Put back ESM helpers in a folder where we can use .js

.gitignore

@@ -26,24 +26,20 @@ package-lock.json
 /packages/babel-compat-data/build
 
 /packages/babel-runtime/helpers/*.js
-/packages/babel-runtime/helpers/*/*.js
-/packages/babel-runtime/helpers/*/*.mjs
-!/packages/babel-runtime/helpers/toArray/*
-!/packages/babel-runtime/helpers/iterableToArray/*
-!/packages/babel-runtime/helpers/temporalRef/*
-!/packages/babel-runtime/helpers/typeof/*
+!/packages/babel-runtime/helpers/toArray.js
+!/packages/babel-runtime/helpers/iterableToArray.js
+!/packages/babel-runtime/helpers/temporalRef.js
+!/packages/babel-runtime/helpers/typeof.js
 /packages/babel-runtime/helpers/esm/*.js
 !/packages/babel-runtime/helpers/esm/toArray.js
 !/packages/babel-runtime/helpers/esm/iterableToArray.js
 !/packages/babel-runtime/helpers/esm/temporalRef.js
 
 /packages/babel-runtime-corejs2/helpers/*.js
-/packages/babel-runtime-corejs2/helpers/*/*.js
-/packages/babel-runtime-corejs2/helpers/*/*.mjs
-!/packages/babel-runtime-corejs2/helpers/toArray/*
-!/packages/babel-runtime-corejs2/helpers/iterableToArray/*
-!/packages/babel-runtime-corejs2/helpers/temporalRef/*
-!/packages/babel-runtime-corejs2/helpers/typeof/*
+!/packages/babel-runtime-corejs2/helpers/toArray.js
+!/packages/babel-runtime-corejs2/helpers/iterableToArray.js
+!/packages/babel-runtime-corejs2/helpers/temporalRef.js
+!/packages/babel-runtime-corejs2/helpers/typeof.js
 /packages/babel-runtime-corejs2/helpers/esm/*.js
 !/packages/babel-runtime-corejs2/helpers/esm/toArray.js
 !/packages/babel-runtime-corejs2/helpers/esm/iterableToArray.js
@@ -52,8 +48,6 @@ package-lock.json
 !/packages/babel-runtime-corejs2/core-js/map.js
 
 /packages/babel-runtime-corejs3/helpers/*.js
-/packages/babel-runtime-corejs3/helpers/*/*.js
-/packages/babel-runtime-corejs3/helpers/*/*.mjs
 /packages/babel-runtime-corejs3/helpers/esm/*.js
 /packages/babel-runtime-corejs3/core-js/**/*.js
 /packages/babel-runtime-corejs3/core-js-stable/**/*.js

packages/babel-plugin-transform-runtime/scripts/build-dist.js

@@ -116,7 +116,10 @@ function writeHelperFile(
   helperName,
   { esm, corejs }
 ) {
-  const filePath = path.join(helperPath, esm ? "_index.mjs" : "index.js");
+  const fileName = `${helperName}.js`;
+  const filePath = esm
+    ? path.join("helpers", "esm", fileName)
+    : path.join("helpers", fileName);
   const fullPath = path.join(pkgDirname, filePath);
 
   outputFile(
@@ -127,12 +130,6 @@ function writeHelperFile(
   return `./${filePath}`;
 }
 
-function writeHelperLegacyESMFile(pkgDirname, helperName) {
-  const fullPath = path.join(pkgDirname, "helpers", "esm", `${helperName}.js`);
-
-  outputFile(fullPath, `export { default } from "../${helperName}/_index.mjs"`);
-}
-
 function writeHelpers(runtimeName, { corejs } = {}) {
   const pkgDirname = getRuntimeRoot(runtimeName);
   const helperSubExports = {};
@@ -173,8 +170,6 @@ function writeHelpers(runtimeName, { corejs } = {}) {
     ];
     // For backward compatibility. We can remove this in Babel 8.
     helperSubExports[`./${path.join("helpers", "esm", helperName)}`] = esm;
-
-    writeHelperLegacyESMFile(pkgDirname, helperName);
   }
 
