feat: add export-namespace-from to preset-env

packages/babel-preset-env/package.json

@@ -22,6 +22,7 @@
     "@babel/plugin-proposal-async-generator-functions": "^7.10.4",
     "@babel/plugin-proposal-class-properties": "^7.10.4",
     "@babel/plugin-proposal-dynamic-import": "^7.10.4",
+    "@babel/plugin-proposal-export-namespace-from": "^7.10.4",
     "@babel/plugin-proposal-json-strings": "^7.10.4",
     "@babel/plugin-proposal-nullish-coalescing-operator": "^7.10.4",
     "@babel/plugin-proposal-numeric-separator": "^7.10.4",
@@ -33,6 +34,7 @@
     "@babel/plugin-syntax-async-generators": "^7.8.0",
     "@babel/plugin-syntax-class-properties": "^7.10.4",
     "@babel/plugin-syntax-dynamic-import": "^7.8.0",
+    "@babel/plugin-syntax-export-namespace-from": "^7.8.3",
     "@babel/plugin-syntax-json-strings": "^7.8.0",
     "@babel/plugin-syntax-nullish-coalescing-operator": "^7.8.0",
     "@babel/plugin-syntax-numeric-separator": "^7.10.4",

packages/babel-preset-env/src/available-plugins.js

@@ -4,6 +4,7 @@
 import syntaxAsyncGenerators from "@babel/plugin-syntax-async-generators";
 import syntaxClassProperties from "@babel/plugin-syntax-class-properties";
 import syntaxDynamicImport from "@babel/plugin-syntax-dynamic-import";
+import syntaxExportNamespaceFrom from "@babel/plugin-syntax-export-namespace-from";
 import syntaxJsonStrings from "@babel/plugin-syntax-json-strings";
 import syntaxNullishCoalescingOperator from "@babel/plugin-syntax-nullish-coalescing-operator";
 import syntaxNumericSeparator from "@babel/plugin-syntax-numeric-separator";
@@ -14,6 +15,7 @@ import syntaxTopLevelAwait from "@babel/plugin-syntax-top-level-await";
 import proposalAsyncGeneratorFunctions from "@babel/plugin-proposal-async-generator-functions";
 import proposalClassProperties from "@babel/plugin-proposal-class-properties";
 import proposalDynamicImport from "@babel/plugin-proposal-dynamic-import";
+import proposalExportNamespaceFrom from "@babel/plugin-proposal-export-namespace-from";
 import proposalJsonStrings from "@babel/plugin-proposal-json-strings";
 import proposalNullishCoalescingOperator from "@babel/plugin-proposal-nullish-coalescing-operator";
 import proposalNumericSeparator from "@babel/plugin-proposal-numeric-separator";
@@ -72,6 +74,7 @@ export default {
   "proposal-async-generator-functions": proposalAsyncGeneratorFunctions,
   "proposal-class-properties": proposalClassProperties,
   "proposal-dynamic-import": proposalDynamicImport,
+  "proposal-export-namespace-from": proposalExportNamespaceFrom,
   "proposal-json-strings": proposalJsonStrings,
   "proposal-nullish-coalescing-operator": proposalNullishCoalescingOperator,
   "proposal-numeric-separator": proposalNumericSeparator,
@@ -83,6 +86,7 @@ export default {
   "syntax-async-generators": syntaxAsyncGenerators,
   "syntax-class-properties": syntaxClassProperties,
   "syntax-dynamic-import": syntaxDynamicImport,
+  "syntax-export-namespace-from": syntaxExportNamespaceFrom,
   "syntax-json-strings": syntaxJsonStrings,
   "syntax-nullish-coalescing-operator": syntaxNullishCoalescingOperator,
   "syntax-numeric-separator": syntaxNumericSeparator,

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

@@ -99,14 +99,16 @@ export const getModulesPluginNames = ({
   transformations,
   shouldTransformESM,
   shouldTransformDynamicImport,
+  shouldTransformExportNamespaceFrom,
   shouldParseTopLevelAwait,
-}: {
+}: {|
   modules: ModuleOption,
   transformations: ModuleTransformationsType,
   shouldTransformESM: boolean,
   shouldTransformDynamicImport: boolean,
+  shouldTransformExportNamespaceFrom: boolean,
   shouldParseTopLevelAwait: boolean,
-}) => {
+|}) => {
   const modulesPluginNames = [];
   if (modules !== false && transformations[modules]) {
     if (shouldTransformESM) {
@@ -132,6 +134,12 @@ export const getModulesPluginNames = ({
     modulesPluginNames.push("syntax-dynamic-import");
   }
 
+  if (shouldTransformExportNamespaceFrom) {
+    modulesPluginNames.push("proposal-export-namespace-from");
+  } else {
+    modulesPluginNames.push("syntax-export-namespace-from");
+  }
+
   if (shouldParseTopLevelAwait) {
     modulesPluginNames.push("syntax-top-level-await");
   }
@@ -206,6 +214,10 @@ function supportsDynamicImport(caller) {
   return !!caller?.supportsDynamicImport;
 }
 
