support Telugu and probably other Asian scripts (#3)

lib/auto_linker/parser.ex

@@ -44,7 +44,7 @@ defmodule AutoLinker.Parser do
   # https://www.w3.org/TR/html5/forms.html#valid-e-mail-address
   @match_email ~r"^[a-zA-Z0-9.!#$%&'*+\/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$"u
 
-  @match_hashtag ~r/^(?<tag>\#[[:word:]_]*[[:alpha:]_·][[:word:]_·]*)/u
+  @match_hashtag ~r/^(?<tag>\#[[:word:]_]*[[:alpha:]_·][[:word:]_·\p{M}]*)/u
 
   @prefix_extra [
     "magnet:?",

test/auto_linker_test.exs

@@ -195,6 +195,21 @@ defmodule AutoLinkerTest do
              ) == expected
     end
 
+    test "support Telugu" do
+      text = "#చక్రం #కకకకక్ #కకకకాక #కకకక్రకకకక"
+
+      expected =
+        "<a href=\"/t/చక్రం\">#చక్రం</a> <a href=\"/t/కకకకక్\">#కకకకక్</a> <a href=\"/t/కకకకాక\">#కకకకాక</a> <a href=\"/t/కకకక్రకకకక\">#కకకక్రకకకక</a>"
+
+      assert AutoLinker.link(text,
+               hashtag: true,
+               hashtag_prefix: "/t/",
+               class: false,
+               rel: false,
+               new_window: false
+             ) == expected
+    end
+
     test "do not turn urls with hashes into hashtags" do
       text = "google.com#test #test google.com/#test #tag"