\usemodule[art-01,fnt-20]

\enabletrackers[otf.bugs]

\starttext

\def\sample{نَسْتَعِينُ وَلَا الضَّالِّينَ}
% \def\sample{نَسْتَعِينُ}
% \def\sample{\Uchar"0643\Uchar"0644\Uchar"0651\Uchar"0627\Uchar"064E}
% \def\sample{لرَّحْمَـٰنِ}
% \def\sample{حْمَن}

\setvariables
  [otftracker]
  [font=file:uthmantn1ver10.ttf,
   size=24pt,
   features=arabic,
   direction=-1,
   title=Feature Check,
   sample=\sample]

\page

\setvariables
  [otftracker]
  [font=file:arabtype,
   size=24pt,
   features=arabic,
   direction=-1,
   title=Feature Check,
   sample=\sample]

\stoptext

