Feature: add compare view between gem versions

[grosser]

Problem: Github is not a reliable source version diff (because it is sometimes not linked, sometimes not tagged, sometimes does not show the exact diff)

Solution: "compare [v1.2.3] to [v1.2.2]" form with 2 selects so users can see the exact diff of what they are about to install, will be useful when making gem bump PRs to link these.

Bonus: the compare page can link to the source-control compare if available #1630.

Related:

• https://github.com/fedora-ruby/gem-compare which does not seem to show a full file diff

/cc @sinsoku

[dwradcliffe]

What are you suggesting we show on the diff page? Are you suggesting we extract and diff the files for every gem version?

[grosser]

extract files of requested versions and run a diff on them ... maybe have some limit on number of files/size (don't diff images etc stuff)

Maybe more efficient to make a git repo per gem and have all versions as tags ... could host that independently anyway ... would be pretty awesome tool to build things on ...

[grosser]

we can just link to http://diff.coditsu.io 🤷‍♂

[mensfeld]

Hey. I'm the author of the differ.

Couple things related to it:

• It is going to be OSS. I'm constantly working on fixing all the critical bugs and improving quality a bit (it was a POC).
• It does allow a link building like so: https://diff.coditsu.io/gems/rugged/0.28.1/0.28.2
  so in general you can do GEM_NAME/version_a/version_b
• It does work on a "per requested" base when doing the calculations.
• I don't mind giving early access to the code to anyone that wants it
• I am working on providing a "social voting" feature so people can mark gem upgrades as safe or unsafe (similar to how google does traffic notifications about the police etc).

[sonalkr132]

Hi, this has a PR #2499 and we will be closing this issue when that gets merged. Please check the pr/site if you have comments.

[sonalkr132]

Closed by #2499