debug nestJS application with nodemon in VS Code - node.js

Question

Is there a way to debug a nestJS project with nodemon.
i tried this code in launch.json
{
"type": "node",
"request": "launch",
"name": "NestJs Watch",
"runtimeExecutable": "npm",
"runtimeArgs": ["run-script", "start:dev"],
"cwd": "${workspaceFolder}",
"port": 3000
}
but i got this error
and my nodemon.json file
{
"watch": ["src"],
"ext": "ts",
"ignore": ["src/**/*.spec.ts"],
"exec": "ts-node -r --inspect=3000 tsconfig-paths/register src/main.ts"
}

Answer 1

If we want to work in the debug mode, with a better chance to see what is happening in the code, we need to use "nodemon" with dedicated a "nodemon.json" configuration file to run our development "nestjs" server with the ts-node module hooking up the typescript compiler.
The steps that worked for me are:
Install nodemon and ts-node:
npm i --save-dev nodemon ts-node
Next, add a nodemon.json file with debug and ts-node support in the root of your project:
file: (project root) nodemon.json
and insert this config. JSON text:
{
"watch": ["src"],
"ext": "ts",
"ignore": ["src/**/*.spec.ts"],
"exec": "node --inspect-brk -r ts-node/register src/main.ts"
}
Next adjust file: package.json - section: "start:debug"
file: (project root) package.json
The original value typically is:
...
> "start:debug": "nest start --debug --watch",
...
Change it to:
...
> "start:debug": "nodemon --config nodemon.json"
...
Now, in VSC (Visual Studio Code) make sure that you can see on the very bottom status bar:
"Auto Attach: On"
if not, on your keyboar press the keys:
Ctrl + Shift + p
to open the Command Palette, and paste in this command:
Debug: Toggle auto attach
and press Enter.
Now you should see the:
"Auto Attach: On"
Now debugging with break points should work.
Start with placing a break point in the beginning of your program code
(to make sure the flow does not end before your breakpoint ...)
file: (project root) 'main.ts'
> function: bootstrap() {
console.log('test'); // -- place break point here
// ... other code ...
}
In VSC (Visula Studio Code) select menu item:
Start debugging (or F5)
and select Node.js as the Environment option in the popup menu.
The breakpoint should be caught now in the bootstrap() function.

Answer 2

I run this command:
npm run start:dev

Answer 3

Try this nodemon config:
{
"watch": ["src"],
"ext": "ts",
"ignore": ["src/**/*.spec.ts"],
"exec": "node --inspect-brk -r tsconfig-paths/register -r ts-node/register src/main.ts"
}
and then you can run: nodemon --config nodemon.json