看起来你在你的 index 中调用了 fs file-exists 方法.js 文件.我不确定您在什么上下文中调用该方法，但这看起来像是对服务器端方法的客户端调用.我最近遇到了类似的问题.

It looks like you're calling the fs file-exists method in your index.js file. I'm not sure in what context you're calling the method, but this looks like a client-side call to a server-side method. I ran into a similar issue just recently.

据我了解，主要问题似乎是您无法在浏览器解释的客户端(前端)代码中调用服务器端(节点)方法.您必须从服务器调用它们.

From what I understand, the main issue seems to be that you can't call server-side (Node) methods in browser-interpreted client-side (front end) code. You have to call them from a server.

Webpack 可以将 fs 模块代码加载到您的前端，但浏览器实际上无法解释这些 Node 方法并运行它们；只有 Node 环境可以做到这一点.(更多在这里)

Webpack can load the fs module code into your front end, but the browser can't actually interpret those Node methods and run them; only a Node environment can do that. (more here)

您可以通过修改对 fs 方法的调用以在服务器端某处发生，或者通过查找提供与 fs 相同功能的等效浏览器支持包来解决核心问题 您需要的方法，但可以在浏览器中运行.

You could fix the core issue by modifying the call to fs methods to happen somewhere server-side, or by finding an equivalent browser-supported package that offers the same functionality as the fs methods you need but that can be run in a browser.

快速搜索浏览器的 fs 模块"会显示各种可能满足您需求的选项，例如 fs-web、browserify-fs 或 文件管理器.

A quick search for "fs module for browser" brings up a variety of options that might work for what you need, like fs-web, browserify-fs or filer.

这是一个类似的问题，但有一些见解.在 React.js,node.js 中使用 fs 模块.js、webpack、babel、express

Here is a similar question with some insight. Use fs module in React.js,node.js, webpack, babel,express