better error message when $SD_ROOT does not exist

And also when it exists but is not a directory.

README.md

@@ -265,6 +265,11 @@ Bash doesn't support the fancy completion-with-description feature that is sort
 
 # Changelog
 
+## v1.0.1 2022-04-17
+
+- better error message if `~/sd` does not exist
+- better error message if `~/sd` exists but is not a directory
+
 ## v1.0.0 2022-02-27
 
 `sd` is now released under the MIT license. There are no functional changes from the pre-1.0 releases.

sd

@@ -174,10 +174,32 @@ __sd_new() {
   fi
 }
 
+__sd_new_user_help() {
+  root=$1
+  echo >&2 "error: $root not found"
+  echo >&2
+  echo >&2 "It looks like you don't have a script directory yet!"
+  echo >&2
+  echo >&2 "Get started by creating your first script:"
+  echo >&2
+  echo >&2 "    sd hello --new 'echo \"Hello, sd!\"'"
+  echo >&2
+  echo >&2 "And then run it like this:"
+  echo >&2
+  echo >&2 "    sd hello"
+}
+
 __sd() {
   set -euo pipefail
 
-  local target=${SD_ROOT:-$HOME/sd}
+  local root=${SD_ROOT:-$HOME/sd}
+
+  if [[ -e "$root" && ! -d "$root" ]]; then
+    echo "error: $root is not a directory" >&2
+    exit 1
+  fi
+
+  local target=$root
   local arg
 
   while [[ $# -gt 0 ]]; do
@@ -212,6 +234,15 @@ __sd() {
     esac
   done
 
+  # you're allowed to run --new even if there is no
+  # script directory root, in order to bootstrap it
+  if [[ "$found_really" = "true" || "$found_new" = "false" ]]; then
+    if [[ ! -d "$root" ]]; then
+        __sd_new_user_help "$root"
+        exit 1
+      fi
+  fi
+
   if [[ "$found_really" = "true" ]]; then
     local -a preserved=()
     for arg in "$@"; do
@@ -223,12 +254,12 @@ __sd() {
     if [[ ${#preserved[@]} -gt 0 ]]; then
       set -- "${preserved[@]}" "$@"
     fi
-  elif [[ "$found_help" = "true" ]]; then
-    __sd_help "$target"
-    exit 0
   elif [[ "$found_new" = "true" ]]; then
     __sd_new "$target" "$@"
     exit 0
+  elif [[ "$found_help" = "true" ]]; then
+    __sd_help "$target"
+    exit 0
   elif [[ "$found_edit" = "true" ]]; then
     __sd_edit "$target"
     exit 0