v7.0.0-beta.36

Remove extraneous console output when running preset-env tests (#6576 )
Fix generation flow unnamed computed property (#7095 )
2017-12-25 14:04:08 -05:00 · 2017-12-25 13:47:19 -05:00 · 2017-12-22 12:55:40 -06:00 · 2017-12-22 10:42:06 -05:00 · 2017-12-21 19:57:07 -08:00 · 2017-12-21 19:06:36 -08:00
334 changed files with 4516 additions and 3164 deletions
--- a/codemods/babel-plugin-codemod-optional-catch-binding/package.json
+++ b/codemods/babel-plugin-codemod-optional-catch-binding/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-codemod-optional-catch-binding",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Remove unused catch bindings",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-transform-remove-unused-catch-binding",
  "license": "MIT",
@@ -9,13 +9,13 @@
    "@babel/plugin"
  ],
  "dependencies": {
-    "@babel/plugin-syntax-optional-catch-binding": "7.0.0-beta.35"
+    "@babel/plugin-syntax-optional-catch-binding": "7.0.0-beta.36"
  },
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35",
-    "@babel/helper-plugin-test-runner": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36",
+    "@babel/helper-plugin-test-runner": "7.0.0-beta.36"
  }
 }
--- a/lerna.json
+++ b/lerna.json
@@ -1,6 +1,6 @@
 {
  "lerna": "2.0.0-rc.4",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "changelog": {
    "repo": "babel/babel",
    "labels": {
--- a/lib/types.js
+++ b/lib/types.js
@@ -1262,7 +1262,7 @@ declare class BabelNodeTSTypeParameter extends BabelNode {
  name?: string;
 }

-type BabelNodeExpression = BabelNodeArrayExpression | BabelNodeAssignmentExpression | BabelNodeBinaryExpression | BabelNodeCallExpression | BabelNodeConditionalExpression | BabelNodeFunctionExpression | BabelNodeIdentifier | BabelNodeStringLiteral | BabelNodeNumericLiteral | BabelNodeNullLiteral | BabelNodeBooleanLiteral | BabelNodeRegExpLiteral | BabelNodeLogicalExpression | BabelNodeMemberExpression | BabelNodeNewExpression | BabelNodeObjectExpression | BabelNodeSequenceExpression | BabelNodeThisExpression | BabelNodeUnaryExpression | BabelNodeUpdateExpression | BabelNodeArrowFunctionExpression | BabelNodeClassExpression | BabelNodeMetaProperty | BabelNodeSuper | BabelNodeTaggedTemplateExpression | BabelNodeTemplateLiteral | BabelNodeYieldExpression | BabelNodeTypeCastExpression | BabelNodeJSXElement | BabelNodeJSXEmptyExpression | BabelNodeJSXIdentifier | BabelNodeJSXMemberExpression | BabelNodeJSXFragment | BabelNodeParenthesizedExpression | BabelNodeAwaitExpression | BabelNodeBindExpression | BabelNodeImport | BabelNodeDoExpression | BabelNodeTSAsExpression | BabelNodeTSTypeAssertion | BabelNodeTSNonNullExpression;
+type BabelNodeExpression = BabelNodeArrayExpression | BabelNodeAssignmentExpression | BabelNodeBinaryExpression | BabelNodeCallExpression | BabelNodeConditionalExpression | BabelNodeFunctionExpression | BabelNodeIdentifier | BabelNodeStringLiteral | BabelNodeNumericLiteral | BabelNodeNullLiteral | BabelNodeBooleanLiteral | BabelNodeRegExpLiteral | BabelNodeLogicalExpression | BabelNodeMemberExpression | BabelNodeNewExpression | BabelNodeObjectExpression | BabelNodeSequenceExpression | BabelNodeThisExpression | BabelNodeUnaryExpression | BabelNodeUpdateExpression | BabelNodeArrowFunctionExpression | BabelNodeClassExpression | BabelNodeMetaProperty | BabelNodeSuper | BabelNodeTaggedTemplateExpression | BabelNodeTemplateLiteral | BabelNodeYieldExpression | BabelNodeTypeCastExpression | BabelNodeJSXElement | BabelNodeJSXFragment | BabelNodeParenthesizedExpression | BabelNodeAwaitExpression | BabelNodeBindExpression | BabelNodeImport | BabelNodeDoExpression | BabelNodeTSAsExpression | BabelNodeTSTypeAssertion | BabelNodeTSNonNullExpression;
 type BabelNodeBinary = BabelNodeBinaryExpression | BabelNodeLogicalExpression;
 type BabelNodeScopable = BabelNodeBlockStatement | BabelNodeCatchClause | BabelNodeDoWhileStatement | BabelNodeForInStatement | BabelNodeForStatement | BabelNodeFunctionDeclaration | BabelNodeFunctionExpression | BabelNodeProgram | BabelNodeObjectMethod | BabelNodeSwitchStatement | BabelNodeWhileStatement | BabelNodeArrowFunctionExpression | BabelNodeClassDeclaration | BabelNodeClassExpression | BabelNodeForOfStatement | BabelNodeClassMethod;
 type BabelNodeBlockParent = BabelNodeBlockStatement | BabelNodeCatchClause | BabelNodeDoWhileStatement | BabelNodeForInStatement | BabelNodeForStatement | BabelNodeFunctionDeclaration | BabelNodeFunctionExpression | BabelNodeProgram | BabelNodeObjectMethod | BabelNodeSwitchStatement | BabelNodeWhileStatement | BabelNodeArrowFunctionExpression | BabelNodeForOfStatement | BabelNodeClassMethod;
--- a/packages/babel-cli/package.json
+++ b/packages/babel-cli/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/cli",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Babel command line.",
  "author": "Sebastian McKenzie <sebmck@gmail.com>",
  "homepage": "https://babeljs.io/",
@@ -29,11 +29,11 @@
    "chokidar": "^1.6.1"
  },
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35",
-    "@babel/helper-fixtures": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36",
+    "@babel/helper-fixtures": "7.0.0-beta.36"
  },
  "bin": {
    "babel": "./bin/babel.js",
--- a/packages/babel-code-frame/package.json
+++ b/packages/babel-code-frame/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/code-frame",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Generate errors that contain a code frame that point to source locations.",
  "author": "Sebastian McKenzie <sebmck@gmail.com>",
  "homepage": "https://babeljs.io/",
--- a/packages/babel-core/package.json
+++ b/packages/babel-core/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/core",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Babel compiler core.",
  "main": "./lib/index.js",
  "author": "Sebastian McKenzie <sebmck@gmail.com>",
@@ -23,18 +23,18 @@
    "compiler"
  ],
  "browser": {
-    "./lib/config/loading/files/index.js": "./lib/config/loading/files/index-browser.js",
+    "./lib/config/files/index.js": "./lib/config/files/index-browser.js",
    "./lib/transform-file.js": "./lib/transform-file-browser.js",
    "./lib/transform-file-sync.js": "./lib/transform-file-sync-browser.js"
  },
  "dependencies": {
-    "@babel/code-frame": "7.0.0-beta.35",
-    "@babel/generator": "7.0.0-beta.35",
-    "@babel/helpers": "7.0.0-beta.35",
-    "@babel/template": "7.0.0-beta.35",
-    "@babel/traverse": "7.0.0-beta.35",
-    "@babel/types": "7.0.0-beta.35",
-    "babylon": "7.0.0-beta.35",
+    "@babel/code-frame": "7.0.0-beta.36",
+    "@babel/generator": "7.0.0-beta.36",
+    "@babel/helpers": "7.0.0-beta.36",
+    "@babel/template": "7.0.0-beta.36",
+    "@babel/traverse": "7.0.0-beta.36",
+    "@babel/types": "7.0.0-beta.36",
+    "babylon": "7.0.0-beta.36",
    "convert-source-map": "^1.1.0",
    "debug": "^3.0.1",
    "json5": "^0.5.0",
@@ -44,7 +44,7 @@
    "source-map": "^0.5.0"
  },
  "devDependencies": {
-    "@babel/helper-transform-fixture-test-runner": "7.0.0-beta.35",
-    "@babel/register": "7.0.0-beta.35"
+    "@babel/helper-transform-fixture-test-runner": "7.0.0-beta.36",
+    "@babel/register": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-core/src/config/build-config-chain.js
+++ b/packages/babel-core/src/config/build-config-chain.js
@@ -1,424 +0,0 @@
-// @flow
-
-import path from "path";
-import micromatch from "micromatch";
-import buildDebug from "debug";
-import {
-  validate,
-  type ValidatedOptions,
-  type PluginList,
-  type IgnoreList,
-} from "./options";
-
-const debug = buildDebug("babel:config:config-chain");
-
-import { findConfigs, loadConfig, type ConfigFile } from "./loading/files";
-
-import { makeWeakCache, makeStrongCache } from "./caching";
-
-export type ConfigItem = {
-  type: "arguments" | "env" | "file",
-  options: ValidatedOptions,
-  alias: string,
-  dirname: string,
-};
-
-type ConfigPart =
-  | {
-      part: "config",
-      config: ConfigItem,
-      ignore: ?IgnoreList,
-      only: ?IgnoreList,
-      activeEnv: string | null,
-    }
-  | {
-      part: "extends",
-      path: string,
-      dirname: string,
-      activeEnv: string | null,
-    };
-
-export default function buildConfigChain(
-  cwd: string,
-  opts: ValidatedOptions,
-  envName: string,
-): Array<ConfigItem> | null {
-  const filename = opts.filename ? path.resolve(cwd, opts.filename) : null;
-  const builder = new ConfigChainBuilder(
-    filename ? new LoadedFile(filename) : null,
-  );
-
-  try {
-    builder.mergeConfigArguments(opts, cwd, envName);
-
-    // resolve all .babelrc files
-    if (opts.babelrc !== false && filename) {
-      findConfigs(path.dirname(filename), envName).forEach(configFile =>
-        builder.mergeConfigFile(configFile, envName),
-      );
-    }
-  } catch (e) {
-    if (e.code !== "BABEL_IGNORED_FILE") throw e;
-
-    return null;
-  }
-
-  return builder.configs.reverse();
-}
-
-class ConfigChainBuilder {
-  file: LoadedFile | null;
-  configs: Array<ConfigItem> = [];
-  seenFiles: Set<ConfigFile> = new Set();
-
-  constructor(file: LoadedFile | null) {
-    this.file = file;
-  }
-
-  mergeConfigArguments(
-    opts: ValidatedOptions,
-    dirname: string,
-    envKey: string,
-  ) {
-    flattenArgumentsOptionsParts(opts, dirname, envKey).forEach(part =>
-      this._processConfigPart(part, envKey),
-    );
-  }
-
-  mergeConfigFile(file: ConfigFile, envName: string) {
-    if (this.seenFiles.has(file)) {
-      throw new Error(
-        `Cycle detected in Babel configuration file through "${
-          file.filepath
-        }".`,
-      );
-    }
-
-    const parts = flattenFileOptionsParts(file)(envName);
-
-    this.seenFiles.add(file);
-    parts.forEach(part => this._processConfigPart(part, envName));
-    this.seenFiles.delete(file);
-  }
-
-  _processConfigPart(part: ConfigPart, envName: string) {
-    if (part.part === "config") {
-      const { ignore, only } = part;
-
-      // Bail out ASAP if this file is ignored so that we run as little logic as possible on ignored files.
-      if (
-        this.file &&
-        this.file.shouldIgnore(ignore, only, part.config.dirname)
-      ) {
-        // TODO(logan): This is a really gross way to bail out. Avoid this in rewrite.
-        throw Object.assign((new Error("This file has been ignored."): any), {
-          code: "BABEL_IGNORED_FILE",
-        });
-      }
-
-      this.configs.push(part.config);
-    } else {
-      this.mergeConfigFile(
-        loadConfig(part.path, part.dirname, envName),
-        envName,
-      );
-    }
-  }
-}
-
-/**
- * Given the root config object passed to Babel, split it into the separate
- * config parts. The resulting config objects in the 'ConfigPart' have their
- * object identity preserved between calls so that they can be used for caching.
- */
-function flattenArgumentsOptionsParts(
-  opts: ValidatedOptions,
-  dirname: string,
-  envName: string,
-): Array<ConfigPart> {
-  const {
-    env,
-    plugins,
-    presets,
-    passPerPreset,
-    extends: extendsPath,
-    ...options
-  } = opts;
-
-  const raw = [];
-  if (env) {
-    raw.push(...flattenArgumentsEnvOptionsParts(env)(dirname)(envName));
-  }
-
-  if (Object.keys(options).length > 0) {
-    raw.push(...flattenOptionsParts(buildArgumentsItem(options, dirname)));
-  }
-
-  if (plugins) {
-    raw.push(...flattenArgumentsPluginsOptionsParts(plugins)(dirname));
-  }
-  if (presets) {
-    raw.push(
-      ...flattenArgumentsPresetsOptionsParts(presets)(!!passPerPreset)(dirname),
-    );
-  }
-
-  if (extendsPath != null) {
-    raw.push(
-      ...flattenOptionsParts(
-        buildArgumentsItem({ extends: extendsPath }, dirname),
-      ),
-    );
-  }
-
-  return raw;
-}
-
-/**
- * For the top-level 'options' object, we cache the env list based on
- * the object identity of the 'env' object.
- */
-const flattenArgumentsEnvOptionsParts = makeWeakCache((env: {}) => {
-  const options: ValidatedOptions = { env };
-
-  return makeStrongCache((dirname: string) =>
-    flattenOptionsPartsLookup(buildArgumentsItem(options, dirname)),
-  );
-});
-
-/**
- * For the top-level 'options' object, we cache the plugin list based on
- * the object identity of the 'plugins' object.
- */
-const flattenArgumentsPluginsOptionsParts = makeWeakCache(
-  (plugins: PluginList) => {
-    const options: ValidatedOptions = { plugins };
-
-    return makeStrongCache((dirname: string) =>
-      flattenOptionsParts(buildArgumentsItem(options, dirname)),
-    );
-  },
-);
-
-/**
- * For the top-level 'options' object, we cache the preset list based on
- * the object identity of the 'presets' object.
- */
-const flattenArgumentsPresetsOptionsParts = makeWeakCache(
-  (presets: PluginList) =>
-    makeStrongCache((passPerPreset: boolean) => {
-      // The concept of passPerPreset is integrally tied to the preset list
-      // so unfortunately we need to copy both values here, adding an extra
-      // layer of caching functions.
-      const options = { presets, passPerPreset };
-
-      return makeStrongCache((dirname: string) =>
-        flattenOptionsParts(buildArgumentsItem(options, dirname)),
-      );
-    }),
-);
-
-function buildArgumentsItem(
-  options: ValidatedOptions,
-  dirname: string,
-): ConfigItem {
-  return {
-    type: "arguments",
-    options,
-    alias: "base",
-    dirname,
-  };
-}
-
-/**
- * Given a config from a specific file, return a list of ConfigPart objects
- * with object identity preserved for all 'config' part objects for use
- * with caching later in config processing.
- */
-const flattenFileOptionsParts = makeWeakCache((file: ConfigFile) => {
-  return flattenOptionsPartsLookup({
-    type: "file",
-    options: validate("file", file.options),
-    alias: file.filepath,
-    dirname: file.dirname,
-  });
-});
-
-/**
- * Given a config, create a function that will return the config parts for
- * the environment passed as the first argument.
- */
-function flattenOptionsPartsLookup(
-  config: ConfigItem,
-): (string | null) => Array<ConfigPart> {
-  const parts = flattenOptionsParts(config);
-
-  const def = parts.filter(part => part.activeEnv === null);
-  const lookup = new Map();
-
-  parts.forEach(part => {
-    if (part.activeEnv !== null) lookup.set(part.activeEnv, []);
-  });
-
-  for (const [activeEnv, values] of lookup) {
-    parts.forEach(part => {
-      if (part.activeEnv === null || part.activeEnv === activeEnv) {
-        values.push(part);
-      }
-    });
-  }
-
-  return envName => lookup.get(envName) || def;
-}
-
-/**
- * Given a generic config object, flatten it into its various parts so that
- * then can be cached and processed later.
- */
-function flattenOptionsParts(
-  config: ConfigItem,
-  activeEnv: string | null = null,
-): Array<ConfigPart> {
-  const { options: rawOpts, alias, dirname } = config;
-
-  const parts = [];
-
-  if (rawOpts.env) {
-    for (const envKey of Object.keys(rawOpts.env)) {
-      if (rawOpts.env[envKey]) {
-        parts.push(
-          ...flattenOptionsParts(
-            {
-              type: "env",
-              options: rawOpts.env[envKey],
-              alias: alias + `.env.${envKey}`,
-              dirname,
-            },
-            envKey,
-          ),
-        );
-      }
-    }
-  }
-
-  parts.push({
-    part: "config",
-    config,
-    ignore: rawOpts.ignore,
-    only: rawOpts.only,
-    activeEnv,
-  });
-
-  if (rawOpts.extends != null) {
-    parts.push({
-      part: "extends",
-      path: rawOpts.extends,
-      dirname,
-      activeEnv,
-    });
-  }
-
-  return parts;
-}
-
-/**
- * Track a given file and expose function to check if it should be ignored.
- */
-class LoadedFile {
-  filename: string;
-  possibleDirs: null | Array<string> = null;
-
-  constructor(filename) {
-    this.filename = filename;
-  }
-
-  /**
-   * Tests if a filename should be ignored based on "ignore" and "only" options.
-   */
-  shouldIgnore(
-    ignore: ?IgnoreList,
-    only: ?IgnoreList,
-    dirname: string,
-  ): boolean {
-    if (ignore) {
-      if (this._matchesPatterns(ignore, dirname)) {
-        debug(
-          "Ignored %o because it matched one of %O from %o",
-          this.filename,
-          ignore,
-          dirname,
-        );
-        return true;
-      }
-    }
-
-    if (only) {
-      if (!this._matchesPatterns(only, dirname)) {
-        debug(
-          "Ignored %o because it failed to match one of %O from %o",
-          this.filename,
-          only,
-          dirname,
-        );
-        return true;
-      }
-    }
-
-    return false;
-  }
-
-  /**
-   * Returns result of calling function with filename if pattern is a function.
-   * Otherwise returns result of matching pattern Regex with filename.
-   */
-  _matchesPatterns(patterns: IgnoreList, dirname: string): boolean {
-    const res = [];
-    const strings = [];
-    const fns = [];
-
-    patterns.forEach(pattern => {
-      if (typeof pattern === "string") strings.push(pattern);
-      else if (typeof pattern === "function") fns.push(pattern);
-      else res.push(pattern);
-    });
-
-    const filename = this.filename;
-    if (res.some(re => re.test(filename))) return true;
-    if (fns.some(fn => fn(filename))) return true;
-
-    if (strings.length > 0) {
-      let possibleDirs = this.possibleDirs;
-      // Lazy-init so we don't initialize this for files that have no glob patterns.
-      if (!possibleDirs) {
-        possibleDirs = this.possibleDirs = [];
-
-        possibleDirs.push(filename);
-
-        let current = filename;
-        while (true) {
-          const previous = current;
-          current = path.dirname(current);
-          if (previous === current) break;
-
-          possibleDirs.push(current);
-        }
-      }
-
-      const absolutePatterns = strings.map(pattern => {
-        // Preserve the "!" prefix so that micromatch can use it for negation.
-        const negate = pattern[0] === "!";
-        if (negate) pattern = pattern.slice(1);
-
-        return (negate ? "!" : "") + path.resolve(dirname, pattern);
-      });
-
-      if (
-        micromatch(possibleDirs, absolutePatterns, { nocase: true }).length > 0
-      ) {
-        return true;
-      }
-    }
-
-    return false;
-  }
-}
--- a/packages/babel-core/src/config/caching.js
+++ b/packages/babel-core/src/config/caching.js
@@ -14,9 +14,10 @@ type SimpleCacheConfiguratorObj = {
  invalidate: <T>(handler: () => T) => T,
 };

