Add guard condition for Podcast::TIMESTAMP_REGEX

Author: yasulab

app/controllers/podcasts_controller.rb

@@ -45,7 +45,9 @@ def convert_shownote(content)
     HTML
 
     content.gsub!(/(#+) Shownote/) { shownote }
-    content.gsub!(/-\s((\d:)?\d{1,}:\d{2})/) do
+    return content unless content.match?(Podcast::TIMESTAMP_REGEX)
+
+    content.gsub!(Podcast::TIMESTAMP_REGEX) do
         t = $1
         t = (t.size ==  '0:00'.size) ?   '0' + t : t
         t = (t.size == '00:00'.size) ? '00:' + t : t

app/models/podcast.rb

@@ -2,6 +2,7 @@ class Podcast < ApplicationRecord
   self.table_name = 'podcasts'
   DIR_PATH        = 'public/podcasts'
   WDAY2JAPANESE   = %w(日 月 火 水 木 金 土)
+  TIMESTAMP_REGEX = /-\s((\d:)?\d{1,}:\d{2})/
 
   validates :title,          presence: true
   validates :content_size,   presence: true