@@ -2,7 +2,7 @@
 
 > A JavaScript parser
 
-See our website [@babel/parser](https://babeljs.io/docs/en/next/babel-parser.html) for more information or the [issues](https://github.com/babel/babel/issues?utf8=%E2%9C%93&q=is%3Aissue+label%3A%22pkg%3A%20babylon%22+is%3Aopen) associated with this package.
+See our website [@babel/parser](https://babeljs.io/docs/en/next/babel-parser.html) for more information or the [issues](https://github.com/babel/babel/issues?utf8=%E2%9C%93&q=is%3Aissue+label%3A%22pkg%3A+parser+%28babylon%29%22+is%3Aopen) associated with this package.
 
 ## Install
 

packages/babel-parser/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@babel/parser",
-  "version": "7.3.0",
+  "version": "7.3.2",
   "description": "A JavaScript parser",
   "author": "Sebastian McKenzie <sebmck@gmail.com>",
   "homepage": "https://babeljs.io/",

packages/babel-parser/src/parser/base.js

@@ -1,8 +1,6 @@
 // @flow
 
 import type { Options } from "../options";
-import { isES2015ReservedWord } from "../util/identifier";
-
 import type State from "../tokenizer/state";
 import type { PluginsMap } from "./index";
 
@@ -17,14 +15,6 @@ export default class BaseParser {
   // Initialized by Tokenizer
   state: State;
 
-  isReservedWord(word: string): boolean {
-    if (word === "await") {
-      return this.inModule;
-    } else {
-      return isES2015ReservedWord(word);
-    }
-  }
-
   hasPlugin(name: string): boolean {
     return this.plugins.has(name);
   }

packages/babel-parser/src/parser/expression.js

@@ -22,9 +22,10 @@ import { types as tt, type TokenType } from "../tokenizer/types";
 import * as N from "../types";
 import LValParser from "./lval";
 import {
+  isKeyword,
+  isReservedWord,
   isStrictReservedWord,
   isStrictBindReservedWord,
-  isKeyword,
 } from "../util/identifier";
 import type { Pos, Position } from "../util/location";
 import * as charCodes from "charcodes";
@@ -126,12 +127,18 @@ export default class ExpressionParser extends LValParser {
   ): N.Expression {
     const startPos = this.state.start;
     const startLoc = this.state.startLoc;
-    if (this.match(tt._yield) && this.state.inGenerator) {
-      let left = this.parseYield();
-      if (afterLeftParse) {
-        left = afterLeftParse.call(this, left, startPos, startLoc);
+    if (this.isContextual("yield")) {
+      if (this.state.inGenerator) {
+        let left = this.parseYield(noIn);
+        if (afterLeftParse) {
+          left = afterLeftParse.call(this, left, startPos, startLoc);
+        }
+        return left;
+      } else {
+        // The tokenizer will assume an expression is allowed after
+        // `yield`, but this isn't that kind of yield
+        this.state.exprAllowed = false;
       }
-      return left;
     }
 
     const oldCommaAfterSpreadAt = this.state.commaAfterSpreadAt;
@@ -145,7 +152,7 @@ export default class ExpressionParser extends LValParser {
       failOnShorthandAssign = true;
     }
 
-    if (this.match(tt.parenL) || this.match(tt.name) || this.match(tt._yield)) {
+    if (this.match(tt.parenL) || this.match(tt.name)) {
       this.state.potentialArrowAt = this.state.start;
     }
 
@@ -412,7 +419,13 @@ export default class ExpressionParser extends LValParser {
   // Parse unary operators, both prefix and postfix.
 
   parseMaybeUnary(refShorthandDefaultPos: ?Pos): N.Expression {
-    if (this.state.type.prefix) {
+    if (
+      this.isContextual("await") &&
+      (this.state.inAsync ||
+        (!this.state.inFunction && this.options.allowAwaitOutsideFunction))
+    ) {
+      return this.parseAwait();
+    } else if (this.state.type.prefix) {
       const node = this.startNode();
       const update = this.match(tt.incDec);
       node.operator = this.state.value;
@@ -584,9 +597,11 @@ export default class ExpressionParser extends LValParser {
       return this.finishNode(node, "MemberExpression");
     } else if (!noCalls && this.match(tt.parenL)) {
       const oldMaybeInArrowParameters = this.state.maybeInArrowParameters;
-      const oldYOAIPAP = this.state.yieldOrAwaitInPossibleArrowParameters;
+      const oldYieldPos = this.state.yieldPos;
+      const oldAwaitPos = this.state.awaitPos;
       this.state.maybeInArrowParameters = true;
-      this.state.yieldOrAwaitInPossibleArrowParameters = null;
+      this.state.yieldPos = 0;
+      this.state.awaitPos = 0;
 
       const possibleAsync = this.atPossibleAsync(base);
       this.next();
@@ -617,14 +632,16 @@ export default class ExpressionParser extends LValParser {
           this.startNodeAt(startPos, startLoc),
           node,
         );
-        this.state.yieldOrAwaitInPossibleArrowParameters = oldYOAIPAP;
+        this.checkYieldAwaitInDefaultParams();
+        this.state.yieldPos = oldYieldPos;
+        this.state.awaitPos = oldAwaitPos;
       } else {
         this.toReferencedListDeep(node.arguments);
 
         // We keep the old value if it isn't null, for cases like
         //   (x = async(yield)) => {}
-        this.state.yieldOrAwaitInPossibleArrowParameters =
-          this.state.yieldOrAwaitInPossibleArrowParameters || oldYOAIPAP;
+        this.state.yieldPos = oldYieldPos || this.state.yieldPos;
+        this.state.awaitPos = oldAwaitPos || this.state.awaitPos;
       }
 
       this.state.maybeInArrowParameters = oldMaybeInArrowParameters;
@@ -841,29 +858,12 @@ export default class ExpressionParser extends LValParser {
         this.next();
         return this.finishNode(node, "ThisExpression");
 
-      case tt._yield:
-        if (this.state.inGenerator) this.unexpected();
-
       case tt.name: {
         node = this.startNode();
-        const allowAwait =
-          this.state.value === "await" &&
-          (this.state.inAsync ||
-            (!this.state.inFunction && this.options.allowAwaitOutsideFunction));
-
         const containsEsc = this.state.containsEsc;
-        const allowYield = this.shouldAllowYieldIdentifier();
-        const id = this.parseIdentifier(allowAwait || allowYield);
+        const id = this.parseIdentifier();
 
-        if (id.name === "await") {
-          if (
-            this.state.inAsync ||
-            this.inModule ||
-            (!this.state.inFunction && this.options.allowAwaitOutsideFunction)
-          ) {
-            return this.parseAwait(node);
-          }
-        } else if (
+        if (
           !containsEsc &&
           id.name === "async" &&
           this.match(tt._function) &&
@@ -877,25 +877,19 @@ export default class ExpressionParser extends LValParser {
           this.match(tt.name) &&
           !this.canInsertSemicolon()
         ) {
-          const oldYOAIPAP = this.state.yieldOrAwaitInPossibleArrowParameters;
           const oldInAsync = this.state.inAsync;
-          this.state.yieldOrAwaitInPossibleArrowParameters = null;
           this.state.inAsync = true;
           const params = [this.parseIdentifier()];
           this.expect(tt.arrow);
           // let foo = async bar => {};
           this.parseArrowExpression(node, params, true);
-          this.state.yieldOrAwaitInPossibleArrowParameters = oldYOAIPAP;
           this.state.inAsync = oldInAsync;
           return node;
         }
 
         if (canBeArrow && this.match(tt.arrow) && !this.canInsertSemicolon()) {
           this.next();
-          const oldYOAIPAP = this.state.yieldOrAwaitInPossibleArrowParameters;
-          this.state.yieldOrAwaitInPossibleArrowParameters = null;
-          this.parseArrowExpression(node, [id]);
-          this.state.yieldOrAwaitInPossibleArrowParameters = oldYOAIPAP;
+          this.parseArrowExpression(node, [id], false);
           return node;
         }
 
@@ -1176,9 +1170,11 @@ export default class ExpressionParser extends LValParser {
     this.expect(tt.parenL);
 
     const oldMaybeInArrowParameters = this.state.maybeInArrowParameters;
-    const oldYOAIPAP = this.state.yieldOrAwaitInPossibleArrowParameters;
+    const oldYieldPos = this.state.yieldPos;
+    const oldAwaitPos = this.state.awaitPos;
     this.state.maybeInArrowParameters = true;
-    this.state.yieldOrAwaitInPossibleArrowParameters = null;
+    this.state.yieldPos = 0;
+    this.state.awaitPos = 0;
 
     const innerStartPos = this.state.start;
     const innerStartLoc = this.state.startLoc;
@@ -1239,21 +1235,23 @@ export default class ExpressionParser extends LValParser {
       this.shouldParseArrow() &&
       (arrowNode = this.parseArrow(arrowNode))
     ) {
+      this.checkYieldAwaitInDefaultParams();
+      this.state.yieldPos = oldYieldPos;
+      this.state.awaitPos = oldAwaitPos;
       for (const param of exprList) {
         if (param.extra && param.extra.parenthesized) {
           this.unexpected(param.extra.parenStart);
         }
       }
 
-      this.parseArrowExpression(arrowNode, exprList);
-      this.state.yieldOrAwaitInPossibleArrowParameters = oldYOAIPAP;
+      this.parseArrowExpression(arrowNode, exprList, false);
       return arrowNode;
     }
 