-type CacheEntry<ResultT, SideChannel> = Array<
-  [ResultT, (SideChannel) => boolean],
->;
+type CacheEntry<ResultT, SideChannel> = Array<{
+  value: ResultT,
+  valid: SideChannel => boolean,
+}>;

 export type { CacheConfigurator };

@@ -64,7 +65,7 @@ function makeCachedFunction<
    );

    if (cachedValue) {
-      for (const [value, valid] of cachedValue) {
+      for (const { value, valid } of cachedValue) {
        if (valid(data)) return value;
      }
    }
@@ -79,18 +80,18 @@ function makeCachedFunction<

    switch (cache.mode()) {
      case "forever":
-        cachedValue = [[value, () => true]];
+        cachedValue = [{ value, valid: () => true }];
        callCache.set(arg, cachedValue);
        break;
      case "invalidate":
-        cachedValue = [[value, cache.validator()]];
+        cachedValue = [{ value, valid: cache.validator() }];
        callCache.set(arg, cachedValue);
        break;
      case "valid":
        if (cachedValue) {
-          cachedValue.push([value, cache.validator()]);
+          cachedValue.push({ value, valid: cache.validator() });
        } else {
-          cachedValue = [[value, cache.validator()]];
+          cachedValue = [{ value, valid: cache.validator() }];
          callCache.set(arg, cachedValue);
        }
    }
--- a/packages/babel-core/src/config/config-chain.js
+++ b/packages/babel-core/src/config/config-chain.js
@@ -0,0 +1,452 @@
+// @flow
+
+import path from "path";
+import micromatch from "micromatch";
+import buildDebug from "debug";
+import {
+  validate,
+  type ValidatedOptions,
+  type IgnoreList,
+} from "./validation/options";
+
+const debug = buildDebug("babel:config:config-chain");
+
+import {
+  findBabelrc,
+  findBabelignore,
+  loadConfig,
+  type ConfigFile,
+} from "./files";
+
+import { makeWeakCache, makeStrongCache } from "./caching";
+
+import {
+  createCachedDescriptors,
+  createUncachedDescriptors,
+  type UnloadedDescriptor,
+  type OptionsAndDescriptors,
+  type ValidatedFile,
+} from "./config-descriptors";
+
+export type ConfigChain = {
+  plugins: Array<UnloadedDescriptor>,
+  presets: Array<UnloadedDescriptor>,
+  options: Array<ValidatedOptions>,
+};
+
+export type PresetInstance = {
+  options: ValidatedOptions,
+  alias: string,
+  dirname: string,
+};
+
+type ConfigContext = {
+  filename: string | null,
+  cwd: string,
+  envName: string,
+};
+
+type ConfigContextNamed = {
+  ...ConfigContext,
+  filename: string,
+};
+
+/**
+ * Build a config chain for a given preset.
+ */
+export const buildPresetChain = makeWeakCache(
+  ({ dirname, options, alias }: PresetInstance): ConfigChain => {
+    const result = createUncachedDescriptors(dirname, options, alias);
+    const { plugins, presets } = result;
+    return {
+      plugins: plugins(),
+      presets: presets(),
+      options: [normalizeOptions(result.options)],
+    };
+  },
+);
+
+/**
+ * Build a config chain for Babel's full root configuration.
+ */
+export function buildRootChain(
+  cwd: string,
+  opts: ValidatedOptions,
+  envName: string,
+): ConfigChain | null {
+  const context = {
+    filename: opts.filename ? path.resolve(cwd, opts.filename) : null,
+    cwd,
+    envName,
+  };
+
+  const programmaticChain = loadProgrammaticChain(
+    {
+      options: opts,
+      dirname: context.cwd,
+    },
+    context,
+  );
+  if (!programmaticChain) return null;
+
+  const fileChain = emptyChain();
+  // resolve all .babelrc files
+  if (opts.babelrc !== false && context.filename !== null) {
+    const filename = context.filename;
+    const babelrcFile = findBabelrc(filename, context.envName);
+    if (babelrcFile) {
+      const result = loadFileChain(babelrcFile, context);
+      if (!result) return null;
+
+      mergeChain(fileChain, result);
+    }
+
+    const babelignoreFile = findBabelignore(filename);
+    if (
+      babelignoreFile &&
+      shouldIgnore(
+        context,
+        babelignoreFile.ignore,
+        null,
+        babelignoreFile.dirname,
+      )
+    ) {
+      return null;
+    }
+  }
+
+  // Insert file chain in front so programmatic options have priority
+  // over configuration file chain items.
+  const chain = mergeChain(
+    mergeChain(emptyChain(), fileChain),
+    programmaticChain,
+  );
+
+  return {
+    plugins: dedupDescriptors(chain.plugins),
+    presets: dedupDescriptors(chain.presets),
+    options: chain.options.map(o => normalizeOptions(o)),
+  };
+}
+
+/**
+ * Build a config chain for just the programmatic options passed into Babel.
+ */
+const loadProgrammaticChain = makeChainWalker({
+  init: arg => arg,
+  root: input => buildRootDescriptors(input, "base", createCachedDescriptors),
+  env: (input, envName) =>
+    buildEnvDescriptors(input, "base", createCachedDescriptors, envName),
+});
+
+/**
+ * Build a config chain for a given file.
+ */
+const loadFileChain = makeChainWalker({
+  init: input => validateFile(input),
+  root: file => loadFileDescriptors(file),
+  env: (file, envName) => loadFileEnvDescriptors(file)(envName),
+});
+const validateFile = makeWeakCache((file: ConfigFile): ValidatedFile => ({
+  filepath: file.filepath,
+  dirname: file.dirname,
+  options: validate("file", file.options),
+}));
+const loadFileDescriptors = makeWeakCache((file: ValidatedFile) =>
+  buildRootDescriptors(file, file.filepath, createUncachedDescriptors),
+);
+const loadFileEnvDescriptors = makeWeakCache((file: ValidatedFile) =>
+  makeStrongCache((envName: string) =>
+    buildEnvDescriptors(
+      file,
+      file.filepath,
+      createUncachedDescriptors,
+      envName,
+    ),
+  ),
+);
+
+function buildRootDescriptors({ dirname, options }, alias, descriptors) {
+  return descriptors(dirname, options, alias);
+}
+
+function buildEnvDescriptors(
+  { dirname, options },
+  alias,
+  descriptors,
+  envName,
+) {
+  const opts = options.env && options.env[envName];
+  return opts ? descriptors(dirname, opts, `${alias}.env["${envName}"]`) : null;
+}
+
+function makeChainWalker<
+  ArgT,
+  InnerT: { options: ValidatedOptions, dirname: string },
+>({
+  init,
+  root,
+  env,
+}: {
+  init: ArgT => InnerT,
+  root: InnerT => OptionsAndDescriptors,
+  env: (InnerT, string) => OptionsAndDescriptors | null,
+}): (ArgT, ConfigContext, Set<ConfigFile> | void) => ConfigChain | null {
+  return (arg, context, files = new Set()) => {
+    const input = init(arg);
+
+    const { dirname } = input;
+
+    const flattenedConfigs = [];
+
+    const rootOpts = root(input);
+    flattenedConfigs.push(rootOpts);
+
+    const envOpts = env(input, context.envName);
+    if (envOpts) {
+      flattenedConfigs.push(envOpts);
+    }
+
+    // Process 'ignore' and 'only' before 'extends' items are processed so
+    // that we don't do extra work loading extended configs if a file is
+    // ignored.
+    if (
+      flattenedConfigs.some(({ options: { ignore, only } }) =>
+        shouldIgnore(context, ignore, only, dirname),
+      )
+    ) {
+      return null;
+    }
+
+    const chain = emptyChain();
+
+    for (const op of flattenedConfigs) {
+      if (!mergeExtendsChain(chain, op.options, dirname, context, files)) {
+        return null;
+      }
+
+      mergeChainOpts(chain, op);
+    }
+    return chain;
+  };
+}
+
+function mergeExtendsChain(
+  chain: ConfigChain,
+  opts: ValidatedOptions,
+  dirname: string,
+  context: ConfigContext,
+  files: Set<ConfigFile>,
+): boolean {
+  if (opts.extends === undefined) return true;
+
+  const file = loadConfig(opts.extends, dirname, context.envName);
+
+  if (files.has(file)) {
+    throw new Error(
+      `Configuration cycle detected loading ${file.filepath}.\n` +
+        `File already loaded following the config chain:\n` +
+        Array.from(files, file => ` - ${file.filepath}`).join("\n"),
+    );
+  }
+
+  files.add(file);
+  const fileChain = loadFileChain(file, context, files);
+  files.delete(file);
+
+  if (!fileChain) return false;
+
+  mergeChain(chain, fileChain);
+
+  return true;
+}
+
+function mergeChain(target: ConfigChain, source: ConfigChain): ConfigChain {
+  target.options.push(...source.options);
+  target.plugins.push(...source.plugins);
+  target.presets.push(...source.presets);
+
+  return target;
+}
+
+function mergeChainOpts(
+  target: ConfigChain,
+  { options, plugins, presets }: OptionsAndDescriptors,
+): ConfigChain {
+  target.options.push(options);
+  target.plugins.push(...plugins());
+  target.presets.push(...presets());
+
+  return target;
+}
+
+function emptyChain(): ConfigChain {
+  return {
+    options: [],
+    presets: [],
+    plugins: [],
+  };
+}
+
+function normalizeOptions(opts: ValidatedOptions): ValidatedOptions {
+  const options = Object.assign({}, opts);
+  delete options.extends;
+  delete options.env;
+  delete options.plugins;
+  delete options.presets;
+  delete options.passPerPreset;
+  delete options.ignore;
+  delete options.only;
+
+  // "sourceMap" is just aliased to sourceMap, so copy it over as
+  // we merge the options together.
+  if (options.sourceMap) {
+    options.sourceMaps = options.sourceMap;
+    delete options.sourceMap;
+  }
+  return options;
+}
+
+function dedupDescriptors(
+  items: Array<UnloadedDescriptor>,
+): Array<UnloadedDescriptor> {
+  const map: Map<
+    Function,
+    Map<string | void, { value: UnloadedDescriptor | null }>,
+  > = new Map();
+
+  const descriptors = [];
+
+  for (const item of items) {
+    if (typeof item.value === "function") {
+      const fnKey = item.value;
+      let nameMap = map.get(fnKey);
+      if (!nameMap) {
+        nameMap = new Map();
+        map.set(fnKey, nameMap);
+      }
+      let desc = nameMap.get(item.name);
+      if (!desc) {
+        desc = { value: null };
+        descriptors.push(desc);
+
+        // Treat passPerPreset presets as unique, skipping them
+        // in the merge processing steps.
+        if (!item.ownPass) nameMap.set(item.name, desc);
+      }
+
+      if (item.options === false) {
+        desc.value = null;
+      } else {
+        desc.value = item;
+      }
+    } else {
+      descriptors.push({ value: item });
+    }
+  }
+
+  return descriptors.reduce((acc, desc) => {
+    if (desc.value) acc.push(desc.value);
+    return acc;
+  }, []);
+}
+
+/**
+ * Tests if a filename should be ignored based on "ignore" and "only" options.
+ */
+function shouldIgnore(
+  context: ConfigContext,
+  ignore: ?IgnoreList,
+  only: ?IgnoreList,
+  dirname: string,
+): boolean {
+  if (context.filename === null) return false;
+  // $FlowIgnore - Flow refinements aren't quite smart enough for this :(
+  const ctx: ConfigContextNamed = context;
+
+  if (ignore) {
+    if (matchesPatterns(ctx, ignore, dirname)) {
+      debug(
+        "Ignored %o because it matched one of %O from %o",
+        context.filename,
+        ignore,
+        dirname,
+      );
+      return true;
+    }
+  }
+
+  if (only) {
+    if (!matchesPatterns(ctx, only, dirname)) {
+      debug(
+        "Ignored %o because it failed to match one of %O from %o",
+        context.filename,
+        only,
+        dirname,
+      );
+      return true;
+    }
+  }
+
+  return false;
+}
+
+/**
+ * Returns result of calling function with filename if pattern is a function.
+ * Otherwise returns result of matching pattern Regex with filename.
+ */
+function matchesPatterns(
+  context: ConfigContextNamed,
+  patterns: IgnoreList,
+  dirname: string,
+): boolean {
+  const res = [];
+  const strings = [];
+  const fns = [];
+
+  patterns.forEach(pattern => {
+    if (typeof pattern === "string") strings.push(pattern);
+    else if (typeof pattern === "function") fns.push(pattern);
+    else res.push(pattern);
+  });
+
+  const filename = context.filename;
+  if (res.some(re => re.test(context.filename))) return true;
+  if (fns.some(fn => fn(filename))) return true;
+
+  if (strings.length > 0) {
+    const possibleDirs = getPossibleDirs(context);
+
+    const absolutePatterns = strings.map(pattern => {
+      // Preserve the "!" prefix so that micromatch can use it for negation.
+      const negate = pattern[0] === "!";
+      if (negate) pattern = pattern.slice(1);
+
+      return (negate ? "!" : "") + path.resolve(dirname, pattern);
+    });
+
+    if (
+      micromatch(possibleDirs, absolutePatterns, { nocase: true }).length > 0
+    ) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+const getPossibleDirs = makeWeakCache((context: ConfigContextNamed) => {
+  let current = context.filename;
+  if (current === null) return [];
+
+  const possibleDirs = [current];
+  while (true) {
+    const previous = current;
+    current = path.dirname(current);
+    if (previous === current) break;
+
+    possibleDirs.push(current);
+  }
+
+  return possibleDirs;
+});
--- a/packages/babel-core/src/config/config-descriptors.js
+++ b/packages/babel-core/src/config/config-descriptors.js
@@ -0,0 +1,272 @@
+// @flow
+
+import { loadPlugin, loadPreset } from "./files";
+
+import {
+  makeWeakCache,
+  makeStrongCache,
+  type CacheConfigurator,
+} from "./caching";
+
+import type {
+  ValidatedOptions,
+  PluginList,
+  PluginItem,
+} from "./validation/options";
+
+// Represents a config object and functions to lazily load the descriptors
+// for the plugins and presets so we don't load the plugins/presets unless
+// the options object actually ends up being applicable.
+export type OptionsAndDescriptors = {
+  options: ValidatedOptions,
+  plugins: () => Array<UnloadedDescriptor>,
+  presets: () => Array<UnloadedDescriptor>,
+};
+
+// Represents a plugin or presets at a given location in a config object.
+// At this point these have been resolved to a specific object or function,
+// but have not yet been executed to call functions with options.
+export type UnloadedDescriptor = {
+  name: string | void,
+  value: {} | Function,
+  options: {} | void | false,
+  dirname: string,
+  alias: string,
+  ownPass?: boolean,
+};
+
+export type ValidatedFile = {
+  filepath: string,
+  dirname: string,
+  options: ValidatedOptions,
+};
+
+/**
+ * Create a set of descriptors from a given options object, preserving
+ * descriptor identity based on the identity of the plugin/preset arrays
+ * themselves.
+ */
+export function createCachedDescriptors(
+  dirname: string,
+  options: ValidatedOptions,
+  alias: string,
+): OptionsAndDescriptors {
+  const { plugins, presets, passPerPreset } = options;
+  return {
+    options,
+    plugins: plugins
+      ? () => createCachedPluginDescriptors(plugins, dirname)(alias)
+      : () => [],
+    presets: presets
+      ? () =>
+          createCachedPresetDescriptors(presets, dirname)(alias)(
+            !!passPerPreset,
+          )
+      : () => [],
+  };
+}
+
+/**
+ * Create a set of descriptors from a given options object, with consistent
+ * identity for the descriptors, but not caching based on any specific identity.
+ */
+export function createUncachedDescriptors(
+  dirname: string,
+  options: ValidatedOptions,
+  alias: string,
+): OptionsAndDescriptors {
+  // The returned result here is cached to represent a config object in
+  // memory, so we build and memoize the descriptors to ensure the same
+  // values are returned consistently.
+  let plugins;
+  let presets;
+
+  return {
+    options,
+    plugins: () => {
+      if (!plugins) {
+        plugins = createPluginDescriptors(
+          options.plugins || [],
+          dirname,
+          alias,
+        );
+      }
+      return plugins;
+    },
+    presets: () => {
+      if (!presets) {
+        presets = createPresetDescriptors(
+          options.presets || [],
+          dirname,
+          alias,
+          !!options.passPerPreset,
+        );
+      }
+      return presets;
+    },
+  };
+}
+
+const createCachedPresetDescriptors = makeWeakCache(
+  (items: PluginList, cache: CacheConfigurator<string>) => {
+    const dirname = cache.using(dir => dir);
+    return makeStrongCache((alias: string) =>
+      makeStrongCache((passPerPreset: boolean) =>
+        createPresetDescriptors(items, dirname, alias, passPerPreset),
+      ),
+    );
+  },
+);
+
+const createCachedPluginDescriptors = makeWeakCache(
+  (items: PluginList, cache: CacheConfigurator<string>) => {
+    const dirname = cache.using(dir => dir);
+    return makeStrongCache((alias: string) =>
+      createPluginDescriptors(items, dirname, alias),
+    );
+  },
+);
+
+function createPresetDescriptors(
+  items: PluginList,
+  dirname: string,
+  alias: string,
+  passPerPreset: boolean,
+): Array<UnloadedDescriptor> {
+  return createDescriptors("preset", items, dirname, alias, passPerPreset);
+}
+
+function createPluginDescriptors(
+  items: PluginList,
+  dirname: string,
+  alias: string,
+): Array<UnloadedDescriptor> {
+  return createDescriptors("plugin", items, dirname, alias);
+}
+
+function createDescriptors(
+  type: "plugin" | "preset",
+  items: PluginList,
+  dirname: string,
+  alias: string,
+  ownPass?: boolean,
+): Array<UnloadedDescriptor> {
+  const descriptors = items.map((item, index) =>
+    createDescriptor(
+      item,
+      type === "plugin" ? loadPlugin : loadPreset,
+      dirname,
+      {
+        index,
+        alias,
+        ownPass: !!ownPass,
+      },
+    ),
+  );
+
+  assertNoDuplicates(descriptors);
+
+  return descriptors;
+}
+
+/**
+ * Given a plugin/preset item, resolve it into a standard format.
+ */
+function createDescriptor(
+  pair: PluginItem,
+  resolver,
+  dirname,
+  {
+    index,
+    alias,
+    ownPass,
+  }: {
+    index: number,
+    alias: string,
+    ownPass?: boolean,
+  },
+): UnloadedDescriptor {
+  let name;
+  let options;
+  let value = pair;
+  if (Array.isArray(value)) {
+    if (value.length === 3) {
+      // $FlowIgnore - Flow doesn't like the multiple tuple types.
+      [value, options, name] = value;
+    } else {
+      [value, options] = value;
+    }
+  }
+
+  let filepath = null;
+  if (typeof value === "string") {
+    ({ filepath, value } = resolver(value, dirname));
+  }
+
+  if (!value) {
+    throw new Error(`Unexpected falsy value: ${String(value)}`);
+  }
+
+  if (typeof value === "object" && value.__esModule) {
+    if (value.default) {
+      value = value.default;
+    } else {
+      throw new Error("Must export a default export when using ES6 modules.");
+    }
+  }
+
+  if (typeof value !== "object" && typeof value !== "function") {
+    throw new Error(
+      `Unsupported format: ${typeof value}. Expected an object or a function.`,
+    );
+  }
+
+  if (filepath !== null && typeof value === "object" && value) {
+    // We allow object values for plugins/presets nested directly within a
+    // config object, because it can be useful to define them in nested
+    // configuration contexts.
+    throw new Error(
+      "Plugin/Preset files are not allowed to export objects, only functions.",
+    );
+  }
+
+  return {
+    name,
+    alias: filepath || `${alias}$${index}`,
+    value,
+    options,
+    dirname,
+    ownPass,
+  };
+}
+
+function assertNoDuplicates(items: Array<UnloadedDescriptor>): void {
+  const map = new Map();
+
+  for (const item of items) {
+    if (typeof item.value !== "function") continue;
+
+    let nameMap = map.get(item.value);
+    if (!nameMap) {
+      nameMap = new Set();
+      map.set(item.value, nameMap);
+    }
+
+    if (nameMap.has(item.name)) {
+      throw new Error(
+        [
+          `Duplicate plugin/preset detected.`,
+          `If you'd like to use two separate instances of a plugin,`,
+          `they neen separate names, e.g.`,
+          ``,
+          `  plugins: [`,
+          `    ['some-plugin', {}],`,
+          `    ['some-plugin', {}, 'some unique name'],`,
+          `  ]`,
+        ].join("\n"),
+      );
+    }
+
+    nameMap.add(item.name);
+  }
+}
--- a/packages/babel-core/src/config/loading/files/configuration.js
+++ b/packages/babel-core/src/config/loading/files/configuration.js
@@ -5,7 +5,7 @@ import path from "path";
 import fs from "fs";
 import json5 from "json5";
 import resolve from "resolve";
-import { makeStrongCache, type CacheConfigurator } from "../../caching";
+import { makeStrongCache, type CacheConfigurator } from "../caching";

