自定义npm脚本在我的代码中如何工作？

Question

I'm reading node js code wherein package.json I found the following script

scripts: {
   start : 'some-dependency start' 
}

So, when I run npm run start it's actually starting my application with a web server, serving static files in my project.

My question is how some-dependency start running? what it can do? how it can serve my static files. I see internally some-dependency using react-scripts . But I can't wrap my head around how all these things working.

Answer 1

react-scripts is a package that comes in built with create-react-app when you run npm run start it executes a script/program that is wrapped in react-scripts package you can see the script for start command here , in that you can see that the script invokes the webpack-dev-server which serves the bundled javascript on a server

Generally when you execute some script through package.json file the same happens, you need to specify a command/ invoke a script

for example consider following script present in package.json file

 script: {
    "development": " cd client/ && NODE_ENV=development webpack -w --config webpack.dev.config.js"
}

In the above example when you run npm run development the following things happen

1. changes the directory to client
2. Node environment is set to development
3. invokes the webpack with the config file webpack.dev.config.js present in the client directory

It executes what ever that is written in the config file

Feel free to ask doubts if any