     // We keep the old value if it isn't null, for cases like
     //   (x = (yield)) => {}
-    this.state.yieldOrAwaitInPossibleArrowParameters =
-      this.state.yieldOrAwaitInPossibleArrowParameters || oldYOAIPAP;
+    this.state.yieldPos = oldYieldPos || this.state.yieldPos;
+    this.state.awaitPos = oldAwaitPos || this.state.awaitPos;
 
     if (!exprList.length) {
       this.unexpected(this.state.lastTokStart);
@@ -1721,21 +1719,28 @@ export default class ExpressionParser extends LValParser {
     const oldInMethod = this.state.inMethod;
     const oldInAsync = this.state.inAsync;
     const oldInGenerator = this.state.inGenerator;
+    const oldYieldPos = this.state.yieldPos;
+    const oldAwaitPos = this.state.awaitPos;
     this.state.inFunction = true;
     this.state.inMethod = node.kind || true;
     this.state.inAsync = isAsync;
     this.state.inGenerator = isGenerator;
+    this.state.yieldPos = 0;
+    this.state.awaitPos = 0;
 
     this.initFunction(node, isAsync);
     node.generator = !!isGenerator;
     const allowModifiers = isConstructor; // For TypeScript parameter properties
     this.parseFunctionParams((node: any), allowModifiers);
+    this.checkYieldAwaitInDefaultParams();
     this.parseFunctionBodyAndFinish(node, type);
 
     this.state.inFunction = oldInFunc;
     this.state.inMethod = oldInMethod;
     this.state.inAsync = oldInAsync;
     this.state.inGenerator = oldInGenerator;
+    this.state.yieldPos = oldYieldPos;
+    this.state.awaitPos = oldAwaitPos;
 
     return node;
   }
@@ -1745,44 +1750,33 @@ export default class ExpressionParser extends LValParser {
   // assignable list.
   parseArrowExpression(
     node: N.ArrowFunctionExpression,
-    params?: ?(N.Expression[]),
-    isAsync?: boolean = false,
+    params: ?(N.Expression[]),
+    isAsync: boolean,
   ): N.ArrowFunctionExpression {
-    // if we got there, it's no more "yield in possible arrow parameters";
-    // it's just "yield in arrow parameters"
-    const yOAIPAP = this.state.yieldOrAwaitInPossibleArrowParameters;
-    if (yOAIPAP) {
-      if (yOAIPAP.type === "YieldExpression") {
-        this.raise(
-          yOAIPAP.start,
-          "yield is not allowed in the parameters of an arrow function" +
-            " inside a generator",
-        );
-      } else {
-        this.raise(
-          yOAIPAP.start,
-          "await is not allowed in the parameters of an arrow function" +
-            " inside an async function",
-        );
-      }
-    }
+    this.initFunction(node, isAsync);
 
     const oldInFunc = this.state.inFunction;
-    this.state.inFunction = true;
-    this.initFunction(node, isAsync);
-    if (params) this.setArrowFunctionParameters(node, params);
-
     const oldInAsync = this.state.inAsync;
     const oldInGenerator = this.state.inGenerator;
     const oldMaybeInArrowParameters = this.state.maybeInArrowParameters;
+    const oldYieldPos = this.state.yieldPos;
+    const oldAwaitPos = this.state.awaitPos;
+    this.state.inFunction = true;
     this.state.inAsync = isAsync;
     this.state.inGenerator = false;
     this.state.maybeInArrowParameters = false;
+    this.state.yieldPos = 0;
+    this.state.awaitPos = 0;
+
+    if (params) this.setArrowFunctionParameters(node, params);
     this.parseFunctionBody(node, true);
+
     this.state.inAsync = oldInAsync;
     this.state.inGenerator = oldInGenerator;
     this.state.inFunction = oldInFunc;
     this.state.maybeInArrowParameters = oldMaybeInArrowParameters;
+    this.state.yieldPos = oldYieldPos;
+    this.state.awaitPos = oldAwaitPos;
 
     return this.finishNode(node, "ArrowFunctionExpression");
   }
@@ -1832,17 +1826,14 @@ export default class ExpressionParser extends LValParser {
     if (isExpression) {
       node.body = this.parseMaybeAssign();
     } else {
-      // Start a new scope with regard to labels and the `inGenerator`
+      // Start a new scope with regard to labels
       // flag (restore them to their old value afterwards).
-      const oldInGen = this.state.inGenerator;
       const oldInFunc = this.state.inFunction;
       const oldLabels = this.state.labels;
-      this.state.inGenerator = node.generator;
       this.state.inFunction = true;
       this.state.labels = [];
       node.body = this.parseBlock(true);
       this.state.inFunction = oldInFunc;
-      this.state.inGenerator = oldInGen;
       this.state.labels = oldLabels;
     }
 
@@ -1952,15 +1943,6 @@ export default class ExpressionParser extends LValParser {
   }
 
   parseIdentifierName(pos: number, liberal?: boolean): string {
-    if (!liberal) {
-      this.checkReservedWord(
-        this.state.value,
-        this.state.start,
-        !!this.state.type.keyword,
-        false,
-      );
-    }
-
     let name: string;
 
     if (this.match(tt.name)) {
@@ -1985,11 +1967,17 @@ export default class ExpressionParser extends LValParser {
       throw this.unexpected();
     }
 
-    if (!liberal && name === "await" && this.state.inAsync) {
-      this.raise(pos, "invalid use of await inside of an async function");
+    if (!liberal) {
+      this.checkReservedWord(
+        name,
+        this.state.start,
+        !!this.state.type.keyword,
+        false,
+      );
     }
 
     this.next();
+
     return name;
   }
 
@@ -1999,43 +1987,58 @@ export default class ExpressionParser extends LValParser {
     checkKeywords: boolean,
     isBinding: boolean,
   ): void {
-    if (
-      this.state.strict &&
-      (isStrictReservedWord(word) ||
-        (isBinding && isStrictBindReservedWord(word)))
-    ) {
-      this.raise(startLoc, word + " is a reserved word in strict mode");
-    }
-
-    if (this.state.inGenerator && word === "yield") {
+    const state = this.state;
+    if (state.inGenerator && word === "yield") {
       this.raise(
         startLoc,
-        "yield is a reserved word inside generator functions",
+        "Can not use 'yield' as identifier inside a generator",
       );
     }
 
-    if (this.state.inClassProperty && word === "arguments") {
+    if (state.inAsync && word === "await") {
+      this.raise(
+        startLoc,
+        "Can not use 'await' as identifier inside an async function",
+      );
+    }
+
+    if (state.inClassProperty && word === "arguments") {
       this.raise(
         startLoc,
         "'arguments' is not allowed in class field initializer",
       );
     }
+    if (checkKeywords && isKeyword(word)) {
+      this.raise(startLoc, `Unexpected keyword '${word}'`);
+    }
 
-    if (this.isReservedWord(word) || (checkKeywords && isKeyword(word))) {
-      this.raise(startLoc, word + " is a reserved word");
+    const reservedTest = !state.strict
+      ? isReservedWord
+      : isBinding
+      ? isStrictBindReservedWord
+      : isStrictReservedWord;
+
+    if (reservedTest(word, this.inModule)) {
+      if (!state.inAsync && word === "await") {
+        this.raise(
+          startLoc,
+          "Can not use keyword 'await' outside an async function",
+        );
+      }
+      this.raise(startLoc, `Unexpected reserved word '${word}'`);
     }
   }
 
   // Parses await expression inside async function.
 
-  parseAwait(node: N.AwaitExpression): N.AwaitExpression {
-    // istanbul ignore next: this condition is checked at the call site so won't be hit here
-    if (
-      !this.state.inAsync &&
-      (this.state.inFunction || !this.options.allowAwaitOutsideFunction)
-    ) {
-      this.unexpected();
+  parseAwait(): N.AwaitExpression {
+    if (!this.state.awaitPos) {
+      this.state.awaitPos = this.state.start;
     }
+    const node = this.startNode();
+
+    this.next();
+
     if (this.state.inParameters) {
       this.raise(
         node.start,
@@ -2048,14 +2051,6 @@ export default class ExpressionParser extends LValParser {
         "await* has been removed from the async functions proposal. Use Promise.all() instead.",
       );
     }
-    if (
-      this.state.maybeInArrowParameters &&
-      // We only set yieldOrAwaitInPossibleArrowParameters if we haven't already
-      // found a possible invalid AwaitExpression.
-      !this.state.yieldOrAwaitInPossibleArrowParameters
-    ) {
-      this.state.yieldOrAwaitInPossibleArrowParameters = node;
-    }
 
     node.argument = this.parseMaybeUnary();
     return this.finishNode(node, "AwaitExpression");
@@ -2063,20 +2058,15 @@ export default class ExpressionParser extends LValParser {
 
   // Parses yield expression inside generator.
 
