Add support for diff-highlight

[dwijnand]

I would be really nice if tig supported diff-highlight.

[dwijnand]

oh how I miss not having this..

[dwijnand]

So.. I was wondering- how viable is including this? Is it possible to "shell out to perl" for this?

I've negligible experience in C, so I could use any help I can get in implementing this.

Thanks

[jonas]

There's two things required to make this work. First, the diff view will need to learn how to parse ASCII control characters. To start with, only the ones to enter/exit highlighting are required. Since the diff view is line-based, `struct line` will need a flag to indicate whether `diff_draw` needs to "interpret" the line characters. Next, is the actual running of `diff-highlight` as a sort of filter of the underlying `git-diff`/`git-show` command. Tig will need to set up the pipe using the IO module. And also have hooks to kill/close the filter process. It is not supported right now.

[danielmanesku]

It would be really nice to have this feature (or even better diff-so-fancy), it saves a lot of time.
It also got some light from git team: https://github.com/blog/2188-git-2-9-has-been-released

[tim-heinsohn]

Would be nice indeed.

[wikimatze]

+1 for that feature

[jonas]

[dwijnand]

What am I doing wrong that I see the following?

[jonas]

How did you configure it? First of all I assume you are using Git's diff-highlight and not the fancy one?

09:17:19 /opt/tig#master > head $(which diff-highlight)
#!/usr/bin/perl

use 5.008;
use warnings FATAL => 'all';
use strict;

# Highlight by reversing foreground and background. You could do
# other things like bold or underline if you prefer.
my @OLD_HIGHLIGHT = (
    color_config('color.diff-highlight.oldnormal'),
09:17:33 /opt/tig#master > grep diff-highlight ~/.tigrc
set diff-highlight = true

Right now it only understands the standout terminal escape codes used by an "unconfigured" diff-highlight so did you configure anything under color.diff-highlight, i.e. what is the output of git config -l | grep diff-highlight? I might have to set GIT_CONFIG to remove such settings.

[dwijnand]

yeah I seem to have configured things under color.diff-highlight:

$ git config -l | grep diff-highlight
color.diff-highlight.oldnormal=red bold
color.diff-highlight.oldhighlight=red bold 52
color.diff-highlight.newnormal=green bold
color.diff-highlight.newhighlight=green bold 22
core.pager=diff-highlight | less -$LESS -F -x1,5 -X
interactive.difffilter=diff-highlight

[edit]

And I'm using git's diff-highlight and configuring .tigrc with true

[jonas]

@dwijnand OK, thanks, reproduced. I am new to diff-highlight so it's great to learn some tricks. I pushed a new commit to fix this so that it works without support for colors. Will add tests for this when I have some time.

Implementing full support for terminal color escape codes would be nice but I think it would be better to support git's porcelain diff format which would open the doors to have split diff view, color words etc.

[dwijnand]

@jonas thanks!

[gweodoo]

@jonas I have some trouble with your awesome diff-highlight feature.
I'm building tig from master branch (dfa26fd) and also git from master branch (be5a750 --> 2.11.0-rc0+).
I'm enabling the capability from .gitconfig file: [tig] diff-highlight = true

But I have this kind of weird stuff in the diff view:

As you mentioned, I've checked that i'm using Git's diff-highlight without any configuration.
I've also tried with an older version of git and specifying the option in .gitrc directly instead of .gitconfig, but none of them solve my issue.

Do you have any idea ?
Thanks.

[jonas]

@gweodoo Do you have the diff-highlight script in your PATH?

[jonas]

@gweodoo I think (hope) that @dtwlin just fixed the issue you reported.

[tim-heinsohn]

Confirming this works nicely. Thanks so much!

(Revision: e59bec5, tigrc: set diff-highlight = true with diff-highlight in $PATH.)

[Liooo]

Can we use diff-so-fancy now?

[jonas]

@Liooo No, not yet. With the infra put in place it should be doable. Do you mind creating a ticket for this?

[Liooo]

@jonas of course not!

.. DONE: #542

[danielmanesku]

I can confirm that this works in tig 2.2.1, but only when used directly from terminal (iTerm2 for instance).
When I am within tmux (2.2), the pieces are not highlighted. Tested with empty tmux.conf, and the issue still reproduces. Does anybody have it working within tmux?

[jonas]

I suggest opening a separate issue. I don't use tmux myself so contributions in that regard would very appreciated.

[danielmanesku]

Issue #559 created.
Somehow I got the feeling that everyone is using either tmux or screen, but seems that I was wrong.

[kadrach]

@danielmanesku No idea how I'd go about troubleshooting it, but it works perfectly well in tmux for me.

[gweodoo]

@jonas I'm sorry, I'm quite a bit late to respond (almost 5 months)
Indeed, with the fix you mentioned, everything goes well now !
tig being updated automatically twice a week with the master branch, I forgot to check for the fix (and I think Github notification went to /dev/null).

Thanks !

[mapad]

For those on OSX who installed tig with the HomeBrew command 'brew install tig', somehow this won't work. You need to compile from sources and install before git through 'brew install git', in order to not use git default installed version.

[keimlink]

Works on macOS after brew upgrade tig, but I had to remove the default configuration in /usr/local/etc/tigrc so that the new default values are used. Otherwise the diff doesn't use the right colors, because they we not defined previously.

[frouo]

What is the best / easiest way to get diff-highlight installed on macOS? For the moment I have git installed though xcode-install (because I am iOS developer). I understand I have to install git via brew install git but I would rather not have 2 versions of git on my mac.

Thank you 🙏🏻

[koutcher]

Installing git via brew install git just to get diff-highlight would be a little overkill. If the Xcode version of git doesn't come with the contrib directory, just grab the diff-highlight script from /usr/local/opt/git/share/git-core/contrib/diff-highlight on another machine and put it somewhere in your PATH. If you don't have access to another machine, https://raw.githubusercontent.com/git/git/3dbfe2b8ae94cbdae5f3d32581aedaa5510fdc87/contrib/diff-highlight/diff-highlight should be good enough (it was the version before it was split in modules).

[frouo]

Thank you so much @koutcher !

For others with git installed though Xcode, here are the steps to "install" diff-highlight:

1. Download the diff-highlight script and put the result in the file /usr/local/bin/diff-highlight:

curl -o /usr/local/bin/diff-highlight https://raw.githubusercontent.com/git/git/3dbfe2b8ae94cbdae5f3d32581aedaa5510fdc87/contrib/diff-highlight/diff-highlight

2. Make the file executable:

chmod +x /usr/local/bin/diff-highlight

3. Add diff-highlight in your PATH (or ~/.bash_profile if using bash):

echo 'export PATH="$PATH:/usr/local/bin/diff-highlight"' >> ~/.zshrc

4. Do not forget to run source command to update your PATH in your current terminal:

source ~/.zshrc