You can define suitable tasks and launch configurations to debug multiple Node.js application(s) in VSCode and use features like breakpoints.
If you want to skip all the details and read the final tasks.json and launch.json, see TLDR: complete tasks.json and launch.json .
Assumption: we are building the apps using the following Node.js and npm versions:
❯ node -v && npm --v
v20.17.0
10.8.2
Also, I am using this version of VSCode:
❯ code -v
1.94.0
d78a74bcdfad14d5d3b1b782f87255d802b57511
arm64
Project structure#
Assuming that you have 2 Node.js projects: vite-gaudi and rsbuild-frank. Gaudi uses Vite and Frank uses Rsbuild as the web bundler.
In addition, I want to define some VSCode tasks to install and run both apps.
npm create vite@latest # vite-gaudi
npm create rsbuild@latest # rsbuild-frank
Create tasks.json and launch.json#
mkdir .vscode
touch .vscode/tasks.json .vscode/launch.json
Define tasks for pre-development#
Add a tasks array in tasks.json:
{
"tasks": [
]
}
Add package install command to vite-gaudi under tasks:
{
"type": "npm",
"script": "install",
"path": "vite-gaudi",
"problemMatcher": [],
"label": "npm: install - vite-gaudi",
"detail": "install dependencies from package"
}
Similarly, add the package install command under tasks for rsbuild-frank:
{
"type": "npm",
"script": "install",
"path": "vite-gaudi",
"problemMatcher": [],
"label": "npm: install - vite-gaudi",
"detail": "install dependencies from package"
}
Optionally, add another command to run both install tasks at once:
{
"label": "npm: install all",
"dependsOn": [
"npm: install - rsbuild-frank",
"npm: install - vite-gaudi"
],
"isBackground": true
}
Tasks and launch settings for development#
We will need another set of tasks to run the dev mode:
tasks.json#
For vite-gaudi, add a new task in tasks.json:
{
"label": "npm: dev - vite-gaudi",
"type": "shell",
"hide": false,
"command": "npm run dev",
"options": {
"cwd": "./vite-gaudi"
},
"presentation": {
"reveal": "always"
},
"isBackground": true,
"problemMatcher": {
"owner": "typescript",
"pattern": "$tsc",
"fileLocation": [
"relative",
"${workspaceFolder}"
],
"background": {
"activeOnStart": true,
"beginsPattern": ".*",
"endsPattern": ".*VITE v.*"
}
}
}
For rsbuild-frank, add a new task in tasks.json:
{
"label": "npm: dev - rsbuild-frank",
"type": "shell",
"hide": false,
"command": "npm run dev",
"options": {
"cwd": "./rsbuild-frank"
},
"presentation": {
"reveal": "always"
},
"isBackground": true,
"problemMatcher": {
"owner": "typescript",
"pattern": "$tsc",
"fileLocation": [
"relative",
"${workspaceFolder}"
],
"background": {
"activeOnStart": true,
"beginsPattern": ".*",
"endsPattern": ".*Rsbuild v.*"
}
}
}
About problemMatcher#
Configure problem matcher to detect if a task has been started and reached to a point that the debugger can be linked:
For a Vite project, we can monitor the keyword VITE v.*:
VITE v5.4.8 ready in 714 ms
➜ Local: http://localhost:5173/
➜ Network: use --host to expose
➜ press h + enter to show help
For a Rsbuild project, we can use Rsbuild v.*:
> rsbuild-frank@1.0.0 dev
> rsbuild dev
Rsbuild v1.0.9
➜ Local: http://localhost:3000/
➜ Network: http://192.168.2.14:3000/
start Compiling...
ready Compiled in 0.06 s (web)
When the endPattern has been defined, VSCode browser debugger will be launched once the console output contains the words that match with the defined pattern.
For example, if you use .* as the endPattern, the debugger will be launched whenever some text has been printed out in the console.
launch.json#
Add version and configurations[] in launch.json:
{
"version": "0.2.0",
"configurations": [
]
}
For vite-gaudi:
{
"type": "msedge",
"request": "launch",
"name": "Dev (vite-gaudi)",
"url": "http://localhost:5173/",
"webRoot": "${workspaceFolder}/vite-gaudi",
"preLaunchTask": "npm: dev - vite-gaudi",
"runtimeArgs": ["-inPrivate"],
"postDebugTask": "Terminate All Tasks",
}
For rsbuild-frank:
{
"type": "msedge",
"request": "launch",
"name": "Dev (rsbuild-frank)",
"url": "http://localhost:3000/",
"webRoot": "${workspaceFolder}/rsbuild-frank",
"preLaunchTask": "npm: dev - rsbuild-frank",
"runtimeArgs": ["-inPrivate"],
"postDebugTask": "Terminate All Tasks",
}
You can choose either msedge or chrome as the launching browser type.
If you wish to use Firefox as the debugging browser, you will need to install Debugger for Firefox and change the value of type into firefox.