 const debug = buildDebug("babel:config:loading:files:configuration");

@@ -15,68 +15,75 @@ export type ConfigFile = {
  options: {},
 };

+export type IgnoreFile = {
+  filepath: string,
+  dirname: string,
+  ignore: Array<string>,
+};
+
 const BABELRC_FILENAME = ".babelrc";
 const BABELRC_JS_FILENAME = ".babelrc.js";
 const PACKAGE_FILENAME = "package.json";
 const BABELIGNORE_FILENAME = ".babelignore";

-export function findConfigs(
-  dirname: string,
+export function findBabelrc(
+  filepath: string,
  envName: string,
-): Array<ConfigFile> {
-  let foundConfig = false;
-  let foundIgnore = false;
-
-  const confs = [];
-
+): ConfigFile | null {
+  const dirname = path.dirname(filepath);
  let loc = dirname;
  while (true) {
-    if (!foundIgnore) {
-      const ignoreLoc = path.join(loc, BABELIGNORE_FILENAME);
-      const ignore = readIgnoreConfig(ignoreLoc);
+    const conf = [
+      BABELRC_FILENAME,
+      BABELRC_JS_FILENAME,
+      PACKAGE_FILENAME,
+    ].reduce((previousConfig: ConfigFile | null, name) => {
+      const filepath = path.join(loc, name);
+      const config = readConfig(filepath, envName);

-      if (ignore) {
-        debug("Found ignore %o from %o.", ignore.filepath, dirname);
-        confs.push(ignore);
-        foundIgnore = true;
+      if (config && previousConfig) {
+        throw new Error(
+          `Multiple configuration files found. Please remove one:\n` +
+            ` - ${path.basename(previousConfig.filepath)}\n` +
+            ` - ${name}\n` +
+            `from ${loc}`,
+        );
      }
+
+      return config || previousConfig;
+    }, null);
+
+    if (conf) {
+      debug("Found configuration %o from %o.", conf.filepath, dirname);
+      return conf;
    }

-    if (!foundConfig) {
-      const conf = [
-        BABELRC_FILENAME,
-        BABELRC_JS_FILENAME,
-        PACKAGE_FILENAME,
-      ].reduce((previousConfig: ConfigFile | null, name) => {
-        const filepath = path.join(loc, name);
-        const config = readConfig(filepath, envName);
-
-        if (config && previousConfig) {
-          throw new Error(
-            `Multiple configuration files found. Please remove one:\n- ${path.basename(
-              previousConfig.filepath,
-            )}\n- ${name}\nfrom ${loc}`,
-          );
-        }
-
-        return config || previousConfig;
-      }, null);
-
-      if (conf) {
-        debug("Found configuration %o from %o.", conf.filepath, dirname);
-        confs.push(conf);
-        foundConfig = true;
-      }
-    }
-
-    if (foundIgnore && foundConfig) break;
-
-    if (loc === path.dirname(loc)) break;
-
-    loc = path.dirname(loc);
+    const nextLoc = path.dirname(loc);
+    if (loc === nextLoc) break;
+    loc = nextLoc;
  }

-  return confs;
+  return null;
+}
+
+export function findBabelignore(filepath: string): IgnoreFile | null {
+  const dirname = path.dirname(filepath);
+  let loc = dirname;
+  while (true) {
+    const ignoreLoc = path.join(loc, BABELIGNORE_FILENAME);
+    const ignore = readIgnoreConfig(ignoreLoc);
+
+    if (ignore) {
+      debug("Found ignore %o from %o.", ignore.filepath, dirname);
+      return ignore;
+    }
+
+    const nextLoc = path.dirname(loc);
+    if (loc === nextLoc) break;
+    loc = nextLoc;
+  }
+
+  return null;
 }

 export function loadConfig(
@@ -224,7 +231,7 @@ const readIgnoreConfig = makeStaticFileCache((filepath, content) => {
  return {
    filepath,
    dirname: path.dirname(filepath),
-    options: { ignore },
+    ignore,
  };
 });

--- a/packages/babel-core/src/config/loading/files/index-browser.js
+++ b/packages/babel-core/src/config/loading/files/index-browser.js
@@ -6,9 +6,22 @@ export type ConfigFile = {
  options: {},
 };

+export type IgnoreFile = {
+  filepath: string,
+  dirname: string,
+  ignore: Array<string>,
+};
+
+export function findBabelrc(
+  filepath: string,
+  envName: string, // eslint-disable-line no-unused-vars
+): ConfigFile | null {
+  return null;
+}
+
 // eslint-disable-next-line no-unused-vars
-export function findConfigs(dirname: string): Array<ConfigFile> {
-  return [];
+export function findBabelignore(filepath: string): IgnoreFile | null {
+  return null;
 }

 export function loadConfig(name: string, dirname: string): ConfigFile {
--- a/packages/babel-core/src/config/loading/files/index.js
+++ b/packages/babel-core/src/config/loading/files/index.js
--- a/packages/babel-core/src/config/loading/files/plugins.js
+++ b/packages/babel-core/src/config/loading/files/plugins.js
--- a/packages/babel-core/src/config/index.js
+++ b/packages/babel-core/src/config/index.js
@@ -1,9 +1,31 @@
 // @flow

-import type Plugin from "./plugin";
-import manageOptions from "./option-manager";
+import path from "path";
+import * as context from "../index";
+import Plugin from "./plugin";
+import merge from "lodash/merge";
+import {
+  buildRootChain,
+  buildPresetChain,
+  type ConfigChain,
+  type PresetInstance,
+} from "./config-chain";
+import type { UnloadedDescriptor } from "./config-descriptors";
+import traverse from "@babel/traverse";
+import clone from "lodash/clone";
+import { makeWeakCache, type CacheConfigurator } from "./caching";
+import { getEnv } from "./helpers/environment";
+import { validate } from "./validation/options";
+import { validatePluginObject } from "./validation/plugins";

-export type { InputOptions } from "./options";
+type LoadedDescriptor = {
+  value: {},
+  options: {},
+  dirname: string,
+  alias: string,
+};
+
+export type { InputOptions } from "./validation/options";

 export type ResolvedConfig = {
  options: Object,
@@ -14,13 +36,257 @@ export type { Plugin };
 export type PluginPassList = Array<Plugin>;
 export type PluginPasses = Array<PluginPassList>;

-/**
- * Standard API for loading Babel configuration data. Not for public consumption.
- */
-export default function loadConfig(opts: mixed): ResolvedConfig | null {
-  if (opts != null && (typeof opts !== "object" || Array.isArray(opts))) {
+export default function loadConfig(inputOpts: mixed): ResolvedConfig | null {
+  if (
+    inputOpts != null &&
+    (typeof inputOpts !== "object" || Array.isArray(inputOpts))
+  ) {
    throw new Error("Babel options must be an object, null, or undefined");
  }

