Announcing Hex Diff

Github and hex are completely unrelated. Files are directly uploaded from the maintainers computer. They might just have a .gitignore setup for .DS_Store files.

Just read it today, hex diff seems nice!

however i am confused on .DS_Store. while trying hex diff on Ecto 3.3.1 to 3.3.2 (ecto 3.3.1..3.3.2 | hexdiff), .DS_Store file (mac related?) is included on the change. But when i try to see github repo for 3.3.2 (ecto/lib/mix/tasks at v3.3.2 · elixir-ecto/ecto · GitHub) i could not find .DS_Store file.

image1841×951 67.3 KB

I have spotted that Elixir already provides functionality that I wanted to implement - List.myers_difference/2, however I would need to dig more if there is space for optimisations, I am still learning the Myer’s algorithm.

@jola you can see that one and see how much performance difference is there between calling external Git command vs using above function on in-memory data. If there is noticeable difference that cannot be solved by caching then I can try to implement NIF for Git’s xdiff library.

Yeah, I have seen that. PR is ready.

You can see the exact command run here diff/lib/diff/hex/hex.ex at main · hexpm/diff · GitHub

A solution that doesn’t require shelling out to git is absolutely welcome!

xdiff is library used by Git, so there should be no difference. By the way, do you use regular algorithm or patience? Patience one should give slightly better results while being slightly more computationally expensive (but caching should made it neglible difference).

I will try to write something like that in some spare time.

Using git diff was a pragmatic choice with libraries support (we use git_diff | Hex to parse hunks to provide better user experience).

I think a pure Elixir solution would be interesting and in fact that could be a great default for another tool: mix hex.package diff (we couldn’t use a NIF there)

I have checked it out, and for now one thing brought my attention - why fire git diff to compare two projects? Now I am thinking about writing diff algorithm in Elixir or to bring it via NIF to xdiff.

That’s something we can look into, don’t hesitate to make an issue on the diff repo with your ideas and examples of what it would look like!

There are links to the diffs, but they might be a bit tricky to see

image716×601 33.8 KB

If you have ideas for how to improve the UI and make the diffs easier to see, please make an issue on the hexpm repo

Very useful tool, thanks! Would it be possible to add some information like a total X files changed, Y lines added, Z lines removed and then +X lines, -Y lines per file?

And what about a link on hex.pm/package to the latest diff?