Avoid compiling the _typeof helper with itself

packages/babel-helpers/src/helpers.js

@@ -12,6 +12,8 @@ const helper = (minVersion: string) => tpl => ({
 
 helpers.typeof = helper("7.0.0-beta.0")`
   export default function _typeof(obj) {
+    "@babel/helpers - typeof";
+
     if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") {
       _typeof = function (obj) { return typeof obj; };
     } else {

packages/babel-plugin-proposal-class-properties/test/fixtures/regression/6154/output.js

@@ -1,4 +1,4 @@
-function _typeof(obj) { if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function _typeof(obj) { return typeof obj; }; } else { _typeof = function _typeof(obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }
+function _typeof(obj) { "@babel/helpers - typeof"; if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function _typeof(obj) { return typeof obj; }; } else { _typeof = function _typeof(obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }
 
 function _possibleConstructorReturn(self, call) { if (call && (_typeof(call) === "object" || typeof call === "function")) { return call; } return _assertThisInitialized(self); }
 

packages/babel-plugin-proposal-decorators/test/fixtures/legacy-regression/7030/output.js

@@ -1,4 +1,4 @@
-function _typeof(obj) { if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function _typeof(obj) { return typeof obj; }; } else { _typeof = function _typeof(obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }
+function _typeof(obj) { "@babel/helpers - typeof"; if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function _typeof(obj) { return typeof obj; }; } else { _typeof = function _typeof(obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }
 
 function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
 

packages/babel-plugin-transform-classes/test/fixtures/regression/T7537/output.js

@@ -1,4 +1,4 @@
-function _typeof(obj) { if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function _typeof(obj) { return typeof obj; }; } else { _typeof = function _typeof(obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }
+function _typeof(obj) { "@babel/helpers - typeof"; if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function _typeof(obj) { return typeof obj; }; } else { _typeof = function _typeof(obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }
 
 function _possibleConstructorReturn(self, call) { if (call && (_typeof(call) === "object" || typeof call === "function")) { return call; } return _assertThisInitialized(self); }
 

packages/babel-plugin-transform-parameters/test/fixtures/regression/6057-expanded/output.js

@@ -9,7 +9,7 @@ var _args = _interopRequireDefault(require("utils/url/args"));
 
 function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { "default": obj }; }
 
-function _typeof(obj) { if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function _typeof(obj) { return typeof obj; }; } else { _typeof = function _typeof(obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }
+function _typeof(obj) { "@babel/helpers - typeof"; if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function _typeof(obj) { return typeof obj; }; } else { _typeof = function _typeof(obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }
 
 function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
 

packages/babel-plugin-transform-typeof-symbol/package.json

@@ -19,6 +19,10 @@
   },
   "devDependencies": {
     "@babel/core": "^7.8.3",
-    "@babel/helper-plugin-test-runner": "^7.8.3"
+    "@babel/helper-plugin-test-runner": "^7.8.3",
+    "@babel/runtime": "^7.8.3",
+    "@babel/runtime-corejs2": "^7.8.3",
+    "@babel/runtime-corejs3": "^7.8.3",
+    "resolve": "^1.15.0"
   }
 }

packages/babel-plugin-transform-typeof-symbol/src/index.js

@@ -36,8 +36,23 @@ export default declare(api => {
           }
         }
 
+        let isUnderHelper = path.findParent(path => {
+          if (path.isFunction()) {
+            return (
+              path.get("body.directives.0")?.node.value.value ===
+              "@babel/helpers - typeof"
+            );
+          }
+        });
+
+        if (isUnderHelper) return;
+
         const helper = this.addHelper("typeof");
-        const isUnderHelper = path.findParent(path => {
+
+        // TODO: This is needed for backward compatibility with
+        // @babel/helpers <= 7.8.3.
+        // Remove in Babel 8
+        isUnderHelper = path.findParent(path => {
           return (
             (path.isVariableDeclarator() && path.node.id === helper) ||
             (path.isFunctionDeclaration() &&

packages/babel-plugin-transform-typeof-symbol/test/fixtures/symbols/builtin-global/output.mjs

@@ -1,3 +1,3 @@
-function _typeof(obj) { if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function (obj) { return typeof obj; }; } else { _typeof = function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }
+function _typeof(obj) { "@babel/helpers - typeof"; if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function (obj) { return typeof obj; }; } else { _typeof = function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }
 