-  return manageOptions(opts || {});
+  const args = inputOpts ? validate("arguments", inputOpts) : {};
+
+  const { envName = getEnv(), cwd = "." } = args;
+  const absoluteCwd = path.resolve(cwd);
+
+  const configChain = buildRootChain(absoluteCwd, args, envName);
+  if (!configChain) return null;
+
+  const optionDefaults = {};
+  const options = {};
+  const passes = [[]];
+  try {
+    (function recurseDescriptors(
+      config: {
+        plugins: Array<UnloadedDescriptor>,
+        presets: Array<UnloadedDescriptor>,
+      },
+      pass: Array<Plugin>,
+      envName: string,
+    ) {
+      const plugins = config.plugins.map(descriptor =>
+        loadPluginDescriptor(descriptor, envName),
+      );
+      const presets = config.presets.map(descriptor => {
+        return {
+          preset: loadPresetDescriptor(descriptor, envName),
+          pass: descriptor.ownPass ? [] : pass,
+        };
+      });
+
+      // resolve presets
+      if (presets.length > 0) {
+        // The passes are created in the same order as the preset list, but are inserted before any
+        // existing additional passes.
+        passes.splice(
+          1,
+          0,
+          ...presets.map(o => o.pass).filter(p => p !== pass),
+        );
+
+        for (const { preset, pass } of presets) {
+          recurseDescriptors(
+            {
+              plugins: preset.plugins,
+              presets: preset.presets,
+            },
+            pass,
+            envName,
+          );
+
+          preset.options.forEach(opts => {
+            merge(optionDefaults, opts);
+          });
+        }
+      }
+
+      // resolve plugins
+      if (plugins.length > 0) {
+        pass.unshift(...plugins);
+      }
+    })(
+      {
+        plugins: configChain.plugins,
+        presets: configChain.presets,
+      },
+      passes[0],
+      envName,
+    );
+
+    configChain.options.forEach(opts => {
+      merge(options, opts);
+    });
+  } catch (e) {
+    // There are a few case where thrown errors will try to annotate themselves multiple times, so
+    // to keep things simple we just bail out if re-wrapping the message.
+    if (!/^\[BABEL\]/.test(e.message)) {
+      e.message = `[BABEL] ${args.filename || "unknown"}: ${e.message}`;
+    }
+
+    throw e;
+  }
+
+  const opts: Object = merge(optionDefaults, options);
+
+  // Tack the passes onto the object itself so that, if this object is passed back to Babel a second time,
+  // it will be in the right structure to not change behavior.
+  opts.babelrc = false;
+  opts.plugins = passes[0];
+  opts.presets = passes
+    .slice(1)
+    .filter(plugins => plugins.length > 0)
+    .map(plugins => ({ plugins }));
+  opts.passPerPreset = opts.presets.length > 0;
+  opts.envName = envName;
+  opts.cwd = absoluteCwd;
+
+  return {
+    options: opts,
+    passes: passes,
+  };
+}
+
+/**
+ * Load a generic plugin/preset from the given descriptor loaded from the config object.
+ */
+const loadDescriptor = makeWeakCache(
+  (
+    { value, options, dirname, alias }: UnloadedDescriptor,
+    cache: CacheConfigurator<{ envName: string }>,
+  ): LoadedDescriptor => {
+    // Disabled presets should already have been filtered out
+    if (options === false) throw new Error("Assertion failure");
+
+    options = options || {};
+
+    let item = value;
+    if (typeof value === "function") {
+      const api = Object.assign(Object.create(context), {
+        cache: cache.simple(),
+        env: () => cache.using(data => data.envName),
+        async: () => false,
+      });
+
+      try {
+        item = value(api, options, dirname);
+      } catch (e) {
+        if (alias) {
+          e.message += ` (While processing: ${JSON.stringify(alias)})`;
+        }
+        throw e;
+      }
+    }
+
+    if (!item || typeof item !== "object") {
+      throw new Error("Plugin/Preset did not return an object.");
+    }
+
+    if (typeof item.then === "function") {
+      throw new Error(
+        `You appear to be using an async plugin, ` +
+          `which your current version of Babel does not support.` +
+          `If you're using a published plugin, ` +
+          `you may need to upgrade your @babel/core version.`,
+      );
+    }
+
+    return { value: item, options, dirname, alias };
+  },
+);
+
+/**
+ * Instantiate a plugin for the given descriptor, returning the plugin/options pair.
+ */
+function loadPluginDescriptor(
+  descriptor: UnloadedDescriptor,
+  envName: string,
+): Plugin {
+  if (descriptor.value instanceof Plugin) {
+    if (descriptor.options) {
+      throw new Error(
+        "Passed options to an existing Plugin instance will not work.",
+      );
+    }
+
+    return descriptor.value;
+  }
+
+  return instantiatePlugin(loadDescriptor(descriptor, { envName }), {
+    envName,
+  });
+}
+
+const instantiatePlugin = makeWeakCache(
+  (
+    { value, options, dirname, alias }: LoadedDescriptor,
+    cache: CacheConfigurator<{ envName: string }>,
+  ): Plugin => {
+    const pluginObj = validatePluginObject(value);
+
+    const plugin = Object.assign({}, pluginObj);
+    if (plugin.visitor) {
+      plugin.visitor = traverse.explode(clone(plugin.visitor));
+    }
+
+    if (plugin.inherits) {
+      const inheritsDescriptor = {
+        name: undefined,
+        alias: `${alias}$inherits`,
+        value: plugin.inherits,
+        options,
+        dirname,
+      };
+
+      // If the inherited plugin changes, reinstantiate this plugin.
+      const inherits = cache.invalidate(data =>
+        loadPluginDescriptor(inheritsDescriptor, data.envName),
+      );
+
+      plugin.pre = chain(inherits.pre, plugin.pre);
+      plugin.post = chain(inherits.post, plugin.post);
+      plugin.manipulateOptions = chain(
+        inherits.manipulateOptions,
+        plugin.manipulateOptions,
+      );
+      plugin.visitor = traverse.visitors.merge([
+        inherits.visitor || {},
+        plugin.visitor || {},
+      ]);
+    }
+
+    return new Plugin(plugin, options, alias);
+  },
+);
+
+/**
+ * Generate a config object that will act as the root of a new nested config.
+ */
+const loadPresetDescriptor = (
+  descriptor: UnloadedDescriptor,
+  envName: string,
+): ConfigChain => {
+  return buildPresetChain(
+    instantiatePreset(loadDescriptor(descriptor, { envName })),
+  );
+};
+
+const instantiatePreset = makeWeakCache(
+  ({ value, dirname, alias }: LoadedDescriptor): PresetInstance => {
+    return {
+      options: validate("preset", value),
+      alias,
+      dirname,
+    };
+  },
+);
+
+function chain(a, b) {
+  const fns = [a, b].filter(Boolean);
+  if (fns.length <= 1) return fns[0];
+
+  return function(...args) {
+    for (const fn of fns) {
+      fn.apply(this, args);
+    }
+  };
 }
--- a/packages/babel-core/src/config/option-manager.js
+++ b/packages/babel-core/src/config/option-manager.js
@@ -1,535 +0,0 @@
-// @flow
-
-import path from "path";
-import * as context from "../index";
-import Plugin, { validatePluginObject } from "./plugin";
-import merge from "lodash/merge";
-import buildConfigChain, { type ConfigItem } from "./build-config-chain";
-import traverse from "@babel/traverse";
-import clone from "lodash/clone";
-import { makeWeakCache, type CacheConfigurator } from "./caching";
-import { getEnv } from "./helpers/environment";
-import { validate, type ValidatedOptions, type PluginItem } from "./options";
-
-import { loadPlugin, loadPreset } from "./loading/files";
-
-type MergeOptions =
-  | ConfigItem
-  | {
-      type: "preset",
-      options: ValidatedOptions,
-      alias: string,
-      dirname: string,
-    };
-
-export default function manageOptions(opts: {}): {
-  options: Object,
-  passes: Array<Array<Plugin>>,
-} | null {
-  return new OptionManager().init(opts);
-}
-
-class OptionManager {
-  optionDefaults: ValidatedOptions = {};
-  options: ValidatedOptions = {};
-  passes: Array<Array<Plugin>> = [[]];
-
-  /**
-   * This is called when we want to merge the input `opts` into the
-   * base options.
-   *
-   *  - `alias` is used to output pretty traces back to the original source.
-   *  - `loc` is used to point to the original config.
-   *  - `dirname` is used to resolve plugins relative to it.
-   */
-  mergeOptions(
-    config: {
-      plugins: Array<BasicDescriptor>,
-      presets: Array<BasicDescriptor>,
-    },
-    pass: Array<Plugin>,
-    envName: string,
-  ) {
-    const plugins = config.plugins.map(descriptor =>
-      loadPluginDescriptor(descriptor, envName),
-    );
-    const presets = config.presets.map(descriptor => {
-      return {
-        preset: loadPresetDescriptor(descriptor, envName),
-        pass: descriptor.ownPass ? [] : pass,
-      };
-    });
-
-    // resolve presets
-    if (presets.length > 0) {
-      // The passes are created in the same order as the preset list, but are inserted before any
-      // existing additional passes.
-      this.passes.splice(
-        1,
-        0,
-        ...presets.map(o => o.pass).filter(p => p !== pass),
-      );
-
-      presets.forEach(({ preset, pass }) => {
-        const loadedConfig = loadConfig(preset);
-        this.mergeOptions(
-          {
-            // Call dedupDescriptors() to remove 'false' descriptors.
-            plugins: dedupDescriptors(loadedConfig.plugins),
-            presets: dedupDescriptors(loadedConfig.presets),
-          },
-          pass,
-          envName,
-        );
-
-        merge(this.optionDefaults, normalizeOptions(loadedConfig.options));
-      });
-    }
-
-    // resolve plugins
-    if (plugins.length > 0) {
-      pass.unshift(...plugins);
-    }
-  }
-
-  mergeConfigChain(chain: $ReadOnlyArray<MergeOptions>, envName: string) {
-    const config = dedupLoadedConfigs(chain.map(config => loadConfig(config)));
-
-    this.mergeOptions(
-      {
-        plugins: config.plugins,
-        presets: config.presets,
-      },
-      this.passes[0],
-      envName,
-    );
-
-    config.options.forEach(opts => {
-      merge(this.options, normalizeOptions(opts));
-    });
-  }
-
-  init(inputOpts: {}) {
-    const args = validate("arguments", inputOpts);
-
-    const { envName = getEnv(), cwd = "." } = args;
-    const absoluteCwd = path.resolve(cwd);
-
-    const configChain = buildConfigChain(absoluteCwd, args, envName);
-    if (!configChain) return null;
-
-    try {
-      this.mergeConfigChain(configChain, envName);
-    } catch (e) {
-      // There are a few case where thrown errors will try to annotate themselves multiple times, so
-      // to keep things simple we just bail out if re-wrapping the message.
-      if (!/^\[BABEL\]/.test(e.message)) {
-        e.message = `[BABEL] ${args.filename || "unknown"}: ${e.message}`;
-      }
-
-      throw e;
-    }
-
-    const opts: Object = merge(this.optionDefaults, this.options);
-
-    // Tack the passes onto the object itself so that, if this object is passed back to Babel a second time,
-    // it will be in the right structure to not change behavior.
-    opts.babelrc = false;
-    opts.plugins = this.passes[0];
-    opts.presets = this.passes
-      .slice(1)
-      .filter(plugins => plugins.length > 0)
-      .map(plugins => ({ plugins }));
-    opts.passPerPreset = opts.presets.length > 0;
-    opts.envName = envName;
-    opts.cwd = absoluteCwd;
-
-    return {
-      options: opts,
-      passes: this.passes,
-    };
-  }
-}
-
-function normalizeOptions(opts: ValidatedOptions): ValidatedOptions {
-  const options = Object.assign({}, opts);
-  delete options.extends;
-  delete options.env;
-  delete options.plugins;
-  delete options.presets;
-  delete options.passPerPreset;
-  delete options.ignore;
-  delete options.only;
-
-  // "sourceMap" is just aliased to sourceMap, so copy it over as
-  // we merge the options together.
-  if (options.sourceMap) {
-    options.sourceMaps = options.sourceMap;
-    delete options.sourceMap;
-  }
-  return options;
-}
-
-type BasicDescriptor = {
-  name: string | void,
-  value: {} | Function,
-  options: {} | void | false,
-  dirname: string,
-  alias: string,
-  ownPass?: boolean,
-};
-
-type LoadedDescriptor = {
-  value: {},
-  options: {},
-  dirname: string,
-  alias: string,
-};
-
-type LoadedConfig = {
-  options: ValidatedOptions,
-  plugins: Array<BasicDescriptor>,
-  presets: Array<BasicDescriptor>,
-};
-
-/**
- * Load and validate the given config into a set of options, plugins, and presets.
- */
-const loadConfig = makeWeakCache((config: MergeOptions): LoadedConfig => {
-  const options = config.options;
-
-  const plugins = (config.options.plugins || []).map((plugin, index) =>
-    createDescriptor(plugin, loadPlugin, config.dirname, {
-      index,
-      alias: config.alias,
-    }),
-  );
-
-  assertNoDuplicates(plugins);
-
-  const presets = (config.options.presets || []).map((preset, index) =>
-    createDescriptor(preset, loadPreset, config.dirname, {
-      index,
-      alias: config.alias,
-      ownPass: options.passPerPreset,
-    }),
-  );
-
-  assertNoDuplicates(presets);
-
-  return { options, plugins, presets };
-});
-
-function assertNoDuplicates(items: Array<BasicDescriptor>): void {
-  const map = new Map();
-
-  for (const item of items) {
-    if (typeof item.value !== "function") continue;
-
-    let nameMap = map.get(item.value);
-    if (!nameMap) {
-      nameMap = new Set();
-      map.set(item.value, nameMap);
-    }
-
-    if (nameMap.has(item.name)) {
-      throw new Error(
-        [
-          `Duplicate plugin/preset detected.`,
-          `If you'd like to use two separate instances of a plugin,`,
-          `they neen separate names, e.g.`,
-          ``,
-          `  plugins: [`,
-          `    ['some-plugin', {}],`,
-          `    ['some-plugin', {}, 'some unique name'],`,
-          `  ]`,
-        ].join("\n"),
-      );
-    }
-
-    nameMap.add(item.name);
-  }
-}
-
-function dedupLoadedConfigs(
-  items: Array<LoadedConfig>,
-): {
-  plugins: Array<BasicDescriptor>,
-  presets: Array<BasicDescriptor>,
-  options: Array<ValidatedOptions>,
-} {
-  const options = [];
-  const plugins = [];
-  const presets = [];
-
-  for (const item of items) {
-    plugins.push(...item.plugins);
-    presets.push(...item.presets);
-    options.push(item.options);
-  }
-
-  return {
-    options,
-    plugins: dedupDescriptors(plugins),
-    presets: dedupDescriptors(presets),
-  };
-}
-
-function dedupDescriptors(
-  items: Array<BasicDescriptor>,
-): Array<BasicDescriptor> {
-  const map: Map<
-    Function,
-    Map<string | void, { value: BasicDescriptor | null }>,
-  > = new Map();
-
-  const descriptors = [];
-
-  for (const item of items) {
-    if (typeof item.value === "function") {
-      const fnKey = item.value;
-      let nameMap = map.get(fnKey);
-      if (!nameMap) {
-        nameMap = new Map();
-        map.set(fnKey, nameMap);
-      }
-      let desc = nameMap.get(item.name);
-      if (!desc) {
-        desc = { value: null };
-        descriptors.push(desc);
-
-        // Treat passPerPreset presets as unique, skipping them
-        // in the merge processing steps.
-        if (!item.ownPass) nameMap.set(item.name, desc);
-      }
-
-      if (item.options === false) {
-        desc.value = null;
-      } else {
-        desc.value = item;
-      }
-    } else {
-      descriptors.push({ value: item });
-    }
-  }
-
-  return descriptors.reduce((acc, desc) => {
-    if (desc.value) acc.push(desc.value);
-    return acc;
-  }, []);
-}
-
-/**
- * Load a generic plugin/preset from the given descriptor loaded from the config object.
- */
-const loadDescriptor = makeWeakCache(
-  (
-    { value, options, dirname, alias }: BasicDescriptor,
-    cache: CacheConfigurator<{ envName: string }>,
-  ): LoadedDescriptor => {
-    // Disabled presets should already have been filtered out
-    if (options === false) throw new Error("Assertion failure");
-
-    options = options || {};
-
-    let item = value;
-    if (typeof value === "function") {
-      const api = Object.assign(Object.create(context), {
-        cache: cache.simple(),
-        env: () => cache.using(data => data.envName),
-        async: () => false,
-      });
-
-      try {
-        item = value(api, options, dirname);
-      } catch (e) {
-        if (alias) {
-          e.message += ` (While processing: ${JSON.stringify(alias)})`;
-        }
-        throw e;
-      }
-    }
-
-    if (!item || typeof item !== "object") {
-      throw new Error("Plugin/Preset did not return an object.");
-    }
-
-    if (typeof item.then === "function") {
-      throw new Error(
-        `You appear to be using an async plugin, ` +
-          `which your current version of Babel does not support.` +
-          `If you're using a published plugin, ` +
-          `you may need to upgrade your @babel/core version.`,
-      );
-    }
-
-    return { value: item, options, dirname, alias };
-  },
-);
-
-/**
- * Instantiate a plugin for the given descriptor, returning the plugin/options pair.
- */
-function loadPluginDescriptor(
-  descriptor: BasicDescriptor,
-  envName: string,
-): Plugin {
-  if (descriptor.value instanceof Plugin) {
-    if (descriptor.options) {
-      throw new Error(
-        "Passed options to an existing Plugin instance will not work.",
-      );
-    }
-
-    return descriptor.value;
-  }
-
-  return instantiatePlugin(loadDescriptor(descriptor, { envName }), {
-    envName,
-  });
-}
-
-const instantiatePlugin = makeWeakCache(
-  (
-    { value, options, dirname, alias }: LoadedDescriptor,
-    cache: CacheConfigurator<{ envName: string }>,
-  ): Plugin => {
-    const pluginObj = validatePluginObject(value);
-
-    const plugin = Object.assign({}, pluginObj);
-    if (plugin.visitor) {
-      plugin.visitor = traverse.explode(clone(plugin.visitor));
-    }
-
-    if (plugin.inherits) {
-      const inheritsDescriptor = {
-        name: undefined,
-        alias: `${alias}$inherits`,
-        value: plugin.inherits,
-        options,
-        dirname,
-      };
-
-      // If the inherited plugin changes, reinstantiate this plugin.
-      const inherits = cache.invalidate(data =>
-        loadPluginDescriptor(inheritsDescriptor, data.envName),
-      );
-
-      plugin.pre = chain(inherits.pre, plugin.pre);
-      plugin.post = chain(inherits.post, plugin.post);
-      plugin.manipulateOptions = chain(
-        inherits.manipulateOptions,
-        plugin.manipulateOptions,
-      );
-      plugin.visitor = traverse.visitors.merge([
-        inherits.visitor || {},
-        plugin.visitor || {},
-      ]);
-    }
-
-    return new Plugin(plugin, options, alias);
-  },
-);
-
-/**
- * Generate a config object that will act as the root of a new nested config.
- */
-const loadPresetDescriptor = (
-  descriptor: BasicDescriptor,
-  envName: string,
-): MergeOptions => {
-  return instantiatePreset(loadDescriptor(descriptor, { envName }));
-};
-
-const instantiatePreset = makeWeakCache(
-  ({ value, dirname, alias }: LoadedDescriptor): MergeOptions => {
-    return {
-      type: "preset",
-      options: validate("preset", value),
-      alias,
-      dirname,
-    };
-  },
-);
-
-/**
- * Given a plugin/preset item, resolve it into a standard format.
- */
-function createDescriptor(
-  pair: PluginItem,
-  resolver,
-  dirname,
-  {
-    index,
-    alias,
-    ownPass,
-  }: {
-    index: number,
-    alias: string,
-    ownPass?: boolean,
-  },
-): BasicDescriptor {
-  let name;
-  let options;
-  let value = pair;
-  if (Array.isArray(value)) {
-    if (value.length === 3) {
-      // $FlowIgnore - Flow doesn't like the multiple tuple types.
-      [value, options, name] = value;
-    } else {
-      [value, options] = value;
-    }
-  }
-
-  let filepath = null;
-  if (typeof value === "string") {
-    ({ filepath, value } = resolver(value, dirname));
-  }
-
-  if (!value) {
-    throw new Error(`Unexpected falsy value: ${String(value)}`);
-  }
-
-  if (typeof value === "object" && value.__esModule) {
-    if (value.default) {
-      value = value.default;
-    } else {
-      throw new Error("Must export a default export when using ES6 modules.");
-    }
-  }
-
-  if (typeof value !== "object" && typeof value !== "function") {
-    throw new Error(
-      `Unsupported format: ${typeof value}. Expected an object or a function.`,
-    );
-  }
-
-  if (filepath !== null && typeof value === "object" && value) {
-    // We allow object values for plugins/presets nested directly within a
-    // config object, because it can be useful to define them in nested
-    // configuration contexts.
-    throw new Error(
-      "Plugin/Preset files are not allowed to export objects, only functions.",
-    );
-  }
-
-  return {
-    name,
-    alias: filepath || `${alias}$${index}`,
-    value,
-    options,
-    dirname,
-    ownPass,
-  };
-}
-
-function chain(a, b) {
-  const fns = [a, b].filter(Boolean);
-  if (fns.length <= 1) return fns[0];
-
-  return function(...args) {
-    for (const fn of fns) {
-      fn.apply(this, args);
-    }
-  };
-}
--- a/packages/babel-core/src/config/plugin.js
+++ b/packages/babel-core/src/config/plugin.js
@@ -1,100 +1,6 @@
 // @flow

-import {
-  assertString,
-  assertFunction,
-  assertObject,
-  type ValidatorSet,
-  type Validator,
-} from "./option-assertions";
-
-// Note: The casts here are just meant to be static assertions to make sure
-// that the assertion functions actually assert that the value's type matches
-// the declared types.
-const VALIDATORS: ValidatorSet = {
-  name: (assertString: Validator<$PropertyType<PluginObject, "name">>),
-  manipulateOptions: (assertFunction: Validator<
-    $PropertyType<PluginObject, "manipulateOptions">,
-  >),
-  pre: (assertFunction: Validator<$PropertyType<PluginObject, "pre">>),
-  post: (assertFunction: Validator<$PropertyType<PluginObject, "post">>),
-  inherits: (assertFunction: Validator<
-    $PropertyType<PluginObject, "inherits">,
-  >),
-  visitor: (assertVisitorMap: Validator<
-    $PropertyType<PluginObject, "visitor">,
-  >),
-
-  parserOverride: (assertFunction: Validator<
-    $PropertyType<PluginObject, "parserOverride">,
-  >),
-  generatorOverride: (assertFunction: Validator<
-    $PropertyType<PluginObject, "generatorOverride">,
-  >),
-};
-
-function assertVisitorMap(key: string, value: mixed): VisitorMap {
-  const obj = assertObject(key, value);
-  if (obj) {
-    Object.keys(obj).forEach(prop => assertVisitorHandler(prop, obj[prop]));
-
-    if (obj.enter || obj.exit) {
-      throw new Error(
-        `.${key} cannot contain catch-all "enter" or "exit" handlers. Please target individual nodes.`,
-      );
-    }
-  }
-  return (obj: any);
-}
-
-function assertVisitorHandler(
-  key: string,
-  value: mixed,
-): VisitorHandler | void {
-  if (value && typeof value === "object") {
-    Object.keys(value).forEach(handler => {
-      if (handler !== "enter" && handler !== "exit") {
-        throw new Error(
-          `.visitor["${key}"] may only have .enter and/or .exit handlers.`,
-        );
-      }
-    });
-  } else if (typeof value !== "function") {
-    throw new Error(`.visitor["${key}"] must be a function`);
-  }
-
-  return (value: any);
-}
-
-type VisitorHandler = Function | { enter?: Function, exit?: Function };
-export type VisitorMap = {
-  [string]: VisitorHandler,
-};
-
-export type PluginObject = {
-  name?: string,
-  manipulateOptions?: Function,
-
-  pre?: Function,
-  post?: Function,
-
-  inherits?: Function,
-  visitor?: VisitorMap,
-
-  parserOverride?: Function,
-  generatorOverride?: Function,
-};
-
-export function validatePluginObject(obj: {}): PluginObject {
-  Object.keys(obj).forEach(key => {
-    const validator = VALIDATORS[key];
-
-    if (validator) validator(key, obj[key]);
-    else throw new Error(`.${key} is not a valid Plugin property`);
-  });
-
-  return (obj: any);
-}
+import type { PluginObject } from "./validation/plugins";