   writeHelperExports(runtimeName, helperSubExports);
@@ -251,7 +246,6 @@ function buildHelper(
       [transformRuntime, { corejs, version: runtimeVersion }],
       buildRuntimeRewritePlugin(runtimeName, helperName),
       esm ? null : addDefaultCJSExport,
-      esm ? useRelativeImports : null,
     ].filter(Boolean),
     overrides: [
       {
@@ -272,7 +266,7 @@ function buildRuntimeRewritePlugin(runtimeName, helperName) {
    */
   function adjustImportPath(node) {
     if (helpers.list.includes(node.value)) {
-      node.value = `${runtimeName}/helpers/${node.value}`;
+      node.value = `./${node.value}.js`;
     }
   }
 
@@ -322,18 +316,3 @@ function addDefaultCJSExport({ template }) {
     },
   };
 }
-
-function useRelativeImports() {
-  const RE = /^@babel\/runtime(?:-corejs[23])?\/helpers\/(?<name>.+)$/;
-
-  return {
-    visitor: {
-      ImportDeclaration(path) {
-        path.node.source.value = path.node.source.value.replace(
-          RE,
-          "../$<name>/_index.mjs"
-        );
-      },
-    },
-  };
-}

packages/babel-runtime-corejs2/helpers/esm/iterableToArray.js

@@ -1 +1,6 @@
-export { default } from "../iterableToArray/_index.mjs"
+import _Symbol from "@babel/runtime-corejs2/core-js/symbol";
+import _isIterable from "@babel/runtime-corejs2/core-js/is-iterable";
+import _Array$from from "@babel/runtime-corejs2/core-js/array/from";
+export default function _iterableToArray(iter) {
+  if (typeof _Symbol !== "undefined" && _isIterable(Object(iter))) return _Array$from(iter);
+}

packages/babel-runtime-corejs2/helpers/esm/temporalRef.js

@@ -1 +1,5 @@
-export { default } from "../temporalRef/_index.mjs"
+import undef from "./temporalUndefined.js";
+import err from "./tdz.js";
+export default function _temporalRef(val, name) {
+  return val === undef ? err(name) : val;
+}

packages/babel-runtime-corejs2/helpers/esm/toArray.js

@@ -1 +1,7 @@
-export { default } from "../toArray/_index.mjs"
+import arrayWithHoles from "./arrayWithHoles.js";
+import iterableToArray from "./iterableToArray.js";
+import unsupportedIterableToArray from "./unsupportedIterableToArray.js";
+import nonIterableRest from "./nonIterableRest.js";
+export default function _toArray(arr) {
+  return arrayWithHoles(arr) || iterableToArray(arr) || unsupportedIterableToArray(arr) || nonIterableRest();
+}

packages/babel-runtime/helpers/temporalRef/index.js → packages/babel-runtime-corejs2/helpers/temporalRef.js

@@ -1,6 +1,6 @@
-var temporalUndefined = require("@babel/runtime/helpers/temporalUndefined");
+var temporalUndefined = require("./temporalUndefined.js");
 
-var tdz = require("@babel/runtime/helpers/tdz");
+var tdz = require("./tdz.js");
 
 function _temporalRef(val, name) {
   return val === temporalUndefined ? tdz(name) : val;

packages/babel-runtime-corejs2/helpers/toArray.js

@@ -0,0 +1,14 @@
+var arrayWithHoles = require("./arrayWithHoles.js");
+
+var iterableToArray = require("./iterableToArray.js");
+
+var unsupportedIterableToArray = require("./unsupportedIterableToArray.js");
+
+var nonIterableRest = require("./nonIterableRest.js");
+
+function _toArray(arr) {
+  return arrayWithHoles(arr) || iterableToArray(arr) || unsupportedIterableToArray(arr) || nonIterableRest();
+}
+
+module.exports = _toArray;
+module.exports["default"] = module.exports, module.exports.__esModule = true;