Merge pull request #8485 from loganfsmyth/caller-option

Allow preset-env to toggle module handling based on flags from the caller (like babel-loader)

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

@@ -49,9 +49,14 @@ export function addSourceMappingUrl(code, loc) {
   return code + "\n//# sourceMappingURL=" + path.basename(loc);
 }
 
+const CALLER = {
+  name: "@babel/cli",
+};
+
 export function transform(filename, code, opts) {
   opts = {
     ...opts,
+    caller: CALLER,
     filename,
   };
 
@@ -64,6 +69,11 @@ export function transform(filename, code, opts) {
 }
 
 export function compile(filename, opts) {
+  opts = {
+    ...opts,
+    caller: CALLER,
+  };
+
   return new Promise((resolve, reject) => {
     babel.transformFile(filename, opts, (err, result) => {
       if (err) reject(err);

packages/babel-core/src/config/caching.js

@@ -206,12 +206,29 @@ function makeSimpleConfigurator(
       return;
     }
 
-    return cache.using(val);
+    return cache.using(() => assertSimpleType(val()));
   }
   cacheFn.forever = () => cache.forever();
   cacheFn.never = () => cache.never();
-  cacheFn.using = cb => cache.using(() => cb());
+  cacheFn.using = cb => cache.using(() => assertSimpleType(cb()));
-  cacheFn.invalidate = cb => cache.invalidate(() => cb());
+  cacheFn.invalidate = cb => cache.invalidate(() => assertSimpleType(cb()));
 
   return (cacheFn: any);
 }
+
+// Types are limited here so that in the future these values can be used
+// as part of Babel's caching logic.
+type SimpleType = string | boolean | number | null | void;
+export function assertSimpleType(value: mixed): SimpleType {
+  if (
+    value != null &&
+    typeof value !== "string" &&
+    typeof value !== "boolean" &&
+    typeof value !== "number"
+  ) {
+    throw new Error(
+      "Cache keys must be either string, boolean, number, null, or undefined.",
+    );
+  }
+  return value;
+}

packages/babel-core/src/config/config-chain.js

@@ -8,6 +8,7 @@ import {
   type IgnoreList,
   type ConfigApplicableTest,
   type BabelrcSearch,
+  type CallerMetadata,
 } from "./validation/options";
 import pathPatternToRegex from "./pattern-to-regex";
 
@@ -50,12 +51,27 @@ export type ConfigContext = {
   cwd: string,
   root: string,
   envName: string,
+  caller: CallerMetadata | void,
 };
 
 /**
  * Build a config chain for a given preset.
  */
-export const buildPresetChain: (
+export function buildPresetChain(
+  arg: PresetInstance,
+  context: *,
+): ConfigChain | null {
+  const chain = buildPresetChainWalker(arg, context);
+  if (!chain) return null;
+
+  return {
+    plugins: dedupDescriptors(chain.plugins),
+    presets: dedupDescriptors(chain.presets),
+    options: chain.options,
+  };
+}
+
+export const buildPresetChainWalker: (
   arg: PresetInstance,
   context: *,
 ) => * = makeChainWalker({
@@ -128,9 +144,14 @@ export function buildRootChain(
 
   let configFile;
   if (typeof opts.configFile === "string") {
-    configFile = loadConfig(opts.configFile, context.cwd, context.envName);
+    configFile = loadConfig(
+      opts.configFile,
+      context.cwd,
+      context.envName,
+      context.caller,
+    );
   } else if (opts.configFile !== false) {
-    configFile = findRootConfig(context.root, context.envName);
+    configFile = findRootConfig(context.root, context.envName, context.caller);
   }
 
   let { babelrc, babelrcRoots } = opts;
@@ -234,7 +255,7 @@ function babelrcLoadEnabled(
     if (typeof pat === "string") pat = pathPatternToRegex(pat, context.cwd);
 
     return pkgData.directories.some(directory => {
-      return matchPattern(pat, context.cwd, directory);
+      return matchPattern(pat, context.cwd, directory, context);
     });
   });
 }
@@ -449,7 +470,12 @@ function mergeExtendsChain(
 ): boolean {
   if (opts.extends === undefined) return true;
 
