Get numerical hashes like #123 to link to notes, not generate tag links

#1825 (#1826)

* Updated constant.rb

* Updated answer.rb

* Updated comment.rb

* Updated revision.rb

* Added Test for HASHTAGNUMBER regex

app/models/answer.rb

@@ -12,7 +12,8 @@ class Answer < ActiveRecord::Base
 
   def body
     finder = content.gsub(Callouts.const_get(:FINDER), Callouts.const_get(:PRETTYLINKMD))
-    finder.gsub(Callouts.const_get(:HASHTAG), Callouts.const_get(:HASHLINKMD))
+    finder = finder.gsub(Callouts.const_get(:HASHTAGNUMBER), Callouts.const_get(:NODELINKMD)) 
+    finder = finder.gsub(Callouts.const_get(:HASHTAG), Callouts.const_get(:HASHLINKMD))  
   end
 
   # users who like this answer

app/models/comment.rb

@@ -39,7 +39,8 @@ def created_at
 
   def body
     finder = comment.gsub(Callouts.const_get(:FINDER), Callouts.const_get(:PRETTYLINKMD))
-    finder.gsub(Callouts.const_get(:HASHTAG), Callouts.const_get(:HASHLINKMD))
+    finder = finder.gsub(Callouts.const_get(:HASHTAGNUMBER), Callouts.const_get(:NODELINKMD)) 
+    finder = finder.gsub(Callouts.const_get(:HASHTAG), Callouts.const_get(:HASHLINKMD))  
   end
 
   def icon

app/models/revision.rb

@@ -103,6 +103,7 @@ def render_body
     body = RDiscount.new(body)
     body = body.to_html
     body = body.gsub(Callouts.const_get(:FINDER), Callouts.const_get(:PRETTYLINKHTML))
+    body = body.gsub(Callouts.const_get(:HASHTAGNUMBER), Callouts.const_get(:NODELINKHTML))
     body = body.gsub(Callouts.const_get(:HASHTAG), Callouts.const_get(:HASHLINKHTML))
     body_extras(body)
   end

config/initializers/constants.rb

@@ -3,6 +3,9 @@ module Callouts
   HASHTAG = /(\s)\#([:a-zA-Z0-9_-]+)/
   PRETTYLINKMD = '\1[@\2](/profile/\2)'
   HASHLINKMD = '\1[#\2](/tag/\2)'
+  HASHTAGNUMBER = /(\s)\#([:0-9]+)/
+  NODELINKMD = '\1[#\2](/n/\2)'
   PRETTYLINKHTML = '\1<a href="/profile/\2">@\2</a>'
   HASHLINKHTML = '\1<a href="/tag/\2">#\2</a>'
+  NODELINKHTML = '\1<a href="/n/\2">#\2</a>'
 end

test/unit/constants_test.rb

@@ -27,4 +27,11 @@ class ConstantsTest < ActiveSupport::TestCase
     string = 'this is a #tag #anotheRTag, #question:spectrometer'
     assert string.scan(Callouts.const_get(:HASHTAG)).length == 3
   end
+
+  test 'hashtagnumber regex should match non-initial hash' do 
+    string = "hello #123 #hello " ;
+    assert string.scan(Callouts.const_get(:HASHTAGNUMBER)).length == 1
+    expect = "hello REPLACE #hello " ;
+    assert_equal expect, string.gsub(Callouts.const_get(:HASHTAGNUMBER), ' REPLACE') ;
+  end
 end