 (typeof Reflect === "undefined" ? "undefined" : _typeof(Reflect)) === "object";

packages/babel-plugin-transform-typeof-symbol/test/fixtures/symbols/default-export/output.mjs

@@ -1,4 +1,4 @@
-function _typeof(obj) { if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function (obj) { return typeof obj; }; } else { _typeof = function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }
+function _typeof(obj) { "@babel/helpers - typeof"; if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function (obj) { return typeof obj; }; } else { _typeof = function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }
 
 export default function () {
   _typeof({}) === "object";

packages/babel-plugin-transform-typeof-symbol/test/fixtures/symbols/shadow/output.js

@@ -1,4 +1,4 @@
-function _typeof(obj) { if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function (obj) { return typeof obj; }; } else { _typeof = function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }
+function _typeof(obj) { "@babel/helpers - typeof"; if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function (obj) { return typeof obj; }; } else { _typeof = function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }
 
 var _Symbol = foo();
 

packages/babel-plugin-transform-typeof-symbol/test/helper.spec.js

@@ -0,0 +1,52 @@
+import * as babel from "@babel/core";
+import resolvePath from "resolve";
+import fs from "fs";
+
+import transformTypeofSymbol from "..";
+
+const resolve = path =>
+  new Promise((resolve, reject) =>
+    resolvePath(path, (err, path) => (err ? reject(err) : resolve(path))),
+  );
+const readFile = path =>
+  new Promise((resolve, reject) =>
+    fs.readFile(path, "utf8", (err, contents) => {
+      if (err) reject(err);
+      else resolve(contents);
+    }),
+  );
+
+describe("@babel/plugin-transform-typeof-symbol", () => {
+  test.each`
+    runtime                     | type
+    ${"@babel/runtime"}         | ${"esm"}
+    ${"@babel/runtime"}         | ${"cjs"}
+    ${"@babel/runtime-corejs2"} | ${"esm"}
+    ${"@babel/runtime-corejs2"} | ${"cjs"}
+    ${"@babel/runtime-corejs3"} | ${"esm"}
+    ${"@babel/runtime-corejs3"} | ${"cjs"}
+  `(
+    "shouldn't transpile the $type $runtime helper",
+    async ({ type, runtime }) => {
+      const path = await resolve(
+        `${runtime}/helpers${type === "esm" ? "/esm/" : "/"}typeof`,
+      );
+      const src = await readFile(path);
+
+      const ast = babel.parseSync(src, {
+        configFile: false,
+        sourceType: type === "esm" ? "module" : "script",
+      });
+
+      const withPlugin = babel.transformFromAstSync(ast, src, {
+        configFile: false,
+        plugins: [transformTypeofSymbol],
+      });
+      const withoutPlugin = babel.transformFromAstSync(ast, src, {
+        configFile: false,
+      });
+
+      expect(withPlugin.code).toBe(withoutPlugin.code);
+    },
+  );
+});

packages/babel-preset-env/test/fixtures/plugins-integration/issue-10662/output.js

@@ -13,7 +13,7 @@
 })(typeof globalThis !== "undefined" ? globalThis : typeof self !== "undefined" ? self : this, function () {
   "use strict";
 
-  function _typeof(obj) { if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function _typeof(obj) { return typeof obj; }; } else { _typeof = function _typeof(obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }
+  function _typeof(obj) { "@babel/helpers - typeof"; if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function _typeof(obj) { return typeof obj; }; } else { _typeof = function _typeof(obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }
 
   var globalThis = {};
 

packages/babel-preset-env/test/fixtures/plugins-integration/issue-7527/output.js

@@ -1,6 +1,6 @@
 "use strict";
 
-function _typeof(obj) { if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function _typeof(obj) { return typeof obj; }; } else { _typeof = function _typeof(obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }
+function _typeof(obj) { "@babel/helpers - typeof"; if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function _typeof(obj) { return typeof obj; }; } else { _typeof = function _typeof(obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }
 
 function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
 

packages/babel-preset-env/test/fixtures/preset-options/loose-with-typeof-symbol-includes/output.js

@@ -1,5 +1,5 @@
 "use strict";
 
-function _typeof(obj) { if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function _typeof(obj) { return typeof obj; }; } else { _typeof = function _typeof(obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }
+function _typeof(obj) { "@babel/helpers - typeof"; if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function _typeof(obj) { return typeof obj; }; } else { _typeof = function _typeof(obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }
 
 _typeof(Symbol());