This plugin transforms ES2015 modules to SystemJS. 

This plugin transforms ES2015 modules to SystemJS

hzoo

nicolo-ribaudo

jlhwung

existentialism

@babel/plugin-transform-modules-systemjs

import { declare } from '@babel/helper-plugin-utils';

import hoistVariables from '@babel/helper-hoist-variables';

import { template, types } from '@babel/core';

import { buildDynamicImport, rewriteThis, getModuleName } from '@babel/helper-module-transforms';

import { isIdentifierName } from '@babel/helper-validator-identifier';

const buildTemplate = template.statement(`

  SYSTEM_REGISTER(MODULE_NAME, SOURCES, function (EXPORT_IDENTIFIER, CONTEXT_IDENTIFIER) {

const buildExportAll = template.statement(`

    if (KEY !== "default" && KEY !== "__esModule") EXPORT_OBJ[KEY] = TARGET[KEY];

ERROR: Dynamic import() transformation must be enabled using the

       @babel/plugin-transform-dynamic-import plugin. Babel 8

       no longer transforms import() without using that plugin.

function getExportSpecifierName(node, stringSpecifiers) {

  } else if (node.type === "StringLiteral") {

    if (!isIdentifierName(stringValue)) {

    throw new Error(`Expected export specifier to be either Identifier or StringLiteral, got ${node.type}`);

function constructExportCall(path, exportIdent, exportNames, exportValues, exportStarTarget, stringSpecifiers) {

      statements.push(types.expressionStatement(types.callExpression(exportIdent, [types.stringLiteral(exportNames[0]), exportValues[0]])));

      for (let i = 0; i < exportNames.length; i++) {

        const exportName = exportNames[i];

        const exportValue = exportValues[i];

        objectProperties.push(types.objectProperty(stringSpecifiers.has(exportName) ? types.stringLiteral(exportName) : types.identifier(exportName), exportValue));

      statements.push(types.expressionStatement(types.callExpression(exportIdent, [types.objectExpression(objectProperties)])));

    const exportObj = path.scope.generateUid("exportObj");

    statements.push(types.variableDeclaration("var", [types.variableDeclarator(types.identifier(exportObj), types.objectExpression([]))]));

      KEY: path.scope.generateUidIdentifier("key"),

      EXPORT_OBJ: types.identifier(exportObj),

    for (let i = 0; i < exportNames.length; i++) {

      const exportValue = exportValues[i];

      statements.push(types.expressionStatement(types.assignmentExpression("=", types.memberExpression(types.identifier(exportObj), types.identifier(exportName)), exportValue)));

    statements.push(types.expressionStatement(types.callExpression(exportIdent, [types.identifier(exportObj)])));

  const reassignmentVisited = new WeakSet();

    "AssignmentExpression|UpdateExpression"(path) {

      if (reassignmentVisited.has(path.node)) return;

      reassignmentVisited.add(path.node);

      const arg = path.isAssignmentExpression() ? path.get("left") : path.get("argument");

      if (arg.isObjectPattern() || arg.isArrayPattern()) {

        for (const name of Object.keys(arg.getBindingIdentifiers())) {

          if (this.scope.getBinding(name) !== path.scope.getBinding(name)) {

          const exportedNames = this.exports[name];

          for (const exportedName of exportedNames) {

            exprs.push(this.buildCall(exportedName, types.identifier(name)).expression);

        path.replaceWith(types.sequenceExpression(exprs));

      if (this.scope.getBinding(name) !== path.scope.getBinding(name)) return;

      const exportedNames = this.exports[name];

      const isPostUpdateExpression = types.isUpdateExpression(node, {

        node = types.binaryExpression(node.operator[0], types.unaryExpression("+", types.cloneNode(node.argument)), types.numericLiteral(1));

      for (const exportedName of exportedNames) {

        node = this.buildCall(exportedName, node).expression;

        node = types.sequenceExpression([node, path.node]);

      this.file.set("@babel/plugin-transform-modules-*", "systemjs");

      ["CallExpression" + (api.types.importExpression ? "|ImportExpression" : "")](path, state) {

        if (path.isCallExpression() && !types.isImport(path.node.callee)) return;

          if (!this.file.has("@babel/plugin-proposal-dynamic-import")) {

              throw new Error(MISSING_PLUGIN_ERROR);

        path.replaceWith(buildDynamicImport(path.node, false, true, specifier => types.callExpression(types.memberExpression(types.identifier(state.contextIdent), types.identifier("import")), [specifier])));

        if (path.node.meta.name === "import" && path.node.property.name === "meta") {

          path.replaceWith(types.memberExpression(types.identifier(state.contextIdent), types.identifier("meta")));