-  parseYield(): N.YieldExpression {
+  parseYield(noIn?: ?boolean): N.YieldExpression {
+    if (!this.state.yieldPos) {
+      this.state.yieldPos = this.state.start;
+    }
     const node = this.startNode();
 
     if (this.state.inParameters) {
       this.raise(node.start, "yield is not allowed in generator parameters");
     }
-    if (
-      this.state.maybeInArrowParameters &&
-      // We only set yieldOrAwaitInPossibleArrowParameters if we haven't already
-      // found a possible invalid YieldExpression.
-      !this.state.yieldOrAwaitInPossibleArrowParameters
-    ) {
-      this.state.yieldOrAwaitInPossibleArrowParameters = node;
-    }
 
     this.next();
     if (
@@ -2088,7 +2078,7 @@ export default class ExpressionParser extends LValParser {
       node.argument = null;
     } else {
       node.delegate = this.eat(tt.star);
-      node.argument = this.parseMaybeAssign();
+      node.argument = this.parseMaybeAssign(noIn);
     }
     return this.finishNode(node, "YieldExpression");
   }

packages/babel-parser/src/parser/lval.js

@@ -14,16 +14,11 @@ import type {
   SpreadElement,
 } from "../types";
 import type { Pos, Position } from "../util/location";
+import { isStrictBindReservedWord } from "../util/identifier";
 import { NodeUtils } from "./node";
 
 export default class LValParser extends NodeUtils {
   // Forward-declaration: defined in expression.js
-  +checkReservedWord: (
-    word: string,
-    startLoc: number,
-    checkKeywords: boolean,
-    isBinding: boolean,
-  ) => void;
   +parseIdentifier: (liberal?: boolean) => Identifier;
   +parseMaybeAssign: (
     noIn?: ?boolean,
@@ -224,22 +219,11 @@ export default class LValParser extends NodeUtils {
     return this.finishNode(node, "RestElement");
   }
 
-  shouldAllowYieldIdentifier(): boolean {
-    return (
-      this.match(tt._yield) && !this.state.strict && !this.state.inGenerator
-    );
-  }
-
-  parseBindingIdentifier(): Identifier {
-    return this.parseIdentifier(this.shouldAllowYieldIdentifier());
-  }
-
   // Parses lvalue (assignable) atom.
   parseBindingAtom(): Pattern {
     switch (this.state.type) {
-      case tt._yield:
       case tt.name:
-        return this.parseBindingIdentifier();
+        return this.parseIdentifier();
 
       case tt.bracketL: {
         const node = this.startNode();
@@ -347,7 +331,17 @@ export default class LValParser extends NodeUtils {
   ): void {
     switch (expr.type) {
       case "Identifier":
-        this.checkReservedWord(expr.name, expr.start, false, true);
+        if (
+          this.state.strict &&
+          isStrictBindReservedWord(expr.name, this.inModule)
+        ) {
+          this.raise(
+            expr.start,
+            `${isBinding ? "Binding" : "Assigning to"} '${
+              expr.name
+            }' in strict mode`,
+          );
+        }
 
         if (checkClashes) {
           // we need to prefix this with an underscore for the cases where we have a key of

packages/babel-parser/src/parser/node.js

@@ -91,12 +91,16 @@ export class NodeUtils extends UtilParser {
     return node;
   }
 
+  resetStartLocation(node: NodeBase, start: number, startLoc: Position): void {
+    node.start = start;
+    node.loc.start = startLoc;
+    if (this.options.ranges) node.range[0] = start;
+  }
+
   /**
    * Reset the start location of node to the start location of locationNode
    */
   resetStartLocationFromNode(node: NodeBase, locationNode: NodeBase): void {
-    node.start = locationNode.start;
-    node.loc.start = locationNode.loc.start;
-    if (this.options.ranges) node.range[0] = locationNode.range[0];
+    this.resetStartLocation(node, locationNode.start, locationNode.loc.start);
   }
 }

packages/babel-parser/src/parser/statement.js

@@ -3,8 +3,13 @@
 import * as N from "../types";
 import { types as tt, type TokenType } from "../tokenizer/types";
 import ExpressionParser from "./expression";
-import { isIdentifierChar } from "../util/identifier";
+import {
+  isIdentifierChar,
+  isIdentifierStart,
+  keywordRelationalOperator,
+} from "../util/identifier";
 import { lineBreak, skipWhiteSpace } from "../util/whitespace";
+import * as charCodes from "charcodes";
 
 // Reused empty array added for node fields that are always empty.
 
@@ -71,6 +76,39 @@ export default class StatementParser extends ExpressionParser {
     return this.finishNode(node, "InterpreterDirective");
   }
 
+  isLet(declaration?: boolean): boolean {
+    if (!this.isContextual("let")) {
+      return false;
+    }
+    skipWhiteSpace.lastIndex = this.state.pos;
+    const skip = skipWhiteSpace.exec(this.state.input);
+    // $FlowIgnore
+    const next = this.state.pos + skip[0].length;
+    const nextCh = this.state.input.charCodeAt(next);
+    if (
+      (nextCh === charCodes.leftCurlyBrace &&
+        !lineBreak.test(this.state.input.slice(this.state.end, next))) ||
+      nextCh === charCodes.leftSquareBracket
+    ) {
+      return true;
+    }
+    if (isIdentifierStart(nextCh)) {
+      if (
+        !declaration &&
+        lineBreak.test(this.state.input.slice(this.state.end, next))
+      ) {
+        return false;
+      }
+      let pos = next + 1;
+      while (isIdentifierChar(this.state.input.charCodeAt(pos))) {
+        ++pos;
+      }
+      const ident = this.state.input.slice(next, pos);
+      if (!keywordRelationalOperator.test(ident)) return true;
+    }
+    return false;
+  }
+
   // Parse a single statement.
   //
   // If expecting a statement and finding a slash operator, parse a
@@ -86,8 +124,14 @@ export default class StatementParser extends ExpressionParser {
   }
 
   parseStatementContent(declaration: boolean, topLevel: ?boolean): N.Statement {
-    const starttype = this.state.type;
+    let starttype = this.state.type;
     const node = this.startNode();
+    let kind;
+
+    if (this.isLet(declaration)) {
+      starttype = tt._var;
+      kind = "let";
+    }
 
     // Most types of statements are recognized by the keyword they
     // start with. Many are trivial to parse, some require a bit of
@@ -129,12 +173,11 @@ export default class StatementParser extends ExpressionParser {
       case tt._try:
         return this.parseTryStatement(node);
 
-      case tt._let:
       case tt._const:
-        if (!declaration) this.unexpected(); // NOTE: falls through to _var
-
       case tt._var:
-        return this.parseVarStatement(node, starttype);
+        kind = kind || this.state.value;
+        if (!declaration && kind !== "var") this.unexpected();
+        return this.parseVarStatement(node, kind);
 
       case tt._while:
         return this.parseWhileStatement(node);
@@ -410,32 +453,36 @@ export default class StatementParser extends ExpressionParser {
     this.next();
     this.state.labels.push(loopLabel);
 
-    let forAwait = false;
-    if (this.state.inAsync && this.isContextual("await")) {
-      forAwait = true;
-      this.next();
+    let awaitAt = -1;
+    if (
+      (this.state.inAsync ||
+        (!this.state.inFunction && this.options.allowAwaitOutsideFunction)) &&
+      this.eatContextual("await")
+    ) {
+      awaitAt = this.state.lastTokStart;
     }
     this.expect(tt.parenL);
 
     if (this.match(tt.semi)) {
-      if (forAwait) {
-        this.unexpected();
+      if (awaitAt > -1) {
+        this.unexpected(awaitAt);
       }
       return this.parseFor(node, null);
     }
 
-    if (this.match(tt._var) || this.match(tt._let) || this.match(tt._const)) {
+    const isLet = this.isLet();
+    if (this.match(tt._var) || this.match(tt._const) || isLet) {
       const init = this.startNode();
-      const varKind = this.state.type;
+      const kind = isLet ? "let" : this.state.value;
       this.next();
-      this.parseVar(init, true, varKind);
+      this.parseVar(init, true, kind);
       this.finishNode(init, "VariableDeclaration");
 
       if (this.match(tt._in) || this.isContextual("of")) {
         if (init.declarations.length === 1) {
           const declaration = init.declarations[0];
           const isForInInitializer =
-            varKind === tt._var &&
+            kind === "var" &&
             declaration.init &&
             declaration.id.type != "ObjectPattern" &&
             declaration.id.type != "ArrayPattern" &&
@@ -443,12 +490,12 @@ export default class StatementParser extends ExpressionParser {
           if (this.state.strict && isForInInitializer) {
             this.raise(this.state.start, "for-in initializer in strict mode");
           } else if (isForInInitializer || !declaration.init) {
-            return this.parseForIn(node, init, forAwait);
+            return this.parseForIn(node, init, awaitAt);
           }
         }
       }
-      if (forAwait) {
-        this.unexpected();
+      if (awaitAt > -1) {
+        this.unexpected(awaitAt);
       }
       return this.parseFor(node, init);
     }
@@ -461,12 +508,12 @@ export default class StatementParser extends ExpressionParser {
         : "for-in statement";
       this.toAssignable(init, undefined, description);
       this.checkLVal(init, undefined, undefined, description);
-      return this.parseForIn(node, init, forAwait);
+      return this.parseForIn(node, init, awaitAt);
     } else if (refShorthandDefaultPos.start) {
       this.unexpected(refShorthandDefaultPos.start);
     }
-    if (forAwait) {
-      this.unexpected();
+    if (awaitAt > -1) {
+      this.unexpected(awaitAt);
     }
     return this.parseFor(node, init);
   }
@@ -606,7 +653,7 @@ export default class StatementParser extends ExpressionParser {
 
   parseVarStatement(
     node: N.VariableDeclaration,
-    kind: TokenType,
+    kind: "var" | "let" | "const",
   ): N.VariableDeclaration {
     this.next();
     this.parseVar(node, false, kind);
@@ -828,16 +875,16 @@ export default class StatementParser extends ExpressionParser {
   parseForIn(
     node: N.ForInOf,
     init: N.VariableDeclaration,
-    forAwait: boolean,
+    awaitAt: number,
   ): N.ForInOf {
     const type = this.match(tt._in) ? "ForInStatement" : "ForOfStatement";
-    if (forAwait) {
+    if (awaitAt > -1) {
       this.eatContextual("of");
     } else {
       this.next();
     }
     if (type === "ForOfStatement") {
-      node.await = !!forAwait;
+      node.await = awaitAt > -1;
     }
     node.left = init;
     node.right = this.parseExpression();
@@ -862,20 +909,19 @@ export default class StatementParser extends ExpressionParser {
   parseVar(
     node: N.VariableDeclaration,
     isFor: boolean,
-    kind: TokenType,
+    kind: "var" | "let" | "const",
   ): N.VariableDeclaration {
     const declarations = (node.declarations = []);
     const isTypescript = this.hasPlugin("typescript");
-    // $FlowFixMe
-    node.kind = kind.keyword;
+    node.kind = kind;
     for (;;) {
       const decl = this.startNode();
-      this.parseVarHead(decl);
+      this.parseVarId(decl, kind);
       if (this.eat(tt.eq)) {
         decl.init = this.parseMaybeAssign(isFor);
       } else {
         if (
-          kind === tt._const &&
+          kind === "const" &&
           !(this.match(tt._in) || this.isContextual("of"))
         ) {
           // `const` with no initializer is allowed in TypeScript.
@@ -900,7 +946,10 @@ export default class StatementParser extends ExpressionParser {
     return node;
   }
 
