Enable fish to complete recipes in modules

src/completions.rs

@@ -94,40 +94,111 @@ export extern "just" [
 ]"#;
 
 const FISH_RECIPE_COMPLETIONS: &str = r#"function __fish_just_complete_recipes
-        if string match -rq '(-f|--justfile)\s*=?(?<justfile>[^\s]+)' -- (string split -- ' -- ' (commandline -pc))[1]
-          set -fx JUST_JUSTFILE "$justfile"
+    if string match -rq '(-f|--justfile)\s*=?(?<justfile>[^\s]+)' -- (string split -- ' -- ' (commandline -pc))[1]
+        set -fx JUST_JUSTFILE "$justfile"
+    end
+
+    # We need the command line tokens to compare them against the module path
+    # of recipies within modules.
+    set commandline_tokens (commandline --current-process --tokenize --cut-at-cursor)
+
+    # Used to track the deepest matching module path. Once a path of a certain
+    # depth matches, all suggestions with shorter paths are invalidated.
+    set max_matching_module_depth 1
+
+    for line in (just --list --list-heading='' --list-prefix='>' --list-submodules 2>/dev/null)
+        if [ $line = '' ]
+            continue
         end
-        just --list 2> /dev/null | tail -n +2 | awk '{
-        command = $1;
-        args = $0;
-        desc = "";
-        delim = "";
-        sub(/^[[:space:]]*[^[:space:]]*/, "", args);
-        gsub(/^[[:space:]]+|[[:space:]]+$/, "", args);
-
-        if (match(args, /#.*/)) {
-          desc = substr(args, RSTART+2, RLENGTH);
-          args = substr(args, 0, RSTART-1);
-          gsub(/^[[:space:]]+|[[:space:]]+$/, "", args);
-        }
 
-        gsub(/\+|=[`\'"][^`\'"]*[`\'"]/, "", args);
-        gsub(/ /, ",", args);
+        # Determine the module depth of the current recipe.
+        set depth 0
+        while [ (string sub --end 1 $line) = '>' ]
+            set depth (math "$depth + 1")
+            set line (string sub --start 2 $line)
+        end
+        if [ (string sub --end 1 $line) = '[' ]
+            # Group headings start with '[', ignore this line.
+            continue
+        end
+        if [ $depth -lt $max_matching_module_depth ]
+            # We have previously found a deeper matching module. There is no
+            # chance any other recipes will match from this point forward.
+            break
+        end
+        # Pop segments off the module stack that aren't valid anymore.
+        for i in (seq $depth (count $module_stack))
+            set --erase module_stack[$i]
+        end
+        set cmd_args_desc (string split " # " $line)
+        set cmd_args "$cmd_args_desc[1]"
+        set desc "$cmd_args_desc[2]"
+
+        set cmd_args (string split " " $cmd_args)
+        set cmd "$cmd_args[1]"
+        set args "$cmd_args[2]"
+
+        # Detect modules based on the colon at the end. Strip the colon for
+        # completions and add it to the module stack.
+        if [ (string sub --start -1 $cmd) = ':' ]
+            set cmd (string sub --end -1 $cmd)
+            set --append module_stack $cmd
+        end
 
-        if (args != ""){
-          args = "Args: " args;
-        }
+        # If the current recipe is within a module, make sure its path is
+        # present on the commandline.
+        if [ $depth -gt 1 ]
+            set modules_to_find $module_stack[1..(math "$depth - 1")]
+            set num_modules (count $modules_to_find)
+            set commandline_offset (math "$(count $commandline_tokens) - $num_modules + 1")
+
+            if [ $commandline_offset -lt 1 ]
+                # The current commandline is shorter than the module path of
+                # the current recipe. No way it will match.
+                continue
+            end
+
+            set commandline_tail $commandline_tokens[$commandline_offset..-1]
+
+            if [ "$modules_to_find" != "$commandline_tail" ]
+                # The module path of the current recipe isn't on the
+                # commandline, so we shouldn't suggest it.
+                continue
+            end
+
+            if [ $depth -gt $max_matching_module_depth ]
+                set max_matching_module_depth $depth
+                # All the previous suggestions are now invalid, because they
+                # matched a shorter module path.
+                set --erase suggestions
+            end
+        end
 
-        if (args != "" && desc != "") {
-          delim = "; ";
-        }
+        # Register current recipe as suggestion. It may be invalidated later if
+        # a longer module path matches.
+        if [ "$args" != '' ]
+            if [ "$desc" != '' ]
+                set --append suggestions "$cmd\tArgs: $args; $desc"
+            else
+                set --append suggestions "$cmd\tArgs: $args"
+            end
+        else
+            if [ "$desc" != '' ]
+                set --append suggestions "$cmd\t$desc"
+            else
+                set --append suggestions "$cmd"
+            end
+        end
+    end
 
-        print command "\t" args delim desc
-  }'
+    # Print the final suggestions
+    for s in $suggestions
+        printf "$s\n"
+    end
 end
 
-# don't suggest files right off
-complete -c just -n "__fish_is_first_arg" --no-files
+# don't suggest files
+complete -c just --no-files
 
 # complete recipes
 complete -c just -a '(__fish_just_complete_recipes)'