[Bug?] npm i doesn't install mysql package

[Master-Guy]

Currently I'm trying to expand my NodeJS knowledge with some database access, and it's going pretty good.
Now I'm trying to get my package running, and as I usually do, I commit the code (excluding the node_modules folder and some other files) to Github, and download it on another system. There I run npm i --omit=dev and npm run to start my application.
Even though npm i --omit=dev reports no failures or issues, npm run fails due to the mysql package missing, even though it is listed in package.json and package-lock.json. Also I can see a folder called node_modules/mysql, which further adds to the confusion..

"dependencies": {
	"mysql": "^2.18.1",
	[...]
},
"devDependencies": {
	"@types/mysql": "^2.15.21",
	[...]
}

When I run npm i without --omit=dev it somehow remembers to install the mysql package that I'm missing before, showing: added 1 package
What could be the cause of this? The same happens with npm ci.

[Master-Guy]

Doing a file compare between node_modules with and without, I see these two differences:

1. package-lock.json contains an entry for @types/mysql:

		"node_modules/@types/mysql": {
			"version": "2.15.21",
			"resolved": "https://registry.npmjs.org/@types/mysql/-/mysql-2.15.21.tgz",
			"integrity": "sha512-NPotx5CVful7yB+qZbWtXL2fA4e7aEHkihHLjklc6ID8aq7bhguHgeIoC1EmSNTAuCgI6ZXrjt2ZSaXnYX0EUg==",
			"dev": true,
			"dependencies": {
				"@types/node": "*"
			}
		},

2. @types/mysql is added

There is however, not a single other difference..

[MylesBorins]

We don't offer general support here.