-  parseVarHead(decl: N.VariableDeclarator): void {
+  parseVarId(decl: N.VariableDeclarator, kind: "var" | "let" | "const"): void {
+    if ((kind === "const" || kind === "let") && this.isContextual("let")) {
+      this.unexpected(null, "let is disallowed as a lexically bound name");
+    }
     decl.id = this.parseBindingAtom();
     this.checkLVal(decl.id, true, undefined, "variable declaration");
   }
@@ -920,23 +969,19 @@ export default class StatementParser extends ExpressionParser {
     const oldInAsync = this.state.inAsync;
     const oldInGenerator = this.state.inGenerator;
     const oldInClassProperty = this.state.inClassProperty;
+    const oldYieldPos = this.state.yieldPos;
+    const oldAwaitPos = this.state.awaitPos;
     this.state.inFunction = true;
     this.state.inMethod = false;
     this.state.inClassProperty = false;
+    this.state.yieldPos = 0;
+    this.state.awaitPos = 0;
 
     this.initFunction(node, isAsync);
 
-    if (this.match(tt.star)) {
-      node.generator = true;
-      this.next();
-    }
+    node.generator = this.eat(tt.star);
 
-    if (
-      isStatement &&
-      !optionalId &&
-      !this.match(tt.name) &&
-      !this.match(tt._yield)
-    ) {
+    if (isStatement && !optionalId && !this.match(tt.name)) {
       this.unexpected();
     }
 
@@ -953,8 +998,8 @@ export default class StatementParser extends ExpressionParser {
       this.state.inAsync = isAsync;
       this.state.inGenerator = node.generator;
     }
-    if (this.match(tt.name) || this.match(tt._yield)) {
-      node.id = this.parseBindingIdentifier();
+    if (this.match(tt.name)) {
+      node.id = this.parseIdentifier();
     }
     if (isStatement) {
       this.state.inAsync = isAsync;
@@ -980,6 +1025,8 @@ export default class StatementParser extends ExpressionParser {
     this.state.inAsync = oldInAsync;
     this.state.inGenerator = oldInGenerator;
     this.state.inClassProperty = oldInClassProperty;
+    this.state.yieldPos = oldYieldPos;
+    this.state.awaitPos = oldAwaitPos;
 
     return node;
   }
@@ -996,6 +1043,7 @@ export default class StatementParser extends ExpressionParser {
     );
 
     this.state.inParameters = oldInParameters;
+    this.checkYieldAwaitInDefaultParams();
   }
 
   // Parse a class declaration or literal (depending on the
@@ -1008,12 +1056,12 @@ export default class StatementParser extends ExpressionParser {
   ): T {
     this.next();
     this.takeDecorators(node);
-    this.parseClassId(node, isStatement, optionalId);
 
-    // class bodies and heritages are implicitly strict
+    // A class definition is always strict mode code.
     const oldStrict = this.state.strict;
     this.state.strict = true;
 
+    this.parseClassId(node, isStatement, optionalId);
     this.parseClassSuper(node);
     this.parseClassBody(node);
 
@@ -1470,35 +1518,109 @@ export default class StatementParser extends ExpressionParser {
 
   // Parses module export declaration.
 
-  // TODO: better type. Node is an N.AnyExport.
-  parseExport(node: N.Node): N.Node {
-    // export * from '...'
-    if (this.shouldParseExportStar()) {
-      this.parseExportStar(node);
-      if (node.type === "ExportAllDeclaration") return node;
-    } else if (this.isExportDefaultSpecifier()) {
-      this.expectPlugin("exportDefaultFrom");
-      const specifier = this.startNode();
-      specifier.exported = this.parseIdentifier(true);
-      const specifiers = [this.finishNode(specifier, "ExportDefaultSpecifier")];
-      node.specifiers = specifiers;
-      if (this.match(tt.comma) && this.lookahead().type === tt.star) {
-        this.expect(tt.comma);
-        const specifier = this.startNode();
-        this.expect(tt.star);
-        this.expectContextual("as");
-        specifier.exported = this.parseIdentifier();
-        specifiers.push(this.finishNode(specifier, "ExportNamespaceSpecifier"));
-      } else {
-        this.parseExportSpecifiersMaybe(node);
-      }
+  parseExport(node: N.Node): N.AnyExport {
+    const hasDefault = this.maybeParseExportDefaultSpecifier(node);
+    const parseAfterDefault = !hasDefault || this.eat(tt.comma);
+    const hasStar = parseAfterDefault && this.eatExportStar(node);
+    const hasNamespace =
+      hasStar && this.maybeParseExportNamespaceSpecifier(node);
+    const parseAfterNamespace =
+      parseAfterDefault && (!hasNamespace || this.eat(tt.comma));
+    const isFromRequired = hasDefault || hasStar;
+
+    if (hasStar && !hasNamespace) {
+      if (hasDefault) this.unexpected();
       this.parseExportFrom(node, true);
-    } else if (this.eat(tt._default)) {
+
+      return this.finishNode(node, "ExportAllDeclaration");
+    }
+
+    const hasSpecifiers = this.maybeParseExportNamedSpecifiers(node);
+
+    if (
+      (hasDefault && parseAfterDefault && !hasStar && !hasSpecifiers) ||
+      (hasNamespace && parseAfterNamespace && !hasSpecifiers)
+    ) {
+      throw this.unexpected(null, tt.braceL);
+    }
+
+    let hasDeclaration;
+    if (isFromRequired || hasSpecifiers) {
+      hasDeclaration = false;
+      this.parseExportFrom(node, isFromRequired);
+    } else {
+      hasDeclaration = this.maybeParseExportDeclaration(node);
+    }
+
+    if (isFromRequired || hasSpecifiers || hasDeclaration) {
+      this.checkExport(node, true);
+      return this.finishNode(node, "ExportNamedDeclaration");
+    }
+
+    if (this.eat(tt._default)) {
       // export default ...
       node.declaration = this.parseExportDefaultExpression();
       this.checkExport(node, true, true);
+
       return this.finishNode(node, "ExportDefaultDeclaration");
-    } else if (this.shouldParseExportDeclaration()) {
+    }
+
+    throw this.unexpected(null, tt.braceL);
+  }
+
+  // eslint-disable-next-line no-unused-vars
+  eatExportStar(node: N.Node): boolean {
+    return this.eat(tt.star);
+  }
+
+  maybeParseExportDefaultSpecifier(node: N.Node): boolean {
+    if (this.isExportDefaultSpecifier()) {
+      // export defaultObj ...
+      this.expectPlugin("exportDefaultFrom");
+      const specifier = this.startNode();
+      specifier.exported = this.parseIdentifier(true);
+      node.specifiers = [this.finishNode(specifier, "ExportDefaultSpecifier")];
+      return true;
+    }
+    return false;
+  }
+
+  maybeParseExportNamespaceSpecifier(node: N.Node): boolean {
+    if (this.isContextual("as")) {
+      if (!node.specifiers) node.specifiers = [];
+      this.expectPlugin("exportNamespaceFrom");
+
+      const specifier = this.startNodeAt(
+        this.state.lastTokStart,
+        this.state.lastTokStartLoc,
+      );
+
+      this.next();
+
+      specifier.exported = this.parseIdentifier(true);
+      node.specifiers.push(
+        this.finishNode(specifier, "ExportNamespaceSpecifier"),
+      );
+      return true;
+    }
+    return false;
+  }
+
+  maybeParseExportNamedSpecifiers(node: N.Node): boolean {
+    if (this.match(tt.braceL)) {
+      if (!node.specifiers) node.specifiers = [];
+      node.specifiers.push(...this.parseExportSpecifiers());
+
+      node.source = null;
+      node.declaration = null;
+
+      return true;
+    }
+    return false;
+  }
+
+  maybeParseExportDeclaration(node: N.Node): boolean {
+    if (this.shouldParseExportDeclaration()) {
       if (this.isContextual("async")) {
         const next = this.lookahead();
 
