Add support for global justfile completions

[spkane]

I have only tested the Bash version of this change, but I used Claude Code to update the rest of them to match the general logic.

[spkane]

Fixes: #2394

[spkane]

Related to: #3017, #3012, #2686, and maybe others...

[hposca]

This is the diff, which worked on my machine (running zsh 5.9 (x86_64-pc-linux-gnu) just 1.46.0 on Linux 6.12.63-1-lts), using your completions/just.zsh as base:

diff --git a/completions/just.zsh b/completions/just.zsh
index a69f7c4d..69e40ef4 100644
--- a/completions/just.zsh
+++ b/completions/just.zsh
@@ -44,6 +44,7 @@ _just() {
 '--request=[Execute <REQUEST>. For internal testing purposes only. May be changed or removed at any time.]: :_default' \
 '-s+[Show recipe at <PATH>]: :(_just_commands)' \
 '--show=[Show recipe at <PATH>]: :(_just_commands)' \
+'()--usage=[Print recipe usage information]:PATH:_default' \
 '--check[Run \`--fmt\` in '\''check'\'' mode. Exits with 0 if justfile is formatted correctly. Exits with 1 and prints a diff if formatting is required.]' \
 '--clear-shell-args[Clear shell arguments]' \
 '(-q --quiet)-n[Print what just would do without doing it]' \
@@ -101,7 +102,7 @@ _just() {
 
             # Check if --global-justfile or -g flag is present
             local use_global=""
-            for word in ${words[@]}; do
+            for word in "${words[@]}"; do
                 if [[ "$word" == "-g" || "$word" == "--global-justfile" ]]; then
                     use_global="--global-justfile"
                     break
@@ -128,7 +129,7 @@ _just() {
                 _message "value"
             elif [[ $recipe ]]; then
                 # Show usage message
-                _message "`just --show $recipe`"
+                _message "`just $use_global --show $recipe`"
                 # Or complete with other commands
                 #_arguments -s -S $common '*:: :_just_commands'
             else
@@ -148,29 +149,24 @@ _just_commands() {
 
     # Check if --global-justfile or -g flag is present
     local use_global=""
-    for word in ${words[@]}; do
+    for word in "${words[@]}"; do
         if [[ "$word" == "-g" || "$word" == "--global-justfile" ]]; then
             use_global="--global-justfile"
             break
         fi
     done
 
-    local variables; variables=(
-        ${(s: :)$(_call_program commands just $use_global --variables)}
-    )
-    local commands; commands=(
-        ${${${(M)"${(f)$(_call_program commands just $use_global --list)}":#    *}/ ##/}/ ##/:Args: }
-    )
+    # Get recipes from --summary (includes full module::recipe paths)
+    local summary_output=$(_call_program commands just $use_global --summary)
 
-    if compset -P '*='; then
-        case "${${words[-1]%=*}#*=}" in
-            *) _message 'value' && ret=0 ;;
-        esac
-    else
-        _describe -t variables 'variables' variables -qS "=" && ret=0
-        _describe -t commands 'just commands' commands "$@"
-    fi
+    # Split into array properly
+    local -a recipes
+    recipes=("${(@s: :)summary_output}")
 
+    # Add recipes directly to completion
+    compadd -a recipes
+
+    return 0
 }
 
 if [ "$funcstack[1]" = "_just" ]; then
@@ -178,16 +174,14 @@ if [ "$funcstack[1]" = "_just" ]; then
 _just_variables() {
     [[ $PREFIX = -* ]] && return 1
     integer ret=1
-
     # Check if --global-justfile or -g flag is present
     local use_global=""
-    for word in ${words[@]}; do
+    for word in "${words[@]}"; do
         if [[ "$word" == "-g" || "$word" == "--global-justfile" ]]; then
             use_global="--global-justfile"
             break
         fi
     done
-
     local variables; variables=(
         ${(s: :)$(_call_program commands just $use_global --variables)}
     )

[spkane]

@casey It is likely this PR needs some confirmation for the non-bash/ZSH shells, but is there anything I can do to help get this merged as it would be really helpful.