Resolve bad import of @mui/x-date-pickers to date-fns internal file

Author: Tristan-WorkGH

vite.config.ts

@@ -11,6 +11,7 @@ import { CommonServerOptions, defineConfig } from 'vite';
 import eslint from 'vite-plugin-eslint';
 import svgr from 'vite-plugin-svgr';
 import tsconfigPaths from 'vite-tsconfig-paths';
+import path from 'node:path';
 
 const serverSettings: CommonServerOptions = {
     port: 3002,
@@ -43,4 +44,18 @@ export default defineConfig((config) => ({
     build: {
         outDir: 'build',
     },
+    resolve: {
+        alias: {
+            /* "@mui/x-date-pickers/AdapterDateFns/AdapterDateFns" do an import from 'date-fns/_lib/format/longFormatters'
+             * which cause rollup error '[commonjs--resolver] Missing "./_lib/format/longFormatters" specifier in "date-fns" package'.
+             *   - we fix the no default import with a shim that will fix that
+             *   - we do a second alias to resolve the import to a non-exported file to date-fns/_lib/...
+             */
+            'date-fns/_lib/format/longFormatters': path.resolve(import.meta.dirname, 'vite.shim.x-date-pickers.js'),
+            'virtual:date-fns/_lib/format/longFormatters': path.resolve(
+                import.meta.dirname,
+                'node_modules/date-fns/_lib/format/longFormatters'
+            ),
+        },
+    },
 }));

vite.shim.x-date-pickers.js

@@ -0,0 +1,10 @@
+/*
+ * Copyright © 2025, RTE (http://www.rte-france.com)
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+import { longFormatters } from 'virtual:date-fns/_lib/format/longFormatters';
+export default longFormatters; // patch bad import of @mui/x-date-pickers/AdapterDateFns/AdapterDateFns.js
+export * from 'virtual:date-fns/_lib/format/longFormatters';