@@ -1511,14 +1633,10 @@ export default class StatementParser extends ExpressionParser {
       node.specifiers = [];
       node.source = null;
       node.declaration = this.parseExportDeclaration(node);
-    } else {
-      // export { x, y as z } [from '...']
-      node.declaration = null;
-      node.specifiers = this.parseExportSpecifiers();
-      this.parseExportFrom(node);
+
+      return true;
     }
-    this.checkExport(node, true);
-    return this.finishNode(node, "ExportNamedDeclaration");
+    return false;
   }
 
   isAsyncFunction() {
@@ -1568,11 +1686,7 @@ export default class StatementParser extends ExpressionParser {
       }
       this.parseDecorators(false);
       return this.parseClass(expr, true, true);
-    } else if (
-      this.match(tt._let) ||
-      this.match(tt._const) ||
-      this.match(tt._var)
-    ) {
+    } else if (this.match(tt._const) || this.match(tt._var) || this.isLet()) {
       return this.raise(
         this.state.start,
         "Only expressions, functions or classes are allowed as the `default` export.",
@@ -1591,7 +1705,7 @@ export default class StatementParser extends ExpressionParser {
 
   isExportDefaultSpecifier(): boolean {
     if (this.match(tt.name)) {
-      return this.state.value !== "async";
+      return this.state.value !== "async" && this.state.value !== "let";
     }
 
     if (!this.match(tt._default)) {
@@ -1605,17 +1719,9 @@ export default class StatementParser extends ExpressionParser {
     );
   }
 
-  parseExportSpecifiersMaybe(node: N.ExportNamedDeclaration): void {
-    if (this.eat(tt.comma)) {
-      node.specifiers = node.specifiers.concat(this.parseExportSpecifiers());
-    }
-  }
-
   parseExportFrom(node: N.ExportNamedDeclaration, expect?: boolean): void {
     if (this.eatContextual("from")) {
-      node.source = this.match(tt.string)
-        ? this.parseExprAtom()
-        : this.unexpected();
+      node.source = this.parseImportSource();
       this.checkExport(node);
     } else {
       if (expect) {
@@ -1628,39 +1734,6 @@ export default class StatementParser extends ExpressionParser {
     this.semicolon();
   }
 
-  shouldParseExportStar(): boolean {
-    return this.match(tt.star);
-  }
-
-  parseExportStar(node: N.ExportNamedDeclaration): void {
-    this.expect(tt.star);
-
-    if (this.isContextual("as")) {
-      this.parseExportNamespace(node);
-    } else {
-      this.parseExportFrom(node, true);
-      this.finishNode(node, "ExportAllDeclaration");
-    }
-  }
-
-  parseExportNamespace(node: N.ExportNamedDeclaration): void {
-    this.expectPlugin("exportNamespaceFrom");
-
-    const specifier = this.startNodeAt(
-      this.state.lastTokStart,
-      this.state.lastTokStartLoc,
-    );
-
-    this.next();
-
-    specifier.exported = this.parseIdentifier(true);
-
-    node.specifiers = [this.finishNode(specifier, "ExportNamespaceSpecifier")];
-
-    this.parseExportSpecifiersMaybe(node);
-    this.parseExportFrom(node, true);
-  }
-
   shouldParseExportDeclaration(): boolean {
     if (this.match(tt.at)) {
       this.expectOnePlugin(["decorators", "decorators-legacy"]);
@@ -1681,9 +1754,9 @@ export default class StatementParser extends ExpressionParser {
     return (
       this.state.type.keyword === "var" ||
       this.state.type.keyword === "const" ||
-      this.state.type.keyword === "let" ||
       this.state.type.keyword === "function" ||
       this.state.type.keyword === "class" ||
+      this.isLet() ||
       this.isAsyncFunction()
     );
   }
@@ -1760,27 +1833,24 @@ export default class StatementParser extends ExpressionParser {
   }
 
   checkDuplicateExports(
-    node: N.Identifier | N.ExportNamedDeclaration | N.ExportSpecifier,
+    node:
+      | N.Identifier
+      | N.ExportNamedDeclaration
+      | N.ExportSpecifier
+      | N.ExportDefaultSpecifier,
     name: string,
   ): void {
     if (this.state.exportedIdentifiers.indexOf(name) > -1) {
-      this.raiseDuplicateExportError(node, name);
+      throw this.raise(
+        node.start,
+        name === "default"
+          ? "Only one default export allowed per module."
+          : `\`${name}\` has already been exported. Exported identifiers must be unique.`,
+      );
     }
     this.state.exportedIdentifiers.push(name);
   }
 
-  raiseDuplicateExportError(
-    node: N.Identifier | N.ExportNamedDeclaration | N.ExportSpecifier,
-    name: string,
-  ): empty {
-    throw this.raise(
-      node.start,
-      name === "default"
-        ? "Only one default export allowed per module."
-        : `\`${name}\` has already been exported. Exported identifiers must be unique.`,
-    );
-  }
-
   // Parses a comma-separated list of module exports.
 
   parseExportSpecifiers(): Array<N.ExportSpecifier> {
@@ -1820,23 +1890,26 @@ export default class StatementParser extends ExpressionParser {
 
   // Parses import declaration.
 
-  parseImport(node: N.Node): N.ImportDeclaration | N.TsImportEqualsDeclaration {
+  parseImport(node: N.Node): N.AnyImport {
     // import '...'
-    if (this.match(tt.string)) {
-      node.specifiers = [];
-      node.source = this.parseExprAtom();
-    } else {
-      node.specifiers = [];
-      this.parseImportSpecifiers(node);
+    node.specifiers = [];
+    if (!this.match(tt.string)) {
+      const hasDefault = this.maybeParseDefaultImportSpecifier(node);
+      const parseNext = !hasDefault || this.eat(tt.comma);
+      const hasStar = parseNext && this.maybeParseStarImportSpecifier(node);
+      if (parseNext && !hasStar) this.parseNamedImportSpecifiers(node);
       this.expectContextual("from");
-      node.source = this.match(tt.string)
-        ? this.parseExprAtom()
-        : this.unexpected();
     }
+    node.source = this.parseImportSource();
     this.semicolon();
     return this.finishNode(node, "ImportDeclaration");
   }
 
+  parseImportSource(): N.StringLiteral {
+    if (!this.match(tt.string)) this.unexpected();
+    return this.parseExprAtom();
+  }
+
   // eslint-disable-next-line no-unused-vars
   shouldParseDefaultImport(node: N.ImportDeclaration): boolean {
     return this.match(tt.name);
@@ -1853,9 +1926,7 @@ export default class StatementParser extends ExpressionParser {
     node.specifiers.push(this.finishNode(specifier, type));
   }
 
-  // Parses a comma-separated list of module imports.
-  parseImportSpecifiers(node: N.ImportDeclaration): void {
-    let first = true;
+  maybeParseDefaultImportSpecifier(node: N.ImportDeclaration): boolean {
     if (this.shouldParseDefaultImport(node)) {
       // import defaultObj, { x, y as z } from '...'
       this.parseImportSpecifierLocal(
@@ -1864,10 +1935,12 @@ export default class StatementParser extends ExpressionParser {
         "ImportDefaultSpecifier",
         "default import specifier",
       );
-
-      if (!this.eat(tt.comma)) return;
+      return true;
     }
+    return false;
+  }
 
+  maybeParseStarImportSpecifier(node: N.ImportDeclaration): boolean {
     if (this.match(tt.star)) {
       const specifier = this.startNode();
       this.next();
@@ -1879,10 +1952,13 @@ export default class StatementParser extends ExpressionParser {
         "ImportNamespaceSpecifier",
         "import namespace specifier",
       );
-
-      return;
+      return true;
     }
+    return false;
+  }
 
+  parseNamedImportSpecifiers(node: N.ImportDeclaration) {
+    let first = true;
     this.expect(tt.braceL);
     while (!this.eat(tt.braceR)) {
       if (first) {

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

@@ -147,4 +147,22 @@ export default class UtilParser extends Tokenizer {
       );
     }
   }
+
+  checkYieldAwaitInDefaultParams() {
+    if (
+      this.state.yieldPos &&
+      (!this.state.awaitPos || this.state.yieldPos < this.state.awaitPos)
+    ) {
+      this.raise(
+        this.state.yieldPos,
+        "Yield cannot be used as name inside a generator function",
+      );
+    }
+    if (this.state.awaitPos) {
+      this.raise(
+        this.state.awaitPos,
+        "Await cannot be used as name inside an async function",
+      );
+    }
+  }
 }

packages/babel-parser/src/plugins/flow.js

@@ -344,7 +344,7 @@ export default (superClass: Class<Parser>): Class<Parser> =>
       } else {
         if (
           this.match(tt._const) ||
-          this.match(tt._let) ||
+          this.isLet() ||
           ((this.isContextual("type") || this.isContextual("interface")) &&
             !insideModule)
         ) {
@@ -1847,17 +1847,15 @@ export default (superClass: Class<Parser>): Class<Parser> =>
       super.assertModuleNodeAllowed(node);
     }
 
-    parseExport(
-      node: N.ExportNamedDeclaration | N.ExportAllDeclaration,
-    ): N.ExportNamedDeclaration | N.ExportAllDeclaration {
-      node = super.parseExport(node);
+    parseExport(node: N.Node): N.AnyExport {
+      const decl = super.parseExport(node);
       if (
-        node.type === "ExportNamedDeclaration" ||
-        node.type === "ExportAllDeclaration"
+        decl.type === "ExportNamedDeclaration" ||
+        decl.type === "ExportAllDeclaration"
       ) {
-        node.exportKind = node.exportKind || "value";
+        decl.exportKind = decl.exportKind || "value";
       }
-      return node;
+      return decl;
     }
 
     parseExportDeclaration(node: N.ExportNamedDeclaration): ?N.Declaration {
@@ -1893,27 +1891,26 @@ export default (superClass: Class<Parser>): Class<Parser> =>
       }
     }
 
