Develop Reference

npm parallel execution of commands not working

I have a package.json file at the root of my project folder which contains client and server folders.
in the root package.json I have the following scripts:
"scripts": {
"server": "npm run watch --prefix server",
"client": "npm start --prefix client",
"watch": "npm run server & npm run client"
}
but when i try to run npm run watch only the server script runs, what I don't understand is if I paste the contents of the watch script into the terminal it works just fine.

npm run <script> uses cmd.exe by default if you are on windows, and cmd does not support & to run commands in parallel, so it is better to use a package like npm-run-all.

npm - install command downloading files outside node_modules

I have a project with two folders, client and server, and I also have a package.json at the root of the project to manage starting and installing on the client and server from one place. The problem occurs when I try to install packages from the root using one of the install scripts I have:
"scripts": {
"install-server": "npm install --prefix server",
}
when I run the above script it not only creates a node_modules folder but also downloads additional files into the server folder, which I think are supposed to go into the node_modules folder.
But the following script works fine
"scripts": {
"install-server": "cd server && npm install",
}
why is that?

Lerna.js Setup in NodeJS

I am trying to set up my project based on MonoRepo for that I have used lerna.js now as far as I know lerna.js work as follows.
For Dev
Create lerna.json and update all packages and workspace details to package.json and lerna.json
run yarn or npm client as usual you do.
any folder inside packages/ will be treated as node_module so you can directly call them.
Now running my application as dev works fine but when to build or transpile my es6 code using Babel for production than lerna.json doesn't work right following are problems which are making me confused about how to use it.
Do I have to Publish all my packages to npm for using them in production?
running lerna Bootstrap links packages but when I view my package inside node_modules it still contains es6 code..due to this node application throws an error for using import statement which node didn't understand unless you use experimental flag.
Following is the Example:
lerna.json
{
"packages": [
"packages/*"
],
"version": "independent",
"npmClient": "yarn",
"useWorkspaces": true
}
packages Directory
packages/
context/
dyna_modules/
www/
npm scripts
"clean": "lerna clean --yes && rimraf node_modules && rm -rf package-lock.json yarn.lock",
"build::js": "babel ./packages --out-dir ./build/packages/ --ignore node_modules",
"build::nonjs": "babel package.json prisma.yml Dockerfile docker-compose.yml .env --out-dir ./build --copy-files && babel ./packages/routes --out-dir ./build/packages/routes --copy-files",
"build": "rm -rf ./build && mkdir ./build && npm run build::js && npm run build::nonjs",
"dev:nodemon": "DEBUG=*,-babel,-babel:*,-express:*,-nodemon:*,-nodemon,-snapdragon:*,-finalhandler,-follow-redirects nodemon -L --exec babel-node --inspect index.js",
"dev": "yarn dev:nodemon --ignore-engines",
"prestart": "npm run build && lerna bootstrap",
"start": "cd ./build && node ./packages/www/index.js",
Problem
Running yarn start always fails with error for using the Import statement. During the inspection, I found out that all my packages/modules inside node_module contain es6 syntax instead of a trans-piled code.

Watch template files and copy them to dist/ folder

I'm using typescript on my project and I can successfully watch + compile .ts files and output them to dist folder.
here is the scripts part of my package.json
"start": "npm run build && npm run watch",
"build": "npm run build-ts && npm run tslint",
"test": "cross-env NODE_ENV=test jest --watch",
"watch": "concurrently -k -p \"[{name}]\" -n \"Typescript,Node\" -c \"cyan.bold,green.bold\" \"npm run watch-ts\" \"npm run serve\"",
"serve": "nodemon dist/server.js",
"build-ts": "tsc",
"watch-ts": "tsc -w",
"tslint": "tslint -c tslint.json -p tsconfig.json"
The problem is I want to use js templating engine (nunjucks) and I need to watch the view files inside the views folder and move them to the dist folder.
Is there a way by just using npm scripts or nodejs?
Or do I need to use other tools like gulp or webpack?

I have the "same" request to for a CRUD graphql back-end server, but don't want to use gulp or webpack just to keep it simple.
I see that you use nodemon like me. Then, according the docs at https://github.com/remy/nodemon, it can be used it to monitor changes of any kind of file other than the default js. More over, nodemon can monitor the status of other transactional server other than node.
The first task is detecting the changes of wanted files: in my case I want copy the *.gql files in my src/schema folder to build/schema folder. For that, you can use the ext for the kind of files, and watch option for the source folder to explore.
The second one task is matter of copying the files. Naturally, you can use the copy command of your host OS. In my case I use the DOS xcopy command of the Windows shell (or cp in Unix like OS). nodemon has an "event-hook" with the event option, that can execute a command line when an event occurs. Just we need the restart event of the node server when the changes are detected for nodemon.
You can use the command line options, or a global config file, or in you local package.json project config file. I show up the last one using nodemonConfig section of package.json:
"nodemonConfig": {
"watch": [
"./src/schema",
"./build"
],
"ext": "js,gql",
"events": {
"restart": "xcopy .\\src\\schema\\*.gql .\\build\\schema /Y /O /R /F /I /V /E"
}
}

Ozkr's answer is great, I just want to add what worked for me, I had to change it a bit as nodemon was running into an infinite restart otherwise:
"nodemonConfig": {
"watch": [
"./views",
"./public"
],
"ext": "hjs,js",
"events": {
"restart": "cp -r views dist \n cp -r public dist"
}
}

copy-and-watch does just that:
I use this code to copy html files during development:
"copy_html": "yarn copy-and-watch src/mail_templates/* prod/mail_templates --watch --clean",

How to use node-inspector with `npm start` for my application?

I am using npm start to start my MEAN stack application, but I would like to use the node-inspector to debug some Mongoose. I know I can start the node inspector with node-inspector, but what can I substitute node --debug app.js with to make npm start work in my case?
This is my MEAN stack directory structure:
HTML views/
Angular.js public/javascript/
Express.js routes/
Node.js app.js
Mongoose js models/, connected in app.js
Mongo db connected in app.js
For more information, this is my related question.

You may want to add a seperate debug script to package.json. That way you won't have to remember to revert npm start when you're finished debugging.
"scripts": {
"start": "node ./bin/www",
"debug": "node --debug ./bin/www"
}
Start with npm run:
$ npm run debug

In package.json modify the start run command:
"scripts": {
"start": "node --debug app.js"
}

I use it like this, I also set a variable and run the inspector in one command:
npm run debug
"scripts": {
"start": "set SOAPAPI=https://example.com/&&nodemon",
"debug": "start node-inspector --web-port=8081&&set SOAPAPI=https://example.com/&&nodemon --debug"
}
*nodemon is an utility wrapper for node, you can use node instead