Add another check for non-English queries

Author: LOU Xun

lib/halosir/rules.ex

@@ -7,7 +7,7 @@ defmodule HaloSir.Rules do
   Don't cache sentences.
   """
   def should_cache_word?(word) do
-    not_too_long?(word) && not_sentence?(word)
+    not_too_long?(word) && not_sentence?(word) && has_english_letter?(word)
   end
 
   defp not_sentence?(word) do
@@ -20,4 +20,9 @@ defmodule HaloSir.Rules do
   defp not_too_long?(word) do
     String.length(word) <= 20
   end
+
+  @reg ~r/[a-zA-Z]/
+  defp has_english_letter?(word) do
+    Regex.match?(@reg, word)
+  end
 end

test/halosir/rules_test.exs

@@ -25,4 +25,10 @@ defmodule HaloSir.RulesTest do
 
     refute should_cache_word?(sentence)
   end
+
+  test "Should not cache words with no English letter" do
+    word = "『氷菓』"
+
+    refute should_cache_word?(word)
+  end
 end