 export default class Plugin {
  key: ?string;
--- a/packages/babel-core/src/config/validation/option-assertions.js
+++ b/packages/babel-core/src/config/validation/option-assertions.js
--- a/packages/babel-core/src/config/validation/options.js
+++ b/packages/babel-core/src/config/validation/options.js
--- a/packages/babel-core/src/config/validation/plugins.js
+++ b/packages/babel-core/src/config/validation/plugins.js
@@ -0,0 +1,95 @@
+import {
+  assertString,
+  assertFunction,
+  assertObject,
+  type ValidatorSet,
+  type Validator,
+} from "./option-assertions";
+
+// Note: The casts here are just meant to be static assertions to make sure
+// that the assertion functions actually assert that the value's type matches
+// the declared types.
+const VALIDATORS: ValidatorSet = {
+  name: (assertString: Validator<$PropertyType<PluginObject, "name">>),
+  manipulateOptions: (assertFunction: Validator<
+    $PropertyType<PluginObject, "manipulateOptions">,
+  >),
+  pre: (assertFunction: Validator<$PropertyType<PluginObject, "pre">>),
+  post: (assertFunction: Validator<$PropertyType<PluginObject, "post">>),
+  inherits: (assertFunction: Validator<
+    $PropertyType<PluginObject, "inherits">,
+  >),
+  visitor: (assertVisitorMap: Validator<
+    $PropertyType<PluginObject, "visitor">,
+  >),
+
+  parserOverride: (assertFunction: Validator<
+    $PropertyType<PluginObject, "parserOverride">,
+  >),
+  generatorOverride: (assertFunction: Validator<
+    $PropertyType<PluginObject, "generatorOverride">,
+  >),
+};
+
+function assertVisitorMap(key: string, value: mixed): VisitorMap {
+  const obj = assertObject(key, value);
+  if (obj) {
+    Object.keys(obj).forEach(prop => assertVisitorHandler(prop, obj[prop]));
+
+    if (obj.enter || obj.exit) {
+      throw new Error(
+        `.${key} cannot contain catch-all "enter" or "exit" handlers. Please target individual nodes.`,
+      );
+    }
+  }
+  return (obj: any);
+}
+
+function assertVisitorHandler(
+  key: string,
+  value: mixed,
+): VisitorHandler | void {
+  if (value && typeof value === "object") {
+    Object.keys(value).forEach(handler => {
+      if (handler !== "enter" && handler !== "exit") {
+        throw new Error(
+          `.visitor["${key}"] may only have .enter and/or .exit handlers.`,
+        );
+      }
+    });
+  } else if (typeof value !== "function") {
+    throw new Error(`.visitor["${key}"] must be a function`);
+  }
+
+  return (value: any);
+}
+
+type VisitorHandler = Function | { enter?: Function, exit?: Function };
+export type VisitorMap = {
+  [string]: VisitorHandler,
+};
+
+export type PluginObject = {
+  name?: string,
+  manipulateOptions?: Function,
+
+  pre?: Function,
+  post?: Function,
+
+  inherits?: Function,
+  visitor?: VisitorMap,
+
+  parserOverride?: Function,
+  generatorOverride?: Function,
+};
+
+export function validatePluginObject(obj: {}): PluginObject {
+  Object.keys(obj).forEach(key => {
+    const validator = VALIDATORS[key];
+
+    if (validator) validator(key, obj[key]);
+    else throw new Error(`.${key} is not a valid Plugin property`);
+  });
+
+  return (obj: any);
+}
--- a/packages/babel-core/src/config/validation/removed.js
+++ b/packages/babel-core/src/config/validation/removed.js
--- a/packages/babel-core/src/index.js
+++ b/packages/babel-core/src/index.js
@@ -4,7 +4,7 @@ export { default as File } from "./transformation/file/file";
 export {
  default as buildExternalHelpers,
 } from "./tools/build-external-helpers";
-export { resolvePlugin, resolvePreset } from "./config/loading/files";
+export { resolvePlugin, resolvePreset } from "./config/files";

 export { version } from "../package.json";
 export { getEnv } from "./config/helpers/environment";
--- a/packages/babel-core/src/transformation/normalize-file.js
+++ b/packages/babel-core/src/transformation/normalize-file.js
@@ -6,6 +6,7 @@ import convertSourceMap, { typeof Converter } from "convert-source-map";
 import { parse } from "babylon";
 import { codeFrameColumns } from "@babel/code-frame";
 import File from "./file/file";
+import generateMissingPluginMessage from "./util/missing-plugin-helper";

 const shebangRegex = /^#!.*/;

@@ -88,21 +89,27 @@ function parser(pluginPasses, options, code) {
    }
    throw new Error("More than one plugin attempted to override parsing.");
  } catch (err) {
-    const loc = err.loc;
+    const { loc, missingPlugin } = err;
    if (loc) {
      err.loc = null;
-      err.message =
-        `${options.filename || "unknown"}: ${err.message}\n` +
-        codeFrameColumns(
-          code,
-          {
-            start: {
-              line: loc.line,
-              column: loc.column + 1,
-            },
+      const codeFrame = codeFrameColumns(
+        code,
+        {
+          start: {
+            line: loc.line,
+            column: loc.column + 1,
          },
-          options,
-        );
+        },
+        options,
+      );
+      if (missingPlugin) {
+        err.message =
+          `${options.filename || "unknown"}: ` +
+          generateMissingPluginMessage(missingPlugin[0], loc, codeFrame);
+      } else {
+        err.message =
+          `${options.filename || "unknown"}: ${err.message}\n\n` + codeFrame;
+      }
    }
    throw err;
  }
--- a/packages/babel-core/src/transformation/util/missing-plugin-helper.js
+++ b/packages/babel-core/src/transformation/util/missing-plugin-helper.js
@@ -0,0 +1,236 @@
+// @flow
+
+const pluginNameMap = {
+  asyncGenerators: {
+    syntax: {
+      name: "@babel/plugin-syntax-async-generators",
+      url: "https://git.io/vb4SY",
+    },
+    transform: {
+      name: "@babel/plugin-proposal-async-generator-functions",
+      url: "https://git.io/vb4yp",
+    },
+  },
+  classProperties: {
+    syntax: {
+      name: "@babel/plugin-syntax-class-properties",
+      url: "https://git.io/vb4yQ",
+    },
+    transform: {
+      name: "@babel/plugin-proposal-class-properties",
+      url: "https://git.io/vb4SL",
+    },
+  },
+  decorators: {
+    syntax: {
+      name: "@babel/plugin-syntax-decorators",
+      url: "https://git.io/vb4y9",
+    },
+    transform: {
+      name: "@babel/plugin-proposal-decorators",
+      url: "https://git.io/vb4ST",
+    },
+  },
+  doExpressions: {
+    syntax: {
+      name: "@babel/plugin-syntax-do-expressions",
+      url: "https://git.io/vb4yh",
+    },
+    transform: {
+      name: "@babel/plugin-proposal-do-expressions",
+      url: "https://git.io/vb4S3",
+    },
+  },
+  dynamicImport: {
+    syntax: {
+      name: "@babel/plugin-syntax-dynamic-import",
+      url: "https://git.io/vb4Sv",
+    },
+  },
+  exportDefaultFrom: {
+    syntax: {
+      name: "@babel/plugin-syntax-export-default-from",
+      url: "https://git.io/vb4SO",
+    },
+    transform: {
+      name: "@babel/plugin-proposal-export-default-from",
+      url: "https://git.io/vb4yH",
+    },
+  },
+  exportNamespaceFrom: {
+    syntax: {
+      name: "@babel/plugin-syntax-export-namespace-from",
+      url: "https://git.io/vb4Sf",
+    },
+    transform: {
+      name: "@babel/plugin-proposal-export-namespace-from",
+      url: "https://git.io/vb4SG",
+    },
+  },
+  flow: {
+    syntax: {
+      name: "@babel/plugin-syntax-flow",
+      url: "https://git.io/vb4yb",
+    },
+    transform: {
+      name: "@babel/plugin-transform-flow-strip-types",
+      url: "https://git.io/vb49g",
+    },
+  },
+  functionBind: {
+    syntax: {
+      name: "@babel/plugin-syntax-function-bind",
+      url: "https://git.io/vb4y7",
+    },
+    transform: {
+      name: "@babel/plugin-proposal-function-bind",
+      url: "https://git.io/vb4St",
+    },
+  },
+  functionSent: {
+    syntax: {
+      name: "@babel/plugin-syntax-function-sent",
+      url: "https://git.io/vb4yN",
+    },
+    transform: {
+      name: "@babel/plugin-proposal-function-sent",
+      url: "https://git.io/vb4SZ",
+    },
+  },
+  importMeta: {
+    syntax: {
+      name: "@babel/plugin-syntax-import-meta",
+      url: "https://git.io/vbKK6",
+    },
+  },
+  jsx: {
+    syntax: {
+      name: "@babel/plugin-syntax-jsx",
+      url: "https://git.io/vb4yA",
+    },
+    transform: {
+      name: "@babel/plugin-transform-react-jsx",
+      url: "https://git.io/vb4yd",
+    },
+  },
+  nullishCoalescingOperator: {
+    syntax: {
+      name: "@babel/plugin-syntax-nullish-coalescing-operator",
+      url: "https://git.io/vb4yx",
+    },
+    transform: {
+      name: "@babel/plugin-proposal-nullish-coalescing-operator",
+      url: "https://git.io/vb4Se",
+    },
+  },
+  numericSeparator: {
+    syntax: {
+      name: "@babel/plugin-syntax-numeric-separator",
+      url: "https://git.io/vb4Sq",
+    },
+    transform: {
+      name: "@babel/plugin-proposal-numeric-separator",
+      url: "https://git.io/vb4yS",
+    },
+  },
+  objectRestSpread: {
+    syntax: {
+      name: "@babel/plugin-syntax-object-rest-spread",
+      url: "https://git.io/vb4y5",
+    },
+    transform: {
+      name: "@babel/plugin-proposal-object-rest-spread",
+      url: "https://git.io/vb4Ss",
+    },
+  },
+  optionalCatchBinding: {
+    syntax: {
+      name: "@babel/plugin-syntax-optional-catch-binding",
+      url: "https://git.io/vb4Sn",
+    },
+    transform: {
+      name: "@babel/plugin-proposal-optional-catch-binding",
+      url: "https://git.io/vb4SI",
+    },
+  },
+  optionalChaining: {
+    syntax: {
+      name: "@babel/plugin-syntax-optional-chaining",
+      url: "https://git.io/vb4Sc",
+    },
+    transform: {
+      name: "@babel/plugin-proposal-optional-chaining",
+      url: "https://git.io/vb4Sk",
+    },
+  },
+  pipelineOperator: {
+    syntax: {
+      name: "@babel/plugin-syntax-pipeline-operator",
+      url: "https://git.io/vb4yj",
+    },
+    transform: {
+      name: "@babel/plugin-proposal-pipeline-operator",
+      url: "https://git.io/vb4SU",
+    },
+  },
+  throwExpressions: {
+    syntax: {
+      name: "@babel/plugin-syntax-throw-expressions",
+      url: "https://git.io/vb4SJ",
+    },
+    transform: {
+      name: "@babel/plugin-proposal-throw-expressions",
+      url: "https://git.io/vb4yF",
+    },
+  },
+  typescript: {
+    syntax: {
+      name: "@babel/plugin-syntax-typescript",
+      url: "https://git.io/vb4SC",
+    },
+    transform: {
+      name: "@babel/plugin-transform-typescript",
+      url: "https://git.io/vb4Sm",
+    },
+  },
+};
+
+const getNameURLCombination = ({ name, url }) => `${name} (${url})`;
+
+/*
+Returns a string of the format:
+Support for the experimental syntax [babylon plugin name] isn't currently enabled ([loc]):
+
+[code frame]
+
+Add [npm package name] ([url]) to the 'plugins' section of your Babel config
+to enable [parsing|transformation].
+*/
+export default function generateMissingPluginMessage(
+  missingPluginName: string,
+  loc: { line: number, column: number },
+  codeFrame: string,
+): string {
+  let helpMessage =
+    `Support for the experimental syntax '${missingPluginName}' isn't currently enabled ` +
+    `(${loc.line}:${loc.column + 1}):\n\n` +
+    codeFrame;
+  const pluginInfo = pluginNameMap[missingPluginName];
+  if (pluginInfo) {
+    const { syntax: syntaxPlugin, transform: transformPlugin } = pluginInfo;
+    if (syntaxPlugin) {
+      if (transformPlugin) {
+        const transformPluginInfo = getNameURLCombination(transformPlugin);
+        helpMessage +=
+          `\n\nAdd ${transformPluginInfo} to the 'plugins' section of your Babel config ` +
+          `to enable transformation.`;
+      } else {
+        const syntaxPluginInfo = getNameURLCombination(syntaxPlugin);
+        helpMessage +=
+          `\n\nAdd ${syntaxPluginInfo} to the 'plugins' section of your Babel config ` +
+          `to enable parsing.`;
+      }
+    }
+  }
+  return helpMessage;
+}
--- a/packages/babel-core/test/api.js
+++ b/packages/babel-core/test/api.js
@@ -599,4 +599,52 @@ describe("api", function() {
      assert.ok(script.indexOf("typeof") >= 0);
    });
  });
+
+  describe("handle parsing errors", function() {
+    const options = {
+      babelrc: false,
+    };
+
+    it("only syntax plugin available", function(done) {
+      babel.transformFile(
+        __dirname + "/fixtures/api/parsing-errors/only-syntax/file.js",
+        options,
+        function(err) {
+          assert.ok(
+            RegExp(
+              "Support for the experimental syntax 'dynamicImport' isn't currently enabled \\(1:9\\):",
+            ).exec(err.message),
+          );
+          assert.ok(
+            RegExp(
+              "Add @babel/plugin-syntax-dynamic-import \\(https://git.io/vb4Sv\\) to the " +
+                "'plugins' section of your Babel config to enable parsing.",
+            ).exec(err.message),
+          );
+          done();
+        },
+      );
+    });
+
+    it("both syntax and transform plugin available", function(done) {
+      babel.transformFile(
+        __dirname + "/fixtures/api/parsing-errors/syntax-and-transform/file.js",
+        options,
+        function(err) {
+          assert.ok(
+            RegExp(
+              "Support for the experimental syntax 'asyncGenerators' isn't currently enabled \\(1:15\\):",
+            ).exec(err.message),
+          );
+          assert.ok(
+            RegExp(
+              "Add @babel/plugin-proposal-async-generator-functions \\(https://git.io/vb4yp\\) to the " +
+                "'plugins' section of your Babel config to enable transformation.",
+            ).exec(err.message),
+          );
+          done();
+        },
+      );
+    });
+  });
 });
--- a/packages/babel-core/test/config-chain.js
+++ b/packages/babel-core/test/config-chain.js
@@ -194,17 +194,50 @@ describe("buildConfigChain", function() {
        assert.notEqual(opts1.plugins[0], opts2.plugins[1]);
      });

-      it("should cache the env options by identity", () => {
-        const env = {
-          foo: {
-            plugins: plugins1,
+      it("should cache the env plugins by identity", () => {
+        const plugins = [() => ({})];
+
+        const opts1 = loadOptions({
+          envName: "foo",
+          env: {
+            foo: {
+              plugins,
+            },
          },
-        };
+        });
+        const opts2 = loadOptions({
+          envName: "foo",
+          env: {
+            foo: {
+              plugins,
+            },
+          },
+        });

-        const opts1 = loadOptions({ envName: "foo", env });
+        assert.equal(opts1.plugins.length, 1);
+        assert.equal(opts2.plugins.length, 1);
+        assert.equal(opts1.plugins[0], opts2.plugins[0]);
+      });

-        env.foo.plugins = plugins2;
-        const opts2 = loadOptions({ envName: "foo", env });
+      it("should cache the env presets by identity", () => {
+        const presets = [() => ({ plugins: [() => ({})] })];
+
+        const opts1 = loadOptions({
+          envName: "foo",
+          env: {
+            foo: {
+              presets,
+            },
+          },
+        });
+        const opts2 = loadOptions({
+          envName: "foo",
+          env: {
+            foo: {
+              presets,
+            },
+          },
+        });

        assert.equal(opts1.plugins.length, 1);
        assert.equal(opts2.plugins.length, 1);
--- a/packages/babel-core/test/fixtures/api/parsing-errors/only-syntax/file.js
+++ b/packages/babel-core/test/fixtures/api/parsing-errors/only-syntax/file.js
@@ -0,0 +1 @@
+var $ = import("jquery");
--- a/packages/babel-core/test/fixtures/api/parsing-errors/syntax-and-transform/file.js
+++ b/packages/babel-core/test/fixtures/api/parsing-errors/syntax-and-transform/file.js
@@ -0,0 +1,4 @@
+async function* agf() {
+  await 1;
+  yield 2;
+}
--- a/packages/babel-generator/package.json
+++ b/packages/babel-generator/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/generator",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Turns an AST into code.",
  "author": "Sebastian McKenzie <sebmck@gmail.com>",
  "homepage": "https://babeljs.io/",
@@ -11,14 +11,14 @@
    "lib"
  ],
  "dependencies": {
-    "@babel/types": "7.0.0-beta.35",
+    "@babel/types": "7.0.0-beta.36",
    "jsesc": "^2.5.1",
    "lodash": "^4.2.0",
    "source-map": "^0.5.0",
    "trim-right": "^1.0.1"
  },
  "devDependencies": {
-    "@babel/helper-fixtures": "7.0.0-beta.35",
-    "babylon": "7.0.0-beta.35"
+    "@babel/helper-fixtures": "7.0.0-beta.36",
+    "babylon": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-generator/src/generators/flow.js
+++ b/packages/babel-generator/src/generators/flow.js
@@ -420,9 +420,11 @@ export function ObjectTypeIndexer(node: Object) {
  }
  this._variance(node);
  this.token("[");
-  this.print(node.id, node);
-  this.token(":");
-  this.space();
+  if (node.id) {
+    this.print(node.id, node);
+    this.token(":");
+    this.space();
+  }
  this.print(node.key, node);
  this.token("]");
  this.token(":");
--- a/packages/babel-generator/test/fixtures/flow/object-literal-types/actual.js
+++ b/packages/babel-generator/test/fixtures/flow/object-literal-types/actual.js
@@ -7,3 +7,5 @@ type T = { ...U, p: V, };
 type T = { ...{}|{ p: V, }};
 type T = { foo(): number }
 type T = { foo: () => number }
+type T = { [string]: U };
+type T = { [param: string]: U };
--- a/packages/babel-generator/test/fixtures/flow/object-literal-types/expected.js
+++ b/packages/babel-generator/test/fixtures/flow/object-literal-types/expected.js
@@ -22,3 +22,9 @@ type T = {
 type T = {
  foo: () => number
 };
+type T = {
+  [string]: U
+};
+type T = {
+  [param: string]: U
+};
--- a/packages/babel-generator/test/fixtures/flow/type-annotations/actual.js
+++ b/packages/babel-generator/test/fixtures/flow/type-annotations/actual.js
@@ -98,7 +98,7 @@ import type { foo, bar } from "baz";
 import type { foo as bar } from "baz";
 import type from "foo";
 import type, { foo } from "bar";
-import type * as namespace from "bar";
+import typeof * as namespace from "bar";
 import { type Foo } from "bar";
 import { typeof Foo } from "bar";
 import { type Foo as Bar } from "bar";
--- a/packages/babel-generator/test/fixtures/flow/type-annotations/expected.js
+++ b/packages/babel-generator/test/fixtures/flow/type-annotations/expected.js
@@ -221,7 +221,7 @@ import type { foo, bar } from "baz";
 import type { foo as bar } from "baz";
 import type from "foo";
 import type, { foo } from "bar";
-import type * as namespace from "bar";
+import typeof * as namespace from "bar";
 import { type Foo } from "bar";
 import { typeof Foo } from "bar";
 import { type Foo as Bar } from "bar";
--- a/packages/babel-generator/test/fixtures/typescript/class-abstract/actual.js
+++ b/packages/babel-generator/test/fixtures/typescript/class-abstract/actual.js
@@ -2,5 +2,6 @@ abstract class C {}
 declare abstract class C {}
 export abstract class C {}
 // `export abstract class { }` is not valid.
-// `export default abstract class C { }` is not valid.
+export default abstract class { }
+export default abstract class C { }
 // `abstract class` is not valid as an expression.
--- a/packages/babel-generator/test/fixtures/typescript/class-abstract/expected.js
+++ b/packages/babel-generator/test/fixtures/typescript/class-abstract/expected.js
@@ -3,5 +3,6 @@ abstract class C {}
 declare abstract class C {}