+function supportsExportNamespaceFrom(caller) {
+  return !!caller?.supportsExportNamespaceFrom;
+}
+
 function supportsTopLevelAwait(caller) {
   return !!caller?.supportsTopLevelAwait;
 }
@@ -265,6 +277,7 @@ export default declare((api, opts) => {
 
   const transformTargets = forceAllTransforms || hasUglifyTarget ? {} : targets;
 
+  const compatData = getPluginList(shippedProposals, bugfixes);
   const modulesPluginNames = getModulesPluginNames({
     modules,
     transformations: moduleTransformations,
@@ -273,11 +286,20 @@ export default declare((api, opts) => {
     shouldTransformESM: modules !== "auto" || !api.caller?.(supportsStaticESM),
     shouldTransformDynamicImport:
       modules !== "auto" || !api.caller?.(supportsDynamicImport),
+    shouldTransformExportNamespaceFrom: !(
+      (modules === "auto" && api.caller?.(supportsExportNamespaceFrom)) ||
+      (modules === false &&
+        !isRequired("proposal-export-namespace-from", transformTargets, {
+          compatData,
+          includes: include.plugins,
+          excludes: exclude.plugins,
+        }))
+    ),
     shouldParseTopLevelAwait: !api.caller || api.caller(supportsTopLevelAwait),
   });
 
   const pluginNames = filterItems(
-    getPluginList(shippedProposals, bugfixes),
+    compatData,
     include.plugins,
     exclude.plugins,
     transformTargets,

packages/babel-preset-env/test/fixtures/export-namespace-from/auto-esm-not-supported/input.mjs

@@ -0,0 +1 @@
+export * as foo from "./foo.mjs";

packages/babel-preset-env/test/fixtures/export-namespace-from/auto-esm-not-supported/options.json

@@ -0,0 +1,10 @@
+{
+  "validateLogs": true,
+  "caller": {
+    "name": "test-fixture",
+    "supportsStaticESM": false,
+    "supportsDynamicImport": false,
+    "supportsExportNamespaceFrom": false
+  },
+  "presets": ["env"]
+}

packages/babel-preset-env/test/fixtures/export-namespace-from/auto-esm-not-supported/output.js

@@ -0,0 +1,12 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.foo = void 0;
+
+var _foo = _interopRequireDefault(require("./foo.mjs"));
+
+exports.foo = _foo;
+
+function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { "default": obj }; }

packages/babel-preset-env/test/fixtures/export-namespace-from/auto-export-namespace-not-supported/input.mjs

@@ -0,0 +1 @@
+export * as foo from "./foo.mjs";

packages/babel-preset-env/test/fixtures/export-namespace-from/auto-export-namespace-not-supported/options.json

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

packages/babel-preset-env/test/fixtures/export-namespace-from/auto-export-namespace-not-supported/output.mjs

@@ -0,0 +1,2 @@
+import * as _foo from "./foo.mjs";
+export { _foo as foo };

packages/babel-preset-env/test/fixtures/export-namespace-from/false-export-namespace-not-supported-caller-supported/input.mjs

@@ -0,0 +1 @@
+export * as foo from "./foo.mjs";

packages/babel-preset-env/test/fixtures/export-namespace-from/false-export-namespace-not-supported-caller-supported/options.json

@@ -0,0 +1,7 @@
+{
+  "caller": {
+    "name": "test-fixture",
+    "supportsExportNamespaceFrom": true
+  },
+  "presets": [["env", { "modules": false, "targets": "chrome 71" }]]
+}

packages/babel-preset-env/test/fixtures/export-namespace-from/false-export-namespace-not-supported-caller-supported/output.mjs

@@ -0,0 +1,2 @@
+import * as _foo from "./foo.mjs";
+export { _foo as foo };

packages/babel-preset-env/test/fixtures/export-namespace-from/false-export-namespace-not-supported/input.mjs

@@ -0,0 +1 @@
+export * as foo from "./foo.mjs";

packages/babel-preset-env/test/fixtures/export-namespace-from/false-export-namespace-not-supported/options.json

@@ -0,0 +1,7 @@
+{
+  "caller": {
+    "name": "test-fixture",
+    "supportsExportNamespaceFrom": false
+  },
+  "presets": [["env", { "modules": false, "targets": "chrome 71" }]]
+}

packages/babel-preset-env/test/fixtures/export-namespace-from/false-export-namespace-not-supported/output.mjs

@@ -0,0 +1,2 @@
+import * as _foo from "./foo.mjs";
+export { _foo as foo };

packages/babel-preset-env/test/fixtures/export-namespace-from/false-export-namespace-supported/input.mjs

@@ -0,0 +1 @@
+export * as foo from "./foo.mjs";

packages/babel-preset-env/test/fixtures/export-namespace-from/false-export-namespace-supported/options.json

@@ -0,0 +1,7 @@
+{
+  "caller": {
+    "name": "test-fixture",
+    "supportsExportNamespaceFrom": false
+  },
+  "presets": [["env", { "modules": false, "targets": "chrome 72" }]]
+}

packages/babel-preset-env/test/fixtures/export-namespace-from/false-export-namespace-supported/output.mjs

@@ -0,0 +1 @@
+export * as foo from "./foo.mjs";