-  const file = loadConfig(opts.extends, dirname, context.envName);
+  const file = loadConfig(
+    opts.extends,
+    dirname,
+    context.envName,
+    context.caller,
+  );
 
   if (files.has(file)) {
     throw new Error(
@@ -629,12 +655,23 @@ function matchesPatterns(
   dirname: string,
 ): boolean {
   return patterns.some(pattern =>
-    matchPattern(pattern, dirname, context.filename),
+    matchPattern(pattern, dirname, context.filename, context),
   );
 }
 
-function matchPattern(pattern, dirname, pathToTest): boolean {
+function matchPattern(
-  if (typeof pattern === "function") return !!pattern(pathToTest);
+  pattern,
+  dirname,
+  pathToTest,
+  context: ConfigContext,
+): boolean {
+  if (typeof pattern === "function") {
+    return !!pattern(pathToTest, {
+      dirname,
+      envName: context.envName,
+      caller: context.caller,
+    });
+  }
 
   if (typeof pathToTest !== "string") {
     throw new Error(

packages/babel-core/src/config/files/configuration.js

@@ -14,6 +14,7 @@ import makeAPI from "../helpers/config-api";
 import { makeStaticFileCache } from "./utils";
 import pathPatternToRegex from "../pattern-to-regex";
 import type { FilePackageData, RelativeConfig, ConfigFile } from "./types";
+import type { CallerMetadata } from "../validation/options";
 
 const debug = buildDebug("babel:config:loading:files:configuration");
 
@@ -26,6 +27,7 @@ const BABELIGNORE_FILENAME = ".babelignore";
 export function findRelativeConfig(
   packageData: FilePackageData,
   envName: string,
+  caller: CallerMetadata | void,
 ): RelativeConfig {
   let config = null;
   let ignore = null;
@@ -37,7 +39,7 @@ export function findRelativeConfig(
       config = [BABELRC_FILENAME, BABELRC_JS_FILENAME].reduce(
         (previousConfig: ConfigFile | null, name) => {
           const filepath = path.join(loc, name);
-          const config = readConfig(filepath, envName);
+          const config = readConfig(filepath, envName, caller);
 
           if (config && previousConfig) {
             throw new Error(
@@ -91,10 +93,11 @@ export function findRelativeConfig(
 export function findRootConfig(
   dirname: string,
   envName: string,
+  caller: CallerMetadata | void,
 ): ConfigFile | null {
   const filepath = path.resolve(dirname, BABEL_CONFIG_JS_FILENAME);
 
-  const conf = readConfig(filepath, envName);
+  const conf = readConfig(filepath, envName, caller);
   if (conf) {
     debug("Found root config %o in $o.", BABEL_CONFIG_JS_FILENAME, dirname);
   }
@@ -105,10 +108,11 @@ export function loadConfig(
   name: string,
   dirname: string,
   envName: string,
+  caller: CallerMetadata | void,
 ): ConfigFile {
   const filepath = resolve.sync(name, { basedir: dirname });
 
-  const conf = readConfig(filepath, envName);
+  const conf = readConfig(filepath, envName, caller);
   if (!conf) {
     throw new Error(`Config file ${filepath} contains no configuration data`);
   }
@@ -121,16 +125,22 @@ export function loadConfig(
  * Read the given config file, returning the result. Returns null if no config was found, but will
  * throw if there are parsing errors while loading a config.
  */
-function readConfig(filepath, envName): ConfigFile | null {
+function readConfig(filepath, envName, caller): ConfigFile | null {
   return path.extname(filepath) === ".js"
-    ? readConfigJS(filepath, { envName })
+    ? readConfigJS(filepath, { envName, caller })
     : readConfigJSON5(filepath);
 }
 
 const LOADING_CONFIGS = new Set();
 
 const readConfigJS = makeStrongCache(
-  (filepath, cache: CacheConfigurator<{ envName: string }>) => {
+  (
+    filepath,
+    cache: CacheConfigurator<{
+      envName: string,
+      caller: CallerMetadata | void,
+    }>,
+  ) => {
     if (!fs.existsSync(filepath)) {
       cache.forever();
       return null;

packages/babel-core/src/config/files/index-browser.js

@@ -7,6 +7,8 @@ import type {
   FilePackageData,
 } from "./types";
 
