adopt to 'available' lib changes

Author: Tom Hensel

README.md

@@ -7,7 +7,7 @@
 Fasd Package for [Wahoo][Wahoo] / [fish](fishshell.com).
 
 ## Install
-> _Note_: You need to have `fasd` installed to loading Wahoo.
+> _Note_: You need to have `fasd` installed prior to loading Wahoo.
 
 On OSX `homebrew` has a keg for `fasd`:
 

fasd.fish

@@ -1,9 +1,8 @@
 # extracted from https://jurriaan.ninja/2014/12/21/fish-shell-and-fasd.html
 
 function init --on-event init_fasd
-  set -l fasd_bin (which fasd)
-  if not test -n "$fasd_bin"
-    echo "🍒  Please install 'fasd' first: brew install fasd"
+  if not exec_avail fasd
+    echo "🍒  Please install 'fasd' first!"
   else
     function -e fish_preexec _run_fasd
       fasd --proc (fasd --sanitize "$argv") > "/dev/null" 2>&1