Refactor reference gathering to use a dedicated filter

app/helpers/gitlab_markdown_helper.rb

@@ -19,7 +19,8 @@ module GitlabMarkdownHelper
                      escape_once(body)
                    end
 
-    gfm_body = Gitlab::Markdown.gfm(escaped_body, project: @project, current_user: current_user)
+    user = current_user if defined?(current_user)
+    gfm_body = Gitlab::Markdown.gfm(escaped_body, project: @project, current_user: user)
 
     fragment = Nokogiri::HTML::DocumentFragment.parse(gfm_body)
     if fragment.children.size == 1 && fragment.children[0].name == 'a'
@@ -55,8 +56,10 @@ module GitlabMarkdownHelper
       ref:          @ref
     )
 
+    user = current_user if defined?(current_user)
+
     html = Gitlab::Markdown.render(text, context)
-    Gitlab::Markdown.post_process(html, pipeline: context[:pipeline], user: current_user)
+    Gitlab::Markdown.post_process(html, pipeline: context[:pipeline], user: user)
   end
 
   # TODO (rspeicher): Remove all usages of this helper and just call `markdown`
@@ -72,8 +75,10 @@ module GitlabMarkdownHelper
       ref:          @ref
     )
 
+    user = current_user if defined?(current_user)
+
     html = Gitlab::Markdown.gfm(text, options)
-    Gitlab::Markdown.post_process(html, pipeline: options[:pipeline], user: current_user)
+    Gitlab::Markdown.post_process(html, pipeline: options[:pipeline], user: user)
   end
 
   def asciidoc(text)

lib/gitlab/markdown/commit_range_reference_filter.rb

@@ -26,6 +26,18 @@ module Gitlab
         end
       end
 
+      def self.referenced_by(node)
+        project = Project.find(node.attr("data-project")) rescue nil
+        return unless project
+
+        id = node.attr("data-commit-range")
+        range = CommitRange.new(id, project)
+
+        return unless range.valid_commits?
+
+        { commit_range: range }
+      end
+
       def initialize(*args)
         super
 
@@ -53,13 +65,11 @@ module Gitlab
           range = CommitRange.new(id, project)
 
           if range.valid_commits?
-            push_result(:commit_range, range)
-
             url = url_for_commit_range(project, range)
 
             title = range.reference_title
             klass = reference_class(:commit_range)
-            data  = data_attribute(project.id)
+            data  = data_attribute(project: project.id, commit_range: id)
 
             project_ref += '@' if project_ref
 

lib/gitlab/markdown/commit_reference_filter.rb

@@ -26,6 +26,18 @@ module Gitlab
         end
       end
 
+      def self.referenced_by(node)
+        project = Project.find(node.attr("data-project")) rescue nil
+        return unless project
+
+        id = node.attr("data-commit")
+        commit = commit_from_ref(project, id)
+
+        return unless commit
+
+        { commit: commit }
+      end
+
       def call
         replace_text_nodes_matching(Commit.reference_pattern) do |content|
           commit_link_filter(content)
@@ -39,17 +51,15 @@ module Gitlab
       # Returns a String with commit references replaced with links. All links
       # have `gfm` and `gfm-commit` class names attached for styling.
       def commit_link_filter(text)
-        self.class.references_in(text) do |match, commit_ref, project_ref|
+        self.class.references_in(text) do |match, id, project_ref|
           project = self.project_from_ref(project_ref)
 
-          if commit = commit_from_ref(project, commit_ref)
-            push_result(:commit, commit)
-
+          if commit = self.class.commit_from_ref(project, id)
             url = url_for_commit(project, commit)
 
             title = escape_once(commit.link_title)
             klass = reference_class(:commit)
-            data  = data_attribute(project.id)
+            data  = data_attribute(project: project.id, commit: id)
 
             project_ref += '@' if project_ref
 
@@ -62,9 +72,9 @@ module Gitlab
         end
       end
 
-      def commit_from_ref(project, commit_ref)
+      def self.commit_from_ref(project, id)
         if project && project.valid_repo?
-          project.commit(commit_ref)
+          project.commit(id)
         end
       end
 

lib/gitlab/markdown/external_issue_reference_filter.rb

@@ -47,8 +47,9 @@ module Gitlab
 
           title = escape_once("Issue in #{project.external_issue_tracker.title}")
           klass = reference_class(:issue)
+          data  = data_attribute(project: project.id)
 
