Merge pull request #6304 from loganfsmyth/import-helper

Rewrite import insertion to insert import..from/require() based on module type

packages/babel-cli/test/fixtures/babel-external-helpers/--whitelist/stdout.txt

@@ -17,5 +17,5 @@
     return Constructor;
   }
 
-  babelHelpers.createClass = _createClass
+  babelHelpers.createClass = _createClass;
 })(typeof global === "undefined" ? self : global);

packages/babel-core/src/transformation/file/index.js

@@ -178,49 +178,13 @@ export default class File extends Store {
     return source;
   }
 
-  addImport(
-    source: string,
-    imported?: string = "",
-    name?: string = imported,
-  ): Object | null {
-    const prependDeclaration = (
-      specifiers: Array<BabelNodeImportSpecifier>,
-    ): void => {
-      const declar = t.importDeclaration(specifiers, t.stringLiteral(source));
-      declar._blockHoist = 3;
-
-      this.path.unshiftContainer("body", declar);
-    };
-
-    // import "module-name";
-    if (!imported) {
-      prependDeclaration([]);
-      return null;
-    }
-
-    const alias = `${source}:${imported}`;
-    let id = this.dynamicImportIds[alias];
-
-    if (!id) {
-      source = this.resolveModuleSource(source);
-      id = this.dynamicImportIds[alias] = this.scope.generateUidIdentifier(
-        name,
-      );
-
-      const specifiers = [];
-
-      if (imported === "*") {
-        specifiers.push(t.importNamespaceSpecifier(id));
-      } else if (imported === "default") {
-        specifiers.push(t.importDefaultSpecifier(id));
-      } else {
-        specifiers.push(t.importSpecifier(id, t.identifier(imported)));
-      }
-
-      prependDeclaration(specifiers);
-    }
-
-    return t.identifier(id.name);
+  addImport() {
+    throw new Error(
+      "This API has been removed. If you're looking for this " +
+        "functionality in Babel 7, you should import the " +
+        "'babel-helper-module-imports' module and use the functions exposed " +
+        " from that module, such as 'addNamed' or 'addDefault'.",
+    );
   }
 
   addHelper(name: string): Object {

packages/babel-core/src/transformation/internal-plugins/block-hoist.js

@@ -10,6 +10,7 @@ export default {
    *  - 1 Default node position
    *  - 2 Priority over normal nodes
    *  - 3 We want this to be at the **very** top
+   *  - 4 Reserved for the helpers used to implement module imports.
    */
 
   name: "internal.blockHoist",

packages/babel-core/test/fixtures/plugins/file-add-import/exec.js

@@ -1,30 +0,0 @@
-var res = transform("", {
-  plugins: [
-    function (b) {
-      return {
-        visitor: {
-          Program: function(path, state) {
-            var file = state.file;
-            file.addImport("import-star", "*", "lib");
-            file.addImport("import-default", "default", "foo");
-            file.addImport("import-alias", "bar", "baz");
-            file.addImport("import-default-alias", "quux");
-            file.addImport("import-empty", "");
-            file.addImport("import-none");
-          }
-        }
-      };
-    }
-  ]
-});
-
-var expected = multiline([
-  'import "import-none";',
-  'import "import-empty";',
-  'import { quux as _quux } from "import-default-alias";',
-  'import { bar as _baz } from "import-alias";',
-  'import _foo from "import-default";',
-  'import * as _lib from "import-star";',
-]);
-
-assert.equal(res.code, expected);

packages/babel-helper-module-imports/.npmignore

@@ -0,0 +1,3 @@
+src
+test
+*.log

packages/babel-helper-module-imports/README.md

@@ -0,0 +1,27 @@
+# babel-helper-module-imports
+
+## Usage
+
+### Adding a named import
+
+```
+import { addNamed } from "babel-helper-module-imports";
+
+export default function({ types: t }) {
+  return {
+    visitor: {
+      ReferencedIdentifier(path) {
+        let importName = this.importName;
+        if (importName) {
+          importName = t.cloneDeep(importName);
+        } else {
+          // require('bluebird').coroutine
+          importName = this.importName = addName(path, 'coroutine', 'bluebird');
+        }
+
+        path.replaceWith(importName);
+      }
+    },
+  };
+}
+```

packages/babel-helper-module-imports/package.json

@@ -0,0 +1,14 @@
+{
+  "name": "babel-helper-module-imports",
+  "version": "7.0.0-beta.2",
+  "description": "Babel helper functions for inserting module loads",
+  "author": "Logan Smyth <loganfsmyth@gmail.com>",
+  "homepage": "https://babeljs.io/",
+  "license": "MIT",
+  "repository": "https://github.com/babel/babel/tree/master/packages/babel-helper-module-imports",
+  "main": "lib/index.js",
+  "dependencies": {
+    "babel-types": "7.0.0-beta.2",
+    "lodash": "^4.2.0"
+  }
+}

