Start: vite config `build.assetsDir` does not work with nitro config `publicAssets`

[KevinLu]

Which project does this relate to?

Start

Describe the bug

When using @tanstack/nitro-v2-vite-plugin to configure the publicAssets option in Nitro v2, the build output folder specified by the Vite config option build.assetsDir does not get copied into the .output/public folder.

This results in missing chunks for the production build and thus breaking the build.

Your Example Website or App

https://stackblitz.com/edit/github-egpnw7wu?file=vite.config.js

Steps to Reproduce the Bug or Issue

1. Specify the build.assetsDir option in vite.config.ts
2. Use the Nitro plugin
3. Specify the publicAssets option in the Nitro plugin config in vite.config.ts

Expected behavior

.output/public should contain chunks from the specified build.assetsDir folder but it doesn't.

Screenshots or Videos

After running build (with build.assetsDir set and publicAssets set):

• you can see there is no custom folder

After running build (with build.assetsDir set and publicAssets NOT set):

• you can see there is the custom folder

Platform

• Router / Start Version: 1.134.12
• OS: macOS
• Browser: Chrome
• Browser Version: 141
• Bundler: vite
• Bundler Version: 7.1.7

Additional context

No response

[coderabbitai]

A summary of the changes CodeRabbit can apply:

• Update packages/nitro-v2-vite-plugin/src/index.ts to spread user nitroConfig before defining publicAssets and merge the default client build.outDir entry with any nitroConfig.publicAssets (i.e., move ...nitroConfig above publicAssets and add ...(nitroConfig?.publicAssets || [])).

• Update packages/nitro-v2-vite-plugin/src/index.ts to merge user nitroConfig into the generated Nitro config earlier and prepend a default publicAssets entry while appending any existing nitroConfig.publicAssets (i.e., add "...nitroConfig" and "...(nitroConfig?.publicAssets || [])" into the config).

• ✅ Create PR with these edits
• 📋 Get copyable edits

[pi0]

You can try with nitro v3 native vite plugin. Only setting build.assetsDir is enough:

import { defineConfig } from "vite";
import { nitro } from "nitro/vite";
import tsConfigPaths from "vite-tsconfig-paths";
import { tanstackStart } from "@tanstack/react-start/plugin/vite";
import viteReact from "@vitejs/plugin-react";

export default defineConfig({
  plugins: [tsConfigPaths(), tanstackStart(), viteReact(), nitro({})],
  build: {
    assetsDir: "custom",
  },
});

Tested with "nitro": "npm:nitro-nightly@3.0.1-20251104-085747-6a78f735"