 export abstract class C {} // `export abstract class { }` is not valid.
-// `export default abstract class C { }` is not valid.
-// `abstract class` is not valid as an expression.
+
+export default abstract class {}
+export default abstract class C {} // `abstract class` is not valid as an expression.
--- a/packages/babel-generator/test/fixtures/typescript/class-abstract/options.json
+++ b/packages/babel-generator/test/fixtures/typescript/class-abstract/options.json
@@ -1,4 +1,4 @@
 {
  "sourceType": "module",
-  "plugins": ["typescript", "classProperties"]
+  "plugins": ["typescript"]
 }
--- a/packages/babel-helper-annotate-as-pure/package.json
+++ b/packages/babel-helper-annotate-as-pure/package.json
@@ -1,11 +1,11 @@
 {
  "name": "@babel/helper-annotate-as-pure",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Helper function to annotate paths and nodes with #__PURE__ comment",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-helper-annotate-as-pure",
  "license": "MIT",
  "main": "lib/index.js",
  "dependencies": {
-    "@babel/types": "7.0.0-beta.35"
+    "@babel/types": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-helper-bindify-decorators/package.json
+++ b/packages/babel-helper-bindify-decorators/package.json
@@ -1,12 +1,12 @@
 {
  "name": "@babel/helper-bindify-decorators",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Helper function to bindify decorators",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-helper-bindify-decorators",
  "license": "MIT",
  "main": "lib/index.js",
  "dependencies": {
-    "@babel/traverse": "7.0.0-beta.35",
-    "@babel/types": "7.0.0-beta.35"
+    "@babel/traverse": "7.0.0-beta.36",
+    "@babel/types": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-helper-builder-binary-assignment-operator-visitor/package.json
+++ b/packages/babel-helper-builder-binary-assignment-operator-visitor/package.json
@@ -1,12 +1,12 @@
 {
  "name": "@babel/helper-builder-binary-assignment-operator-visitor",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Helper function to build binary assignment operator visitors",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-helper-builder-binary-assignment-operator-visitor",
  "license": "MIT",
  "main": "lib/index.js",
  "dependencies": {
-    "@babel/helper-explode-assignable-expression": "7.0.0-beta.35",
-    "@babel/types": "7.0.0-beta.35"
+    "@babel/helper-explode-assignable-expression": "7.0.0-beta.36",
+    "@babel/types": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-helper-builder-react-jsx/package.json
+++ b/packages/babel-helper-builder-react-jsx/package.json
@@ -1,12 +1,12 @@
 {
  "name": "@babel/helper-builder-react-jsx",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Helper function to build react jsx",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-helper-builder-react-jsx",
  "license": "MIT",
  "main": "lib/index.js",
  "dependencies": {
-    "@babel/types": "7.0.0-beta.35",
+    "@babel/types": "7.0.0-beta.36",
    "esutils": "^2.0.0"
  }
 }
--- a/packages/babel-helper-call-delegate/package.json
+++ b/packages/babel-helper-call-delegate/package.json
@@ -1,13 +1,13 @@
 {
  "name": "@babel/helper-call-delegate",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Helper function to call delegate",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-helper-call-delegate",
  "license": "MIT",
  "main": "lib/index.js",
  "dependencies": {
-    "@babel/helper-hoist-variables": "7.0.0-beta.35",
-    "@babel/traverse": "7.0.0-beta.35",
-    "@babel/types": "7.0.0-beta.35"
+    "@babel/helper-hoist-variables": "7.0.0-beta.36",
+    "@babel/traverse": "7.0.0-beta.36",
+    "@babel/types": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-helper-define-map/package.json
+++ b/packages/babel-helper-define-map/package.json
@@ -1,13 +1,13 @@
 {
  "name": "@babel/helper-define-map",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Helper function to define a map",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-helper-define-map",
  "license": "MIT",
  "main": "lib/index.js",
  "dependencies": {
-    "@babel/helper-function-name": "7.0.0-beta.35",
-    "@babel/types": "7.0.0-beta.35",
+    "@babel/helper-function-name": "7.0.0-beta.36",
+    "@babel/types": "7.0.0-beta.36",
    "lodash": "^4.2.0"
  }
 }
--- a/packages/babel-helper-explode-assignable-expression/package.json
+++ b/packages/babel-helper-explode-assignable-expression/package.json
@@ -1,12 +1,12 @@
 {
  "name": "@babel/helper-explode-assignable-expression",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Helper function to explode an assignable expression",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-helper-explode-assignable-expression",
  "license": "MIT",
  "main": "lib/index.js",
  "dependencies": {
-    "@babel/traverse": "7.0.0-beta.35",
-    "@babel/types": "7.0.0-beta.35"
+    "@babel/traverse": "7.0.0-beta.36",
+    "@babel/types": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-helper-explode-class/package.json
+++ b/packages/babel-helper-explode-class/package.json
@@ -1,13 +1,13 @@
 {
  "name": "@babel/helper-explode-class",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Helper function to explode class",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-helper-explode-class",
  "license": "MIT",
  "main": "lib/index.js",
  "dependencies": {
-    "@babel/helper-bindify-decorators": "7.0.0-beta.35",
-    "@babel/traverse": "7.0.0-beta.35",
-    "@babel/types": "7.0.0-beta.35"
+    "@babel/helper-bindify-decorators": "7.0.0-beta.36",
+    "@babel/traverse": "7.0.0-beta.36",
+    "@babel/types": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-helper-fixtures/package.json
+++ b/packages/babel-helper-fixtures/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/helper-fixtures",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Helper function to support fixtures",
  "author": "Sebastian McKenzie <sebmck@gmail.com>",
  "license": "MIT",
--- a/packages/babel-helper-function-name/package.json
+++ b/packages/babel-helper-function-name/package.json
@@ -1,13 +1,13 @@
 {
  "name": "@babel/helper-function-name",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Helper function to change the property 'name' of every function",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-helper-function-name",
  "license": "MIT",
  "main": "lib/index.js",
  "dependencies": {
-    "@babel/helper-get-function-arity": "7.0.0-beta.35",
-    "@babel/template": "7.0.0-beta.35",
-    "@babel/types": "7.0.0-beta.35"
+    "@babel/helper-get-function-arity": "7.0.0-beta.36",
+    "@babel/template": "7.0.0-beta.36",
+    "@babel/types": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-helper-get-function-arity/package.json
+++ b/packages/babel-helper-get-function-arity/package.json
@@ -1,11 +1,11 @@
 {
  "name": "@babel/helper-get-function-arity",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Helper function to get function arity",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-helper-get-function-arity",
  "license": "MIT",
  "main": "lib/index.js",
  "dependencies": {
-    "@babel/types": "7.0.0-beta.35"
+    "@babel/types": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-helper-hoist-variables/package.json
+++ b/packages/babel-helper-hoist-variables/package.json
@@ -1,11 +1,11 @@
 {
  "name": "@babel/helper-hoist-variables",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Helper function to hoist variables",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-helper-hoist-variables",
  "license": "MIT",
  "main": "lib/index.js",
  "dependencies": {
-    "@babel/types": "7.0.0-beta.35"
+    "@babel/types": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-helper-module-imports/package.json
+++ b/packages/babel-helper-module-imports/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/helper-module-imports",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Babel helper functions for inserting module loads",
  "author": "Logan Smyth <loganfsmyth@gmail.com>",
  "homepage": "https://babeljs.io/",
@@ -8,10 +8,10 @@
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-helper-module-imports",
  "main": "lib/index.js",
  "dependencies": {
-    "@babel/types": "7.0.0-beta.35",
+    "@babel/types": "7.0.0-beta.36",
    "lodash": "^4.2.0"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-helper-module-transforms/package.json
+++ b/packages/babel-helper-module-transforms/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/helper-module-transforms",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Babel helper functions for implementing ES6 module transformations",
  "author": "Logan Smyth <loganfsmyth@gmail.com>",
  "homepage": "https://babeljs.io/",
@@ -8,10 +8,10 @@
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-helper-module-transforms",
  "main": "lib/index.js",
  "dependencies": {
-    "@babel/helper-module-imports": "7.0.0-beta.35",
-    "@babel/helper-simple-access": "7.0.0-beta.35",
-    "@babel/template": "7.0.0-beta.35",
-    "@babel/types": "7.0.0-beta.35",
+    "@babel/helper-module-imports": "7.0.0-beta.36",
+    "@babel/helper-simple-access": "7.0.0-beta.36",
+    "@babel/template": "7.0.0-beta.36",
+    "@babel/types": "7.0.0-beta.36",
    "lodash": "^4.2.0"
  }
 }
--- a/packages/babel-helper-module-transforms/src/index.js
+++ b/packages/babel-helper-module-transforms/src/index.js
@@ -22,7 +22,7 @@ export { hasExports, isSideEffectImport, isModule };
 */
 export function rewriteModuleStatementsAndPrepareHeader(
  path: NodePath,
-  { exportName, strict, allowTopLevelThis, strictMode, loose, noInterop },
+  { exportName, strict, allowTopLevelThis, strictMode, loose, noInterop, lazy },
 ) {
  assert(isModule(path), "Cannot process module statements in a script");
  path.node.sourceType = "script";
@@ -30,6 +30,7 @@ export function rewriteModuleStatementsAndPrepareHeader(
  const meta = normalizeAndLoadModuleMetadata(path, exportName, {
    noInterop,
    loose,
+    lazy,
  });

  if (!allowTopLevelThis) {
@@ -117,6 +118,9 @@ export function buildNamespaceInitStatements(
 ) {
  const statements = [];

+  let srcNamespace = t.identifier(sourceMetadata.name);
+  if (sourceMetadata.lazy) srcNamespace = t.callExpression(srcNamespace, []);
+
  for (const localName of sourceMetadata.importsNamespace) {
    if (localName === sourceMetadata.name) continue;

@@ -124,7 +128,7 @@ export function buildNamespaceInitStatements(
    statements.push(
      template.statement`var NAME = SOURCE;`({
        NAME: localName,
-        SOURCE: sourceMetadata.name,
+        SOURCE: t.cloneDeep(srcNamespace),
      }),
    );
  }
@@ -134,17 +138,26 @@ export function buildNamespaceInitStatements(
  for (const exportName of sourceMetadata.reexportNamespace) {
    // Assign export to namespace object.
    statements.push(
-      template.statement`EXPORTS.NAME = NAMESPACE;`({
+      (sourceMetadata.lazy
+        ? template.statement`
+            Object.defineProperty(EXPORTS, "NAME", {
+              enumerable: true,
+              get: function() {
+                return NAMESPACE;
+              }
+            });
+          `
+        : template.statement`EXPORTS.NAME = NAMESPACE;`)({
        EXPORTS: metadata.exportName,
        NAME: exportName,
-        NAMESPACE: sourceMetadata.name,
+        NAMESPACE: t.cloneDeep(srcNamespace),
      }),
    );
  }
  if (sourceMetadata.reexportAll) {
    const statement = buildNamespaceReexport(
      metadata,
-      sourceMetadata.name,
+      t.cloneDeep(srcNamespace),
      loose,
    );
    statement.loc = sourceMetadata.reexportAll.loc;
@@ -169,12 +182,16 @@ const getTemplateForReexport = loose => {
 };

 const buildReexportsFromMeta = (meta, metadata, loose) => {
+  const namespace = metadata.lazy
+    ? t.callExpression(t.identifier(metadata.name), [])
+    : t.identifier(metadata.name);
+
  const templateForCurrentMode = getTemplateForReexport(loose);
  return Array.from(metadata.reexports, ([exportName, importName]) =>
    templateForCurrentMode({
      EXPORTS: meta.exportName,
      EXPORT_NAME: exportName,
-      NAMESPACE: metadata.name,
+      NAMESPACE: t.cloneDeep(namespace),
      IMPORT_NAME: importName,
    }),
  );
--- a/packages/babel-helper-module-transforms/src/normalize-and-load-metadata.js
+++ b/packages/babel-helper-module-transforms/src/normalize-and-load-metadata.js
@@ -86,7 +86,7 @@ export function isSideEffectImport(source: SourceModuleMetadata) {
 export default function normalizeModuleAndLoadMetadata(
  programPath: NodePath,
  exportName?: string,
-  { noInterop = false, loose = false } = {},
+  { noInterop = false, loose = false, lazy = false } = {},
 ): ModuleMetadata {
  if (!exportName) {
    exportName = programPath.scope.generateUidIdentifier("exports").name;
@@ -94,7 +94,7 @@ export default function normalizeModuleAndLoadMetadata(

  nameAnonymousExports(programPath);

-  const { local, source } = getModuleMetadata(programPath, loose);
+  const { local, source } = getModuleMetadata(programPath, { loose, lazy });

  removeModuleDeclarations(programPath);

@@ -120,7 +120,10 @@ export default function normalizeModuleAndLoadMetadata(
 /**
 * Get metadata about the imports and exports present in this module.
 */
-function getModuleMetadata(programPath: NodePath, loose: boolean) {
+function getModuleMetadata(
+  programPath: NodePath,
+  { loose, lazy }: { loose: boolean, lazy: boolean },
+) {
  const localData = getLocalExportMetadata(programPath, loose);

  const sourceData = new Map();
@@ -146,6 +149,8 @@ function getModuleMetadata(programPath: NodePath, loose: boolean) {
        reexports: new Map(),
        reexportNamespace: new Set(),
        reexportAll: null,
+
+        lazy: false,
      };
      sourceData.set(source, data);
    }
@@ -249,6 +254,25 @@ function getModuleMetadata(programPath: NodePath, loose: boolean) {
    }
  }

+  for (const [source, metadata] of sourceData) {
+    if (
+      lazy !== false &&
+      !(isSideEffectImport(metadata) || metadata.reexportAll)
+    ) {
+      if (lazy === true) {
+        // 'true' means that local relative files are eagerly loaded and
+        // dependency modules are loaded lazily.
+        metadata.lazy = !/\./.test(source);
+      } else if (Array.isArray(lazy)) {
+        metadata.lazy = lazy.indexOf(source);
+      } else if (typeof lazy === "function") {
+        metadata.lazy = lazy(source);
+      } else {
+        throw new Error(`.lazy must be a boolean, string array, or function`);
+      }
+    }
+  }
+
  return {
    local: localData,
    source: sourceData,
--- a/packages/babel-helper-module-transforms/src/rewrite-live-references.js
+++ b/packages/babel-helper-module-transforms/src/rewrite-live-references.js
@@ -24,7 +24,7 @@ export default function rewriteLiveReferences(
      imported.set(localName, [source, importName, null]);
    }
    for (const localName of data.importsNamespace) {
-      imported.set(localName, [null, null, localName]);
+      imported.set(localName, [source, null, localName]);
    }
  }

@@ -60,12 +60,18 @@ export default function rewriteLiveReferences(
    scope: programPath.scope,
    imported, // local / import
    exported, // local name => exported name list
-    buildImportReference: ([source, importName, localName]) => {
-      if (localName) return null;
+    buildImportReference: ([source, importName, localName], identNode) => {
+      const meta = metadata.source.get(source);

-      const name = metadata.source.get(source).name;
+      if (localName) {
+        if (meta.lazy) identNode = t.callExpression(identNode, []);
+        return identNode;
+      }