packages/babel-helper-module-imports/src/import-builder.js

@@ -0,0 +1,142 @@
+import assert from "assert";
+import * as t from "babel-types";
+
+/**
+ * A class to track and accumulate mutations to the AST that will eventually
+ * output a new require/import statement list.
+ */
+export default class ImportBuilder {
+  _statements = [];
+  _resultName = null;
+
+  _scope = null;
+  _file = null;
+
+  constructor(importedSource, scope, file) {
+    this._scope = scope;
+    this._file = file;
+    this._importedSource = importedSource;
+  }
+
+  done() {
+    return {
+      statements: this._statements,
+      resultName: this._resultName,
+    };
+  }
+
+  import() {
+    const importedSource = this._file.resolveModuleSource(this._importedSource);
+
+    this._statements.push(
+      t.importDeclaration([], t.stringLiteral(importedSource)),
+    );
+    return this;
+  }
+
+  require() {
+    const importedSource = this._file.resolveModuleSource(this._importedSource);
+
+    this._statements.push(
+      t.expressionStatement(
+        t.callExpression(t.identifier("require"), [
+          t.stringLiteral(importedSource),
+        ]),
+      ),
+    );
+    return this;
+  }
+
+  namespace(name) {
+    name = this._scope.generateUidIdentifier(name);
+
+    const statement = this._statements[this._statements.length - 1];
+    assert(statement.type === "ImportDeclaration");
+    assert(statement.specifiers.length === 0);
+    statement.specifiers = [t.importNamespaceSpecifier(name)];
+    this._resultName = t.clone(name);
+    return this;
+  }
+  default(name) {
+    name = this._scope.generateUidIdentifier(name);
+    const statement = this._statements[this._statements.length - 1];
+    assert(statement.type === "ImportDeclaration");
+    assert(statement.specifiers.length === 0);
+    statement.specifiers = [t.importDefaultSpecifier(name)];
+    this._resultName = t.clone(name);
+    return this;
+  }
+  named(name, importName) {
+    if (importName === "default") return this.default(name);
+
+    name = this._scope.generateUidIdentifier(name);
+    const statement = this._statements[this._statements.length - 1];
+    assert(statement.type === "ImportDeclaration");
+    assert(statement.specifiers.length === 0);
+    statement.specifiers = [t.importSpecifier(name, t.identifier(importName))];
+    this._resultName = t.clone(name);
+    return this;
+  }
+
+  var(name) {
+    name = this._scope.generateUidIdentifier(name);
+    let statement = this._statements[this._statements.length - 1];
+    if (statement.type !== "ExpressionStatement") {
+      assert(this._resultName);
+      statement = t.expressionStatement(this._resultName);
+      this._statements.push(statement);
+    }
+    this._statements[
+      this._statements.length - 1
+    ] = t.variableDeclaration("var", [
+      t.variableDeclarator(name, statement.expression),
+    ]);
+    this._resultName = t.clone(name);
+    return this;
+  }
+
+  defaultInterop() {
+    return this._interop(this._file.addHelper("interopRequireDefault"));
+  }
+  wildcardInterop() {
+    return this._interop(this._file.addHelper("interopRequireWildcard"));
+  }
+
+  _interop(callee) {
+    const statement = this._statements[this._statements.length - 1];
+    if (statement.type === "ExpressionStatement") {
+      statement.expression = t.callExpression(callee, [statement.expression]);
+    } else if (statement.type === "VariableDeclaration") {
+      assert(statement.declarations.length === 1);
+      statement.declarations[0].init = t.callExpression(callee, [
+        statement.declarations[0].init,
+      ]);
+    } else {
+      assert.fail("Unexpected type.");
+    }
+    return this;
+  }
+
+  prop(name) {
+    const statement = this._statements[this._statements.length - 1];
+    if (statement.type === "ExpressionStatement") {
+      statement.expression = t.memberExpression(
+        statement.expression,
+        t.identifier(name),
+      );
+    } else if (statement.type === "VariableDeclaration") {
+      assert(statement.declarations.length === 1);
+      statement.declarations[0].init = t.memberExpression(
+        statement.declarations[0].init,
+        t.identifier(name),
+      );
+    } else {
+      assert.fail("Unexpected type:" + statement.type);
+    }
+    return this;
+  }
+
+  read(name) {
+    this._resultName = t.memberExpression(this._resultName, t.identifier(name));
+  }
+}

