Add the .mjs extension to the default extensions

src/normalizeOptions.js

@@ -5,7 +5,7 @@ import findBabelConfig from 'find-babel-config';
 import glob from 'glob';
 import pkgUp from 'pkg-up';
 
-const defaultExtensions = ['.js', '.jsx', '.es', '.es6'];
+const defaultExtensions = ['.js', '.jsx', '.es', '.es6', '.mjs'];
 
 function isRegExp(string) {
   return string.startsWith('^') || string.endsWith('$');

test/index.test.js

@@ -63,6 +63,14 @@ describe('module-resolver', () => {
         );
       });
 
+      it('should resolve the file path with the node module extension', () => {
+        testWithImport(
+          'nodemodule',
+          './test/testproject/src/nodemodule',
+          rootTransformerOpts,
+        );
+      });
+
       it('should not resolve the file path with an unknown extension', () => {
         testWithImport(
           'text',

test/testproject/src/nodemodule.mjs

@@ -0,0 +1 @@
+