-    shouldParseExportStar(): boolean {
-      return (
-        super.shouldParseExportStar() ||
-        (this.isContextual("type") && this.lookahead().type === tt.star)
-      );
-    }
+    eatExportStar(node: N.Node): boolean {
+      if (super.eatExportStar(...arguments)) return true;
 
-    parseExportStar(node: N.ExportNamedDeclaration): void {
-      if (this.eatContextual("type")) {
+      if (this.isContextual("type") && this.lookahead().type === tt.star) {
         node.exportKind = "type";
+        this.next();
+        this.next();
+        return true;
       }
 
-      return super.parseExportStar(node);
+      return false;
     }
 
-    parseExportNamespace(node: N.ExportNamedDeclaration) {
-      if (node.exportKind === "type") {
-        this.unexpected();
+    maybeParseExportNamespaceSpecifier(node: N.Node): boolean {
+      const pos = this.state.start;
+      const hasNamespace = super.maybeParseExportNamespaceSpecifier(node);
+      if (hasNamespace && node.exportKind === "type") {
+        this.unexpected(pos);
       }
-
-      return super.parseExportNamespace(node);
+      return hasNamespace;
     }
 
     parseClassId(node: N.Class, isStatement: boolean, optionalId: ?boolean) {
@@ -2225,7 +2222,7 @@ export default (superClass: Class<Parser>): Class<Parser> =>
     }
 
     // parse typeof and type imports
-    parseImportSpecifiers(node: N.ImportDeclaration): void {
+    maybeParseDefaultImportSpecifier(node: N.ImportDeclaration): boolean {
       node.importKind = "value";
 
       let kind = null;
@@ -2252,7 +2249,7 @@ export default (superClass: Class<Parser>): Class<Parser> =>
         }
       }
 
-      super.parseImportSpecifiers(node);
+      return super.maybeParseDefaultImportSpecifier(node);
     }
 
     // parse import-type/typeof shorthand
@@ -2347,8 +2344,11 @@ export default (superClass: Class<Parser>): Class<Parser> =>
     }
 
     // parse flow type annotations on variable declarator heads - let foo: string = bar
-    parseVarHead(decl: N.VariableDeclarator): void {
-      super.parseVarHead(decl);
+    parseVarId(
+      decl: N.VariableDeclarator,
+      kind: "var" | "let" | "const",
+    ): void {
+      super.parseVarId(decl, kind);
       if (this.match(tt.colon)) {
         decl.id.typeAnnotation = this.flowParseTypeAnnotation();
         this.finishNode(decl.id, decl.id.type);

packages/babel-parser/src/plugins/typescript.js

@@ -1190,8 +1190,15 @@ export default (superClass: Class<Parser>): Class<Parser> =>
       if (this.isLineTerminator()) {
         return;
       }
+      let starttype = this.state.type;
+      let kind;
 
-      switch (this.state.type) {
+      if (this.isContextual("let")) {
+        starttype = tt._var;
+        kind = "let";
+      }
+
+      switch (starttype) {
         case tt._function:
           this.next();
           return this.parseFunction(nany, /* isStatement */ true);
@@ -1210,8 +1217,8 @@ export default (superClass: Class<Parser>): Class<Parser> =>
           }
         // falls through
         case tt._var:
-        case tt._let:
-          return this.parseVarStatement(nany, this.state.type);
+          kind = kind || this.state.value;
+          return this.parseVarStatement(nany, kind);
         case tt.name: {
           const value = this.state.value;
           if (value === "global") {
@@ -1615,16 +1622,14 @@ export default (superClass: Class<Parser>): Class<Parser> =>
     */
     checkDuplicateExports() {}
 
-    parseImport(
-      node: N.Node,
-    ): N.ImportDeclaration | N.TsImportEqualsDeclaration {
+    parseImport(node: N.Node): N.AnyImport {
       if (this.match(tt.name) && this.lookahead().type === tt.eq) {
         return this.tsParseImportEqualsDeclaration(node);
       }
       return super.parseImport(node);
     }
 
-    parseExport(node: N.Node): N.Node {
+    parseExport(node: N.Node): N.AnyExport {
       if (this.match(tt._import)) {
         // `export import A = B;`
         this.expect(tt._import);
@@ -1848,10 +1853,15 @@ export default (superClass: Class<Parser>): Class<Parser> =>
     }
 
     parseExportDeclaration(node: N.ExportNamedDeclaration): ?N.Declaration {
+      // Store original location/position
+      const startPos = this.state.start;
+      const startLoc = this.state.startLoc;
+
       // "export declare" is equivalent to just "export".
       const isDeclare = this.eatContextual("declare");
 
       let declaration: ?N.Declaration;
+
       if (this.match(tt.name)) {
         declaration = this.tsTryParseExportDeclaration();
       }
@@ -1860,6 +1870,9 @@ export default (superClass: Class<Parser>): Class<Parser> =>
       }
 
       if (declaration && isDeclare) {
+        // Reset location to include `declare` in range
+        this.resetStartLocation(declaration, startPos, startLoc);
+
         declaration.declare = true;
       }
 
@@ -1943,8 +1956,11 @@ export default (superClass: Class<Parser>): Class<Parser> =>
     }
 
     // `let x: number;`
-    parseVarHead(decl: N.VariableDeclarator): void {
-      super.parseVarHead(decl);
+    parseVarId(
+      decl: N.VariableDeclarator,
+      kind: "var" | "let" | "const",
+    ): void {
+      super.parseVarId(decl, kind);
       if (decl.id.type === "Identifier" && this.eat(tt.bang)) {
         decl.definite = true;
       }

packages/babel-parser/src/tokenizer/index.js

@@ -1213,6 +1213,8 @@ export default class Tokenizer extends LocationParser {
       case charCodes.lineFeed:
         this.state.lineStart = this.state.pos;
         ++this.state.curLine;
+      case charCodes.lineSeparator:
+      case charCodes.paragraphSeparator:
         return "";
       default:
         if (ch >= charCodes.digit0 && ch <= charCodes.digit7) {
@@ -1242,6 +1244,7 @@ export default class Tokenizer extends LocationParser {
           this.state.pos += octalStr.length - 1;
           return String.fromCharCode(octal);
         }
+
         return String.fromCharCode(ch);
     }
   }
@@ -1360,7 +1363,6 @@ export default class Tokenizer extends LocationParser {
     // `tt.name`.
     if (
       prevType === tt._return ||
-      prevType === tt._yield ||
       (prevType === tt.name && this.state.exprAllowed)
     ) {
       return lineBreak.test(
@@ -1384,8 +1386,8 @@ export default class Tokenizer extends LocationParser {
 
     if (
       prevType === tt._var ||
-      prevType === tt._let ||
-      prevType === tt._const
+      prevType === tt._const ||
+      prevType === tt.name
     ) {
       return false;
     }

packages/babel-parser/src/tokenizer/state.js

@@ -102,13 +102,9 @@ export default class State {
   // where @foo belongs to the outer class and @bar to the inner
   decoratorStack: Array<Array<N.Decorator>> = [[]];
 
-  // The first yield or await expression inside parenthesized expressions
-  // and arrow function parameters. It is used to disallow yield and await in
-  // arrow function parameters.
-  yieldOrAwaitInPossibleArrowParameters:
-    | N.YieldExpression
-    | N.AwaitExpression
-    | null = null;
+  // Positions to delayed-check that yield/await does not exist in default parameters.
+  yieldPos: number = 0;
+  awaitPos: number = 0;
 
   // Token store.
   tokens: Array<Token | N.Comment> = [];

packages/babel-parser/src/tokenizer/types.js

@@ -180,18 +180,16 @@ export const keywords = Object.create(null, {
   throw: makeKeywordProps("throw", { beforeExpr, prefix, startsExpr }),
   try: makeKeywordProps("try"),
   var: makeKeywordProps("var"),
-  let: makeKeywordProps("let"),
   const: makeKeywordProps("const"),
   while: makeKeywordProps("while", { isLoop }),
   with: makeKeywordProps("with"),
-  new: makeKeywordProps("new"),
+  new: makeKeywordProps("new", { beforeExpr, startsExpr }),
   this: makeKeywordProps("this", { startsExpr }),
   super: makeKeywordProps("super", { startsExpr }),
   class: makeKeywordProps("class", { startsExpr }),
   extends: makeKeywordProps("extends", { beforeExpr }),
   export: makeKeywordProps("export"),
   import: makeKeywordProps("import", { startsExpr }),
-  yield: makeKeywordProps("yield", { beforeExpr, startsExpr }),
   null: makeKeywordProps("null", { startsExpr }),
   true: makeKeywordProps("true", { startsExpr }),
   false: makeKeywordProps("false", { startsExpr }),

packages/babel-parser/src/types.js

@@ -783,7 +783,9 @@ export type AnyExport =
   | ExportNamedDeclaration
   | ExportDefaultDeclaration
   | ExportAllDeclaration
-  | TsExportAssignment;
+  | TsExportAssignment
+  | TsImportEqualsDeclaration
+  | TsNamespaceExportDeclaration;
 
 export type ModuleSpecifier = NodeBase & {
   local: Identifier,
@@ -820,7 +822,7 @@ export type ImportNamespaceSpecifier = ModuleSpecifier & {
 export type ExportNamedDeclaration = NodeBase & {
   type: "ExportNamedDeclaration",
   declaration: ?Declaration,
-  specifiers: $ReadOnlyArray<ExportSpecifier>,
+  specifiers: $ReadOnlyArray<ExportSpecifier | ExportDefaultSpecifier>,
   source: ?Literal,
 
   exportKind?: "type" | "value", // TODO: Not in spec
@@ -831,6 +833,11 @@ export type ExportSpecifier = NodeBase & {
   exported: Identifier,
 };
 