packages/babel-helper-module-imports/src/import-injector.js

@@ -0,0 +1,425 @@
+import assert from "assert";
+import * as t from "babel-types";
+
+import ImportBuilder from "./import-builder";
+import isModule from "./is-module";
+
+export type ImportOptions = {
+  /**
+   * The module being referenced.
+   */
+  importedSource: string | null,
+
+  /**
+   * The type of module being imported:
+   *
+   *  * 'es6'      - An ES6 module.
+   *  * 'commonjs' - A CommonJS module. (Default)
+   */
+  importedType: "es6" | "commonjs",
+
+  /**
+   * The type of interop behavior for namespace/default/named when loading
+   * CommonJS modules.
+   *
+   * ## 'babel' (Default)
+   *
+   * Load using Babel's interop.
+   *
+   * If '.__esModule' is true, treat as 'compiled', else:
+   *
+   * * Namespace: A copy of the module.exports with .default
+   *     populated by the module.exports object.
+   * * Default: The module.exports value.
+   * * Named: The .named property of module.exports.
+   *
+   * The 'ensureLiveReference' has no effect on the liveness of these.
+   *
+   * ## 'compiled'
+   *
+   * Assume the module is ES6 compiled to CommonJS. Useful to avoid injecting
+   * interop logic if you are confident that the module is a certain format.
+   *
+   * * Namespace: The root module.exports object.
+   * * Default: The .default property of the namespace.
+   * * Named: The .named property of the namespace.
+   *
+   * Will return erroneous results if the imported module is _not_ compiled
+   * from ES6 with Babel.
+   *
+   * ## 'uncompiled'
+   *
+   * Assume the module is _not_ ES6 compiled to CommonJS. Used a simplified
+   * access pattern that doesn't require additional function calls.
+   *
+   * Will return erroneous results if the imported module _is_ compiled
+   * from ES6 with Babel.
+   *
+   * * Namespace: The module.exports object.
+   * * Default: The module.exports object.
+   * * Named: The .named property of module.exports.
+   */
+  importedInterop: "babel" | "node" | "compiled" | "uncompiled",
+
+  /**
+   * The type of CommonJS interop included in the environment that will be
+   * loading the output code.
+   *
+   *  * 'babel' - CommonJS modules load with Babel's interop. (Default)
+   *  * 'node'  - CommonJS modules load with Node's interop.
+   *
+   * See descriptions in 'importedInterop' for more details.
+   */
+  importingInterop: "babel" | "node",
+
+  /**
+   * Define whether we explicitly care that the import be a live reference.
+   * Only applies when importing default and named imports, not the namespace.
+   *
+   *  * true  - Force imported values to be live references.
+   *  * false - No particular requirements. Keeps the code simplest. (Default)
+   */
+  ensureLiveReference: boolean,
+
+  /**
+   * Define if we explicitly care that the result not be a property reference.
+   *
+   *  * true  - Force calls to exclude context. Useful if the value is going to
+   *            be used as function callee.
+   *  * false - No particular requirements for context of the access. (Default)
+   */
+  ensureNoContext: boolean,
+};
+
+/**
+ * A general helper classes add imports via transforms. See README for usage.
+ */
+export default class ImportInjector {
+  /**
+   * The path used for manipulation.
+   */
+  _programPath: NodePath;
+
+  /**
+   * The scope used to generate unique variable names.
+   */
+  _programScope;
+
+  /**
+   * The file used to inject helpers and resolve paths.
+   */
+  _file;
+
+  /**
+   * The default options to use with this instance when imports are added.
+   */
+  _defaultOpts: ImportOptions = {
+    importedSource: null,
+    importedType: "commonjs",
+    importedInterop: "babel",
+    importingInterop: "babel",
+    ensureLiveReference: false,
+    ensureNoContext: false,
+  };
+
+  constructor(path, importedSource, opts) {
+    const programPath = path.find(p => p.isProgram());
+
+    this._programPath = programPath;
+    this._programScope = programPath.scope;
+    this._file = programPath.hub.file;
+
+    this._defaultOpts = this._applyDefaults(importedSource, opts, true);
+  }
+
+  addDefault(importedSourceIn, opts) {
+    return this.addNamed("default", importedSourceIn, opts);
+  }
+
+  addNamed(importName, importedSourceIn, opts) {
+    assert(typeof importName === "string");
+
+    return this._generateImport(
+      this._applyDefaults(importedSourceIn, opts),
+      importName,
+    );
+  }
+
+  addNamespace(importedSourceIn, opts) {
+    return this._generateImport(
+      this._applyDefaults(importedSourceIn, opts),
+      null,
+    );
+  }
+
+  addSideEffect(importedSourceIn, opts) {
+    return this._generateImport(
+      this._applyDefaults(importedSourceIn, opts),
+      false,
+    );
+  }
+
+  _applyDefaults(importedSource, opts, isInit = false) {
+    const optsList = [];
+    if (typeof importedSource === "string") {
+      optsList.push({ importedSource });
+      optsList.push(opts);
+    } else {
+      assert(!opts, "Unexpected secondary arguments.");
+
+      optsList.push(importedSource);
+    }
+
+    const newOpts = Object.assign({}, this._defaultOpts);
+    for (const opts of optsList) {
+      if (!opts) continue;
+      Object.keys(newOpts).forEach(key => {
+        if (opts[key] !== undefined) newOpts[key] = opts[key];
+      });
+
+      if (!isInit) {
+        if (opts.nameHint !== undefined) newOpts.nameHint = opts.nameHint;
+        if (opts.blockHoist !== undefined) newOpts.blockHoist = opts.blockHoist;
+      }
+    }
+    return newOpts;
+  }
+
+  _generateImport(opts, importName) {
+    const isDefault = importName === "default";
+    const isNamed = !!importName && !isDefault;
+    const isNamespace = importName === null;
+
+    const {
+      importedSource,
+      importedType,
+      importedInterop,
+      importingInterop,
+      ensureLiveReference,
+      ensureNoContext,
+
+      // Provide a hint for generateUidIdentifier for the local variable name
+      // to use for the import, if the code will generate a simple assignment
+      // to a variable.
+      nameHint = importName,
+
+      // Not meant for public usage. Allows code that absolutely must control
+      // ordering to set a specific hoist value on the import nodes.
+      blockHoist,
+    } = opts;
+
+    const isMod = isModule(this._programPath, true);
+    const isModuleForNode = isMod && importingInterop === "node";
+    const isModuleForBabel = isMod && importingInterop === "babel";
+
+    const builder = new ImportBuilder(
+      importedSource,
+      this._programScope,
+      this._file,
+    );
+
+    if (importedType === "es6") {
+      if (!isModuleForNode && !isModuleForBabel) {
+        throw new Error("Cannot import an ES6 module from CommonJS");
+      }
+
+      // import * as namespace from ''; namespace
+      // import def from ''; def
+      // import { named } from ''; named
+      builder.import();
+      if (isNamespace) {
+        builder.namespace("namespace");
+      } else if (isDefault || isNamed) {
+        builder.named(nameHint, importName);
+      }
+    } else if (importedType !== "commonjs") {
+      throw new Error(`Unexpected interopType "${importedType}"`);
+    } else if (importedInterop === "babel") {
+      if (isModuleForNode) {
+        // import _tmp from ''; var namespace = interopRequireWildcard(_tmp); namespace
+        // import _tmp from ''; var def = interopRequireDefault(_tmp).default; def
+        // import _tmp from ''; _tmp.named
+
+        builder.import();
+        if (isNamespace) {
+          builder
+            .default("es6Default")
+            .var(nameHint || "namespace")
+            .wildcardInterop();
+        } else if (isDefault) {
+          if (ensureLiveReference) {
+            builder
+              .default("es6Default")
+              .var("namespace")
+              .defaultInterop()
+              .read("default");
+          } else {
+            builder
+              .default("es6Default")
+              .var(nameHint)
+              .defaultInterop()
+              .prop(importName);
+          }
+        } else if (isNamed) {
+          builder.default("es6Default").read(importName);
+        }
+      } else if (isModuleForBabel) {
+        // import * as namespace from ''; namespace
+        // import def from ''; def
+        // import { named } from ''; named
+        builder.import();
+        if (isNamespace) {
+          builder.namespace("namespace");
+        } else if (isDefault || isNamed) {
+          builder.named(nameHint, importName);
+        }
+      } else {
+        // var namespace = interopRequireWildcard(require(''));
+        // var def = interopRequireDefault(require('')).default; def
+        // var named = require('').named; named
+        builder.require();
+        if (isNamespace) {
+          builder.var("namespace").wildcardInterop();
+        } else if ((isDefault || isNamed) && ensureLiveReference) {
+          builder.var("namespace").read(importName);
+
+          if (isDefault) builder.defaultInterop();
+        } else if (isDefault) {
+          builder
+            .var(nameHint)
+            .defaultInterop()
+            .prop(importName);
+        } else if (isNamed) {
+          builder.var(nameHint).prop(importName);
+        }
+      }
+    } else if (importedInterop === "compiled") {
+      if (isModuleForNode) {
+        // import namespace from ''; namespace
+        // import namespace from ''; namespace.default
+        // import namespace from ''; namespace.named
+
+        builder.import();
+        if (isNamespace) {
+          builder.default("namespace");
+        } else if (isDefault || isNamed) {
+          builder.default("namespace").read(importName);
+        }
+      } else if (isModuleForBabel) {
+        // import * as namespace from ''; namespace
+        // import def from ''; def
+        // import { named } from ''; named
+        // Note: These lookups will break if the module has no __esModule set,
+        // hence the warning that 'compiled' will not work on standard CommonJS.
+
+        builder.import();
+        if (isNamespace) {
+          builder.namespace("namespace");
+        } else if (isDefault || isNamed) {
+          builder.named(nameHint, importName);
+        }
+      } else {
+        // var namespace = require(''); namespace
+        // var namespace = require(''); namespace.default
+        // var namespace = require(''); namespace.named
+        // var named = require('').named;
+
+        builder.require();
+        if (isNamespace) {
+          builder.var("namespace");
+        } else if (isDefault || isNamed) {
+          if (ensureLiveReference) {
+            builder.var("namespace").read(importName);
+          } else {
+            builder.prop(importName).var(nameHint);
+          }
+        }
+      }
+    } else if (importedInterop === "uncompiled") {
+      if (isDefault && ensureLiveReference) {
+        throw new Error("No live reference for commonjs default");
+      }
+
+      if (isModuleForNode) {
+        // import namespace from ''; namespace
+        // import def from ''; def;
+        // import namespace from ''; namespace.named
+
+        builder.import();
+        if (isNamespace) {
+          builder.default("namespace");
+        } else if (isDefault) {
+          builder.default(nameHint);
+        } else if (isNamed) {
+          builder.default("namespace").read(importName);
+        }
+      } else if (isModuleForBabel) {
+        // import namespace from '';
+        // import def from '';
+        // import { named } from ''; named;
+        // Note: These lookups will break if the module has __esModule set,
+        // hence the warning that 'uncompiled' will not work on ES6 transpiled
+        // to CommonJS.
+
+        builder.import();
+        if (isNamespace) {
+          builder.default("namespace");
+        } else if (isDefault) {
+          builder.default(nameHint);
+        } else if (isNamed) {
+          builder.named(nameHint, importName);
+        }
+      } else {
+        // var namespace = require(''); namespace
+        // var def = require(''); def
+        // var namespace = require(''); namespace.named
+        // var named = require('').named;
+
+        builder.require();
+        if (isNamespace) {
+          builder.var("namespace");
+        } else if (isDefault) {
+          builder.var(nameHint);
+        } else if (isNamed) {
+          if (ensureLiveReference) {
+            builder.var("namespace").read(importName);
+          } else {
+            builder.var(nameHint).prop(importName);
+          }
+        }
+      }
+    } else {
+      throw new Error(`Unknown importedInterop "${importedInterop}".`);
+    }
+
+    const { statements, resultName } = builder.done();
+
+    this._insertStatements(statements, blockHoist);
+
+    if (
+      (isDefault || isNamed) &&
+      ensureNoContext &&
+      resultName.type !== "Identifier"
+    ) {
+      return t.sequenceExpression([t.numericLiteral(0), resultName]);
+    }
+    return resultName;
+  }
+
+  _insertStatements(statements, blockHoist = 3) {
+    statements.forEach(node => {
+      node._blockHoist = blockHoist;
+    });
+
+    const targetPath = this._programPath.get("body").filter(p => {
+      const val = p.node._blockHoist;
+      return Number.isFinite(val) && val < 4;
+    })[0];
+
+    if (targetPath) {
+      targetPath.insertBefore(statements);
+    } else {
+      this._programPath.unshiftContainer("body", statements);
+    }
+  }
+}

