--- title: "Debugging Notes for Node.js / Vue CLI / Webpack Plugin in VSCode" description: "Notes on how to debug Node.js, Vue CLI, and Webpack plugins in VSCode and Chrome, including configuration and step-by-step instructions." canonical_url: "https://blog.markkulab.net/en/post/node-debug-note" author: "Mark Ku" author_url: "https://blog.markkulab.net/en/author/mark-ku" site: "Mark Ku's Tech Notes" date_published: "2021-10-20 01:01:01 +0800" category: "Frontend" tags: ["nodejs", "vue", "webpack", "vscode", "debug", "chrome", "frontend"] language: "en" license: "CC BY 4.0" license_url: "https://creativecommons.org/licenses/by/4.0/" attribution: "when reusing or quoting, credit the author and link back to the original" --- # Debugging Notes for Node.js / Vue CLI / Webpack Plugin in VSCode ## The Problem More and more applications are built with Node.js, and they often throw confusing errors. So I put together a quick reference on how to debug Node.js, Vue CLI, and Webpack plugins. ## 1. Debugging Node.js ### 1. Add the --inspect flag to the JS file you want to run for remote debugging (default port is 9229) ``` node --inspect app.js ``` ### 2. Then in Chrome's address bar, type chrome://inspect, and you'll see the screen below. ![Chrome inspect page showing DevTools devices and remote target](https://blog.markkulab.net/content/markku/posts/node-debug-note/images/djsaQb7.png) ### 3. Enter the default debugging port ![Chrome DevTools port forwarding settings showing localhost:9229](https://blog.markkulab.net/content/markku/posts/node-debug-note/images/a6eAScz.png) ### 4. Or click the debug button in DevTools ![Chrome DevTools Network tab with highlighted debug button](https://blog.markkulab.net/content/markku/posts/node-debug-note/images/05G7pd0.png) ## 2. Debugging Vue CLI (main.js) ![VSCode debugging Vue.js code, showing debug options and terminal](https://blog.markkulab.net/content/markku/posts/node-debug-note/images/hHUTg3Z.png) ### 1. Add a debugger statement in main.js ![Vue CLI main.js code in VSCode with a debugger statement](https://blog.markkulab.net/content/markku/posts/node-debug-note/images/1EPxSlN.png) ### 2. Add the following script to package.json ``` "debug": "node ./node_modules/@vue/cli-service/bin/vue-cli-service.js serve" ``` ### 3. Run npm run debug ### 4. In main.js, press F5 ### 5. Enter the debug URL "localhost:8080" ![VSCode debugging Vue.js code with debug panel and terminal](https://blog.markkulab.net/content/markku/posts/node-debug-note/images/PSK7zsy.png) ## At this point the breakpoint will hit in main.js ![VSCode debugging main.js, breakpoint paused on line 17](https://blog.markkulab.net/content/markku/posts/node-debug-note/images/MuNOOwy.png) ## 3. Debugging the Webpack Plugin in vue.config ### 1. Add a debugger statement in the chainWebpack method of vue.config ![VSCode chainWebpack method showing debugger and path aliases](https://blog.markkulab.net/content/markku/posts/node-debug-note/images/lBJV36N.png) ### 2. Add the following script to package.json ``` "debugbuild": "node --inspect-brk=9229 ./node_modules/@vue/cli-service/bin/vue-cli-service.js build" ``` ### 3. Type chrome://inspect into the browser address bar > enter the network target port ### 4. Back in VS Code > run npm run debug in the terminal ### 5. The breakpoint will now hit inside the chainWebpack function --- ## About this article and its author Originally published on [Mark Ku's Tech Notes](https://blog.markkulab.net/en/post/node-debug-note) License: [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/) — when reusing or quoting, credit the author and link back to the original ### About the author **[Mark Ku](https://blog.markkulab.net/en/author/mark-ku)** — Software Solution Provider - 10+ years senior software engineer, now an AI Builder - Focused on large-platform architecture — North-American e-commerce, AI SaaS subscription billing - Combining AI Agents and automation to build evolvable product foundations ### Free tools built by the author All of these are free to use: - [Free PDF Sign Tool](https://blog.markkulab.net/en/tools/pdf-sign): Online PDF sign tool — draw, type, or upload a signature, then drag, resize, and download. Everything runs in your browser; nothing is uploaded. - [VS Code Refactory](https://blog.markkulab.net/en/tools/refactory): Refactory is a VS Code refactoring extension: 34 actions plus a 37-rule code-smell inspection layer with a Code Health dashboard, across 18 languages, backed by 534 tests. It learns your repo's conventions: where interfaces live, where DI is registered, whether 'use client' belongs. It ranks files by git churn × complexity so you know what to fix first, and hands any smell to the Claude Code already on your machine. Free to use, and your source never leaves your computer. - [DB-Kit Database Manager](https://blog.markkulab.net/en/tools/db-kit): DB-Kit is a lightweight, cross-platform database manager built with Tauri + Rust + React. 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No sign-up, nothing uploaded to a server, and mermaid.live share links work as-is. - [React Intl Phone Number](https://blog.markkulab.net/en/tools/react-intl-phone-number): react-intl-phone-number is an open-source React component: framework-agnostic and antd-free, with E.164 in/out, a searchable flag / country-code dropdown, configurable validation levels (strict / mobile-strict / loose), themeable CSS, and i18n — phone logic powered by google-libphonenumber. Lightweight and fully typed. Free and open source (MIT). - [Uptime Kuma Cluster](https://blog.markkulab.net/en/tools/uptime-kuma-cluster): Turn single-node Uptime Kuma into a highly available cluster: OpenResty + Lua smart load balancing, shared MariaDB state, health checks and automatic failover, plus cluster-management REST APIs. One Docker Compose command to start. 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