如何在VS代碼中調試Node.js應用程序

配置launch.json 文件以設置調試環境，確保program 字段指向主入口文件；2. 使用launch 模式直接啟動腳本並傳入args 和env 參數；3. 使用attach 模式連接已通過node --inspect 啟動的運行中進程；4. 調試npm 腳本時設置runtimeExecutable 為npm 並啟用integratedTerminal；5. 通過設置斷點、條件斷點、變量檢查、表達式求值及啟用Auto Attach 提升調試效率；6. 若遇問題，檢查路徑、啟動參數、端口匹配、sourceMaps 配置並重啟調試會話，最終實現無縫調試。

Debugging Node.js applications in VS Code is straightforward once you set up the environment correctly. The built-in debugger in VS Code provides a powerful way to inspect variables, set breakpoints, step through code, and evaluate expressions—all without leaving your editor.

Set up a debug configuration

To start debugging, you need a launch configuration. VS Code uses a launch.json file inside a .vscode folder in your project root.

1. Open your Node.js project in VS Code.
2. Go to the Run and Debug view (Ctrl Shift D or Cmd Shift D).
3. Click create a launch.json file if you don't have one.
4. Select Node.js as the environment.

This generates a default launch.json like:

 {
  "version": "0.2.0",
  "configurations": [
    {
      "type": "node",
      "request": "launch",
      "name": "Launch Index",
      "program": "${workspaceFolder}/index.js"
    }
  ]
}

Make sure the program field points to your main entry file (eg, app.js , server.js , etc.).

Common debugging scenarios

Launch and debug a script

Use the launch mode to start your app directly from the debugger.

 {
  "type": "node",
  "request": "launch",
  "name": "Start Server",
  "program": "${workspaceFolder}/server.js",
  "args": ["--port", "3000"],
  "env": {
    "NODE_ENV": "development"
  }
}

• args : Pass command-line arguments.
• env : Define environment variables.

Start the debug session by selecting this configuration and pressing F5.

Attach to a running Node.js process

If your app is already running (eg, started from terminal), use attach mode.

First, start your app with inspection enabled:

 node --inspect server.js
# or for breaking on first line:
node --inspect-brk server.js

Then use this launch.json configuration:

 {
  "type": "node",
  "request": "attach",
  "name": "Attach to Port",
  "port": 9229
}

VS Code will connect to the Node.js process on port 9229 (default debugging port). You can set breakpoints and inspect runtime state.

Debug npm scripts

Instead of calling node directly, you can debug scripts defined in package.json .

 {
  "type": "node",
  "request": "launch",
  "name": "Debug Start",
  "runtimeExecutable": "npm",
  "runtimeArgs": ["run", "start"],
  "console": "integratedTerminal",
  "port": 9229
}

• Use runtimeExecutable to specify npm .
• console: "integratedTerminal" ensures output appears in the terminal, which is useful for interactive apps.

Make sure your start script runs Node with --inspect if needed.

Tips for effective debugging

• Set breakpoints by clicking the left margin next to line numbers or pressing F9.
• Use conditional breakpoints by right-clicking a breakpoint and setting a condition (eg, user.id === 123 ).
• Inspect variables in the VARIABLES pane or WATCH window.
• Use Debug Console to evaluate expressions or call functions during a breakpoint.
• Enable Auto Attach for simple cases:
  Run Ctrl Shift P → "Debug: Toggle Auto Attach" → choose "Always".
  Now any node script started from the integrated terminal will auto-attach.

Troubleshooting common issues

• Breakpoints not hit?
  Check that the program path is correct and the file is actually being executed. Use --inspect-brk to pause on startup.

• Can't connect when attaching?
  Ensure the Node.js process was started with --inspect and that the port matches.

• Source maps not working?
  If using TypeScript or bundlers, add "sourceMaps": true and point to generated files:

   "resolveSourceMapLocations": [
    "${workspaceFolder}/**",
    "!**/node_modules/**"
  ]

• Changes not reflected?
  The debugger runs a specific version of your code. Restart the debug session after saving changes unless using a file watcher.

Basically, with the right launch.json setup, VS Code gives you a seamless debugging experience for most Node.js apps—whether launching directly, attaching to processes, or debugging through npm scripts.

以上是如何在VS代碼中調試Node.js應用程序的詳細內容。更多資訊請關注PHP中文網其他相關文章！