Add git diff for every modified/added file

[ViktorBarzin]

My idea is to add a git diff behaviour to each changed file - maybe show file contents in git diff-like format?

Cheers

[wagoodman]

indeed! I've been wanting to do this for a while (https://github.com/wagoodman/dive/projects/1#card-10593675), though there are a few (small) blockers:

1. we only capture the md5 of the file instead of the entire file contents. We could keep the temp image directory open and not immediately delete it to facilitate diffing... otherwise we'd need to fetch each file from separate layer tars on the fly, which could be expensive.

2. there isn't a lot of screen real estate left! I think we'd have to swap out a pane or add a new tab/window to see contents. I feel like it would have to be a pane swapout otherwise you'd have to select a file, switch to the view, then when you want the next file switch back to the view to select another layer/file. The pane that I would swap out is the contents of the details pane, which currently isn't scrollable -- a feature that would need to be added to show the diff.

3. This isn't a blocker, but something that I'd like to do later... it would be awesome to have a couple of diff formatting options (leveraging other tools, not home growing)... such as the typical linux diff/patch format or a split side-by-side diff (like https://github.com/jeffkaufman/icdiff). Ideally I would want to pull in a go library to facilitate this.

I do feel like a prototype could get mocked up pretty quickly that lacks several features and can be incrementally worked on.

[wagoodman]

My current thought is to allow for multiple layouts, where the current layout is:

+-------------+------------+
|             |            |
|             |            |
|  layerview  |  fileview  |
|             |            |
|             |            |
+-------------|            |     
|             |            |
|             |            |
| detailview  |            |
|             |            |
|             |            |
+-------------+------------+

add support to switch to the (new) layout:

 slim layer view
  v
+-----+------------+------------+
|     |            |            |
|     |  fileview  |  diffview  |
|     |            |            |
|     |            |            |
+-----+------------+------------+
| layer detail view             |
|                               |
+-------------------------------+

where the user can still select a layer in the slim layer view, navigate the filetree as usual, but see specific file content changes in the diff view. The slim layer view would only have the compare bar and a number no other layer information). The layer detail view would hold the information for the single currently selected layer usually visible in the layer view (which now does not have that information).

This way you can still navigate a layer, filetree, and contents without having to toggle layouts, but you can always go back to the existing layout (that exists today) if you are not interested in file contents.

[ericsmalling]

Resurecting an old issue here. I was just using dive to show changes in the layers of an image for one of my clients and this use case was something I really could have used. Are there any updates on plans to implement something?

(FYI @luhring this is related to our chat last night)