-          %(<a href="#{url}"
+          %(<a href="#{url}" #{data}
                title="#{title}"
                class="#{klass}">#{match}</a>)
         end

lib/gitlab/markdown/issue_reference_filter.rb

@@ -27,6 +27,13 @@ module Gitlab
         end
       end
 
+      def self.referenced_by(node)
+        issue = Issue.find(node.attr("data-issue")) rescue nil
+        return unless issue
+
+        { issue: issue }
+      end
+
       def call
         replace_text_nodes_matching(Issue.reference_pattern) do |content|
           issue_link_filter(content)
@@ -45,13 +52,11 @@ module Gitlab
           project = self.project_from_ref(project_ref)
 
           if project && issue = project.get_issue(id)
-            push_result(:issue, issue)
-
             url = url_for_issue(id, project, only_path: context[:only_path])
 
             title = escape_once("Issue: #{issue.title}")
             klass = reference_class(:issue)
-            data  = data_attribute(project.id)
+            data  = data_attribute(project: project.id, issue: issue.id)
 
             %(<a href="#{url}" #{data}
                  title="#{title}"

lib/gitlab/markdown/label_reference_filter.rb

@@ -22,6 +22,13 @@ module Gitlab
         end
       end
 
+      def self.referenced_by(node)
+        label = Label.find(node.attr("data-label")) rescue nil
+        return unless label
+
+        { label: label }
+      end
+
       def call
         replace_text_nodes_matching(Label.reference_pattern) do |content|
           label_link_filter(content)
@@ -41,11 +48,9 @@ module Gitlab
           params = label_params(id, name)
 
           if label = project.labels.find_by(params)
-            push_result(:label, label)
-
             url = url_for_label(project, label)
             klass = reference_class(:label)
-            data = data_attribute(project.id)
+            data = data_attribute(project: project.id, label: label.id)
 
             %(<a href="#{url}" #{data}
                  class="#{klass}">#{render_colored_label(label)}</a>)

lib/gitlab/markdown/merge_request_reference_filter.rb

@@ -27,6 +27,13 @@ module Gitlab
         end
       end
 
+      def self.referenced_by(node)
+        merge_request = MergeRequest.find(node.attr("data-merge-request")) rescue nil
+        return unless merge_request
+
+        { merge_request: merge_request }
+      end
+
       def call
         replace_text_nodes_matching(MergeRequest.reference_pattern) do |content|
           merge_request_link_filter(content)
@@ -45,11 +52,9 @@ module Gitlab
           project = self.project_from_ref(project_ref)
 
           if project && merge_request = project.merge_requests.find_by(iid: id)
-            push_result(:merge_request, merge_request)
-
             title = escape_once("Merge Request: #{merge_request.title}")
             klass = reference_class(:merge_request)
-            data  = data_attribute(project.id)
+            data  = data_attribute(project: project.id, merge_request: merge_request.id)
 
             url = url_for_merge_request(merge_request, project)
 

lib/gitlab/markdown/redactor_filter.rb

@@ -19,47 +19,17 @@ module Gitlab
         doc
       end
 
-      def user_can_reference?(node)
-        if node.has_attribute?('data-group-id')
-          user_can_reference_group?(node.attr('data-group-id'))
-        elsif node.has_attribute?('data-project-id')
-          user_can_reference_project?(node.attr('data-project-id'))
-        elsif node.has_attribute?('data-user-id')
-          user_can_reference_user?(node.attr('data-user-id'))
-        else
-          true
-        end
-      end
-
-      def user_can_reference_group?(id)
-        group = Group.find(id)
-
-        group && can?(:read_group, group)
-      rescue ActiveRecord::RecordNotFound
-        false
-      end
-
-      def user_can_reference_project?(id)
-        project = Project.find(id)
+      private
 
-        project && can?(:read_project, project)
-      rescue ActiveRecord::RecordNotFound
-        false
-      end
+      def user_can_reference?(node)
+        if node.has_attribute?('data-reference-filter')
+          reference_type = node.attr('data-reference-filter')
+          reference_filter = reference_type.constantize
 
