step1_1.sh

$ mkdir myfirstapp
$ cd myfirstapp/
$ npm init -y
Wrote to /Users/shawn/Projects/Sandbox/myfirstapp/package.json:
{
"name": "myfirstapp",
"version": "1.0.0",
"description": "",
"main": "index.js",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"keywords": [],
"author": "",
"license": "ISC"
}
$ npm i express - save
npm notice created a lockfile as package-lock.json. You should commit this file.
npm WARN myfirstapp@1.0.0 No description
npm WARN myfirstapp@1.0.0 No repository field.
+ express@4.16.4
added 48 packages from 36 contributors and audited 121 packages in 4.379s
found 0 vulnerabilities
$ ll
total 40
drwxr-xr-x 5 shawn staff 160B Oct 22 11:30 .
drwxr-xr-x@ 19 shawn staff 608B Oct 22 11:29 ..
drwxr-xr-x 51 shawn staff 1.6K Oct 22 11:30 node_modules
-rw-r - r - 1 shawn staff 13K Oct 22 11:30 package-lock.json
-rw-r - r - 1 shawn staff 274B Oct 22 11:30 package.json
$ touch index.js
$ npm install
npm WARN myfirstapp@1.0.0 No description
npm WARN myfirstapp@1.0.0 No repository field.
audited 121 packages in 1.167s
found 0 vulnerabilities
$