list.sh: improve arg parsing, support brew ls

Library/Homebrew/brew.sh

@@ -161,7 +161,7 @@ case "$@" in
     homebrew-command-path "$@" && exit 0
     ;;
   # falls back to cmd/list.rb on a non-zero return
-  list*)
+  list* | ls*)
     source "${HOMEBREW_LIBRARY}/Homebrew/list.sh"
     homebrew-list "$@" && exit 0
     ;;

Library/Homebrew/list.sh

@@ -4,32 +4,37 @@
 homebrew-list() {
   case "$1" in
     # check we actually have list and not e.g. listsomething
-    list) ;;
-    list*) return 1 ;;
+    list | ls) ;;
+    list* | ls*) return 1 ;;
     *) ;;
   esac
 
   local ls_args=()
   local formula=""
   local cask=""
 
-  local first_arg
-  for arg in "$@"
+  local OPTIND=2 # skip $1 (and localise OPTIND to this function)
+  while getopts ":1lrt-:" arg
   do
-    if [[ -z "${first_arg}" ]]
-    then
-      first_arg=1
-      [[ "${arg}" == "list" ]] && continue
-    fi
     case "${arg}" in
       # check for flags passed to ls
-      -1 | -l | -r | -t) ls_args+=("${arg}") ;;
-      --formula | --formulae) formula=1 ;;
-      --cask | --casks) cask=1 ;;
+      1 | l | r | t) ls_args+=("-${arg}") ;;
+      -)
+        case "${OPTARG}" in
+          formula | formulae) formula=1 ;;
+          cask | casks) cask=1 ;;
+          *) return 1 ;;
+        esac
+        ;;
       # reject all other flags
-      -* | *) return 1 ;;
+      *) return 1 ;;
     esac
   done
+  # If we haven't reached the end of the arg list, we have named args.
+  if ((OPTIND - 1 != $#))
+  then
+    return 1
+  fi
 
   local tty
   if [[ -t 1 ]]

Library/Homebrew/test/cmd/list_spec.rb

@@ -13,7 +13,7 @@
       (HOMEBREW_CELLAR/f/"1.0/somedir").mkpath
     end
 
-    expect { brew "list", "--formula" }
+    expect { brew_sh "list", "--formula" }
       .to output("#{formulae.join("\n")}\n").to_stdout
       .and not_to_output.to_stderr
       .and be_a_success