      ReferencedIdentifier(path, state) {

        if (path.node.name === "__moduleName" && !path.scope.hasBinding("__moduleName")) {

          path.replaceWith(types.memberExpression(types.identifier(state.contextIdent), types.identifier("id")));

          state.contextIdent = path.scope.generateUid("context");

          state.stringSpecifiers = new Set();

          const exportIdent = scope.generateUid("export");

          const exportMap = Object.create(null);

          function addExportName(key, val) {

            exportMap[key] = exportMap[key] || [];

  "name": "@babel/plugin-transform-modules-systemjs",

  "description": "This plugin transforms ES2015 modules to SystemJS",

    "url": "https://github.com/babel/babel.git",

    "directory": "packages/babel-plugin-transform-modules-systemjs"

    "@babel/helper-hoist-variables": "^8.0.0-alpha.6",

    "@babel/helper-module-transforms": "^8.0.0-alpha.6",

    "@babel/helper-plugin-utils": "^8.0.0-alpha.6",

    "@babel/helper-validator-identifier": "^8.0.0-alpha.6"

    "@babel/helper-hoist-variables": "^8.0.0-alpha.7",

    "@babel/helper-module-transforms": "^8.0.0-alpha.7",

    "@babel/helper-plugin-utils": "^8.0.0-alpha.7",

    "@babel/helper-validator-identifier": "^8.0.0-alpha.7"

    "@babel/helper-plugin-test-runner": "^8.0.0-alpha.6",

    "@babel/helper-transform-fixture-test-runner": "^8.0.0-alpha.6",

    "@babel/helper-plugin-test-runner": "^8.0.0-alpha.7",

    "@babel/helper-transform-fixture-test-runner": "^8.0.0-alpha.7",

  "homepage": "https://babel.dev/docs/en/next/babel-plugin-transform-modules-systemjs",

    "node": "^16.20.0 || ^18.16.0 || >=20.0.0"

  "author": "The Babel Team (https://babel.dev/team)",

		@@ -72,3 +72,3 @@ import { declare } from '@babel/helper-plugin-utils';
		var index = declare((api, options) => {
		api.assertVersion("8.0.0-alpha.6");
		api.assertVersion("8.0.0-alpha.7");
		const {
		@@ -75,0 +75,0 @@ systemGlobal = "System",

		{
		"name": "@babel/plugin-transform-modules-systemjs",
		"version": "8.0.0-alpha.6",
		"version": "8.0.0-alpha.7",
		"description": "This plugin transforms ES2015 modules to SystemJS",
		@@ -16,6 +16,6 @@ "repository": {
		"dependencies": {
		"@babel/helper-hoist-variables": "^8.0.0-alpha.6",
		"@babel/helper-module-transforms": "^8.0.0-alpha.6",
		"@babel/helper-plugin-utils": "^8.0.0-alpha.6",
		"@babel/helper-validator-identifier": "^8.0.0-alpha.6"
		"@babel/helper-hoist-variables": "^8.0.0-alpha.7",
		"@babel/helper-module-transforms": "^8.0.0-alpha.7",
		"@babel/helper-plugin-utils": "^8.0.0-alpha.7",
		"@babel/helper-validator-identifier": "^8.0.0-alpha.7"
		},
		@@ -26,8 +26,8 @@ "keywords": [
		"peerDependencies": {
		"@babel/core": "^8.0.0-alpha.6"
		"@babel/core": "^8.0.0-alpha.7"
		},
		"devDependencies": {
		"@babel/core": "^8.0.0-alpha.6",
		"@babel/helper-plugin-test-runner": "^8.0.0-alpha.6",
		"@babel/helper-transform-fixture-test-runner": "^8.0.0-alpha.6",
		"@babel/core": "^8.0.0-alpha.7",
		"@babel/helper-plugin-test-runner": "^8.0.0-alpha.7",
		"@babel/helper-transform-fixture-test-runner": "^8.0.0-alpha.7",
		"core-js": "^3.35.0"
		@@ -34,0 +34,0 @@ },

Dependency changes