packages/babel-helper-module-imports/src/index.js

@@ -0,0 +1,21 @@
+import ImportInjector from "./import-injector";
+
+export { ImportInjector };
+
+export { default as isModule } from "./is-module";
+
+export function addDefault(path, importedSource, opts) {
+  return new ImportInjector(path).addDefault(importedSource, opts);
+}
+
+export function addNamed(path, name, importedSource, opts) {
+  return new ImportInjector(path).addNamed(name, importedSource, opts);
+}
+
+export function addNamespace(path, importedSource, opts) {
+  return new ImportInjector(path).addNamespace(importedSource, opts);
+}
+
+export function addSideEffect(path, importedSource, opts) {
+  return new ImportInjector(path).addSideEffect(importedSource, opts);
+}

packages/babel-helper-module-imports/src/is-module.js

@@ -0,0 +1,31 @@
+/**
+ * A small utility to check if a file qualifies as a module, based on a few
+ * possible conditions.
+ */
+export default function isModule(
+  path: NodePath,
+  requireUnambiguous: boolean = false,
+) {
+  const { sourceType } = path.node;
+  if (sourceType !== "module" && sourceType !== "script") {
+    throw path.buildCodeFrameError(
+      `Unknown sourceType "${sourceType}", cannot transform.`,
+    );
+  }
+
+  const filename = path.hub.file.opts.filename;
+  if (/\.mjs$/.test(filename)) {
+    requireUnambiguous = false;
+  }
+
+  return (
+    path.node.sourceType === "module" &&
+    (!requireUnambiguous || isUnambiguousModule(path))
+  );
+}
+
+// This approach is not ideal. It is here to preserve compatibility for now,
+// but really this should just return true or be deleted.
+function isUnambiguousModule(path) {
+  return path.get("body").some(p => p.isModuleDeclaration());
+}

packages/babel-helper-module-transforms/package.json

@@ -8,6 +8,7 @@
   "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.2",
     "babel-template": "7.0.0-beta.2",
     "babel-types": "7.0.0-beta.2",
     "lodash": "^4.2.0"

packages/babel-helper-module-transforms/src/index.js

@@ -3,6 +3,8 @@ import * as t from "babel-types";
 import template from "babel-template";
 import chunk from "lodash/chunk";
 
