fix(config): bundle files referenced with imports field (#18887)

packages/vite/src/node/config.ts

@@ -1768,7 +1768,7 @@ async function bundleConfigFile(
 
           // externalize bare imports
           build.onResolve(
-            { filter: /^[^.].*/ },
+            { filter: /^[^.#].*/ },
             async ({ path: id, importer, kind }) => {
               if (
                 kind === 'entry-point' ||

playground/config/__tests__/config.spec.ts

@@ -27,6 +27,7 @@ it('loadConfigFromFile', async () => {
           4,
         ],
       ],
+      "importsField": "imports-field",
       "moduleCondition": "import condition",
     }
   `)

playground/config/packages/entry/imports-field.ts

@@ -0,0 +1 @@
+export default 'imports-field'

playground/config/packages/entry/package.json

@@ -3,5 +3,8 @@
   "type": "module",
   "dependencies": {
     "@vite/test-config-plugin-module-condition": "link:../plugin-module-condition"
+  },
+  "imports": {
+    "#imports-field": "./imports-field.ts"
   }
 }

playground/config/packages/entry/vite.config.ts

@@ -1,7 +1,9 @@
 import moduleCondition from '@vite/test-config-plugin-module-condition'
 import { array } from '../siblings/foo'
+import importsField from '#imports-field'
 
 export default {
   array,
   moduleCondition,
+  importsField,
 }