Consider Shared Library Cache

[ghost]

Create an in-browser LibraryCache

This Library Cache would be used for caching any framework/library used on a certain website and then be shared with any website that uses the same libraries.

For example:
I go to aaa.tld, and I get Angular 1.5.5 loaded. So Angular 1.5.5 will be downloaded to my browser.
Then I go to bbb.tld, and that website has indeed the Angular 1.5.5 as well. The browser needs to download it again.

However, both files have the same hash because they look exactly the same, and they come from the same origin (usually bower, npm or the developer's github repo).

My proposal would be to have a manifest.json or even a package.json/bower.json, where I would define which libraries I'd like to use in production.
Browser would lookup for these libraries on the LibraryCache, and if they are not there, the browser would download it from a source, or some other location.
Once downloaded, they will remain on the browser.

Possible problems @AdamModus and I thought:

• Problem: in a case of a concatenated vendor.js file, the hash wouldn't be there. Solution: No need to use the vendor.js concatenated file anymore.
• Problem: customised library files. Solution: Don't use customised libraries. Or if you really want to, you can identify the git repo of it.

[annevk]

Duplicate of #22?

[mozfreddyb]

This has been discussed in multiple places. #22 is the canonical issue, but misses some recent context that I'm going to add just now. (Hint: It's this great explainer: https://hillbrad.github.io/sri-addressable-caching/sri-addressable-caching.html)