+import { isModule } from "babel-helper-module-imports";
+
 import rewriteThis from "./rewrite-this";
 import rewriteLiveReferences from "./rewrite-live-references";
 import normalizeAndLoadModuleMetadata, {
@@ -10,32 +12,7 @@ import normalizeAndLoadModuleMetadata, {
   isSideEffectImport,
 } from "./normalize-and-load-metadata";
 
-export { hasExports, isSideEffectImport };
-
-export function isModule(path: NodePath, requireUnambiguous: boolean = false) {
-  const { sourceType } = path.node;
-  if (sourceType !== "module" && sourceType !== "script") {
-    throw path.buildCodeFrameError(
-      `Unknown sourceType "${sourceType}", cannot transform.`,
-    );
-  }
-
-  const filename = path.hub.file.opts.filename;
-  if (/\.mjs$/.test(filename)) {
-    requireUnambiguous = false;
-  }
-
-  return (
-    path.node.sourceType === "module" &&
-    (!requireUnambiguous || isUnambiguousModule(path))
-  );
-}
-
-// This approach is not ideal. It is here to preserve compatibility for now,
-// but really this should just return true or be deleted.
-function isUnambiguousModule(path) {
-  return path.get("body").some(p => p.isModuleDeclaration());
-}
+export { hasExports, isSideEffectImport, isModule };
 
 /**
  * Perform all of the generic ES6 module rewriting needed to handle initial

packages/babel-helpers/src/index.js

@@ -157,10 +157,14 @@ function permuteHelperAST(file, metadata, id, localBindings) {
           exp.replaceWith(decl);
           path.pushContainer(
             "body",
-            t.assignmentExpression("=", id, t.identifier(exportName)),
+            t.expressionStatement(
+              t.assignmentExpression("=", id, t.identifier(exportName)),
+            ),
           );
         } else {
-          exp.replaceWith(t.assignmentExpression("=", id, decl.node));
+          exp.replaceWith(
+            t.expressionStatement(t.assignmentExpression("=", id, decl.node)),
+          );
         }
       } else {
         throw new Error("Unexpected helper format.");

packages/babel-plugin-transform-async-to-module-method/package.json

@@ -10,6 +10,7 @@
   ],
   "dependencies": {
     "babel-helper-remap-async-to-generator": "7.0.0-beta.2",
+    "babel-helper-module-imports": "7.0.0-beta.2",
     "babel-plugin-syntax-async-functions": "7.0.0-beta.0",
     "babel-types": "7.0.0-beta.2"
   },

packages/babel-plugin-transform-async-to-module-method/src/index.js

@@ -1,7 +1,9 @@
 import remapAsyncToGenerator from "babel-helper-remap-async-to-generator";
 import syntaxAsyncFunctions from "babel-plugin-syntax-async-functions";
 
-export default function() {
+import { addNamed } from "babel-helper-module-imports";
+
+export default function({ types: t }) {
   return {
     inherits: syntaxAsyncFunctions,
 
@@ -9,8 +11,17 @@ export default function() {
       Function(path, state) {
         if (!path.node.async || path.node.generator) return;
 
+        const { module, method } = state.opts;
+
+        let wrapAsync = state.methodWrapper;
+        if (wrapAsync) {
+          wrapAsync = t.cloneDeep(wrapAsync);
+        } else {
+          wrapAsync = state.methodWrapper = addNamed(path, method, module);
+        }
+
         remapAsyncToGenerator(path, state.file, {
-          wrapAsync: state.addImport(state.opts.module, state.opts.method),
+          wrapAsync,
         });
       },
     },

packages/babel-plugin-transform-async-to-module-method/test/fixtures/bluebird-coroutines/arrow-function/expected.js

@@ -1,4 +1,4 @@
-import { coroutine as _coroutine } from "bluebird";
+var _coroutine = require("bluebird").coroutine;
 
 _coroutine(function* () {
   yield foo();

packages/babel-plugin-transform-async-to-module-method/test/fixtures/bluebird-coroutines/class/expected.js

@@ -1,4 +1,4 @@
-import { coroutine as _coroutine } from "bluebird";
+var _coroutine = require("bluebird").coroutine;
 
 class Foo {
   foo() {

packages/babel-plugin-transform-async-to-module-method/test/fixtures/bluebird-coroutines/expression/expected.js

@@ -1,4 +1,4 @@
-import { coroutine as _coroutine } from "bluebird";
+var _coroutine = require("bluebird").coroutine;
 
 var foo = (() => {
   var _ref = _coroutine(function* () {

packages/babel-plugin-transform-async-to-module-method/test/fixtures/bluebird-coroutines/named-expression/expected.js

@@ -1,4 +1,4 @@
-import { coroutine as _coroutine } from "bluebird";
+var _coroutine = require("bluebird").coroutine;
 
 var foo = (() => {
   var _ref = _coroutine(function* () {

packages/babel-plugin-transform-async-to-module-method/test/fixtures/bluebird-coroutines/statement/expected.js