-      return t.memberExpression(t.identifier(name), t.identifier(importName));
+      let namespace = t.identifier(meta.name);
+      if (meta.lazy) namespace = t.callExpression(namespace, []);
+
+      return t.memberExpression(namespace, t.identifier(importName));
    },
  });
 }
@@ -172,7 +178,7 @@ const rewriteReferencesVisitor = {

    const importData = imported.get(localName);
    if (importData) {
-      const ref = buildImportReference(importData) || path.node;
+      const ref = buildImportReference(importData, path.node);

      if (path.parentPath.isCallExpression({ callee: path.node })) {
        path.replaceWith(t.sequenceExpression([t.numericLiteral(0), ref]));
@@ -225,8 +231,7 @@ const rewriteReferencesVisitor = {
          const assignment = path.node;

          if (importData) {
-            assignment.left =
-              buildImportReference(importData) || assignment.left;
+            assignment.left = buildImportReference(importData, assignment.left);

            assignment.right = t.sequenceExpression([
              assignment.right,
--- a/packages/babel-helper-optimise-call-expression/package.json
+++ b/packages/babel-helper-optimise-call-expression/package.json
@@ -1,11 +1,11 @@
 {
  "name": "@babel/helper-optimise-call-expression",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Helper function to optimise call expression",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-helper-optimise-call-expression",
  "license": "MIT",
  "main": "lib/index.js",
  "dependencies": {
-    "@babel/types": "7.0.0-beta.35"
+    "@babel/types": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-helper-plugin-test-runner/package.json
+++ b/packages/babel-helper-plugin-test-runner/package.json
@@ -1,11 +1,11 @@
 {
  "name": "@babel/helper-plugin-test-runner",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Helper function to support test runner",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-helper-plugin-test-runner",
  "license": "MIT",
  "main": "lib/index.js",
  "dependencies": {
-    "@babel/helper-transform-fixture-test-runner": "7.0.0-beta.35"
+    "@babel/helper-transform-fixture-test-runner": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-helper-regex/package.json
+++ b/packages/babel-helper-regex/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/helper-regex",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Helper function to check for literal RegEx",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-helper-regex",
  "license": "MIT",
--- a/packages/babel-helper-remap-async-to-generator/package.json
+++ b/packages/babel-helper-remap-async-to-generator/package.json
@@ -1,15 +1,15 @@
 {
  "name": "@babel/helper-remap-async-to-generator",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Helper function to remap async functions to generators",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-helper-remap-async-to-generator",
  "license": "MIT",
  "main": "lib/index.js",
  "dependencies": {
-    "@babel/helper-annotate-as-pure": "7.0.0-beta.35",
-    "@babel/helper-wrap-function": "7.0.0-beta.35",
-    "@babel/template": "7.0.0-beta.35",
-    "@babel/traverse": "7.0.0-beta.35",
-    "@babel/types": "7.0.0-beta.35"
+    "@babel/helper-annotate-as-pure": "7.0.0-beta.36",
+    "@babel/helper-wrap-function": "7.0.0-beta.36",
+    "@babel/template": "7.0.0-beta.36",
+    "@babel/traverse": "7.0.0-beta.36",
+    "@babel/types": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-helper-replace-supers/package.json
+++ b/packages/babel-helper-replace-supers/package.json
@@ -1,14 +1,14 @@
 {
  "name": "@babel/helper-replace-supers",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Helper function to replace supers",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-helper-replace-supers",
  "license": "MIT",
  "main": "lib/index.js",
  "dependencies": {
-    "@babel/helper-optimise-call-expression": "7.0.0-beta.35",
-    "@babel/template": "7.0.0-beta.35",
-    "@babel/traverse": "7.0.0-beta.35",
-    "@babel/types": "7.0.0-beta.35"
+    "@babel/helper-optimise-call-expression": "7.0.0-beta.36",
+    "@babel/template": "7.0.0-beta.36",
+    "@babel/traverse": "7.0.0-beta.36",
+    "@babel/types": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-helper-simple-access/package.json
+++ b/packages/babel-helper-simple-access/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/helper-simple-access",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Babel helper for ensuring that access to a given value is performed through simple accesses",
  "author": "Logan Smyth <loganfsmyth@gmail.com>",
  "homepage": "https://babeljs.io/",
@@ -8,8 +8,8 @@
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-helper-simple-access",
  "main": "lib/index.js",
  "dependencies": {
-    "@babel/template": "7.0.0-beta.35",
-    "@babel/types": "7.0.0-beta.35",
+    "@babel/template": "7.0.0-beta.36",
+    "@babel/types": "7.0.0-beta.36",
    "lodash": "^4.2.0"
  }
 }
--- a/packages/babel-helper-transform-fixture-test-runner/package.json
+++ b/packages/babel-helper-transform-fixture-test-runner/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/helper-transform-fixture-test-runner",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Transform test runner for @babel/helper-fixtures module",
  "author": "Sebastian McKenzie <sebmck@gmail.com>",
  "homepage": "https://babeljs.io/",
@@ -8,10 +8,10 @@
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-helper-transform-fixture-test-runner",
  "main": "lib/index.js",
  "dependencies": {
-    "@babel/code-frame": "7.0.0-beta.35",
-    "@babel/core": "7.0.0-beta.35",
-    "@babel/helper-fixtures": "7.0.0-beta.35",
-    "@babel/polyfill": "7.0.0-beta.35",
+    "@babel/code-frame": "7.0.0-beta.36",
+    "@babel/core": "7.0.0-beta.36",
+    "@babel/helper-fixtures": "7.0.0-beta.36",
+    "@babel/polyfill": "7.0.0-beta.36",
    "chai": "^4.1.0",
    "lodash": "^4.2.0",
    "resolve": "^1.3.2",
--- a/packages/babel-helper-wrap-function/package.json
+++ b/packages/babel-helper-wrap-function/package.json
@@ -1,14 +1,14 @@
 {
  "name": "@babel/helper-wrap-function",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Helper to wrap functions inside a function call.",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-helper-wrap-function",
  "license": "MIT",
  "main": "lib/index.js",
  "dependencies": {
-    "@babel/helper-function-name": "7.0.0-beta.35",
-    "@babel/template": "7.0.0-beta.35",
-    "@babel/traverse": "7.0.0-beta.35",
-    "@babel/types": "7.0.0-beta.35"
+    "@babel/helper-function-name": "7.0.0-beta.36",
+    "@babel/template": "7.0.0-beta.36",
+    "@babel/traverse": "7.0.0-beta.36",
+    "@babel/types": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-helper-wrap-function/src/index.js
+++ b/packages/babel-helper-wrap-function/src/index.js
@@ -89,11 +89,8 @@ function plainFunction(path: NodePath, callId: Object) {
  });

  if (isDeclaration) {
-    const basePath = path.parentPath.isExportDeclaration()
-      ? path.parentPath
-      : path;
-    basePath.insertAfter(container[1]);
    path.replaceWith(container[0]);
+    path.insertAfter(container[1]);
  } else {
    const retFunction = container.callee.body.body[1].argument;
    if (!functionId) {
--- a/packages/babel-helpers/package.json
+++ b/packages/babel-helpers/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/helpers",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Collection of helper functions used by Babel transforms.",
  "author": "Sebastian McKenzie <sebmck@gmail.com>",
  "homepage": "https://babeljs.io/",
@@ -8,11 +8,11 @@
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-helpers",
  "main": "lib/index.js",
  "dependencies": {
-    "@babel/template": "7.0.0-beta.35",
-    "@babel/traverse": "7.0.0-beta.35",
-    "@babel/types": "7.0.0-beta.35"
+    "@babel/template": "7.0.0-beta.36",
+    "@babel/traverse": "7.0.0-beta.36",
+    "@babel/types": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/helper-plugin-test-runner": "7.0.0-beta.35"
+    "@babel/helper-plugin-test-runner": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-helpers/src/helpers.js
+++ b/packages/babel-helpers/src/helpers.js
@@ -425,6 +425,51 @@ helpers.inheritsLoose = defineHelper(`
  }
 `);

+// Based on https://github.com/WebReflection/babel-plugin-transform-builtin-classes
+helpers.wrapNativeSuper = defineHelper(`
+  var _gPO = Object.getPrototypeOf || function _gPO(o) { return o.__proto__ };
+  var _sPO = Object.setPrototypeOf || function _sPO(o, p) { o.__proto__ = p; return o };
+  var _construct = (typeof Reflect === "object" && Reflect.construct) ||
+    function _construct(Parent, args, Class) {
+      var Constructor, a = [null];
+      a.push.apply(a, args);
+      Constructor = Parent.bind.apply(Parent, a);
+      return _sPO(new Constructor, Class.prototype);
+    };
+
+  var _cache = typeof Map === "function" && new Map();
+
+  export default function _wrapNativeSuper(Class) {
+    if (typeof Class !== "function") {
+      throw new TypeError("Super expression must either be null or a function");
+    }
+
+    if (typeof _cache !== "undefined") {
+      if (_cache.has(Class)) return _cache.get(Class);
+      _cache.set(Class, Wrapper);
+    }
+
+    function Wrapper() {}
+    Wrapper.prototype = Object.create(Class.prototype, {
+      constructor: {
+        value: Wrapper,
+        enumerable: false,
+        writeable: true,
+        configurable: true,
+      }
+    });
+    return _sPO(
+      Wrapper,
+      _sPO(
+        function Super() {
+          return _construct(Class, arguments, _gPO(this).constructor);
+        },
+        Class
+      )
+    );
+  }
+`);
+
 helpers.instanceof = defineHelper(`
  export default function _instanceof(left, right) {
    if (right != null && typeof Symbol !== "undefined" && right[Symbol.hasInstance]) {
--- a/packages/babel-node/package.json
+++ b/packages/babel-node/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/node",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Babel command line",
  "author": "Sebastian McKenzie <sebmck@gmail.com>",
  "homepage": "https://babeljs.io/",
@@ -16,8 +16,8 @@
    "compiler"
  ],
  "dependencies": {
-    "@babel/polyfill": "7.0.0-beta.35",
-    "@babel/register": "7.0.0-beta.35",
+    "@babel/polyfill": "7.0.0-beta.36",
+    "@babel/register": "7.0.0-beta.36",
    "commander": "^2.8.1",
    "fs-readdir-recursive": "^1.0.0",
    "lodash": "^4.2.0",
@@ -25,11 +25,11 @@
    "v8flags": "^3.0.0"
  },
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35",
-    "@babel/helper-fixtures": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36",
+    "@babel/helper-fixtures": "7.0.0-beta.36"
  },
  "bin": {
    "babel-node": "./bin/babel-node.js"
--- a/packages/babel-plugin-check-constants/package.json
+++ b/packages/babel-plugin-check-constants/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-check-constants",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Compile ES2015 constants to ES5",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-check-constants",
  "license": "MIT",
@@ -9,10 +9,10 @@
    "babel-plugin"
  ],
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35",
-    "@babel/helper-plugin-test-runner": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36",
+    "@babel/helper-plugin-test-runner": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-external-helpers/package.json
+++ b/packages/babel-plugin-external-helpers/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-external-helpers",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "This plugin contains helper functions that’ll be placed at the top of the generated code",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-external-helpers",
  "license": "MIT",
@@ -9,10 +9,10 @@
    "babel-plugin"
  ],
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35",
-    "@babel/helper-plugin-test-runner": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36",
+    "@babel/helper-plugin-test-runner": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-proposal-async-generator-functions/package.json
+++ b/packages/babel-plugin-proposal-async-generator-functions/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-proposal-async-generator-functions",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Turn async generator functions into ES2015 generators",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-proposal-async-generator-functions",
  "license": "MIT",
@@ -9,14 +9,14 @@
    "babel-plugin"
  ],
  "dependencies": {
-    "@babel/helper-remap-async-to-generator": "7.0.0-beta.35",
-    "@babel/plugin-syntax-async-generators": "7.0.0-beta.35"
+    "@babel/helper-remap-async-to-generator": "7.0.0-beta.36",
+    "@babel/plugin-syntax-async-generators": "7.0.0-beta.36"
  },
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35",
-    "@babel/helper-plugin-test-runner": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36",
+    "@babel/helper-plugin-test-runner": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-proposal-class-properties/package.json
+++ b/packages/babel-plugin-proposal-class-properties/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-proposal-class-properties",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "This plugin transforms static class properties as well as properties declared with the property initializer syntax",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-proposal-class-properties",
  "license": "MIT",
@@ -9,14 +9,14 @@
    "babel-plugin"
  ],
  "dependencies": {
-    "@babel/helper-function-name": "7.0.0-beta.35",
-    "@babel/plugin-syntax-class-properties": "7.0.0-beta.35"
+    "@babel/helper-function-name": "7.0.0-beta.36",
+    "@babel/plugin-syntax-class-properties": "7.0.0-beta.36"
  },
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35",
-    "@babel/helper-plugin-test-runner": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36",
+    "@babel/helper-plugin-test-runner": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-proposal-class-properties/src/index.js
+++ b/packages/babel-plugin-proposal-class-properties/src/index.js
@@ -228,15 +228,9 @@ export default function(api, options) {
        if (path.isClassExpression()) {
          path.scope.push({ id: ref });
          path.replaceWith(t.assignmentExpression("=", ref, path.node));
-        } else {
-          // path.isClassDeclaration()
-          if (!path.node.id) {
-            path.node.id = ref;
-          }
-
-          if (path.parentPath.isExportDeclaration()) {
-            path = path.parentPath;
-          }
+        } else if (!path.node.id) {
+          // Anonymous class declaration
+          path.node.id = ref;
        }

        path.insertAfter(nodes);
--- a/packages/babel-plugin-proposal-decorators/package.json
+++ b/packages/babel-plugin-proposal-decorators/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-proposal-decorators",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "author": "Logan Smyth <loganfsmyth@gmail.com>",
  "license": "MIT",
  "description": "Compile class and object decorators to ES5",
@@ -12,13 +12,13 @@
    "decorators"
  ],
  "dependencies": {
-    "@babel/plugin-syntax-decorators": "7.0.0-beta.35"
+    "@babel/plugin-syntax-decorators": "7.0.0-beta.36"
  },
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35",
-    "@babel/helper-plugin-test-runner": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36",
+    "@babel/helper-plugin-test-runner": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-proposal-decorators/src/index.js
+++ b/packages/babel-plugin-proposal-decorators/src/index.js
@@ -27,6 +27,8 @@ const buildGetObjectInitializer = template(`
 `);

 export default function() {
+  const WARNING_CALLS = new WeakSet();
+
  /**
   * If the decorator expressions are non-identifiers, hoist them to before the class so we can be sure
   * that they are evaluated in order.
@@ -151,11 +153,14 @@ export default function() {
              t.blockStatement([t.returnStatement(node.value)]),
            )
          : t.nullLiteral();
+
        node.value = t.callExpression(
          state.addHelper("initializerWarningHelper"),
          [descriptor, t.thisExpression()],
        );

+        WARNING_CALLS.add(node.value);
+
        acc = acc.concat([
          t.assignmentExpression(
            "=",
@@ -255,10 +260,7 @@ export default function() {
      },

      AssignmentExpression(path, state) {
-        if (!path.get("left").isMemberExpression()) return;
-        if (!path.get("left.property").isIdentifier()) return;
-        if (!path.get("right").isCallExpression()) return;
-        if (!path.get("right.callee").isIdentifier()) return;
+        if (!WARNING_CALLS.has(path.node.right)) return;

