refactor: bash completion script

autocomplete/bash_autocomplete

@@ -2,63 +2,105 @@
 
 # This is a shell completion script auto-generated by https://github.com/urfave/cli for bash.
 
-# Macs have bash3 for which the bash-completion package doesn't include
-# _init_completion. This is a minimal version of that function.
+# macOS still ships Bash 3, where bash-completion may not provide
+# _init_completion. This is a minimal compatible fallback.
 __%[1]s_init_completion() {
   COMPREPLY=()
-  _get_comp_words_by_ref "$@" cur prev words cword
+  if declare -F _comp_initialize >/dev/null 2>&1; then
+    _comp_initialize "$@"
+  else
+    _get_comp_words_by_ref "$@" cur prev words cword
+  fi
+}
+
+__%[1]s_build_completion_request() {
+  local -a words_before_cursor=("${COMP_WORDS[@]:0:${COMP_CWORD}}")
+  local current_word="${COMP_WORDS[COMP_CWORD]}"
+
+  if [[ "${current_word}" == "-"* ]]; then
+    printf '%%s %%s --generate-shell-completion' "${words_before_cursor[*]}" "${current_word}"
+  else
+    printf '%%s --generate-shell-completion' "${words_before_cursor[*]}"
+  fi
+}
+
+# Keep Bash 3 compatibility: associative arrays require Bash 4+, so
+# descriptions are looked up via parallel indexed arrays.
+__%[1]s_find_description_for() {
+  local candidate="$1"
+  local i
+
+  for i in "${!__cli_completion_tokens[@]}"; do
+    if [[ "${__cli_completion_tokens[i]}" == "${candidate}" ]]; then
+      printf '%%s' "${__cli_completion_descriptions[i]}"
+      return 0
+    fi
+  done
+
+  return 1
 }
 
 __%[1]s_bash_autocomplete() {
-  if [[ "${COMP_WORDS[0]}" != "source" ]]; then
-    local cur opts base words
+  local words=("${COMP_WORDS[@]}")
+
+  if [[ "${words[0]}" != "source" ]]; then
+    local cur opts
+    local cword="${COMP_CWORD}"
+    local request_comp
+
     COMPREPLY=()
-    cur="${COMP_WORDS[COMP_CWORD]}"
-    if declare -F _init_completion >/dev/null 2>&1; then
-      _init_completion -n "=:" || return
-    else
-      __%[1]s_init_completion -n "=:" || return
-    fi
-    words=("${words[@]:0:$cword}")
-    if [[ "$cur" == "-"* ]]; then
-      requestComp="${words[*]} ${cur} --generate-shell-completion"
-    else
-      requestComp="${words[*]} --generate-shell-completion"
-    fi
-    opts=$(eval "${requestComp}" 2>/dev/null)
+    cur="${words[$cword]}"
+
+    __%[1]s_init_completion -n "=:" || return
+
+    request_comp="$(__%[1]s_build_completion_request)"
+    opts=$(eval "${request_comp}" 2>/dev/null)
+
+    # Completion output lines use "token:description" format.
+    # Keep token/description in parallel arrays for Bash 3 compatibility.
+    __cli_completion_tokens=()
+    __cli_completion_descriptions=()
 
-    # Separate completions and descriptions
-    local completions=()
-    local descriptions=()
+    local line
     local longest=0
     while IFS=$'\n' read -r line; do
-      local comp_part desc_part
-      if [[ "$line" == *:* ]]; then
-        comp_part="${line%%:*}"
-        desc_part="${line#*:}"
-      else
-        comp_part="$line"
-        desc_part=""
-      fi
-      completions+=("$comp_part")
-      descriptions+=("$desc_part")
-      (( ${#comp_part} > longest )) && longest=${#comp_part}
-    done <<< "$opts"
-
-    # Format completions with aligned descriptions
-    for i in "${!completions[@]}"; do
-      local padded_completion="${completions[i]}"
-      local pad_len=$((longest - ${#padded_completion}))
-      if (( pad_len > 0 )); then
-        padded_completion="${padded_completion}$(head -c $pad_len < /dev/zero | tr '\0' ' ')"
-      fi
+      local token="${line}"
+      local description=""
 
-      if [[ -n "${descriptions[i]}" ]]; then
-        COMPREPLY+=("${padded_completion}  -- ${descriptions[i]}")
-      else
-        COMPREPLY+=("${padded_completion}")
+      if [[ "${line}" == *:* ]]; then
+        token="${line%%:*}"
+        description="${line#*:}"
+      fi
+
+      if [[ -z "${token}" ]]; then
+        continue
       fi
-    done
+
+      __cli_completion_tokens+=("${token}")
+      __cli_completion_descriptions+=("${description}")
+      (( ${#token} > longest )) && longest=${#token}
+    done <<< "${opts}"
+
+    local matches=( $(compgen -W "${__cli_completion_tokens[*]}" -- "${cur}") )
+
+    # COMP_TYPE=63 means Bash is listing matches (usually on second TAB).
+    if [[ "${COMP_TYPE:-}" == "63" && ${#matches[@]} -gt 0 ]]; then
+      local listed=()
+      local candidate
+      for candidate in "${matches[@]}"; do
+        local desc="$(__%[1]s_find_description_for "${candidate}")"
+
+        if [[ -n "${desc}" ]]; then
+          local padded="$(printf '%%-*s' "${longest}" "${candidate}")"
+          listed+=("${padded}  -- ${desc}")
+        else
+          listed+=("${candidate}")
+        fi
+      done
+      COMPREPLY=("${listed[@]}")
+    else
+      COMPREPLY=("${matches[@]}")
+    fi
 
     return 0
   fi