[internal] Use the Node.js behavior for default imports

babel.config.js

@@ -158,6 +158,7 @@ module.exports = function (api) {
 
       convertESM ? "@babel/proposal-export-namespace-from" : null,
       convertESM ? "@babel/transform-modules-commonjs" : null,
+      convertESM ? pluginNodeImportInterop : null,
 
       pluginPackageJsonMacro,
 
@@ -413,3 +414,54 @@ function pluginPackageJsonMacro({ types: t }) {
     },
   };
 }
+
+// Match the Node.js behavior (the default import is module.exports)
+function pluginNodeImportInterop({ template }) {
+  return {
+    visitor: {
+      ImportDeclaration(path) {
+        const specifiers = path.get("specifiers");
+        if (specifiers.length === 0) {
+          return;
+        }
+
+        const { source } = path.node;
+        if (
+          source.value.startsWith(".") ||
+          source.value.startsWith("@babel/") ||
+          source.value === "charcodes"
+        ) {
+          // For internal modules, it's either "all CJS" or "all ESM".
+          // We don't need to worry about interop.
+          return;
+        }
+
+        const defImport = specifiers.find(s => s.isImportDefaultSpecifier());
+        const nsImport = specifiers.find(s => s.isImportNamespaceSpecifier());
+
+        if (defImport) {
+          path.insertAfter(
+            template.ast`
+              const ${defImport.node.local} = require(${source});
+            `
+          );
+          defImport.remove();
+        }
+
+        if (nsImport) {
+          path.insertAfter(
+            template.ast`
+              const ${nsImport.node.local} = {
+                ...require(${source}),
+                default: require(${source}),
+              };
+            `
+          );
+          nsImport.remove();
+        }
+
+        if (path.node.specifiers.length === 0) path.remove();
+      },
+    },
+  };
+}

lib/babel-polyfills.js.flow

@@ -1,9 +1,9 @@
 declare module "babel-plugin-polyfill-regenerator" {
-    declare module.exports: Function;
+  declare module.exports: { default: Function };
 }
 declare module "babel-plugin-polyfill-corejs2" {
-    declare module.exports: Function;
+  declare module.exports: { default: Function };
 }
 declare module "babel-plugin-polyfill-corejs3" {
-    declare module.exports: Function;
+  declare module.exports: { default: Function };
 }

packages/babel-helper-transform-fixture-test-runner/src/index.js

@@ -13,10 +13,12 @@ import assert from "assert";
 import fs from "fs";
 import path from "path";
 import vm from "vm";
-import checkDuplicatedNodes from "babel-check-duplicated-nodes";
 import QuickLRU from "quick-lru";
 import escapeRegExp from "./escape-regexp.cjs";
 
+import _checkDuplicatedNodes from "babel-check-duplicated-nodes";
+const checkDuplicatedNodes = _checkDuplicatedNodes.default;
+
 const EXTERNAL_HELPERS_VERSION = "7.100.0";
 
 const cachedScripts = new QuickLRU({ maxSize: 10 });

packages/babel-highlight/src/index.ts

@@ -1,7 +1,8 @@
 /// <reference path="../../../lib/third-party-libs.d.ts" />
 
-import jsTokens, * as jsTokensNs from "js-tokens";
 import type { Token, JSXToken } from "js-tokens";
+import jsTokens from "js-tokens";
+
 import {
   isStrictReservedWord,
   isKeyword,
@@ -158,9 +159,6 @@ if (process.env.BABEL_8_BREAKING) {
     }
   };
 } else {
-  // This is only available in js-tokens@4, and not in js-tokens@6
-  const { matchToToken } = jsTokensNs as any;
-
   /**
    * RegExp to test for what seems to be a JSX tag name.
    */
@@ -204,8 +202,8 @@ if (process.env.BABEL_8_BREAKING) {
 
   tokenize = function* (text: string) {
     let match;
-    while ((match = (jsTokens as any).exec(text))) {
-      const token = matchToToken(match);
+    while ((match = (jsTokens as any).default.exec(text))) {
+      const token = (jsTokens as any).matchToToken(match);
 
       yield {
         type: getTokenType(token, match.index, text),

packages/babel-plugin-transform-runtime/src/index.js

@@ -5,9 +5,12 @@ import { types as t } from "@babel/core";
 import { hasMinVersion } from "./helpers";
 import getRuntimePath from "./get-runtime-path";
 
-import pluginCorejs2 from "babel-plugin-polyfill-corejs2";
-import pluginCorejs3 from "babel-plugin-polyfill-corejs3";
-import pluginRegenerator from "babel-plugin-polyfill-regenerator";
+import _pluginCorejs2 from "babel-plugin-polyfill-corejs2";
+import _pluginCorejs3 from "babel-plugin-polyfill-corejs3";
+import _pluginRegenerator from "babel-plugin-polyfill-regenerator";
+const pluginCorejs2 = _pluginCorejs2.default;
+const pluginCorejs3 = _pluginCorejs3.default;
+const pluginRegenerator = _pluginRegenerator.default;
 
 const pluginsCompat = "#__secret_key__@babel/runtime__compatibility";
 

packages/babel-preset-env/src/index.js

@@ -16,9 +16,12 @@ import overlappingPlugins from "@babel/compat-data/overlapping-plugins";
 import removeRegeneratorEntryPlugin from "./polyfills/regenerator";
 import legacyBabelPolyfillPlugin from "./polyfills/babel-polyfill";
 
-import pluginCoreJS2 from "babel-plugin-polyfill-corejs2";
-import pluginCoreJS3 from "babel-plugin-polyfill-corejs3";
-import pluginRegenerator from "babel-plugin-polyfill-regenerator";
+import _pluginCoreJS2 from "babel-plugin-polyfill-corejs2";
+import _pluginCoreJS3 from "babel-plugin-polyfill-corejs3";
+import _pluginRegenerator from "babel-plugin-polyfill-regenerator";
+const pluginCoreJS2 = _pluginCoreJS2.default;
+const pluginCoreJS3 = _pluginCoreJS3.default;
+const pluginRegenerator = _pluginRegenerator.default;
 
 import getTargets, {
   prettifyTargets,