-      def user_can_reference_user?(id)
-        # Permit all user reference links
+          reference_filter.user_can_reference?(current_user, node)
+        else
           true
         end
-
-      private
-
-      def abilities
-        Ability.abilities
-      end
-
-      def can?(ability, object)
-        abilities.allowed?(current_user, ability, object)
       end
 
       def current_user

lib/gitlab/markdown/reference_filter.rb

@@ -15,10 +15,17 @@ module Gitlab
     # Results:
     #   :references - A Hash of references that were found and replaced.
     class ReferenceFilter < HTML::Pipeline::Filter
-      def initialize(*args)
-        super
+      def self.user_can_reference?(user, node)
+        if node.has_attribute?('data-project')
+          project = Project.find(node.attr('data-project')) rescue nil
+          Ability.abilities.allowed?(user, :read_project, project)
+        else
+          true
+        end
+      end
 
-        result[:references] = Hash.new { |hash, type| hash[type] = [] }
+      def self.referenced_by(node)
+        nil
       end
 
       # Returns a data attribute String to attach to a reference link
@@ -28,13 +35,14 @@ module Gitlab
       #
       # Examples:
       #
-      #   data_attribute(1)         # => "data-project-id=\"1\""
-      #   data_attribute(2, :user)  # => "data-user-id=\"2\""
-      #   data_attribute(3, :group) # => "data-group-id=\"3\""
+      #   data_attribute(project: 1)  # => "data-reference-filter=\"SomeReferenceFilter\" data-project=\"1\""
+      #   data_attribute(user: 2)     # => "data-reference-filter=\"SomeReferenceFilter\" data-user=\"2\""
+      #   data_attribute(group: 3)    # => "data-reference-filter=\"SomeReferenceFilter\" data-group=\"3\""
       #
       # Returns a String
-      def data_attribute(id, type = :project)
-        %Q(data-#{type}-id="#{id}")
+      def data_attribute(attributes = {})
+        attributes[:reference_filter] = self.class.name
+        attributes.map { |key, value| %Q(data-#{key.to_s.dasherize}="#{value}") }.join(" ")
       end
 
       def escape_once(html)
@@ -59,16 +67,6 @@ module Gitlab
         context[:project]
       end
 
-      # Add a reference to the pipeline's result Hash
-      #
-      # type   - Singular Symbol reference type (e.g., :issue, :user, etc.)
-      # values - One or more Objects to add
-      def push_result(type, *values)
-        return if values.empty?
-
-        result[:references][type].push(*values)
-      end
-
       def reference_class(type)
         "gfm gfm-#{type}"
       end

lib/gitlab/markdown/reference_gatherer_filter.rb

+require 'gitlab/markdown'
+require 'html/pipeline/filter'
+
+module Gitlab
+  module Markdown
+    # HTML filter that removes references to records that the current user does
+    # not have permission to view.
+    #
+    # Expected to be run in its own post-processing pipeline.
+    #
+    class ReferenceGathererFilter < HTML::Pipeline::Filter
+      def initialize(*)
+        super
+
+        result[:references] ||= Hash.new { |hash, type| hash[type] = [] }
+      end
+
+      def call
+        doc.css('a.gfm').each do |node|
+          gather_references(node)
+        end
+
+        doc
+      end
+
+      private
+
+      def gather_references(node)
+        return unless node.has_attribute?('data-reference-filter')
+
+        reference_type = node.attr('data-reference-filter')
+        reference_filter = reference_type.constantize
+
+        return unless reference_filter.user_can_reference?(current_user, node)
+
+        references = reference_filter.referenced_by(node)
+        return unless references
+        
+        references.each do |type, values|
+          result[:references][type].push(*values)
+        end
+      end
+
+      def current_user
+        context[:current_user]
+      end
+    end
+  end
+end

lib/gitlab/markdown/snippet_reference_filter.rb

@@ -27,6 +27,13 @@ module Gitlab
         end
       end
 
+      def self.referenced_by(node)
+        snippet = Snippet.find(node.attr("data-snippet")) rescue nil
+        return unless snippet
+
+        { snippet: snippet }
+      end
+
       def call
         replace_text_nodes_matching(Snippet.reference_pattern) do |content|
           snippet_link_filter(content)
@@ -45,11 +52,9 @@ module Gitlab
           project = self.project_from_ref(project_ref)
 
