Handling carriage return (\r) by justl-exec-recipe

[BlankSpruce]

Consider the following justfile:

foo:
    #!/bin/bash
    printf "1/5\r"
    sleep 1
    printf "2/5\r"
    sleep 1
    printf "3/5\r"
    sleep 1
    printf "4/5\r"
    sleep 1
    printf "5/5\n"
    sleep 1
    printf "DONE\n"

Consider the outcome of invoking recipe foo in these different approaches:

• in terminal (in this example zsh opened in vterm):
  
• when you invoke M-x compile with just --justfile /tmp/foo/justfile foo:

-*- mode: compilation; default-directory: "/tmp/foo/" -*-
Compilation started at Wed Jun 29 17:24:08

just --justfile /tmp/foo/justfile foo
5/5
DONE

Compilation finished at Wed Jun 29 17:24:13

• when you invoke justl-exec-eshell on recipe foo

Welcome to the Emacs shell

/tmp/foo $ just foo
5/5
DONE
/tmp/foo $ 

• when you invoke justl-exec-recipe on recipe foo:

Just target execution started at Wed Jun 29 17:26:59 

1/5^M2/5^M3/5^M4/5^M5/5
DONE

Target execution finished at Wed Jun 29 17:27:04

As far as I understand the filter used with subprocess handling output of just doesn't handle carriage return in special way that's way justl-exec-recipe behaves differently. If you however do the following change:

diff --git a/justl.el b/justl.el
index 89b4dd8..b7694ee 100644
--- a/justl.el
+++ b/justl.el
@@ -349,7 +349,7 @@ ARGS is a plist that affects how the process is run.
 
         (setq-local justl--justfile (justl--justfile-from-arg (elt command 1)))
         (run-hook-with-args 'compilation-start-hook process)
-        (set-process-filter process 'justl--xterm-color-filter)
+        (set-process-filter process 'compilation-filter)
         (set-process-sentinel process sentinel)
         (set-process-coding-system process 'utf-8-emacs-unix 'utf-8-emacs-unix)
         (pop-to-buffer buf)))))

it'll work as other ways to invoke recipe, namely it'll produce:

Just target execution started at Wed Jun 29 17:26:59 

5/5
DONE

Target execution finished at Wed Jun 29 17:27:04

Is there a good reason to not use compilation-filter? If you are worried about handling coloring of the output it can be done with
(add-hook 'compilation-filter-hook 'ansi-color-compilation-filter).

Special handling of carriage return so that the previously printed line is erased makes sense in a lot of practical applications, for instance with recipes invoking rsync --progress.

[psibi]

Is there a good reason to not use compilation-filter? If you are worried about handling coloring of the output it can be done with
(add-hook 'compilation-filter-hook 'ansi-color-compilation-filter).

Yeah, you're right. I believe we can drop the whole xterm-color dependency itself. Can you send a PR for the same ?

[BlankSpruce]

Here it is #21.