app/javascript/mastodon/rtl.js

   1 // U+0590  to U+05FF  - Hebrew
   2 // U+0600  to U+06FF  - Arabic
   3 // U+0700  to U+074F  - Syriac
   4 // U+0750  to U+077F  - Arabic Supplement
   5 // U+0780  to U+07BF  - Thaana
   6 // U+07C0  to U+07FF  - N'Ko
   7 // U+0800  to U+083F  - Samaritan
   8 // U+08A0  to U+08FF  - Arabic Extended-A
   9 // U+FB1D  to U+FB4F  - Hebrew presentation forms
  10 // U+FB50  to U+FDFF  - Arabic presentation forms A
  11 // U+FE70  to U+FEFF  - Arabic presentation forms B
  12
  13 const rtlChars = /[\u0590-\u083F]|[\u08A0-\u08FF]|[\uFB1D-\uFDFF]|[\uFE70-\uFEFF]/mg;
  14
  15 export function isRtl(text) {
  16   if (text.length === 0) {
  17     return false;
  18   }
  19
  20   text = text.replace(/(?:^|[^\/\w])@([a-z0-9_]+(@[a-z0-9\.\-]+)?)/ig, '');
  21   text = text.replace(/(?:^|[^\/\w])#([\S]+)/ig, '');
  22   text = text.replace(/\s+/g, '');
  23
  24   const matches = text.match(rtlChars);
  25
  26   if (!matches) {
  27     return false;
  28   }
  29
  30   return matches.length / text.length > 0.3;
  31 };