           if project && snippet = project.snippets.find_by(id: id)
-            push_result(:snippet, snippet)
-
             title = escape_once("Snippet: #{snippet.title}")
             klass = reference_class(:snippet)
-            data  = data_attribute(project.id)
+            data  = data_attribute(project: project.id, snippet: snippet.id)
 
             url = url_for_snippet(snippet, project)
 

lib/gitlab/markdown/user_reference_filter.rb

@@ -23,6 +23,34 @@ module Gitlab
         end
       end
 
+      def self.referenced_by(node)
+        if node.has_attribute?('data-group')
+          group = Group.find(node.attr('data-group')) rescue nil
+          return unless group
+
+          { user: group.users }
+        elsif node.has_attribute?('data-user')
+          user = User.find(node.attr('data-user')) rescue nil
+          return unless user
+
+          { user: user }
+        elsif node.has_attribute?('data-project')
+          project = Project.find(node.attr('data-project')) rescue nil
+          return unless project
+
+          { user: project.team.members.flatten }
+        end
+      end
+
+      def self.user_can_reference?(user, node)
+        if node.has_attribute?('data-group')
+          group = Group.find(node.attr('data-group')) rescue nil
+          Ability.abilities.allowed?(user, :read_group, group)
+        else
+          super
+        end
+      end
+
       def call
         replace_text_nodes_matching(User.reference_pattern) do |content|
           user_link_filter(content)
@@ -61,14 +89,12 @@ module Gitlab
       def link_to_all
         project = context[:project]
 
-        # FIXME (rspeicher): Law of Demeter
-        push_result(:user, *project.team.members.flatten)
-
         url = urls.namespace_project_url(project.namespace, project,
                                          only_path: context[:only_path])
+        data = data_attribute(project: project.id)
 
         text = User.reference_prefix + 'all'
-        %(<a href="#{url}" class="#{link_class}">#{text}</a>)
+        %(<a href="#{url}" #{data} class="#{link_class}">#{text}</a>)
       end
 
       def link_to_namespace(namespace)
@@ -80,20 +106,16 @@ module Gitlab
       end
 
       def link_to_group(group, namespace)
-        push_result(:user, *namespace.users)
-
         url = urls.group_url(group, only_path: context[:only_path])
-        data = data_attribute(namespace.id, :group)
+        data = data_attribute(group: namespace.id)
 
         text = Group.reference_prefix + group
         %(<a href="#{url}" #{data} class="#{link_class}">#{text}</a>)
       end
 
       def link_to_user(user, namespace)
-        push_result(:user, namespace.owner)
-
         url = urls.user_url(user, only_path: context[:only_path])
-        data = data_attribute(namespace.owner_id, :user)
+        data = data_attribute(user: namespace.owner_id)
 
         text = User.reference_prefix + user
         %(<a href="#{url}" #{data} class="#{link_class}">#{text}</a>)

lib/gitlab/reference_extractor.rb

@@ -50,7 +50,7 @@ module Gitlab
         ignore_blockquotes: true
       }
 
-      pipeline = HTML::Pipeline.new([filter], context)
+      pipeline = HTML::Pipeline.new([filter, Gitlab::Markdown::ReferenceGathererFilter], context)
       result = pipeline.call(@text)
 
       result[:references][filter_type]

spec/helpers/gitlab_markdown_helper_spec.rb

@@ -44,7 +44,7 @@ describe GitlabMarkdownHelper do
 
     describe "override default project" do
       let(:actual) { issue.to_reference }
-      let(:second_project) { create(:project) }
+      let(:second_project) { create(:project, :public) }
       let(:second_issue) { create(:issue, project: second_project) }
 
       it 'should link to the issue' do

spec/lib/gitlab/markdown/commit_range_reference_filter_spec.rb

@@ -4,7 +4,7 @@ module Gitlab::Markdown
   describe CommitRangeReferenceFilter do
     include FilterSpecHelper
 
-    let(:project) { create(:project) }
+    let(:project) { create(:project, :public) }
     let(:commit1) { project.commit }
     let(:commit2) { project.commit("HEAD~2") }
 
@@ -75,12 +75,20 @@ module Gitlab::Markdown
         expect(doc.css('a').first.attr('class')).to eq 'gfm gfm-commit_range'
       end
 
