As of now, there are some available extensions: for example Minify or JS & CSS Minifier

Note: You can find extensions on the VS Code Marketplace.

Or directly from VS Code by searching from the Extensions pane, on the left side (Ctrl + Shift + X).

You can use the Visual Studio 2015 Bundler & Minifier,extention https://visualstudiogallery.msdn.microsoft.com/9ec27da7-e24b-4d56-8064-fd7e88ac1c40 this used to be apart of Web Essentials in previous versions of Visual Studio, but was separated, into it's own extension.

In settings type JS & CSS Minifier and look for these lines and change to "yes":

// Automatically minify file when saving. 
//Set to "yes" to always minify, 
//"no" to never minify, 
//"exists" to only minify if a minified version already exists.
"es6-css-minify.minifyOnSave": "no"

or you can use the new settings editor that is proposed by the IDE where you will have the user interface for all the settings.

I can't suggest any plugins for you. There may be a limited selection, since this isn't really the proper way to do things, but you seem to realize this.

If you insist on doing this, and can't find a plugin which fits your needs, you can always use CTRL+F with the regular expression (?: |\n):

If you use tabs instead of spaces, then you should be able to replace them with \t.

The catch is that this will obviously replace spaces within your document, but since browsers automatically remove extra spaces, this hopefully shouldn't be an issue.

I would suggest looking into vite. It's a newer and faster alternative to webpack, and I personally find it a lot easier to use and understand.