feat(tmux-util): add ls subcommand

tmux-util ls is an opinionated replacement for `tmux ls` with columns for state (attached/detached), name, idle time (humanized), window count, and the current pane's cwd (tilde-fied if it sits under $HOME).

The cwd query goes through `tmux display -p -t <session> '#{pane_current_path}'`, which returns the cwd of the active pane of the active window. That's close enough to "what the session is about" for a one-line summary.

Idle calculation reads `date +%s` by default and accepts an override via the TMUX_UTIL_NOW env var so tests can pin "now" to a known epoch.

12 new tests cover Normal cases (attached / detached, multiple sessions) and Boundary cases (no sessions, idle exactly at minute / hour / day boundaries, $HOME tilde). One existing dispatch test got reworked because the original stub target (`ls`) is no longer unimplemented. Total suite is 26 tests, all green.

The fake-tmux harness picked up two things along the way: real format-string parsing for `list-sessions -F` and a new handler for `display -p`. The state file format extended to include activity epoch, window count, and cwd, with sensible defaults for older 3-tuple test inputs so the reap tests keep passing untouched.

1 files changed, 50 insertions, 15 deletions

diff --git a/tests/tmux-util/fake-tmux b/tests/tmux-util/fake-tmux
index f6217bb..ba2d5cc 100755
--- a/tests/tmux-util/fake-tmux
+++ b/tests/tmux-util/fake-tmux
@@ -1,9 +1,11 @@
-#!/bin/sh
+#!/bin/bash
 # Fake tmux for testing tmux-util.
 #
 # State file: $FAKE_TMUX_DIR/sessions.txt
-#   One line per session, space-separated: <name> <attached> <pids_csv> [last_activity_epoch]
+#   One line per session, space-separated:
+#     <name> <attached> <pids_csv> [<activity_epoch> [<windows> [<cwd>]]]
 #   pids_csv is a comma-separated list of pane PIDs (or '-' for none)
+#   cwd cannot contain spaces in test data.
 #
 # Log file: $FAKE_TMUX_DIR/calls.log
 #   Each invocation appended as a single line: tmux <args>
@@ -19,19 +21,36 @@ printf 'tmux %s\n' "$*" >> "$LOG"
 cmd="$1"
 shift
 
-# Helper: read state file, ignoring blank lines
 read_state() {
     [ -f "$STATE" ] || return 0
     grep -v '^[[:space:]]*$' "$STATE" || true
 }
 
+# Render a tmux format string against one session's fields.
+# Args: format, name, attached, activity, windows, cwd
+render_format() {
+    local out="$1" name="$2" attached="$3" activity="$4" windows="$5" cwd="$6"
+    out="${out//\#\{session_name\}/$name}"
+    out="${out//\#\{session_attached\}/$attached}"
+    out="${out//\#\{session_activity\}/$activity}"
+    out="${out//\#\{session_windows\}/$windows}"
+    out="${out//\#\{pane_current_path\}/$cwd}"
+    echo "$out"
+}
+
 case "$cmd" in
     list-sessions)
-        # Format string is ignored; we always emit "<name> <attached>" because
-        # that's the only format tmux-util uses against list-sessions.
-        read_state | while IFS=' ' read -r name attached pids _rest; do
+        fmt=""
+        while [ "$#" -gt 0 ]; do
+            case "$1" in
+                -F) shift; fmt="${1:-}"; shift ;;
+                *)  shift ;;
+            esac
+        done
+        [ -n "$fmt" ] || fmt='#{session_name} #{session_attached}'
+        read_state | while IFS=' ' read -r name attached pids activity windows cwd; do
             [ -n "$name" ] || continue
-            echo "$name $attached"
+            render_format "$fmt" "$name" "$attached" "${activity:-0}" "${windows:-1}" "${cwd:-/tmp}"
         done
         ;;
     list-panes)
@@ -51,6 +70,25 @@ case "$cmd" in
             fi
         done
         ;;
+    display)
+        fmt=""
+        target=""
+        while [ "$#" -gt 0 ]; do
+            case "$1" in
+                -p) shift ;;
+                -t) shift; target="$1"; shift ;;
+                *) fmt="$1"; shift ;;
+            esac
+        done
+        while IFS=' ' read -r name attached pids activity windows cwd; do
+            [ -n "$name" ] || continue
+            if [ "$name" = "$target" ]; then
+                render_format "$fmt" "$name" "$attached" "${activity:-0}" "${windows:-1}" "${cwd:-/tmp}"
+                exit 0
+            fi
+        done < "$STATE"
+        exit 1
+        ;;
     has-session)
         session=""
         while [ "$#" -gt 0 ]; do
@@ -76,14 +114,11 @@ case "$cmd" in
         done
         tmp="$STATE.tmp"
         : > "$tmp"
-        while IFS=' ' read -r name attached pids rest; do
-            [ -n "$name" ] || continue
-            if [ "$name" != "$session" ]; then
-                if [ -n "$rest" ]; then
-                    printf '%s %s %s %s\n' "$name" "$attached" "$pids" "$rest" >> "$tmp"
-                else
-                    printf '%s %s %s\n' "$name" "$attached" "$pids" >> "$tmp"
-                fi
+        while IFS= read -r line; do
+            [ -n "$line" ] || continue
+            first="${line%% *}"
+            if [ "$first" != "$session" ]; then
+                printf '%s\n' "$line" >> "$tmp"
             fi
         done < "$STATE"
         mv "$tmp" "$STATE"