v.util: ensure output of color_compare_files is colorized

[ttytm]

Makes the function do what it's name implies. I was really missing this when there is just diff installed and working in the codebase.

Current	Updated

Due to the ansi codes in the output, it will conflict with #21242. Depending on which one is resolved first conflicts in the other will need to be taken care of.

[spytheman]

I've reverted bfd53a9 in 056a443. The reason is that find_working_diff_command can be used to form a diff command, customizable by setting VDIFF_TOOL and VDIFF_OPTIONS, that later can be passed to util.color_compare_files:

import v.util
import v.util.diff
diff_cmd := diff.find_working_diff_command()!
res := util.color_compare_files(diff_cmd, 'v.mod', 'v2.mod')
println(res)

[ttytm]

I think this still can be used with #21242 and that the PR does not need to be reverted or this one closed

[ttytm]

What command does it use for you? Do you have colordiff additionally installed?
It would be nice to get color with the default system diff tool as well that is just diff

[spytheman]

I think this still can be used with #21242 and that the PR does not need to be reverted or this one closed

I disagree. It represents a regress in functionality, and a break on FreeBSD (whose diff tool does not support color output at all).

[spytheman]

What command does it use for you? Do you have colordiff additionally installed? It would be nice to get color with the default system diff tool as well that is just diff

The list of commonly used diff commands is in known_diff_tools in vlib/v/util/diff/diff.v:18:
['colordiff', 'gdiff', 'diff', 'colordiff.exe', 'diff.exe', 'opendiff', 'code', 'code.cmd']

It would be nice, for the diff to work when it is supported, and to be customizable when the user has more sophisticated tools and needs (which currently can be done by setting VDIFF_TOOL and VDIFF_OPTIONS).

That can be done by changing find_working_diff_command, which can add options for the default commands, if it detects that they are supported.

[spytheman]

Something like this for example works on FreeBSD too (if the user has installed diffutils).

[ttytm]

What command does it use for you? Do you have colordiff additionally installed? It would be nice to get color with the default system diff tool as well that is just diff

The list of commonly used diff commands is in known_diff_tools in vlib/v/util/diff/diff.v:18: ['colordiff', 'gdiff', 'diff', 'colordiff.exe', 'diff.exe', 'opendiff', 'code', 'code.cmd']

It would be nice, for the diff to work when it is supported, and to be customizable when the user has more sophisticated tools and needs (which currently can be done by setting VDIFF_TOOL and VDIFF_OPTIONS).

That can be done by changing find_working_diff_command, which can add options for the default commands, if it detects that they are supported.

Yes I wanted to take the diff module there. Though thought it's organic and sophisticated doing it step by step

[spytheman]

Do you have colordiff additionally installed?

Yes, on both Linux and on FreeBSD, but I renamed it while testing.

[ttytm]

Awesome fix thanks 👍

[ttytm]

I was sloppy here with reviewing as well. With two things

1. From research and the tests before I knew that it won't work to put the flag at the beginning, the output will not be colorized if doing so. So the check would have to be in the color_compare function.
2. My initial implementation was on mac which I tried to cover. It's not covered here.

Improving the module while adding test we can eventually get there I believe as both things can be solved.