add tests to redmine integration improvement

CHANGELOG-EE

+v 7.2.0
+  - Improve Redmine integration
+
 v 7.1.0
   - Synchronize LDAP-enabled GitLab administrators with an LDAP group (Marvin Frick, sponsored by SinnerSchrader)
   - Synchronize SSH keys with LDAP (Oleg Girko (Jolla) and Marvin Frick (SinnerSchrader))

lib/gitlab/markdown.rb

@@ -193,7 +193,7 @@ module Gitlab
           link_to("##{identifier}", url, options)
         end
       elsif project.redmine_tracker?
-	reference_redmine_issue(identifier, project)
+        reference_redmine_issue(identifier, project)
       elsif project.jira_tracker?
         reference_jira_issue(identifier, project)
       end

spec/helpers/gitlab_markdown_helper_spec.rb

@@ -229,6 +229,52 @@ describe GitlabMarkdownHelper do
       end
     end
 
+    describe "referencing a Redmine issue" do
+      let(:actual)   { "Reference to Redmine ##{issue.iid}" }
+      let(:expected) { "http://redmine.example/issues/#{issue.iid}" }
+      let(:reference) { "##{issue.iid}" }
+
+      before do
+        issue_tracker_config = { "redmine" => { "title" => "Redmine tracker", "issues_url" => "http://redmine.example/issues/:id" } }
+        Gitlab.config.stub(:issues_tracker).and_return(issue_tracker_config)
+        @project.stub(:issues_tracker).and_return("redmine")
+        @project.stub(:issues_tracker_id).and_return("REDMINE")
+      end
+
+      it "should link using a valid id" do
+        gfm(actual).should match(expected)
+      end
+
+      it "should link with adjacent text" do
+        # Wrap the reference in parenthesis
+        gfm(actual.gsub(reference, "(#{reference})")).should match(expected)
+
+        # Append some text to the end of the reference
+        gfm(actual.gsub(reference, "#{reference}, right?")).should match(expected)
+      end
+
+      it "should keep whitespace intact" do
+        actual   = "Referenced #{reference} already."
+        expected = /Referenced <a.+>[^\s]+<\/a> already/
+        gfm(actual).should match(expected)
+      end
+
+      it "should not link with an invalid id" do
+        # Modify the reference string so it's still parsed, but is invalid
+        invalid_reference = actual.gsub(/(\d+)$/, "r45")
+        gfm(invalid_reference).should == invalid_reference
+      end
+
+      it "should include a title attribute" do
+        title = "Issue in Redmine tracker"
+        gfm(actual).should match(/title="#{title}"/)
+      end
+
+      it "should include standard gfm classes" do
+        gfm(actual).should match(/class="\s?gfm gfm-issue\s?"/)
+      end
+    end
+
     describe "referencing a merge request" do
       let(:object)    { merge_request }
       let(:reference) { "!#{merge_request.iid}" }