@@ -1,4 +1,4 @@
-import { coroutine as _coroutine } from "bluebird";
+var _coroutine = require("bluebird").coroutine;
 
 let foo = (() => {
   var _ref = _coroutine(function* () {

packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/imports-hoisting/expected.js

@@ -1,9 +1,5 @@
-"use strict";
+var _taggedTemplateLiteral = require("babel-runtime/helpers/taggedTemplateLiteral");
 
-var _taggedTemplateLiteral2 = _interopRequireDefault(require("babel-runtime/helpers/taggedTemplateLiteral"));
-
-var _templateObject = (0, _taggedTemplateLiteral2.default)(["foo"], ["foo"]);
-
-function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
+var _templateObject = _taggedTemplateLiteral(["foo"], ["foo"]);
 
 tag(_templateObject);

packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/multi-load/actual.js

@@ -0,0 +1,3 @@
+export {};
+
+console.log(helper);

packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/multi-load/expected.js

@@ -0,0 +1,7 @@
+"use strict";
+
+var _interopRequireDefault3 = require("babel-runtime/helpers/interopRequireDefault");
+
+var _interopRequireDefault2 = _interopRequireDefault3(require("babel-runtime/helpers/interopRequireDefault"));
+
+console.log(_interopRequireDefault2.default);

packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/multi-load/options.json

@@ -0,0 +1,7 @@
+{
+  "plugins": [
+    "transform-es2015-modules-commonjs",
+    "transform-runtime",
+    "./plugin"
+  ]
+}

packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/multi-load/plugin.js

@@ -0,0 +1,11 @@
+module.exports = function() {
+  return {
+    visitor: {
+      Identifier: function(path) {
+        if (path.node.name !== "helper") return;
+
+        path.replaceWith(this.addHelper("interopRequireDefault"));
+      },
+    },
+  };
+};

packages/babel-plugin-transform-regenerator/test/fixtures/regression/T7041/expected.js

@@ -1,19 +1,15 @@
-"use strict";
+var _regeneratorRuntime = require("babel-runtime/regenerator");
 
-var _regenerator = _interopRequireDefault(require("babel-runtime/regenerator"));
-
-var _keys = _interopRequireDefault(require("babel-runtime/core-js/object/keys"));
-
-function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
+var _Object$keys = require("babel-runtime/core-js/object/keys");
 
 var _marked =
 /*#__PURE__*/
-_regenerator.default.mark(fn);
+_regeneratorRuntime.mark(fn);
 
-(0, _keys.default)({});
+_Object$keys({});
 
 function fn() {
-  return _regenerator.default.wrap(function fn$(_context) {
+  return _regeneratorRuntime.wrap(function fn$(_context) {
     while (1) {
       switch (_context.prev = _context.next) {
         case 0:

packages/babel-plugin-transform-runtime/package.json

@@ -8,6 +8,9 @@
   "keywords": [
     "babel-plugin"
   ],
+  "dependencies": {
+    "babel-helper-module-imports": "7.0.0-beta.2"
+  },
   "devDependencies": {
     "babel-helper-plugin-test-runner": "7.0.0-beta.2"
   }

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

@@ -1,3 +1,5 @@
+import { addDefault, isModule } from "babel-helper-module-imports";
+
 import definitions from "./definitions";
 
 export default function({ types: t }) {
@@ -9,7 +11,7 @@ export default function({ types: t }) {
     return Object.prototype.hasOwnProperty.call(obj, key);
   }
 
-  const HELPER_BLACKLIST = ["interopRequireWildcard", "interopRequireDefault"];
+  const HEADER_HELPERS = ["interopRequireWildcard", "interopRequireDefault"];
 
   return {
     pre(file) {
@@ -22,14 +24,20 @@ export default function({ types: t }) {
         const helpersDir = this.opts.useESModules
           ? `${baseHelpersDir}/es6`
           : baseHelpersDir;
-        file.set("helperGenerator", function(name) {
-          if (HELPER_BLACKLIST.indexOf(name) < 0) {
-            return file.addImport(
-              `${moduleName}/${helpersDir}/${name}`,
-              "default",
-              name,
-            );
-          }
+        file.set("helperGenerator", name => {
+          const isInteropHelper = HEADER_HELPERS.indexOf(name) !== -1;
+
+          // Explicitly set the CommonJS interop helpers to their reserve
+          // blockHoist of 4 so they are guaranteed to exist
+          // when other things used them to import.
+          const blockHoist =
+            isInteropHelper && !isModule(file.path) ? 4 : undefined;
+
+          return this.addDefaultImport(
+            `${moduleName}/${helpersDir}/${name}`,
+            name,
+            blockHoist,
+          );
         });
       }
 
@@ -40,6 +48,30 @@ export default function({ types: t }) {
       }
 
       this.moduleName = moduleName;
+
+      const cache = new Map();
+
+      this.addDefaultImport = (source, nameHint, blockHoist) => {
+        // If something on the page adds a helper when the file is an ES6
+        // file, we can't reused the cached helper name after things have been
+        // transformed because it has almost certainly been renamed.
+        const cacheKey = isModule(file.path);
+        const key = `${source}:${nameHint}:${cacheKey || ""}`;
+
+        let cached = cache.get(key);
+        if (cached) {
+          cached = t.cloneDeep(cached);
+        } else {
+          cached = addDefault(file.path, source, {
+            importedInterop: "uncompiled",
+            nameHint,
+            blockHoist,
+          });
+
+          cache.set(key, cached);
+        }
+        return cached;
+      };
     },
 