Finally, create a single launch settings to launch both sites for debugging at once:
Add a task in tasks.json to trigger all dev scripts:
{
"label": "all:dev",
"dependsOn": [
"npm: dev - rsbuild-frank",
"npm: dev - vite-gaudi"
],
"presentation": {
"reveal": "always",
"revealProblems": "never",
"panel": "new"
}
}
Add a launch setting in launch.json to start the task:
{
"type": "firefox",
"request": "launch",
"name": "Dev (all)",
"url": "http://localhost:5173",
"webRoot": "${workspaceFolder}",
"preLaunchTask": "all:dev",
"runtimeArgs": ["-inPrivate"],
"postDebugTask": "Terminate All Tasks",
}
Note: here we choose to launch the Vite app in the browser, but using the same debugging browser session you can visit and debug the Rsbuild app.
TLDR: complete tasks.json and launch.json#
The tasks.json contains tasks to:
- install (
npm: install - vite-gaudi) and launch vite app (npm: dev - vite-gaudi) - install (
npm: install - rsbuild-frank) and launch rsbuild app (npm: dev - rsbuild-frank) - install (
npm: install all) and launch both apps (all:dev)
{
"tasks": [
{
"type": "npm",
"script": "install",
"path": "vite-gaudi",
"problemMatcher": [],
"label": "npm: install - vite-gaudi",
"detail": "install dependencies from package"
},
{
"type": "npm",
"script": "install",
"path": "rsbuild-frank",
"problemMatcher": [],
"label": "npm: install - rsbuild-frank",
"detail": "install dependencies from package"
},
{
"label": "npm: install all",
"dependsOn": [
"npm: install - rsbuild-frank",
"npm: install - vite-gaudi"
],
"isBackground": true,
"problemMatcher": []
},
{
"label": "npm: dev - vite-gaudi",
"type": "shell",
"hide": false,
"command": "npm run dev",
"options": {
"cwd": "./vite-gaudi"
},
"presentation": {
"reveal": "always"
},
"isBackground": true,
"problemMatcher": {
"owner": "typescript",
"pattern": "$tsc",
"fileLocation": [
"relative",
"${workspaceFolder}"
],
"background": {
"activeOnStart": true,
"beginsPattern": ".*",
"endsPattern": ".*VITE v.*"
}
}
},
{
"label": "npm: dev - rsbuild-frank",
"type": "shell",
"hide": false,
"command": "npm run dev",
"options": {
"cwd": "./rsbuild-frank"
},
"presentation": {
"reveal": "always"
},
"isBackground": true,
"problemMatcher": {
"owner": "typescript",
"pattern": "$tsc",
"fileLocation": [
"relative",
"${workspaceFolder}"
],
"background": {
"activeOnStart": true,
"beginsPattern": ".*",
"endsPattern": ".*Rsbuild v.*"
}
}
},
{
"label": "all:dev",
"dependsOn": [
"npm: dev - rsbuild-frank",
"npm: dev - vite-gaudi"
],
"presentation": {
"reveal": "always",
"revealProblems": "never",
"panel": "new"
}
},
{
"label": "Terminate All Tasks",
"command": "echo ${input:terminate}",
"type": "shell",
"problemMatcher": []
}
],
"inputs": [
{
"id": "terminate",
"type": "command",
"command": "workbench.action.tasks.terminate",
"args": "terminateAll"
}
]
}
Similarly, launch.json contains launch settngs to:
- launch and debug Vite app in browser (
Dev (vite-gaudi)) - launch and debug Rsbuild app in browser (
Dev (rsbuild-frank)) - launch and debug both apps (showing Vite app) (
Dev (all))
{
"version": "0.2.0",
"configurations": [
{
"type": "msedge",
"request": "launch",
"name": "Dev (vite-gaudi)",
"url": "http://localhost:5173/",
"webRoot": "${workspaceFolder}/vite-gaudi",
"preLaunchTask": "npm: dev - vite-gaudi",
"runtimeArgs": [
"-inPrivate"
],
"postDebugTask": "Terminate All Tasks",
},
{
"type": "msedge",
"request": "launch",
"name": "Dev (rsbuild-frank)",
"url": "http://localhost:3000/",
"webRoot": "${workspaceFolder}/rsbuild-frank",
"preLaunchTask": "npm: dev - rsbuild-frank",
"runtimeArgs": [
"-inPrivate"
],
"postDebugTask": "Terminate All Tasks",
},
{
"type": "firefox",
"request": "launch",
"name": "Dev (all)",
"url": "http://localhost:5173",
"webRoot": "${workspaceFolder}/vite-gaudi",
"preLaunchTask": "all:dev",
"runtimeArgs": [
"-inPrivate"
],
"postDebugTask": "Terminate All Tasks",
}
]
}
The key to launch the browser debugging session from VSCode is to define a correct endsPattern in problemMatcher to catch the corresponding console output.
- Vite:
.*VITE v.* - Rsbuild:
.*Rsbuild v.*
You can also see the complete example, including the sample Vite app, the sample Rsbuild app, together with the tasks.json and launch.json in this GitHub repository: vscode-debugging-sample.