Svelte + Vite执行npm run build不生成public/dist文件夹问题

执行npm run build时，终端显示所有编译工作已完成，但并未生成public或dist文件夹。使用npm run dev可以正常进行开发和预览操作，网上资料均表明只需执行该命令就能生成对应文件。

build命令输出日志：

npm run build       

> svlt-drag@0.0.1 build
> vite build


vite v4.1.4 building SSR bundle for production...
✓ 51 modules transformed.
5:06:18 PM [vite-plugin-svelte] ssr compile done.
package         files     time     avg
svlt-drag           4   31.5ms   7.9ms
@sveltejs/kit       1   13.1ms  13.1ms

vite v4.1.4 building for production...
✓ 42 modules transformed.
5:06:19 PM [vite-plugin-svelte] dom compile done.
package     files     time     avg
svlt-drag       5   62.0ms  12.4ms
.svelte-kit/output/client/_app/version.json                                 0.03 kB
.svelte-kit/output/client/vite-manifest.json                                2.73 kB
.svelte-kit/output/client/_app/immutable/assets/_layout.ed6dad0e.css        9.13 kB │ gzip: 2.48 kB
.svelte-kit/output/client/_app/immutable/chunks/2.6b2094ff.js               0.08 kB │ gzip: 0.10 kB
.svelte-kit/output/client/_app/immutable/chunks/1.4e7307ad.js               0.08 kB │ gzip: 0.10 kB
.svelte-kit/output/client/_app/immutable/chunks/0.8c6f33b6.js               0.09 kB │ gzip: 0.10 kB
.svelte-kit/output/client/_app/immutable/entry/_layout.svelte.733b317a.js   0.54 kB │ gzip: 0.36 kB
.svelte-kit/output/client/_app/immutable/entry/error.svelte.8dbce21f.js     0.98 kB │ gzip: 0.57 kB
.svelte-kit/output/client/_app/immutable/chunks/singletons.ccd991f9.js      2.65 kB │ gzip: 1.38 kB
.svelte-kit/output/client/_app/immutable/entry/app.c122a3c5.js              5.61 kB │ gzip: 2.25 kB
.svelte-kit/output/client/_app/immutable/entry/_page.svelte.68b65054.js     7.21 kB │ gzip: 3.02 kB
.svelte-kit/output/client/_app/immutable/chunks/index.33c9bb49.js           7.72 kB │ gzip: 3.18 kB
.svelte-kit/output/client/_app/immutable/entry/start.2b8c1d1f.js           23.16 kB │ gzip: 9.22 kB
.svelte-kit/output/server/vite-manifest.json                           1.43 kB
.svelte-kit/output/server/_app/immutable/assets/_layout.ad198ccc.css  15.05 kB
.svelte-kit/output/server/internal.js                                  0.19 kB
.svelte-kit/output/server/entries/pages/_layout.svelte.js              0.25 kB
.svelte-kit/output/server/entries/fallbacks/error.svelte.js            0.83 kB
.svelte-kit/output/server/entries/pages/_page.svelte.js                2.54 kB
.svelte-kit/output/server/chunks/index.js                              3.68 kB
.svelte-kit/output/server/chunks/internal.js                           5.09 kB
.svelte-kit/output/server/index.js                                    85.12 kB

Run npm run preview to preview your production build locally.

> Using @sveltejs/adapter-auto
  Could not detect a supported production environment. See https://kit.svelte.dev/docs/adapters to learn how to configure your app to run on the platform of your choosing
  ✔ done

解决办法 #

从日志里的Could not detect a supported production environment提示就能找到问题根源：你使用的@sveltejs/adapter-auto适配器无法识别当前的部署环境，因此没有生成可直接部署的public/dist目录，编译产物暂时存放在.svelte-kit/output这个中间目录里。

• 安装对应适配器
  根据你的部署目标选择安装对应的适配器：

  • 静态托管（如Nginx、静态CDN）：

    npm install @sveltejs/adapter-static --save-dev
    

  • Node.js服务器部署：

    npm install @sveltejs/adapter-node --save-dev
    

• 修改配置文件
  打开项目根目录的svelte.config.js，替换原适配器配置：
  以静态适配器为例，配置可指定输出目录为dist：

  import adapter from '@sveltejs/adapter-static';
  import { vitePreprocess } from '@sveltejs/kit/vite';
  
  /** @type {import('@sveltejs/kit').Config} */
  const config = {
    preprocess: vitePreprocess(),
    kit: {
      adapter: adapter({
        pages: 'dist',
        assets: 'dist',
        fallback: null
      })
    }
  };
  
  export default config;
  

• 重新执行构建
  再次运行npm run build，此时就会生成你指定的输出目录（如dist）。

内容的提问来源于stack exchange，提问作者Cory Schulz