     visitor: {
@@ -50,9 +82,8 @@ export default function({ types: t }) {
           state.opts.regenerator !== false
         ) {
           path.replaceWith(
-            this.file.addImport(
+            this.addDefaultImport(
               `${this.moduleName}/regenerator`,
-              "default",
               "regeneratorRuntime",
             ),
           );
@@ -68,9 +99,8 @@ export default function({ types: t }) {
         // Symbol() -> _core.Symbol(); new Promise -> new _core.Promise
         const moduleName = getRuntimeModuleName(state.opts);
         path.replaceWith(
-          state.addImport(
+          this.addDefaultImport(
             `${moduleName}/core-js/${definitions.builtins[node.name]}`,
-            "default",
             node.name,
           ),
         );
@@ -93,9 +123,8 @@ export default function({ types: t }) {
         const moduleName = getRuntimeModuleName(state.opts);
         path.replaceWith(
           t.callExpression(
-            state.addImport(
+            this.addDefaultImport(
               `${moduleName}/core-js/get-iterator`,
-              "default",
               "getIterator",
             ),
             [callee.object],
@@ -113,9 +142,8 @@ export default function({ types: t }) {
         const moduleName = getRuntimeModuleName(state.opts);
         path.replaceWith(
           t.callExpression(
-            state.addImport(
+            this.addDefaultImport(
               `${moduleName}/core-js/is-iterable`,
-              "default",
               "isIterable",
             ),
             [path.node.right],
@@ -157,9 +185,8 @@ export default function({ types: t }) {
 
           const moduleName = getRuntimeModuleName(state.opts);
           path.replaceWith(
-            state.addImport(
+            this.addDefaultImport(
               `${moduleName}/core-js/${methods[prop.name]}`,
-              "default",
               `${obj.name}$${prop.name}`,
             ),
           );
@@ -178,9 +205,8 @@ export default function({ types: t }) {
           const moduleName = getRuntimeModuleName(state.opts);
           path.replaceWith(
             t.memberExpression(
-              state.addImport(
+              this.addDefaultImport(
                 `${moduleName}/core-js/${definitions.builtins[obj.name]}`,
-                "default",
                 obj.name,
               ),
               node.property,

packages/babel-plugin-transform-runtime/test/fixtures/runtime/aliased-constructors/expected.js

@@ -1,6 +1,9 @@
-import _Map from "babel-runtime/core-js/map";
-import _Symbol from "babel-runtime/core-js/symbol";
-import _Promise from "babel-runtime/core-js/promise";
+var _Map = require("babel-runtime/core-js/map");
+
+var _Symbol = require("babel-runtime/core-js/symbol");
+
+var _Promise = require("babel-runtime/core-js/promise");
+
 obj.constructor === Object;
 obj.constructor === _Promise;
 

packages/babel-plugin-transform-runtime/test/fixtures/runtime/catch-all/expected.js

@@ -1,2 +1,3 @@
-import _Promise from "babel-runtime/core-js/promise";
+var _Promise = require("babel-runtime/core-js/promise");
+
 _Promise.resolve;

packages/babel-plugin-transform-runtime/test/fixtures/runtime/class/expected.js

@@ -1,4 +1,4 @@
-import _classCallCheck from "babel-runtime/helpers/classCallCheck";
+var _classCallCheck = require("babel-runtime/helpers/classCallCheck");
 
 let Foo = function Foo() {
   _classCallCheck(this, Foo);

packages/babel-plugin-transform-runtime/test/fixtures/runtime/es6-for-of/expected.js

@@ -1,4 +1,5 @@
-import _getIterator from "babel-runtime/core-js/get-iterator";
+var _getIterator = require("babel-runtime/core-js/get-iterator");
+
 var _iteratorNormalCompletion = true;
 var _didIteratorError = false;
 var _iteratorError = undefined;

packages/babel-plugin-transform-runtime/test/fixtures/runtime/modules-helpers/actual.mjs

@@ -0,0 +1,5 @@
+import foo from "foo";
+
+class Example {
+  method() {}
+}

packages/babel-plugin-transform-runtime/test/fixtures/runtime/modules-helpers/expected.js

@@ -0,0 +1,23 @@
+"use strict";
+
+var _interopRequireDefault = require("babel-runtime/helpers/interopRequireDefault");
+
+var _classCallCheck2 = _interopRequireDefault(require("babel-runtime/helpers/classCallCheck"));
+
+var _createClass2 = _interopRequireDefault(require("babel-runtime/helpers/createClass"));
+
+var _foo = _interopRequireDefault(require("foo"));
+
+let Example =
+/*#__PURE__*/
+function () {
+  function Example() {
+    (0, _classCallCheck2.default)(this, Example);
+  }
+
+  (0, _createClass2.default)(Example, [{
+    key: "method",
+    value: function method() {}
+  }]);
+  return Example;
+}();

packages/babel-plugin-transform-runtime/test/fixtures/runtime/modules-helpers/options.json

@@ -0,0 +1,7 @@
+{
+  "plugins": [
+    "transform-runtime",
+    "transform-es2015-modules-commonjs",
+    "transform-es2015-classes"
+  ]
+}

packages/babel-plugin-transform-runtime/test/fixtures/runtime/modules/actual.js

@@ -1,2 +1,4 @@
 import foo from "bar";
 foo;
+
+export * from "mod";

packages/babel-plugin-transform-runtime/test/fixtures/runtime/modules/expected.js

@@ -1,7 +1,28 @@
 "use strict";
 
+var _interopRequireDefault = require("babel-runtime/helpers/interopRequireDefault");
+
+var _Object$defineProperty = require("babel-runtime/core-js/object/define-property");
+
+var _Object$keys = require("babel-runtime/core-js/object/keys");
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+
 var _bar = _interopRequireDefault(require("bar"));
 
-function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
+var _mod = require("mod");
+
+_Object$keys(_mod).forEach(function (key) {
+  if (key === "default" || key === "__esModule") return;
+
+  _Object$defineProperty(exports, key, {
+    enumerable: true,
+    get: function () {
+      return _mod[key];
+    }
+  });
+});
 
 _bar.default;

packages/babel-plugin-transform-runtime/test/fixtures/runtime/regenerator-runtime/expected.js