+import type { CallerMetadata } from "../validation/options";
+
 export type { ConfigFile, IgnoreFile, RelativeConfig, FilePackageData };
 
 export function findPackageData(filepath: string): FilePackageData {
@@ -21,6 +23,7 @@ export function findPackageData(filepath: string): FilePackageData {
 export function findRelativeConfig(
   pkgData: FilePackageData, // eslint-disable-line no-unused-vars
   envName: string, // eslint-disable-line no-unused-vars
+  caller: CallerMetadata | void, // eslint-disable-line no-unused-vars
 ): RelativeConfig {
   return { pkg: null, config: null, ignore: null };
 }
@@ -28,6 +31,7 @@ export function findRelativeConfig(
 export function findRootConfig(
   dirname: string, // eslint-disable-line no-unused-vars
   envName: string, // eslint-disable-line no-unused-vars
+  caller: CallerMetadata | void, // eslint-disable-line no-unused-vars
 ): ConfigFile | null {
   return null;
 }
@@ -36,6 +40,7 @@ export function loadConfig(
   name: string,
   dirname: string,
   envName: string, // eslint-disable-line no-unused-vars
+  caller: CallerMetadata | void, // eslint-disable-line no-unused-vars
 ): ConfigFile {
   throw new Error(`Cannot load ${name} relative to ${dirname} in a browser`);
 }

packages/babel-core/src/config/full.js

@@ -13,7 +13,7 @@ import {
 import type { UnloadedDescriptor } from "./config-descriptors";
 import traverse from "@babel/traverse";
 import { makeWeakCache, type CacheConfigurator } from "./caching";
-import { validate } from "./validation/options";
+import { validate, type CallerMetadata } from "./validation/options";
 import { validatePluginObject } from "./validation/plugins";
 import makeAPI from "./helpers/config-api";
 
@@ -41,6 +41,7 @@ export type PluginPasses = Array<PluginPassList>;
 // process 'ignore'/'only' and other filename-based logic.
 type SimpleContext = {
   envName: string,
+  caller: CallerMetadata | void,
 };
 
 export default function loadFullConfig(

packages/babel-core/src/config/helpers/config-api.js

@@ -2,7 +2,13 @@
 
 import semver from "semver";
 import { version as coreVersion } from "../../";
-import type { CacheConfigurator, SimpleCacheConfigurator } from "../caching";
+import {
+  assertSimpleType,
+  type CacheConfigurator,
+  type SimpleCacheConfigurator,
+} from "../caching";
+
+import type { CallerMetadata } from "../validation/options";
 
 type EnvFunction = {
   (): string,
@@ -20,12 +26,14 @@ export type PluginAPI = {
 };
 
 export default function makeAPI(
-  cache: CacheConfigurator<{ envName: string }>,
+  cache: CacheConfigurator<{ envName: string, caller: CallerMetadata | void }>,
 ): PluginAPI {
   const env: any = value =>
     cache.using(data => {
       if (typeof value === "undefined") return data.envName;
-      if (typeof value === "function") return value(data.envName);
+      if (typeof value === "function") {
+        return assertSimpleType(value(data.envName));
+      }
       if (!Array.isArray(value)) value = [value];
 
       return value.some(entry => {
@@ -36,12 +44,16 @@ export default function makeAPI(
       });
     });
 
+  const caller: any = cb =>
+    cache.using(data => assertSimpleType(cb(data.caller)));
+
   return {
     version: coreVersion,
     cache: cache.simple(),
     // Expose ".env()" so people can easily get the same env that we expose using the "env" key.
     env,
     async: () => false,
+    caller,
     assertVersion,
   };
 }

packages/babel-core/src/config/partial.js

@@ -28,7 +28,7 @@ export default function loadPrivatePartialConfig(
 
   const args = inputOpts ? validate("arguments", inputOpts) : {};
 
-  const { envName = getEnv(), cwd = ".", root: rootDir = "." } = args;
+  const { envName = getEnv(), cwd = ".", root: rootDir = ".", caller } = args;
   const absoluteCwd = path.resolve(cwd);
   const absoluteRootDir = path.resolve(absoluteCwd, rootDir);
 
@@ -40,6 +40,7 @@ export default function loadPrivatePartialConfig(
     cwd: absoluteCwd,
     root: absoluteRootDir,
     envName,
+    caller,
   };
 
   const configChain = buildRootChain(args, context);

packages/babel-core/src/config/validation/option-assertions.js

@@ -14,6 +14,7 @@ import type {
   CompactOption,
   RootInputSourceMapOption,
   NestingPath,
+  CallerMetadata,
 } from "./options";
 
 export type ValidatorSet = {
@@ -103,6 +104,41 @@ export function assertSourceType(
   return value;
 }
 
