启动Express服务器时Node.js持续抛出模块找不到错误的求助

Let's break down what's causing these errors and how to fix them quickly:

The Core Issue: Module Resolution Rules #

Node.js and TypeScript handle module imports differently based on the path format:

• Relative paths (starting with ./ or ../) tell Node to look for your local files/folders starting from the current file's directory.
• Bare module names (like routes or database) make Node search for third-party packages in your node_modules folder, not your project's source code. That's why your first error popped up—Node was trying to find a npm package named routes instead of your local routes folder.

Quick Fix: Use Correct Relative Paths #

Update all your local module imports to use relative paths that match your project structure:

1. In src/index.ts:
   Change import routes from "routes"; to:

   import routes from "./routes";
   

   (This works if your routes folder is in the same src directory as index.ts.)

2. In src/models/User.ts:
   Your error shows it's trying to import database—adjust this path based on where your database files live. For example:

   • If database is a folder in src/ (same level as models), use:

     import database from "../database";
     

   • If database is a file inside src/models/, use:

     import database from "./database";
     

Optional: Set Up Non-Relative Imports (For Large Projects) #

If you want to avoid messy relative paths like ../../database, you can configure TypeScript to resolve bare module names to your local source files:

1. Update tsconfig.json:
   Add these settings to the compilerOptions section:

   {
     "compilerOptions": {
       "baseUrl": "./src", // Set your src folder as the root for module resolution
       "paths": {
         "*": ["*"] // Map all bare module names to files in src
       },
       // Keep your existing compiler options here
     }
   }
   

2. Install tsconfig-paths:
   This package lets Node.js recognize TypeScript's path configuration:

   npm install tsconfig-paths --save-dev
   

3. Adjust your start command:
   Modify your package.json scripts to use the path register:

   {
     "scripts": {
       "start": "ts-node -r tsconfig-paths/register src/index.ts"
     }
   }
   

   Now you can use import routes from "routes" and import database from "database" without relative paths.

Final Checks #

• Double-check that the files/folders you're importing actually exist (e.g., make sure routes/index.ts exists—TypeScript automatically imports the index.ts file from a folder).
• Ensure filename casing matches exactly. Windows ignores case, but Node.js might throw errors if you import Routes.ts instead of routes.ts.

内容的提问来源于stack exchange，提问作者Ahmad ELZohairy