Rewrite _rails-command to work from app subdirectories

modules/rails/init.zsh

@@ -36,12 +36,27 @@ alias rorx='_rails-command destroy'
 #
 
 function _rails-command {
-  if [[ -e "script/server" ]]; then
-    ruby script/"$@"
-  elif [[ -e "bin/rails" ]]; then
-    ruby bin/rails "$@"
-  else
-    ruby script/rails "$@"
+  local root_dir="$PWD"
+  local rails_cmd
+
+  while [[ "$root_dir" != '/' ]]; do
+    if [[ -d "$root_dir/.bundle" ]]; then
+      break
     fi
+    root_dir="$root_dir:h"
+  done
+
+  if [[ -e "$root_dir/bin/rails" ]]; then
+    rails_cmd='bin/rails'
+  elif [[ -e "$root_dir/script/rails" ]]; then
+    rails_cmd='script/rails'
+  elif [[ -e "$root_dir/script/server" ]]; then
+    rails_cmd='script/'
+  else
+    print "$0: not inside of a Rails application: $PWD" >&2
+    return 1
+  fi
+
+  (cd "$root_dir" && ruby "$rails_cmd" "$@")
 }