node-loader · internettrans · Jul 3, 2021 · Jun 30, 2021 · Jun 30, 2021
diff --git a/lib/node-loader-babel.js b/lib/node-loader-babel.js
@@ -1,20 +1,38 @@
 import babel from "@babel/core";
+import path from "path";
 import url from "url";
 
-const { OptionManager, transform } = babel;
+const { loadOptionsAsync, transformAsync } = babel;
+
+function isBabelConfigFile(filename) {
+  const basename = path.basename(filename);
+  return (
+    basename === ".babelrc.js" ||
+    basename === ".babelrc.mjs" ||
+    basename === "babel.config.js" ||
+    basename === "babel.config.mjs"
+  );
+}
 
 export async function transformSource(source, context, defaultGetSource) {
-  const options = new OptionManager().init({
+  const filename = url.fileURLToPath(context.url);
+  // Babel config files can themselves be ES modules,
+  // but we cannot transform those since doing so would cause an infinite loop.
+  if (isBabelConfigFile(filename)) {
+    return { source };
+  }
+
+  const options = await loadOptionsAsync({
     sourceType: "module",
     root: process.cwd(),
     rootMode: "root",
-    filename: url.fileURLToPath(context.url),
+    filename: filename,
     configFile: true,
   });
 
-  const transformedSource = transform(source, options).code;
+  const transformed = await transformAsync(source, options);
 
   return {
-    source: transformedSource,
+    source: transformed.code,
   };
 }
diff --git a/test/basic.test.js b/test/basic.test.js
@@ -2,11 +2,20 @@ import assert from "assert";
 
 describe(`basic babel usage`, () => {
   it(`can transform jsx and run it in node`, async () => {
-    const basicModule = await import("./fixtures/basic.js");
+    const basicModule = await import("./fixtures/basic/basic.js");
     assert.deepEqual(basicModule.default, {
       type: "button",
       props: null,
       children: undefined,
     });
   });
+
+  it(`supports ES module babel config files`, async () => {
+    const mjsConfig = await import("./fixtures/mjs-config/main.js");
+    assert.deepEqual(mjsConfig.default, {
+      type: "div",
+      props: null,
+      children: undefined,
+    });
+  });
 });
diff --git a/test/fixtures/basic.js b/test/fixtures/basic.js
diff --git a/test/fixtures/.babelrc.json → test/fixtures/basic/.babelrc.json b/test/fixtures/.babelrc.json → test/fixtures/basic/.babelrc.json
diff --git a/test/fixtures/basic/basic.js b/test/fixtures/basic/basic.js
@@ -0,0 +1,3 @@
+import { h } from "../../jsx-impl.js";
+
+export default <button />;
diff --git a/test/fixtures/mjs-config/.babelrc.js b/test/fixtures/mjs-config/.babelrc.js
@@ -0,0 +1,11 @@
+export default {
+  plugins: [
+    [
+      "@babel/plugin-transform-react-jsx",
+      {
+        runtime: "classic",
+        pragma: "h",
+      },
+    ],
+  ],
+};
diff --git a/test/fixtures/mjs-config/main.js b/test/fixtures/mjs-config/main.js
@@ -0,0 +1,3 @@
+import { h } from "../../jsx-impl.js";
+
+export default <div />;
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,3 @@
		import { h } from "../../jsx-impl.js";

		export default <button />;
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,3 @@
		import { h } from "../../jsx-impl.js";

		export default <div />;