+export type ExportDefaultSpecifier = NodeBase & {
+  type: "ExportDefaultSpecifier",
+  exported: Identifier,
+};
+
 export type ExportDefaultDeclaration = NodeBase & {
   type: "ExportDefaultDeclaration",
   declaration:

packages/babel-parser/src/util/identifier.js

@@ -4,27 +4,52 @@
 
 import * as charCodes from "charcodes";
 
-export const isES2015ReservedWord = (word: string): boolean => {
-  return word === "enum" || word === "await";
+const reservedWords = {
+  strict: [
+    "implements",
+    "interface",
+    "let",
+    "package",
+    "private",
+    "protected",
+    "public",
+    "static",
+    "yield",
+  ],
+  strictBind: ["eval", "arguments"],
 };
 
-const reservedWordsStrict = new Set([
-  "implements",
-  "interface",
-  "let",
-  "package",
-  "private",
-  "protected",
-  "public",
-  "static",
-  "yield",
-]);
-export function isStrictReservedWord(word: string): boolean {
-  return reservedWordsStrict.has(word);
+const reservedWordsStrictSet = new Set(reservedWords.strict);
+const reservedWordsStrictBindSet = new Set(
+  reservedWords.strict.concat(reservedWords.strictBind),
+);
+
+/**
+ * Checks if word is a reserved word in non-strict mode
+ */
+export const isReservedWord = (word: string, inModule: boolean): boolean => {
+  return (inModule && word === "await") || word === "enum";
+};
+
+/**
+ * Checks if word is a reserved word in non-binding strict mode
+ *
+ * Includes non-strict reserved words
+ */
+export function isStrictReservedWord(word: string, inModule: boolean): boolean {
+  return isReservedWord(word, inModule) || reservedWordsStrictSet.has(word);
 }
 
-export function isStrictBindReservedWord(word: string): boolean {
-  return word === "eval" || word === "arguments";
+/**
+ * Checks if word is a reserved word in binding strict mode
+ *
+ * Includes non-strict reserved words and non-binding strict reserved words
+ */
+export function isStrictBindReservedWord(
+  word: string,
+  inModule: boolean,
+): boolean {
+  return isReservedWord(word, inModule) || reservedWordsStrictBindSet.has(word);
 }
 
 const keywords = new Set([
@@ -57,13 +82,11 @@ const keywords = new Set([
   "new",
   "in",
   "this",
-  "let",
   "const",
   "class",
   "extends",
   "export",
   "import",
-  "yield",
   "super",
 ]);
 
@@ -71,6 +94,8 @@ export function isKeyword(word: string): boolean {
   return keywords.has(word);
 }
 
+export const keywordRelationalOperator = /^in(stanceof)?$/;
+
 // ## Character categories
 
 // Big ugly regular expressions that matches characters in the

packages/babel-parser/test/expressions/is-expression-babel-parser/fail/8/options.json

@@ -1,4 +1,4 @@
 {
   "strictMode": true,
-  "throws": "public is a reserved word in strict mode (2:0)"
+  "throws": "Unexpected reserved word 'public' (2:0)"
 }

packages/babel-parser/test/fixtures/core/opts/allowAwaitOutsideFunction-false/input.js

@@ -0,0 +1 @@
+for await (const i of imports) {}

packages/babel-parser/test/fixtures/core/opts/allowAwaitOutsideFunction-false/options.json

@@ -0,0 +1,3 @@
+{
+  "throws": "Unexpected token, expected \"(\" (1:4)"
+}

packages/babel-parser/test/fixtures/core/opts/allowAwaitOutsideFunction-true/input.js

@@ -0,0 +1 @@
+for await (const i of imports) {}

packages/babel-parser/test/fixtures/core/opts/allowAwaitOutsideFunction-true/options.json

@@ -0,0 +1,3 @@
+{
+  "allowAwaitOutsideFunction": true
+}

packages/babel-parser/test/fixtures/core/opts/allowAwaitOutsideFunction-true/output.json

@@ -0,0 +1,136 @@
+{
+  "type": "File",
+  "start": 0,
+  "end": 33,
+  "loc": {
+    "start": {
+      "line": 1,
+      "column": 0
+    },
+    "end": {
+      "line": 1,
+      "column": 33
+    }
+  },
+  "program": {
+    "type": "Program",
+    "start": 0,
+    "end": 33,
+    "loc": {
+      "start": {
+        "line": 1,
+        "column": 0
+      },
+      "end": {
+        "line": 1,
+        "column": 33
+      }
+    },
+    "sourceType": "script",
+    "interpreter": null,
+    "body": [
+      {
+        "type": "ForOfStatement",
+        "start": 0,
+        "end": 33,
+        "loc": {
+          "start": {
+            "line": 1,
+            "column": 0
+          },
+          "end": {
+            "line": 1,
+            "column": 33
+          }
+        },
+        "await": true,
+        "left": {
+          "type": "VariableDeclaration",
+          "start": 11,
+          "end": 18,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 11
+            },
+            "end": {
+              "line": 1,
+              "column": 18
+            }
+          },
+          "declarations": [
+            {
+              "type": "VariableDeclarator",
+              "start": 17,
+              "end": 18,
+              "loc": {
+                "start": {
+                  "line": 1,
+                  "column": 17
+                },
+                "end": {
+                  "line": 1,
+                  "column": 18
+                }
+              },
+              "id": {
+                "type": "Identifier",
+                "start": 17,
+                "end": 18,
+                "loc": {
+                  "start": {
+                    "line": 1,
+                    "column": 17
+                  },
+                  "end": {
+                    "line": 1,
+                    "column": 18
+                  },
+                  "identifierName": "i"
+                },
+                "name": "i"
+              },
+              "init": null
+            }
+          ],
+          "kind": "const"
+        },
+        "right": {
+          "type": "Identifier",
+          "start": 22,
+          "end": 29,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 22
+            },
+            "end": {
+              "line": 1,
+              "column": 29
+            },
+            "identifierName": "imports"
+          },
+          "name": "imports"
+        },
+        "body": {
+          "type": "BlockStatement",
+          "start": 31,
+          "end": 33,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 31
+            },
+            "end": {
+              "line": 1,
+              "column": 33
+            }
+          },
+          "body": [],
+          "directives": []
+        }
+      }
+    ],
+    "directives": []
+  }
+}

packages/babel-parser/test/fixtures/core/regression/9374/input.js

@@ -0,0 +1,3 @@
+function* test() {
+  yield new Foo();
+}

packages/babel-parser/test/fixtures/core/regression/9374/output.json

@@ -0,0 +1,152 @@
+{
+  "type": "File",
+  "start": 0,
+  "end": 39,
+  "loc": {
+    "start": {
+      "line": 1,
+      "column": 0
+    },
+    "end": {
+      "line": 3,
+      "column": 1
+    }
+  },
+  "program": {
+    "type": "Program",
+    "start": 0,
+    "end": 39,
+    "loc": {
+      "start": {
+        "line": 1,
+        "column": 0
+      },
+      "end": {
+        "line": 3,
+        "column": 1
+      }
+    },
+    "sourceType": "script",
+    "interpreter": null,
+    "body": [
+      {
+        "type": "FunctionDeclaration",
+        "start": 0,
+        "end": 39,
+        "loc": {
+          "start": {
+            "line": 1,
+            "column": 0
+          },
+          "end": {
+            "line": 3,
+            "column": 1
+          }
+        },
+        "id": {
+          "type": "Identifier",
+          "start": 10,
+          "end": 14,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 10
+            },
+            "end": {
+              "line": 1,
+              "column": 14
+            },
+            "identifierName": "test"
+          },
+          "name": "test"
+        },
+        "generator": true,
+        "async": false,
+        "params": [],
+        "body": {
+          "type": "BlockStatement",
+          "start": 17,
+          "end": 39,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 17
+            },
+            "end": {
+              "line": 3,
+              "column": 1
+            }
+          },
+          "body": [
+            {
+              "type": "ExpressionStatement",
+              "start": 21,
+              "end": 37,
+              "loc": {
+                "start": {
+                  "line": 2,
+                  "column": 2
+                },
+                "end": {
+                  "line": 2,
+                  "column": 18
+                }
+              },
+              "expression": {
+                "type": "YieldExpression",
+                "start": 21,
+                "end": 36,
+                "loc": {
+                  "start": {
+                    "line": 2,
+                    "column": 2
+                  },
+                  "end": {
+                    "line": 2,
+                    "column": 17
+                  }
+                },
+                "delegate": false,
+                "argument": {
+                  "type": "NewExpression",
+                  "start": 27,
+                  "end": 36,
+                  "loc": {
+                    "start": {
+                      "line": 2,
+                      "column": 8
+                    },
+                    "end": {
+                      "line": 2,
+                      "column": 17
+                    }
+                  },
+                  "callee": {
+                    "type": "Identifier",
+                    "start": 31,
+                    "end": 34,
+                    "loc": {
+                      "start": {
+                        "line": 2,
+                        "column": 12
+                      },
+                      "end": {
+                        "line": 2,
+                        "column": 15
+                      },
+                      "identifierName": "Foo"
+                    },
+                    "name": "Foo"
+                  },
+                  "arguments": []
+                }
+              }
+            }
+          ],
+          "directives": []
+        }
+      }
+    ],
+    "directives": []
+  }
+}

packages/babel-parser/test/fixtures/core/regression/non-octal-float-strict-mode/options.json