-      it 'includes a data-project-id attribute' do
+      it 'includes a data-project attribute' do
         doc = filter("See #{reference}")
         link = doc.css('a').first
 
-        expect(link).to have_attribute('data-project-id')
-        expect(link.attr('data-project-id')).to eq project.id.to_s
+        expect(link).to have_attribute('data-project')
+        expect(link.attr('data-project')).to eq project.id.to_s
+      end
+
+      it 'includes a data-commit-range attribute' do
+        doc = filter("See #{reference}")
+        link = doc.css('a').first
+
+        expect(link).to have_attribute('data-commit-range')
+        expect(link.attr('data-commit-range')).to eq range.to_reference
       end
 
       it 'supports an :only_path option' do
@@ -92,14 +100,14 @@ module Gitlab::Markdown
       end
 
       it 'adds to the results hash' do
-        result = pipeline_result("See #{reference}")
+        result = reference_pipeline_result("See #{reference}")
         expect(result[:references][:commit_range]).not_to be_empty
       end
     end
 
     context 'cross-project reference' do
       let(:namespace) { create(:namespace, name: 'cross-reference') }
-      let(:project2)  { create(:project, namespace: namespace) }
+      let(:project2)  { create(:project, :public, namespace: namespace) }
       let(:reference) { range.to_reference(project) }
 
       before do
@@ -129,7 +137,7 @@ module Gitlab::Markdown
       end
 
       it 'adds to the results hash' do
-        result = pipeline_result("See #{reference}")
+        result = reference_pipeline_result("See #{reference}")
         expect(result[:references][:commit_range]).not_to be_empty
       end
     end

spec/lib/gitlab/markdown/commit_reference_filter_spec.rb

@@ -4,7 +4,7 @@ module Gitlab::Markdown
   describe CommitReferenceFilter do
     include FilterSpecHelper
 
-    let(:project) { create(:project) }
+    let(:project) { create(:project, :public) }
     let(:commit)  { project.commit }
 
     it 'requires project context' do
@@ -71,12 +71,20 @@ module Gitlab::Markdown
         expect(doc.css('a').first.attr('class')).to eq 'gfm gfm-commit'
       end
 
-      it 'includes a data-project-id attribute' do
+      it 'includes a data-project attribute' do
         doc = filter("See #{reference}")
         link = doc.css('a').first
 
-        expect(link).to have_attribute('data-project-id')
-        expect(link.attr('data-project-id')).to eq project.id.to_s
+        expect(link).to have_attribute('data-project')
+        expect(link.attr('data-project')).to eq project.id.to_s
+      end
+
+      it 'includes a data-commit attribute' do
+        doc = filter("See #{reference}")
+        link = doc.css('a').first
+
+        expect(link).to have_attribute('data-commit')
+        expect(link.attr('data-commit')).to eq commit.id
       end
 
       it 'supports an :only_path context' do
@@ -88,14 +96,14 @@ module Gitlab::Markdown
       end
 
       it 'adds to the results hash' do
-        result = pipeline_result("See #{reference}")
+        result = reference_pipeline_result("See #{reference}")
         expect(result[:references][:commit]).not_to be_empty
       end
     end
 
     context 'cross-project reference' do
       let(:namespace) { create(:namespace, name: 'cross-reference') }
-      let(:project2)  { create(:project, namespace: namespace) }
+      let(:project2)  { create(:project, :public, namespace: namespace) }
       let(:commit)    { project2.commit }
       let(:reference) { commit.to_reference(project) }
 
@@ -119,7 +127,7 @@ module Gitlab::Markdown
       end
 
       it 'adds to the results hash' do
-        result = pipeline_result("See #{reference}")
+        result = reference_pipeline_result("See #{reference}")
         expect(result[:references][:commit]).not_to be_empty
       end
     end

spec/lib/gitlab/markdown/issue_reference_filter_spec.rb

@@ -8,7 +8,7 @@ module Gitlab::Markdown
       IssuesHelper
     end
 
-    let(:project) { create(:empty_project) }
+    let(:project) { create(:empty_project, :public) }
     let(:issue)   { create(:issue, project: project) }
 
     it 'requires project context' do
@@ -68,12 +68,20 @@ module Gitlab::Markdown
         expect(doc.css('a').first.attr('class')).to eq 'gfm gfm-issue'
       end
 