+export function assertCallerMetadata(
+  loc: OptionPath,
+  value: mixed,
+): CallerMetadata | void {
+  const obj = assertObject(loc, value);
+  if (obj) {
+    if (typeof obj[("name": string)] !== "string") {
+      throw new Error(
+        `${msg(loc)} set but does not contain "name" property string`,
+      );
+    }
+
+    for (const prop of Object.keys(obj)) {
+      const propLoc = access(loc, prop);
+      const value = obj[prop];
+      if (
+        value != null &&
+        typeof value !== "boolean" &&
+        typeof value !== "string" &&
+        typeof value !== "number"
+      ) {
+        // NOTE(logan): I'm limiting the type here so that we can guarantee that
+        // the "caller" value will serialize to JSON nicely. We can always
+        // allow more complex structures later though.
+        throw new Error(
+          `${msg(
+            propLoc,
+          )} must be null, undefined, a boolean, a string, or a number.`,
+        );
+      }
+    }
+  }
+  return (value: any);
+}
+
 export function assertInputSourceMap(
   loc: OptionPath,
   value: mixed,

packages/babel-core/src/config/validation/options.js

@@ -11,6 +11,7 @@ import {
   assertBoolean,
   assertObject,
   assertArray,
+  assertCallerMetadata,
   assertInputSourceMap,
   assertIgnoreList,
   assertPluginList,
@@ -33,6 +34,9 @@ const ROOT_VALIDATORS: ValidatorSet = {
     $PropertyType<ValidatedOptions, "configFile">,
   >),
 
+  caller: (assertCallerMetadata: Validator<
+    $PropertyType<ValidatedOptions, "caller">,
+  >),
   filename: (assertString: Validator<
     $PropertyType<ValidatedOptions, "filename">,
   >),
@@ -176,6 +180,7 @@ export type ValidatedOptions = {
   ast?: boolean,
   inputSourceMap?: RootInputSourceMapOption,
   envName?: string,
+  caller?: CallerMetadata,
 
   extends?: string,
   env?: EnvSet<ValidatedOptions>,
@@ -225,6 +230,11 @@ export type ValidatedOptions = {
   generatorOpts?: {},
 };
 
+export type CallerMetadata = {
+  // If 'caller' is specified, require that the name is given for debugging
+  // messages.
+  name: string,
+};
 export type EnvSet<T> = {
   [string]: ?T,
 };

packages/babel-core/test/config-loading.js

@@ -323,4 +323,51 @@ describe("@babel/core config loading", () => {
       }
     });
   });
+
+  describe("caller metadata", () => {
+    it("should pass caller data through", () => {
+      const options1 = loadConfig({
+        ...makeOpts(),
+        caller: {
+          name: "babel-test",
+          someFlag: true,
+        },
+      }).options;
+
+      expect(options1.caller.name).toBe("babel-test");
+      expect(options1.caller.someFlag).toBe(true);
+    });
+
+    it("should pass unknown caller data through", () => {
+      const options1 = loadConfig({
+        ...makeOpts(),
+        caller: undefined,
+      }).options;
+
+      expect(options1.caller).toBeUndefined();
+    });
+
+    it("should pass caller data to test functions", () => {
+      const options1 = loadConfig({
+        ...makeOpts(),
+        caller: {
+          name: "babel-test",
+          someFlag: true,
+        },
+        overrides: [
+          {
+            test: (filename, { caller }) => caller.name === "babel-test",
+            comments: false,
+          },
+          {
+            test: (filename, { caller }) => caller.name !== "babel-test",
+            ast: false,
+          },
+        ],
+      }).options;
+
+      expect(options1.comments).toBe(false);
+      expect(options1.ast).not.toBe(false);
+    });
+  });
 });

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

@@ -60,6 +60,9 @@ program.usage("[options] [ -e script | script.js ] [arguments]");
 program.parse(process.argv);
 
 register({
+  caller: {
+    name: "@babel/node",
+  },
   extensions: program.extensions,
   ignore: program.ignore,
   only: program.only,

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

@@ -155,6 +155,10 @@ const filterItems = (
   return result;
 };
 
+function supportsStaticESM(caller) {
+  return !!(caller && caller.supportsStaticESM);
+}
+
 export default declare((api, opts) => {
   api.assertVersion(7);
 
@@ -232,9 +236,15 @@ export default declare((api, opts) => {
   const plugins = [];
   const pluginUseBuiltIns = useBuiltIns !== false;
 