        path.replaceWith(
          t.callExpression(state.addHelper("initializerDefineProperty"), [
--- a/packages/babel-plugin-proposal-decorators/test/fixtures/regression/7030/actual.js
+++ b/packages/babel-plugin-proposal-decorators/test/fixtures/regression/7030/actual.js
@@ -0,0 +1,22 @@
+function generateAsyncAction(type) {
+  type = type.toUpperCase()
+  const request = createAction(type+'_REQUEST',
+      undefined, requestMetaCreator
+  )
+  request.request = request // crazy
+  request.success = createAction(type+'_SUCCESS', undefined, metaCreator)
+  request.error = createAction(type+'_ERROR', undefined, metaCreator)
+  request.cancel = createAction(type+'_CANCEL', undefined, metaCreator)
+  request.progress = createAction(type+'_PROGRESS', undefined, metaCreator)
+  request.process = createAction(type+'_PROCESS', undefined, metaCreator)
+
+  return request
+}
+
+class A extends B {
+  constructor(timestamp) {
+    super()
+    this.timestamp = timestamp
+    this.moment = moment(timestamp)
+  }
+}
--- a/packages/babel-plugin-proposal-decorators/test/fixtures/regression/7030/expected.js
+++ b/packages/babel-plugin-proposal-decorators/test/fixtures/regression/7030/expected.js
@@ -0,0 +1,41 @@
+function _instanceof(left, right) { if (right != null && typeof Symbol !== "undefined" && right[Symbol.hasInstance]) { return right[Symbol.hasInstance](left); } else { return left instanceof right; } }
+
+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 _classCallCheck(instance, Constructor) { if (!_instanceof(instance, Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
+
+function _possibleConstructorReturn(self, call) { if (call && (_typeof(call) === "object" || typeof call === "function")) { return call; } if (self === void 0) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return self; }
+
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) Object.setPrototypeOf ? Object.setPrototypeOf(subClass, superClass) : subClass.__proto__ = superClass; }
+
+function generateAsyncAction(type) {
+  type = type.toUpperCase();
+  var request = createAction(type + '_REQUEST', undefined, requestMetaCreator);
+  request.request = request; // crazy
+
+  request.success = createAction(type + '_SUCCESS', undefined, metaCreator);
+  request.error = createAction(type + '_ERROR', undefined, metaCreator);
+  request.cancel = createAction(type + '_CANCEL', undefined, metaCreator);
+  request.progress = createAction(type + '_PROGRESS', undefined, metaCreator);
+  request.process = createAction(type + '_PROCESS', undefined, metaCreator);
+  return request;
+}
+
+var A =
+/*#__PURE__*/
+function (_B) {
+  _inherits(A, _B);
+
+  function A(timestamp) {
+    var _this;
+
+    _classCallCheck(this, A);
+
+    _this = _possibleConstructorReturn(this, (A.__proto__ || Object.getPrototypeOf(A)).call(this));
+    _this.timestamp = timestamp;
+    _this.moment = moment(timestamp);
+    return _this;
+  }
+
+  return A;
+}(B);
--- a/packages/babel-plugin-proposal-decorators/test/fixtures/regression/7030/options.json
+++ b/packages/babel-plugin-proposal-decorators/test/fixtures/regression/7030/options.json
@@ -0,0 +1,3 @@
+{
+  "presets": ["es2015", "stage-0"]
+}
--- a/packages/babel-plugin-proposal-do-expressions/package.json
+++ b/packages/babel-plugin-proposal-do-expressions/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-proposal-do-expressions",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Compile do expressions to ES5",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-proposal-do-expressions",
  "license": "MIT",
@@ -9,13 +9,13 @@
    "babel-plugin"
  ],
  "dependencies": {
-    "@babel/plugin-syntax-do-expressions": "7.0.0-beta.35"
+    "@babel/plugin-syntax-do-expressions": "7.0.0-beta.36"
  },
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35",
-    "@babel/helper-plugin-test-runner": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36",
+    "@babel/helper-plugin-test-runner": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-proposal-export-default-from/package.json
+++ b/packages/babel-plugin-proposal-export-default-from/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-proposal-export-default-from",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Compile export default to ES2015",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-proposal-export-default-from",
  "license": "MIT",
@@ -9,13 +9,13 @@
    "babel-plugin"
  ],
  "dependencies": {
-    "@babel/plugin-syntax-export-default-from": "7.0.0-beta.35"
+    "@babel/plugin-syntax-export-default-from": "7.0.0-beta.36"
  },
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35",
-    "@babel/helper-plugin-test-runner": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36",
+    "@babel/helper-plugin-test-runner": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-proposal-export-namespace-from/package.json
+++ b/packages/babel-plugin-proposal-export-namespace-from/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-proposal-export-namespace-from",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Compile export namespace to ES2015",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-proposal-export-namespace-from",
  "license": "MIT",
@@ -9,13 +9,13 @@
    "babel-plugin"
  ],
  "dependencies": {
-    "@babel/plugin-syntax-export-namespace-from": "7.0.0-beta.35"
+    "@babel/plugin-syntax-export-namespace-from": "7.0.0-beta.36"
  },
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35",
-    "@babel/helper-plugin-test-runner": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36",
+    "@babel/helper-plugin-test-runner": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-proposal-function-bind/package.json
+++ b/packages/babel-plugin-proposal-function-bind/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-proposal-function-bind",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Compile function bind operator to ES5",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-proposal-function-bind",
  "license": "MIT",
@@ -9,13 +9,13 @@
    "babel-plugin"
  ],
  "dependencies": {
-    "@babel/plugin-syntax-function-bind": "7.0.0-beta.35"
+    "@babel/plugin-syntax-function-bind": "7.0.0-beta.36"
  },
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35",
-    "@babel/helper-plugin-test-runner": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36",
+    "@babel/helper-plugin-test-runner": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-proposal-function-sent/package.json
+++ b/packages/babel-plugin-proposal-function-sent/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-proposal-function-sent",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Compile the function.sent meta propety to valid ES2015 code",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-proposal-function-sent",
  "license": "MIT",
@@ -9,14 +9,14 @@
    "babel-plugin"
  ],
  "dependencies": {
-    "@babel/helper-wrap-function": "7.0.0-beta.35",
-    "@babel/plugin-syntax-function-sent": "7.0.0-beta.35"
+    "@babel/helper-wrap-function": "7.0.0-beta.36",
+    "@babel/plugin-syntax-function-sent": "7.0.0-beta.36"
  },
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35",
-    "@babel/helper-plugin-test-runner": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36",
+    "@babel/helper-plugin-test-runner": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-proposal-nullish-coalescing-operator/package.json
+++ b/packages/babel-plugin-proposal-nullish-coalescing-operator/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-proposal-nullish-coalescing-operator",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Remove nullish coalescing operator",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-transform-nullish-coalescing-opearator",
  "license": "MIT",
@@ -9,13 +9,13 @@
    "babel-plugin"
  ],
  "dependencies": {
-    "@babel/plugin-syntax-nullish-coalescing-operator": "7.0.0-beta.35"
+    "@babel/plugin-syntax-nullish-coalescing-operator": "7.0.0-beta.36"
  },
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35",
-    "@babel/helper-plugin-test-runner": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36",
+    "@babel/helper-plugin-test-runner": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-proposal-numeric-separator/package.json
+++ b/packages/babel-plugin-proposal-numeric-separator/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-proposal-numeric-separator",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Remove numeric separators from Decimal, Binary, Hex and Octal literals",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-proposal-numeric-separator",
  "license": "MIT",
@@ -9,13 +9,13 @@
    "babel-plugin"
  ],
  "dependencies": {
-    "@babel/plugin-syntax-numeric-separator": "7.0.0-beta.35"
+    "@babel/plugin-syntax-numeric-separator": "7.0.0-beta.36"
  },
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35",
-    "@babel/helper-plugin-test-runner": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36",
+    "@babel/helper-plugin-test-runner": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-proposal-object-rest-spread/package.json
+++ b/packages/babel-plugin-proposal-object-rest-spread/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-proposal-object-rest-spread",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Compile object rest and spread to ES5",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-proposal-object-rest-spread",
  "license": "MIT",
@@ -9,13 +9,13 @@
    "babel-plugin"
  ],
  "dependencies": {
-    "@babel/plugin-syntax-object-rest-spread": "7.0.0-beta.35"
+    "@babel/plugin-syntax-object-rest-spread": "7.0.0-beta.36"
  },
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35",
-    "@babel/helper-plugin-test-runner": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36",
+    "@babel/helper-plugin-test-runner": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-proposal-optional-catch-binding/package.json
+++ b/packages/babel-plugin-proposal-optional-catch-binding/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-proposal-optional-catch-binding",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Compile optional catch bindings",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-proposal-optional-catch-binding",
  "license": "MIT",
@@ -9,13 +9,13 @@
    "babel-plugin"
  ],
  "dependencies": {
-    "@babel/plugin-syntax-optional-catch-binding": "7.0.0-beta.35"
+    "@babel/plugin-syntax-optional-catch-binding": "7.0.0-beta.36"
  },
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35",
-    "@babel/helper-plugin-test-runner": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36",
+    "@babel/helper-plugin-test-runner": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-proposal-optional-chaining/package.json
+++ b/packages/babel-plugin-proposal-optional-chaining/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-proposal-optional-chaining",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Transform optional chaining operators into a series of nil checks",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-proposal-optional-chaining",
  "license": "MIT",
@@ -9,13 +9,13 @@
    "babel-plugin"
  ],
  "dependencies": {
-    "@babel/plugin-syntax-optional-chaining": "7.0.0-beta.35"
+    "@babel/plugin-syntax-optional-chaining": "7.0.0-beta.36"
  },
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35",
-    "@babel/helper-plugin-test-runner": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36",
+    "@babel/helper-plugin-test-runner": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-proposal-pipeline-operator/package.json
+++ b/packages/babel-plugin-proposal-pipeline-operator/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-proposal-pipeline-operator",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Transform pipeline operator into call expressions",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-proposal-pipeline-operator",
  "license": "MIT",
@@ -9,13 +9,13 @@
    "babel-plugin"
  ],
  "dependencies": {
-    "@babel/plugin-syntax-pipeline-operator": "7.0.0-beta.35"
+    "@babel/plugin-syntax-pipeline-operator": "7.0.0-beta.36"
  },
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35",
-    "@babel/helper-plugin-test-runner": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36",
+    "@babel/helper-plugin-test-runner": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-proposal-throw-expressions/package.json
+++ b/packages/babel-plugin-proposal-throw-expressions/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-proposal-throw-expressions",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Wraps Throw Expressions in an IIFE",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-proposal-throw-expressions",
  "license": "MIT",
@@ -9,13 +9,13 @@
    "babel-plugin"
  ],
  "dependencies": {
-    "@babel/plugin-syntax-throw-expressions": "7.0.0-beta.35"
+    "@babel/plugin-syntax-throw-expressions": "7.0.0-beta.36"
  },
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35",
-    "@babel/helper-plugin-test-runner": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36",
+    "@babel/helper-plugin-test-runner": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-proposal-unicode-property-regex/README.md
+++ b/packages/babel-plugin-proposal-unicode-property-regex/README.md
@@ -9,7 +9,7 @@ Compile [Unicode property escapes](https://github.com/mathiasbynens/regexpu-core
 ## Installation

 ```sh
-npm install @babel/plugin-proposal-unicode-property-regex
+npm install --save-dev @babel/plugin-proposal-unicode-property-regex
 ```

 ## Usage
--- a/packages/babel-plugin-proposal-unicode-property-regex/package.json
+++ b/packages/babel-plugin-proposal-unicode-property-regex/package.json
@@ -1,8 +1,9 @@
 {
  "name": "@babel/plugin-proposal-unicode-property-regex",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Compile Unicode property escapes in Unicode regular expressions to ES5.",
  "homepage": "https://babeljs.io/",
+  "license": "MIT",
  "main": "lib/index.js",
  "engines": {
    "node": ">=4"
@@ -18,14 +19,14 @@
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-proposal-unicode-property-regex",
  "bugs": "https://github.com/babel/babel/issues",
  "dependencies": {
-    "@babel/helper-regex": "7.0.0-beta.35",
+    "@babel/helper-regex": "7.0.0-beta.36",
    "regexpu-core": "^4.1.3"
  },
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35",
-    "@babel/helper-plugin-test-runner": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36",
+    "@babel/helper-plugin-test-runner": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-syntax-async-generators/package.json
+++ b/packages/babel-plugin-syntax-async-generators/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-syntax-async-generators",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Allow parsing of async generator functions",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-syntax-async-generators",
  "license": "MIT",
@@ -9,9 +9,9 @@
    "babel-plugin"
  ],
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-syntax-class-properties/package.json
+++ b/packages/babel-plugin-syntax-class-properties/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-syntax-class-properties",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Allow parsing of class properties",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-syntax-class-properties",
  "license": "MIT",
@@ -9,9 +9,9 @@
    "babel-plugin"
  ],
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-syntax-decorators/package.json
+++ b/packages/babel-plugin-syntax-decorators/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-syntax-decorators",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Allow parsing of decorators",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-syntax-decorators",
  "license": "MIT",
@@ -9,9 +9,9 @@
    "babel-plugin"
  ],
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-syntax-do-expressions/package.json
+++ b/packages/babel-plugin-syntax-do-expressions/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-syntax-do-expressions",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Allow parsing of do expressions",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-syntax-do-expressions",
  "license": "MIT",
@@ -9,9 +9,9 @@
    "babel-plugin"
  ],
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-syntax-dynamic-import/package.json
+++ b/packages/babel-plugin-syntax-dynamic-import/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-syntax-dynamic-import",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Allow parsing of import()",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-syntax-dynamic-import",
  "license": "MIT",
@@ -9,9 +9,9 @@
    "babel-plugin"
  ],
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-syntax-export-default-from/package.json
+++ b/packages/babel-plugin-syntax-export-default-from/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-syntax-export-default-from",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Allow parsing of export default from",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-syntax-export-default-from",
  "license": "MIT",
@@ -9,9 +9,9 @@
    "babel-plugin"
  ],
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-syntax-export-namespace-from/package.json
+++ b/packages/babel-plugin-syntax-export-namespace-from/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-syntax-export-namespace-from",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Allow parsing of export namespace from",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-syntax-export-namespace-from",
  "license": "MIT",
@@ -9,9 +9,9 @@
    "babel-plugin"
  ],
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-syntax-flow/package.json
+++ b/packages/babel-plugin-syntax-flow/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-syntax-flow",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Allow parsing of the flow syntax",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-syntax-flow",
  "license": "MIT",
@@ -9,9 +9,9 @@
    "babel-plugin"
  ],
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-syntax-function-bind/package.json
+++ b/packages/babel-plugin-syntax-function-bind/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-syntax-function-bind",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Allow parsing of function bind",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-syntax-function-bind",
  "license": "MIT",
@@ -9,9 +9,9 @@
    "babel-plugin"
  ],
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  }
 }
--- a/packages/babel-plugin-syntax-function-sent/package.json
+++ b/packages/babel-plugin-syntax-function-sent/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@babel/plugin-syntax-function-sent",
-  "version": "7.0.0-beta.35",
+  "version": "7.0.0-beta.36",
  "description": "Allow parsing of the function.sent meta property",
  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-syntax-function-sent",
  "license": "MIT",
@@ -9,9 +9,9 @@
    "babel-plugin"
  ],
  "peerDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  },
  "devDependencies": {
-    "@babel/core": "7.0.0-beta.35"
+    "@babel/core": "7.0.0-beta.36"
  }
 }
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
Henry Zhu	7d798952d2	v7.0.0-beta.36	2017-12-25 14:04:08 -05:00
Joe Lim	ed2b88830e	Remove extraneous console output when running preset-env tests (#6576 )	2017-12-25 13:47:19 -05:00
Bogdan Chadkin	d25918aa5d	Fix generation flow unnamed computed property (#7095 )	2017-12-22 12:55:40 -06:00
Artem Yavorsky	035286a810	[preset-env] Move all defaults to the separate module (#7084 ) * preset-env: Move all defaults to the separate module. * preset-env: Add test cases for defaults.	2017-12-22 10:42:06 -05:00
Logan Smyth	c9a00fbae8	Merge pull request #7090 from loganfsmyth/chain-processing-rewrite Refactor config processing more	2017-12-21 19:57:07 -08:00
Logan Smyth	758fd0369c	Rewrite config chain loading to build chain recursively to keep caching readable.	2017-12-21 19:06:36 -08:00
Logan Smyth	7b861796cf	Centralize validation logic in common folder.	2017-12-21 14:45:19 -08:00
Logan Smyth	f9825394a7	Remove unnecessary folder nesting.	2017-12-21 14:45:19 -08:00
Logan Smyth	43e7d1d2cc	Use an object instead of a 2-tuple.	2017-12-21 12:31:48 -08:00
Logan Smyth	de63443762	Split babelrc and babelignore searching into two functions.	2017-12-21 12:28:51 -08:00
Andy	6a73f39199	Support parsing `export default abstract class {}` (#7075 )	2017-12-21 16:13:31 +01:00
Azharuddin	2190e10e9a	Better error messages when Babel fails to parse import = and export =… (#7079 ) * Better error messages when Babel fails to parse import = and export = syntax from typescript when using babel-plugin-transform-typescript * Fixing Test cases * Ran make fix and broken looong sentence into smaller * Slight changes to Messages after review with Nicolo & existentialism * Removed trailing space	2017-12-21 02:00:36 +02:00
Nicolò Ribaudo	ae3f5b9149	Return the obj in setPrototypeOf fallback (#7080 )	2017-12-20 22:48:10 +01:00
Nicolò Ribaudo	0c885b3200	Add support for extending builtins (#7020 )	2017-12-20 14:46:00 -05:00
Artem Yavorsky	148fe7d3ff	Add proposal-async-generator-functions to babel-standalone (#7073 )	2017-12-20 20:37:16 +01:00
Henry Zhu	cabdf3769d	Merge pull request #7065 from babel/dotall-preset-env Add dot-all regex support to preset-env and standalone	2017-12-19 20:45:18 -05:00
Logan Smyth	1178799f07	Remove the LoadedFile class.	2017-12-19 15:36:54 -08:00
Logan Smyth	b2f1d01965	Add type annotations to utility file.	2017-12-19 15:36:19 -08:00
Logan Smyth	4f53496546	Drop the OptionManager class in favor of function.	2017-12-19 14:19:37 -08:00
Logan Smyth	1312a30d54	Perform normalization in the chain building process.	2017-12-19 14:19:37 -08:00
Logan Smyth	4afbc02476	Move descriptor merging into config chain processing.	2017-12-19 14:19:37 -08:00
Brian Ng	080c7f1e2d	Clean up logPlugin	2017-12-19 14:57:19 -06:00
Brian Ng	3cea9f412a	Add dot-all regex support to preset-env and standalone	2017-12-19 11:39:00 -06:00
Brian Ng	cd10ea03b4	Fix bug with debug output and unreleased versions	2017-12-19 11:38:59 -06:00
Mathias Bynens	5f8a1a2613	Fix unicode-property-regex installation instructions (#7064 )	2017-12-19 11:27:26 -06:00
Mathias Bynens	44da8201a5	Import babel-plugin-transform-dotall-regex (#7059 ) Original: https://github.com/mathiasbynens/babel-plugin-transform-dotall-regex Moving it into the official Babel repository makes it easier to maintain the transform.	2017-12-19 11:01:59 -05:00
Brian Ng	2b065350b5	Treat import type * as a parser error (#7061 )	2017-12-19 10:54:20 -05:00
Nicolò Ribaudo	68476b6ddd	Make .insert{Before,After} work by default when the parent is an eport declaration (#7040 )	2017-12-19 00:05:29 +01:00
Maaz Syed Adeeb	17b37b5013	Handling babylon parsing errors in a better way (#6961 ) * Handling babylon parsing errors in a better way * Better error messages + Helpful URLs * Replaced message from babylon completely * Add importMeta plugin to the map	2017-12-18 15:49:34 -05:00
Bo Lingen	56638e1370	Add pipeline operator plugins to babel-standalone (#6955 )	2017-12-18 10:10:20 -06:00
Francisco Ryan Tolmasky I	f0e46772a6	babel-types lists JSXIdentifier as an Expression (#6960 ) Currently, Babel is treating JSXIdentifier, JSXMemberExpression, and JSXEmptyExpression as expressions as well, which means Babel will for example incorrectly allow you to place these anywhere an expression is wanted. Closes #6851.	2017-12-18 09:27:43 -06:00
Mahmut Surekci	398bc43656	Add MIT license to proposal-unicode-property-regex (#7047 )	2017-12-18 13:48:30 +01:00
Logan Smyth	44ea9433c0	Merge pull request #6952 from loganfsmyth/commonjs-lazy Add a 'lazy' options to modules-commonjs	2017-12-17 19:32:51 -08:00
Logan Smyth	53826aaaa0	Expose a 'lazy' option for the CommonJS transform.	2017-12-17 18:42:35 -08:00
Logan Smyth	b900a3e5c2	Consistently return AST nodes.	2017-12-17 18:33:47 -08:00
dnalborczyk	ed4d90b33d	expose import.meta syntax parser option as plugin (#7008 )	2017-12-16 15:06:23 -06:00
Anthony Bianco	209a598d51	Fix loose option description in transform-modules-commonjs	2017-12-16 14:41:05 -06:00
Nicolò Ribaudo	9a146d01b0	[decorators] Don't transform every AssignmentExpression (#7032 )	2017-12-15 16:17:31 -05:00
Rouven Weßling	f2437583ba	Bump globals to version 11.1.0 (#7006 )	2017-12-15 13:20:22 -05:00
Sven SAULEAU	a24c9f8ed6	Merge pull request #7028 from sophiebits/getLetReferences-n2 Fix O(n^2) getLetReferences – 40% faster on large flat files	2017-12-15 07:59:57 +01:00
Sophie Alpert	6a7223af29	Fix O(n^2) getLetReferences – 40% faster on large flat files `this.blockPath.get("body")` constructs an array of paths corresponding to each node in `blocks.body` so takes O(n) time if n is that length. We were re-constructing that array on each iteration, so the entire loop was O(n^2). On files with many statements in a single block (such as Rollup-generated bundles), this takes a large portion of time. In particular, this makes transforming react-dom.development.js about 40% faster. Not that you should be transforming our bundle with Babel. Test Plan: Make an HTML file with these three lines and watch it in the Chrome Performance tab to see timings (on my machine: 2.9s before, 1.6s after): ``` <!DOCTYPE html> <script src="https://unpkg.com/babel-standalone@7.0.0-beta.3/babel.js"></script> <script type="text/babel" src="https://unpkg.com/react-dom@16.2.0/umd/react-dom.development.js"></script> ```	2017-12-14 21:55:26 -08:00
Diogo Franco	a66845169f	Rename misleading identifier notRegenerator actually _enabled_ transforming regeneratorRuntime references.	2017-12-15 11:20:15 +09:00