-      it 'includes a data-project-id attribute' do
+      it 'includes a data-project attribute' do
         doc = filter("Issue #{reference}")
         link = doc.css('a').first
 
-        expect(link).to have_attribute('data-project-id')
-        expect(link.attr('data-project-id')).to eq project.id.to_s
+        expect(link).to have_attribute('data-project')
+        expect(link.attr('data-project')).to eq project.id.to_s
+      end
+
+      it 'includes a data-issue attribute' do
+        doc = filter("See #{reference}")
+        link = doc.css('a').first
+
+        expect(link).to have_attribute('data-issue')
+        expect(link.attr('data-issue')).to eq issue.id.to_s
       end
 
       it 'supports an :only_path context' do
@@ -85,14 +93,14 @@ module Gitlab::Markdown
       end
 
       it 'adds to the results hash' do
-        result = pipeline_result("Fixed #{reference}")
+        result = reference_pipeline_result("Fixed #{reference}")
         expect(result[:references][:issue]).to eq [issue]
       end
     end
 
     context 'cross-project reference' do
       let(:namespace) { create(:namespace, name: 'cross-reference') }
-      let(:project2)  { create(:empty_project, namespace: namespace) }
+      let(:project2)  { create(:empty_project, :public, namespace: namespace) }
       let(:issue)     { create(:issue, project: project2) }
       let(:reference) { issue.to_reference(project) }
 
@@ -123,7 +131,7 @@ module Gitlab::Markdown
       end
 
       it 'adds to the results hash' do
-        result = pipeline_result("Fixed #{reference}")
+        result = reference_pipeline_result("Fixed #{reference}")
         expect(result[:references][:issue]).to eq [issue]
       end
     end

spec/lib/gitlab/markdown/label_reference_filter_spec.rb

@@ -5,7 +5,7 @@ module Gitlab::Markdown
   describe LabelReferenceFilter do
     include FilterSpecHelper
 
-    let(:project)   { create(:empty_project) }
+    let(:project)   { create(:empty_project, :public) }
     let(:label)     { create(:label, project: project) }
     let(:reference) { label.to_reference }
 
@@ -25,12 +25,20 @@ module Gitlab::Markdown
       expect(doc.css('a').first.attr('class')).to eq 'gfm gfm-label'
     end
 
-    it 'includes a data-project-id attribute' do
+    it 'includes a data-project attribute' do
       doc = filter("Label #{reference}")
       link = doc.css('a').first
 
-      expect(link).to have_attribute('data-project-id')
-      expect(link.attr('data-project-id')).to eq project.id.to_s
+      expect(link).to have_attribute('data-project')
+      expect(link.attr('data-project')).to eq project.id.to_s
+    end
+
+    it 'includes a data-label attribute' do
+      doc = filter("See #{reference}")
+      link = doc.css('a').first
+
+      expect(link).to have_attribute('data-label')
+      expect(link.attr('data-label')).to eq label.id.to_s
     end
 
     it 'supports an :only_path context' do
@@ -42,7 +50,7 @@ module Gitlab::Markdown
     end
 
     it 'adds to the results hash' do
-      result = pipeline_result("Label #{reference}")
+      result = reference_pipeline_result("Label #{reference}")
       expect(result[:references][:label]).to eq [label]
     end
 

spec/lib/gitlab/markdown/merge_request_reference_filter_spec.rb

@@ -4,7 +4,7 @@ module Gitlab::Markdown
   describe MergeRequestReferenceFilter do
     include FilterSpecHelper
 
-    let(:project) { create(:project) }
+    let(:project) { create(:project, :public) }
     let(:merge)   { create(:merge_request, source_project: project) }
 
     it 'requires project context' do
@@ -56,12 +56,20 @@ module Gitlab::Markdown
         expect(doc.css('a').first.attr('class')).to eq 'gfm gfm-merge_request'
       end
 
-      it 'includes a data-project-id attribute' do
+      it 'includes a data-project attribute' do
         doc = filter("Merge #{reference}")
         link = doc.css('a').first
 