-  // NOTE: not giving spec here yet to avoid compatibility issues when
+  if (
-  // transform-modules-commonjs gets its spec mode
+    modules !== false &&
-  if (modules !== false && moduleTransformations[modules]) {
+    moduleTransformations[modules] &&
+    // TODO: Remove the 'api.caller' check eventually. Just here to prevent
+    // unnecessary breakage in the short term for users on older betas/RCs.
+    (modules !== "auto" || !api.caller || !api.caller(supportsStaticESM))
+  ) {
+    // NOTE: not giving spec here yet to avoid compatibility issues when
+    // transform-modules-commonjs gets its spec mode
     plugins.push([getPlugin(moduleTransformations[modules]), { loose }]);
   }
 

packages/babel-preset-env/src/module-transformations.js

@@ -1,4 +1,5 @@
 export default {
+  auto: "transform-modules-commonjs",
   amd: "transform-modules-amd",
   commonjs: "transform-modules-commonjs",
   cjs: "transform-modules-commonjs",

packages/babel-preset-env/src/normalize-options.js

@@ -128,13 +128,16 @@ export const validateIgnoreBrowserslistConfig = (
   );
 
 export const validateModulesOption = (
-  modulesOpt: ModuleOption = ModulesOption.commonjs,
+  modulesOpt: ModuleOption = ModulesOption.auto,
 ) => {
   invariant(
     ModulesOption[modulesOpt] ||
       ModulesOption[modulesOpt] === ModulesOption.false,
-    `Invalid Option: The 'modules' option must be either 'false' to indicate no modules, or a
+    `Invalid Option: The 'modules' option must be one of \n` +
-    module type which can be be one of: 'commonjs' (default), 'amd', 'umd', 'systemjs'.`,
+      ` - 'false' to indicate no module processing\n` +
+      ` - a specific module type: 'commonjs', 'amd', 'umd', 'systemjs'` +
+      ` - 'auto' (default) which will automatically select 'false' if the current\n` +
+      `   process is known to support ES module syntax, or "commonjs" otherwise\n`,
   );
 
   return modulesOpt;

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

@@ -15,6 +15,7 @@ export const TopLevelOptions = {
 
 export const ModulesOption = {
   false: false,
+  auto: "auto",
   amd: "amd",
   commonjs: "commonjs",
   cjs: "cjs",

packages/babel-preset-env/test/debug-fixtures/android/stdout.txt

@@ -5,7 +5,7 @@ Using targets:
   "android": "4"
 }
 
-Using modules transform: commonjs
+Using modules transform: auto
 
 Using plugins:
   transform-template-literals { "android":"4" }
@@ -149,4 +149,4 @@ Using polyfills with `entry` option:
   web.timers { "android":"4" }
   web.immediate { "android":"4" }
   web.dom.iterable { "android":"4" }
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel.

packages/babel-preset-env/test/debug-fixtures/builtins-no-import/stdout.txt

@@ -5,7 +5,7 @@ Using targets:
   "node": "6"
 }
 
-Using modules transform: commonjs
+Using modules transform: auto
 
 Using plugins:
   transform-function-name { "node":"6" }
@@ -23,4 +23,4 @@ Using plugins:
 Using polyfills with `entry` option:
 
 [<CWD>/src/in.js] `import '@babel/polyfill'` was not found.
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel.

packages/babel-preset-env/test/debug-fixtures/builtins/stdout.txt

@@ -7,7 +7,7 @@ Using targets:
   "node": "6"
 }
 
-Using modules transform: commonjs
+Using modules transform: auto
 
 Using plugins:
   transform-template-literals { "ie":"10" }
@@ -165,4 +165,4 @@ Using polyfills with `entry` option:
   web.timers { "chrome":"54", "ie":"10", "node":"6" }
   web.immediate { "chrome":"54", "ie":"10", "node":"6" }
   web.dom.iterable { "chrome":"54", "ie":"10", "node":"6" }
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel.

packages/babel-preset-env/test/debug-fixtures/electron/stdout.txt

@@ -12,7 +12,7 @@ Using targets:
   "electron": "0.36"
 }
 
-Using modules transform: commonjs
+Using modules transform: auto
 
 Using plugins:
   transform-function-name { "electron":"0.36" }
@@ -125,4 +125,4 @@ Using polyfills with `entry` option:
   web.timers { "electron":"0.36" }
   web.immediate { "electron":"0.36" }
   web.dom.iterable { "electron":"0.36" }
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel.

