What does it do when I run this command:
npm install --save-dev package1 package2
It is definitely not installing multiple packages, but it
It is definitely not installing multiple packages
Why? You're installing package1 and package2 and marking them as devDependencies
with --save-dev
.
As stated in the documentation, you may combine multiple arguments, and even multiple types of arguments. In your case, you're combining 2 package names published on the registry.
npm install -save module1 module2
Example: npm install -save morgan chalk errorhandler lusca dotenv path mongoose
The above command will install the latest versions of morgan, chalk, errorhandler, lusca, dotenv, path and mongoose.
Save as dependencies:
npm i package1 package2
Save as dev-dependencies:
npm i -D package1 package2
npm i --save-dev package1 package2