@@ -1,4 +1,5 @@
-import _regeneratorRuntime from "babel-runtime/regenerator";
+var _regeneratorRuntime = require("babel-runtime/regenerator");
+
 void
 /*#__PURE__*/
 _regeneratorRuntime.mark(function _callee() {

packages/babel-plugin-transform-runtime/test/fixtures/runtime/symbol-iterator-in/expected.js

@@ -1,3 +1,3 @@
-import _isIterable from "babel-runtime/core-js/is-iterable";
+var _isIterable = require("babel-runtime/core-js/is-iterable");
 
 _isIterable(Object(arr));

packages/babel-plugin-transform-runtime/test/fixtures/runtime/symbol-iterator/expected.js

@@ -1,2 +1,3 @@
-import _Symbol$iterator from "babel-runtime/core-js/symbol/iterator";
+var _Symbol$iterator = require("babel-runtime/core-js/symbol/iterator");
+
 _Symbol$iterator;

packages/babel-plugin-transform-runtime/test/fixtures/use-options/useBuiltIns-useESModules/expected.js

@@ -1,6 +1,8 @@
-import _classCallCheck from "babel-runtime/helpers/builtin/es6/classCallCheck";
-import _possibleConstructorReturn from "babel-runtime/helpers/builtin/es6/possibleConstructorReturn";
-import _inherits from "babel-runtime/helpers/builtin/es6/inherits";
+var _classCallCheck = require("babel-runtime/helpers/builtin/es6/classCallCheck");
+
+var _possibleConstructorReturn = require("babel-runtime/helpers/builtin/es6/possibleConstructorReturn");
+
+var _inherits = require("babel-runtime/helpers/builtin/es6/inherits");
 
 let Foo =
 /*#__PURE__*/

packages/babel-plugin-transform-runtime/test/fixtures/use-options/useBuiltIns/expected.js

@@ -1,6 +1,8 @@
-import _classCallCheck from "babel-runtime/helpers/builtin/classCallCheck";
-import _possibleConstructorReturn from "babel-runtime/helpers/builtin/possibleConstructorReturn";
-import _inherits from "babel-runtime/helpers/builtin/inherits";
+var _classCallCheck = require("babel-runtime/helpers/builtin/classCallCheck");
+
+var _possibleConstructorReturn = require("babel-runtime/helpers/builtin/possibleConstructorReturn");
+
+var _inherits = require("babel-runtime/helpers/builtin/inherits");
 
 let Foo =
 /*#__PURE__*/

packages/babel-plugin-transform-runtime/test/fixtures/use-options/useESModules/expected.js

@@ -1,7 +1,10 @@
-import _Object$getPrototypeOf from "babel-runtime/core-js/object/get-prototype-of";
-import _classCallCheck from "babel-runtime/helpers/es6/classCallCheck";
-import _possibleConstructorReturn from "babel-runtime/helpers/es6/possibleConstructorReturn";
-import _inherits from "babel-runtime/helpers/es6/inherits";
+var _Object$getPrototypeOf = require("babel-runtime/core-js/object/get-prototype-of");
+
+var _classCallCheck = require("babel-runtime/helpers/es6/classCallCheck");
+
+var _possibleConstructorReturn = require("babel-runtime/helpers/es6/possibleConstructorReturn");
+
+var _inherits = require("babel-runtime/helpers/es6/inherits");
 
 let Foo =
 /*#__PURE__*/

packages/babel-runtime/core-js.js

@@ -1,4 +1 @@
-module.exports = {
-  "default": require("core-js/library"),
-  __esModule: true
-};
+module.exports = require("core-js/library");

packages/babel-runtime/core-js/map.js

@@ -1 +1 @@
-module.exports = { "default": require("core-js/library/fn/map"), __esModule: true };
+module.exports = require("core-js/library/fn/map");

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

@@ -1,6 +1,5 @@
-exports.__esModule = true;
-exports.default = _toArray;
-
 function _toArray(arr) {
   return Array.isArray(arr) ? arr : Array.from(arr);
 }
+
+module.exports = _toArray;

packages/babel-runtime/helpers/toArray.js

@@ -1,10 +1,7 @@
-exports.__esModule = true;
-exports.default = _toArray;
-
-var _from = _interopRequireDefault(require("../core-js/array/from"));
-
-function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
+var _Array$from = require("../core-js/array/from");
 
 function _toArray(arr) {
-  return Array.isArray(arr) ? arr : (0, _from.default)(arr);
+  return Array.isArray(arr) ? arr : _Array$from(arr);
 }
+
+module.exports = _toArray;

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

@@ -33,7 +33,7 @@ function relative(filename) {
 }
 
 function defaultify(name) {
-  return `module.exports = { "default": ${name}, __esModule: true };`;
+  return `module.exports = ${name};`;
 }
 
 function writeRootFile(filename, content) {
@@ -57,14 +57,6 @@ function makeTransformOpts(modules, useBuiltIns) {
       ],
     ],
   };
-  if (modules === "commonjs") {
-    opts.plugins.push([
-      require("../../babel-plugin-transform-es2015-modules-commonjs"),
-      { loose: true, strictMode: false },
-    ]);
-  } else if (modules !== false) {
-    throw new Error("Unsupported module type");
-  }
   return opts;
 }
 
@@ -104,8 +96,13 @@ function buildRuntimeRewritePlugin(relativePath, helperName) {
 }
 
 function buildHelper(helperName, modules, useBuiltIns) {
-  const tree = t.program(helpers.get(helperName).nodes, [], "module");
+  const id =
+    modules === "commonjs"
+      ? t.memberExpression(t.identifier("module"), t.identifier("exports"))
+      : null;
+  const sourceType = modules === "commonjs" ? "script" : "module";
 
+  const tree = t.program(helpers.get(helperName, id).nodes, [], sourceType);
   const transformOpts = makeTransformOpts(modules, useBuiltIns);
 
   const relative = useBuiltIns ? "../.." : "..";