packages/babel-preset-env/test/debug-fixtures/plugins-only/stdout.txt

@@ -13,7 +13,7 @@ Using targets:
   "node": "7.4"
 }
 
-Using modules transform: commonjs
+Using modules transform: auto
 
 Using plugins:
   transform-literals { "firefox":"52" }
@@ -28,4 +28,4 @@ Using plugins:
   proposal-optional-catch-binding { "firefox":"52", "node":"7.4" }
 
 Using polyfills: No polyfills were added, since the `useBuiltIns` option was not set.
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel.

packages/babel-preset-env/test/debug-fixtures/shippedProposals-chrome60/stdout.txt

@@ -5,7 +5,7 @@ Using targets:
   "chrome": "60"
 }
 
-Using modules transform: commonjs
+Using modules transform: auto
 
 Using plugins:
   transform-dotall-regex { "chrome":"60" }
@@ -29,4 +29,4 @@ Using polyfills with `entry` option:
   web.timers { "chrome":"60" }
   web.immediate { "chrome":"60" }
   web.dom.iterable { "chrome":"60" }
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel.

packages/babel-preset-env/test/debug-fixtures/shippedProposals/stdout.txt

@@ -3,7 +3,7 @@
 Using targets:
 {}
 
-Using modules transform: commonjs
+Using modules transform: auto
 
 Using plugins:
   transform-template-literals {}
@@ -183,4 +183,4 @@ Using polyfills with `entry` option:
   web.timers {}
   web.immediate {}
   web.dom.iterable {}
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel.

packages/babel-preset-env/test/debug-fixtures/specific-targets/stdout.txt

@@ -10,7 +10,7 @@ Using targets:
   "safari": "7"
 }
 
-Using modules transform: commonjs
+Using modules transform: auto
 
 Using plugins:
   transform-template-literals { "ie":"10", "safari":"7" }
@@ -169,4 +169,4 @@ Using polyfills with `entry` option:
   web.timers { "chrome":"54", "edge":"13", "firefox":"49", "ie":"10", "ios":"9", "safari":"7" }
   web.immediate { "chrome":"54", "edge":"13", "firefox":"49", "ie":"10", "ios":"9", "safari":"7" }
   web.dom.iterable { "chrome":"54", "edge":"13", "firefox":"49", "ie":"10", "ios":"9", "safari":"7" }
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel.

packages/babel-preset-env/test/debug-fixtures/usage-none/stdout.txt

@@ -7,7 +7,7 @@ Using targets:
   "ie": "11"
 }
 
-Using modules transform: commonjs
+Using modules transform: auto
 
 Using plugins:
   transform-template-literals { "ie":"11" }
@@ -43,4 +43,4 @@ Using polyfills with `usage` option:
 [<CWD>/src/in.js] Based on your code and targets, none were added.
 
 [<CWD>/src/in2.js] Based on your code and targets, none were added.
-Successfully compiled 2 files with Babel.
+Successfully compiled 2 files with Babel.

packages/babel-preset-env/test/debug-fixtures/usage-with-import/stdout.txt

@@ -5,7 +5,7 @@ Using targets:
   "chrome": "55"
 }
 
-Using modules transform: commonjs
+Using modules transform: auto
 
 Using plugins:
   transform-dotall-regex { "chrome":"55" }
@@ -18,4 +18,4 @@ Using plugins:
 Using polyfills with `usage` option:
 
 [<CWD>/src/in.js] Based on your code and targets, none were added.
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel.

packages/babel-preset-env/test/debug-fixtures/usage/stdout.txt

@@ -7,7 +7,7 @@ Using targets:
   "ie": "11"
 }
 
-Using modules transform: commonjs
+Using modules transform: auto
 
 Using plugins:
   transform-template-literals { "ie":"11" }
@@ -49,4 +49,4 @@ Using polyfills with `usage` option:
 [<CWD>/src/in2.js] Added following polyfills:
   regenerator-runtime { "chrome":"52", "firefox":"50", "ie":"11" }
   web.dom.iterable { "chrome":"52", "firefox":"50", "ie":"11" }
-Successfully compiled 2 files with Babel.
+Successfully compiled 2 files with Babel.

