Improve messaging for NoDuplicateTags

Author: mpchadwick

lib/jekyll-pre-commit/checks/no_duplicate_tags.rb

@@ -14,7 +14,9 @@ def check(staged, not_staged, site, args)
 
                 n = Jekyll::Utils.slugify(tag)
                 if !normalized[n]
-                  normalized[n] = post.relative_path
+                  normalized[n] = Hash.new
+                  normalized[n]["path"] = post.relative_path
+                  normalized[n]["tag"] = tag
                 end
               end
             end
@@ -27,7 +29,7 @@ def check(staged, not_staged, site, args)
 
                 if normalized[n] && !raw[tag]
                   @result[:ok] = false
-                  @result[:message] += "#{tag} appears to be duplicated in #{normalized[n]}!"
+                  @result[:message] += "The tag '#{tag}' appears to be duplicated and is listed as '#{normalized[n]["tag"]}' in #{normalized[n]["path"]}. "
                 end
               end
             end

spec/jekyll-pre-commit_spec.rb

@@ -201,7 +201,7 @@
     it "fails if a staged post has duplicate tags" do
       result = runner.run(site, ["spec/fixtures/_posts/2017-07-24-duplicate-tags-2.md"])
       expect(result[:ok]).to eql(false)
-      expect(result[:messages]).to match_array(["duplicate appears to be duplicated in _posts/2017-07-24-duplicate-tags-1.md!"])
+      expect(result[:messages]).to match_array(["The tag 'duplicate' appears to be duplicated and is listed as 'Duplicate' in _posts/2017-07-24-duplicate-tags-1.md. "])
     end
   end