@@ -1,4 +1,4 @@
 {
-    "sourceType": "module",
-    "throws": "Legacy octal literals are not allowed in strict mode (1:0)"
+  "sourceType": "module",
+  "throws": "Legacy octal literals are not allowed in strict mode (1:0)"
 }

packages/babel-parser/test/fixtures/core/regression/octal-float-fail/options.json

@@ -1,3 +1,3 @@
 {
   "throws": "Unexpected token, expected \";\" (1:2)"
-}
+}

packages/babel-parser/test/fixtures/core/uncategorised/468/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "eval is a reserved word in strict mode (1:36)"
-}
+  "throws": "Binding 'eval' in strict mode (1:36)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/469/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "arguments is a reserved word in strict mode (1:36)"
-}
+  "throws": "Binding 'arguments' in strict mode (1:36)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/470/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "eval is a reserved word in strict mode (1:47)"
-}
+  "throws": "Binding 'eval' in strict mode (1:47)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/471/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "arguments is a reserved word in strict mode (1:47)"
-}
+  "throws": "Binding 'arguments' in strict mode (1:47)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/472/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "eval is a reserved word in strict mode (1:32)"
-}
+  "throws": "Assigning to 'eval' in strict mode (1:32)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/473/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "arguments is a reserved word in strict mode (1:32)"
-}
+  "throws": "Assigning to 'arguments' in strict mode (1:32)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/474/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "eval is a reserved word in strict mode (1:34)"
-}
+  "throws": "Assigning to 'eval' in strict mode (1:34)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/475/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "eval is a reserved word in strict mode (1:34)"
-}
+  "throws": "Assigning to 'eval' in strict mode (1:34)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/476/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "arguments is a reserved word in strict mode (1:34)"
-}
+  "throws": "Assigning to 'arguments' in strict mode (1:34)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/477/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "arguments is a reserved word in strict mode (1:34)"
-}
+  "throws": "Assigning to 'arguments' in strict mode (1:34)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/478/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "eval is a reserved word in strict mode (1:32)"
-}
+  "throws": "Assigning to 'eval' in strict mode (1:32)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/479/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "eval is a reserved word in strict mode (1:32)"
-}
+  "throws": "Assigning to 'eval' in strict mode (1:32)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/480/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "arguments is a reserved word in strict mode (1:32)"
-}
+  "throws": "Assigning to 'arguments' in strict mode (1:32)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/481/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "arguments is a reserved word in strict mode (1:32)"
-}
+  "throws": "Assigning to 'arguments' in strict mode (1:32)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/482/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "eval is a reserved word in strict mode (1:41)"
-}
+  "throws": "Binding 'eval' in strict mode (1:41)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/483/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "arguments is a reserved word in strict mode (1:41)"
-}
+  "throws": "Binding 'arguments' in strict mode (1:41)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/484/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "eval is a reserved word in strict mode (1:9)"
-}
+  "throws": "Binding 'eval' in strict mode (1:9)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/485/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "arguments is a reserved word in strict mode (1:9)"
-}
+  "throws": "Binding 'arguments' in strict mode (1:9)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/486/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "eval is a reserved word in strict mode (1:42)"
-}
+  "throws": "Binding 'eval' in strict mode (1:42)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/487/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "arguments is a reserved word in strict mode (1:42)"
-}
+  "throws": "Binding 'arguments' in strict mode (1:42)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/488/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "eval is a reserved word in strict mode (1:10)"
-}
+  "throws": "Binding 'eval' in strict mode (1:10)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/489/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "arguments is a reserved word in strict mode (1:10)"
-}
+  "throws": "Binding 'arguments' in strict mode (1:10)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/490/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "eval is a reserved word in strict mode (1:47)"
-}
+  "throws": "Binding 'eval' in strict mode (1:47)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/491/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "package is a reserved word in strict mode (1:10)"
-}
+  "throws": "Binding 'package' in strict mode (1:10)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/492/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "eval is a reserved word in strict mode (1:48)"
-}
+  "throws": "Binding 'eval' in strict mode (1:48)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/493/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "eval is a reserved word in strict mode (1:41)"
-}
+  "throws": "Binding 'eval' in strict mode (1:41)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/494/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "eval is a reserved word in strict mode (1:49)"
-}
+  "throws": "Binding 'eval' in strict mode (1:49)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/495/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "eval is a reserved word in strict mode (1:15)"
-}
+  "throws": "Binding 'eval' in strict mode (1:15)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/496/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "arguments is a reserved word in strict mode (1:15)"
-}
+  "throws": "Binding 'arguments' in strict mode (1:15)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/497/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "eval is a reserved word in strict mode (1:48)"
-}
+  "throws": "Binding 'eval' in strict mode (1:48)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/498/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "arguments is a reserved word in strict mode (1:48)"
-}
+  "throws": "Binding 'arguments' in strict mode (1:48)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/504/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "implements is a reserved word in strict mode (1:37)"
+  "throws": "Unexpected reserved word 'implements' (1:37)"
 }

packages/babel-parser/test/fixtures/core/uncategorised/505/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "interface is a reserved word in strict mode (1:37)"
+  "throws": "Unexpected reserved word 'interface' (1:37)"
 }

packages/babel-parser/test/fixtures/core/uncategorised/506/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "package is a reserved word in strict mode (1:37)"
+  "throws": "Unexpected reserved word 'package' (1:37)"
 }

packages/babel-parser/test/fixtures/core/uncategorised/507/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "private is a reserved word in strict mode (1:37)"
+  "throws": "Unexpected reserved word 'private' (1:37)"
 }

packages/babel-parser/test/fixtures/core/uncategorised/508/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "protected is a reserved word in strict mode (1:37)"
+  "throws": "Unexpected reserved word 'protected' (1:37)"
 }

packages/babel-parser/test/fixtures/core/uncategorised/509/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "public is a reserved word in strict mode (1:37)"
+  "throws": "Unexpected reserved word 'public' (1:37)"
 }

packages/babel-parser/test/fixtures/core/uncategorised/510/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "static is a reserved word in strict mode (1:37)"
+  "throws": "Unexpected reserved word 'static' (1:37)"
 }

packages/babel-parser/test/fixtures/core/uncategorised/511/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "static is a reserved word in strict mode (1:15)"
-}
+  "throws": "Binding 'static' in strict mode (1:15)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/512/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "static is a reserved word in strict mode (1:9)"
-}
+  "throws": "Binding 'static' in strict mode (1:9)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/513/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "static is a reserved word in strict mode (1:23)"
+  "throws": "Unexpected reserved word 'static' (1:23)"
 }

packages/babel-parser/test/fixtures/core/uncategorised/515/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "eval is a reserved word in strict mode (1:11)"
-}
+  "throws": "Binding 'eval' in strict mode (1:11)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/516/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "package is a reserved word in strict mode (1:11)"
-}
+  "throws": "Binding 'package' in strict mode (1:11)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/520/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "eval is a reserved word in strict mode (1:12)"
-}
+  "throws": "Binding 'eval' in strict mode (1:12)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/521/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "package is a reserved word in strict mode (1:12)"
-}
+  "throws": "Binding 'package' in strict mode (1:12)"
+}

packages/babel-parser/test/fixtures/core/uncategorised/544/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "public is a reserved word in strict mode (2:8)"
+  "throws": "Unexpected reserved word 'public' (2:8)"
 }

packages/babel-parser/test/fixtures/core/uncategorised/545/options.json

@@ -1,4 +1,4 @@
 {
   "sourceType": "module",
-  "throws": "public is a reserved word in strict mode (1:8)"
+  "throws": "Unexpected reserved word 'public' (1:8)"
 }

packages/babel-parser/test/fixtures/core/uncategorised/547/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "arguments is a reserved word in strict mode (2:8)"
+  "throws": "Unexpected reserved word 'arguments' (2:8)"
 }

packages/babel-parser/test/fixtures/core/uncategorised/548/options.json

@@ -1,4 +1,4 @@
 {
   "sourceType": "module",
-  "throws": "arguments is a reserved word in strict mode (1:8)"
+  "throws": "Unexpected reserved word 'arguments' (1:8)"
 }

packages/babel-parser/test/fixtures/es2015/class/extends-strict/options.json

@@ -1,3 +1,3 @@
 {
   "throws": "'with' in strict mode (2:2)"
-}
+}

packages/babel-parser/test/fixtures/es2015/destructuring/binding-this/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "this is a reserved word (1:6)"
+  "throws": "Unexpected keyword 'this' (1:6)"
 }

packages/babel-parser/test/fixtures/es2015/let/let-as-identifier-1/input.js

@@ -0,0 +1 @@
+let + 1

packages/babel-parser/test/fixtures/es2015/let/let-as-identifier-1/output.json

@@ -0,0 +1,103 @@
+{
+  "type": "File",
+  "start": 0,
+  "end": 7,
+  "loc": {
+    "start": {
+      "line": 1,
+      "column": 0
+    },
+    "end": {
+      "line": 1,
+      "column": 7
+    }
+  },
+  "program": {
+    "type": "Program",
+    "start": 0,
+    "end": 7,
+    "loc": {
+      "start": {
+        "line": 1,
+        "column": 0
+      },
+      "end": {
+        "line": 1,
+        "column": 7
+      }
+    },
+    "sourceType": "script",
+    "interpreter": null,
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start": 0,
+        "end": 7,
+        "loc": {
+          "start": {
+            "line": 1,
+            "column": 0
+          },
+          "end": {
+            "line": 1,
+            "column": 7
+          }
+        },
+        "expression": {
+          "type": "BinaryExpression",
+          "start": 0,
+          "end": 7,
+          "loc": {
+            "start": {
+              "line": 1,
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+}