packages/babel-preset-env/test/debug-fixtures/versions-decimals/stdout.txt

@@ -16,7 +16,7 @@ Using targets:
   "node": "6.1"
 }
 
-Using modules transform: commonjs
+Using modules transform: auto
 
 Using plugins:
   transform-template-literals { "ie":"10" }
@@ -195,4 +195,4 @@ Using polyfills with `entry` option:
   web.timers { "chrome":"54", "electron":"0.36", "ie":"10", "node":"6.1" }
   web.immediate { "chrome":"54", "electron":"0.36", "ie":"10", "node":"6.1" }
   web.dom.iterable { "chrome":"54", "electron":"0.36", "ie":"10", "node":"6.1" }
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel.

packages/babel-preset-env/test/debug-fixtures/versions-strings/stdout.txt

@@ -7,7 +7,7 @@ Using targets:
   "node": "6.10"
 }
 
-Using modules transform: commonjs
+Using modules transform: auto
 
 Using plugins:
   transform-template-literals { "ie":"10" }
@@ -165,4 +165,4 @@ Using polyfills with `entry` option:
   web.timers { "chrome":"54", "ie":"10", "node":"6.10" }
   web.immediate { "chrome":"54", "ie":"10", "node":"6.10" }
   web.dom.iterable { "chrome":"54", "ie":"10", "node":"6.10" }
-Successfully compiled 1 file with Babel.
+Successfully compiled 1 file with Babel.

packages/babel-preset-env/test/fixtures/modules/auto-cjs/input.mjs

@@ -0,0 +1,2 @@
+import mod from "mod";
+console.log(mod);

packages/babel-preset-env/test/fixtures/modules/auto-cjs/options.json

@@ -0,0 +1,9 @@
+{
+  "caller": {
+    "name": "test-fixture",
+    "supportsStaticESM": false
+  },
+  "presets": [
+    "env"
+  ]
+}

packages/babel-preset-env/test/fixtures/modules/auto-cjs/output.js

@@ -0,0 +1,7 @@
+"use strict";
+
+var _mod = _interopRequireDefault(require("mod"));
+
+function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
+
+console.log(_mod.default);

packages/babel-preset-env/test/fixtures/modules/auto-esm/input.mjs

@@ -0,0 +1,2 @@
+import mod from "mod";
+console.log(mod);

packages/babel-preset-env/test/fixtures/modules/auto-esm/options.json

@@ -0,0 +1,9 @@
+{
+  "caller": {
+    "name": "test-fixture",
+    "supportsStaticESM": true
+  },
+  "presets": [
+    "env"
+  ]
+}

packages/babel-preset-env/test/fixtures/modules/auto-esm/output.mjs

@@ -0,0 +1,2 @@
+import mod from "mod";
+console.log(mod);

packages/babel-preset-env/test/fixtures/modules/auto-unknown/input.mjs

@@ -0,0 +1,2 @@
+import mod from "mod";
+console.log(mod);

packages/babel-preset-env/test/fixtures/modules/auto-unknown/options.json

@@ -0,0 +1,5 @@
+{
+  "presets": [
+    "env"
+  ]
+}

packages/babel-preset-env/test/fixtures/modules/auto-unknown/output.js

@@ -0,0 +1,7 @@
+"use strict";
+
+var _mod = _interopRequireDefault(require("mod"));
+
+function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
+
+console.log(_mod.default);

packages/babel-preset-env/test/normalize-options.spec.js

@@ -134,16 +134,20 @@ describe("normalize-options", () => {
   });
 
   describe("validateModulesOption", () => {
-    it("`undefined` option returns commonjs", () => {
+    it("`undefined` option returns auto", () => {
-      expect(validateModulesOption()).toBe("commonjs");
+      expect(validateModulesOption()).toBe("auto");
     });
 
-    it("`false` option returns commonjs", () => {
+    it("`false` option returns false", () => {
       expect(validateModulesOption(false)).toBe(false);
     });
 
+    it("auto option is valid", () => {
+      expect(validateModulesOption("auto")).toBe("auto");
+    });
+
     it("commonjs option is valid", () => {
-      expect(validateModulesOption()).toBe("commonjs");
+      expect(validateModulesOption("commonjs")).toBe("commonjs");
     });
 
     it("systemjs option is valid", () => {

packages/babel-register/src/node.js

@@ -125,6 +125,10 @@ export default function register(opts?: Object = {}) {
 
   transformOpts = {
     ...opts,
+    caller: {
+      name: "@babel/register",
+      ...(opts.caller || {}),
+    },
   };
 
   let { cwd = "." } = transformOpts;