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.

[casey]

I switched to using Clap's dynamic completion engine in #3167. The new completion engine calls into the just binary to get completions. This allows us to implement custom completion logic in Rust for all supported shells, instead of having to patch in support for each individual shell.

I created #2406 to track improvements to the new completion engine in one place.

The new completions attempt to respect command line flags as much as possible, so this should work.