-        expect(link).to have_attribute('data-project-id')
-        expect(link.attr('data-project-id')).to eq project.id.to_s
+        expect(link).to have_attribute('data-project')
+        expect(link.attr('data-project')).to eq project.id.to_s
+      end
+
+      it 'includes a data-merge-request attribute' do
+        doc = filter("See #{reference}")
+        link = doc.css('a').first
+
+        expect(link).to have_attribute('data-merge-request')
+        expect(link.attr('data-merge-request')).to eq merge.id.to_s
       end
 
       it 'supports an :only_path context' do
@@ -73,14 +81,14 @@ module Gitlab::Markdown
       end
 
       it 'adds to the results hash' do
-        result = pipeline_result("Merge #{reference}")
+        result = reference_pipeline_result("Merge #{reference}")
         expect(result[:references][:merge_request]).to eq [merge]
       end
     end
 
     context 'cross-project reference' do
       let(:namespace) { create(:namespace, name: 'cross-reference') }
-      let(:project2)  { create(:project, namespace: namespace) }
+      let(:project2)  { create(:project, :public, namespace: namespace) }
       let(:merge)     { create(:merge_request, source_project: project2) }
       let(:reference) { merge.to_reference(project) }
 
@@ -104,7 +112,7 @@ module Gitlab::Markdown
       end
 
       it 'adds to the results hash' do
-        result = pipeline_result("Merge #{reference}")
+        result = reference_pipeline_result("Merge #{reference}")
         expect(result[:references][:merge_request]).to eq [merge]
       end
     end

spec/lib/gitlab/markdown/redactor_filter_spec.rb

@@ -16,73 +16,76 @@ module Gitlab::Markdown
       link_to('text', '', class: 'gfm', data: data)
     end
 
-    context 'with data-group-id' do
-      it 'removes unpermitted Group references' do
+    context 'with data-project' do
+      it 'removes unpermitted Project references' do
         user = create(:user)
-        group = create(:group)
+        project = create(:empty_project)
 
-        link = reference_link(group_id: group.id)
+        link = reference_link(project: project.id, reference_filter: Gitlab::Markdown::ReferenceFilter.name)
         doc = filter(link, current_user: user)
 
         expect(doc.css('a').length).to eq 0
       end
 
-      it 'allows permitted Group references' do
+      it 'allows permitted Project references' do
         user = create(:user)
-        group = create(:group)
-        group.add_developer(user)
+        project = create(:empty_project)
+        project.team << [user, :master]
 
-        link = reference_link(group_id: group.id)
+        link = reference_link(project: project.id, reference_filter: Gitlab::Markdown::ReferenceFilter.name)
         doc = filter(link, current_user: user)
 
         expect(doc.css('a').length).to eq 1
       end
 
-      it 'handles invalid Group references' do
-        link = reference_link(group_id: 12345)
+      it 'handles invalid Project references' do
+        link = reference_link(project: 12345, reference_filter: Gitlab::Markdown::ReferenceFilter.name)
 
         expect { filter(link) }.not_to raise_error
       end
     end
 
-    context 'with data-project-id' do
-      it 'removes unpermitted Project references' do
+    context "for user references" do
+
+      context 'with data-group' do
+        it 'removes unpermitted Group references' do
           user = create(:user)
-        project = create(:empty_project)
+          group = create(:group)
 
-        link = reference_link(project_id: project.id)
+          link = reference_link(group: group.id, reference_filter: Gitlab::Markdown::UserReferenceFilter.name)
           doc = filter(link, current_user: user)
 
           expect(doc.css('a').length).to eq 0
         end
 
-      it 'allows permitted Project references' do
+        it 'allows permitted Group references' do
           user = create(:user)
-        project = create(:empty_project)
-        project.team << [user, :master]
+          group = create(:group)
+          group.add_developer(user)
 
-        link = reference_link(project_id: project.id)
+          link = reference_link(group: group.id, reference_filter: Gitlab::Markdown::UserReferenceFilter.name)
           doc = filter(link, current_user: user)
 
           expect(doc.css('a').length).to eq 1
         end
 
-      it 'handles invalid Project references' do
-        link = reference_link(project_id: 12345)
+        it 'handles invalid Group references' do
+          link = reference_link(group: 12345, reference_filter: Gitlab::Markdown::UserReferenceFilter.name)
 
           expect { filter(link) }.not_to raise_error
         end
       end
 
-    context 'with data-user-id' do
+      context 'with data-user' do
         it 'allows any User reference' do
           user = create(:user)
 
-        link = reference_link(user_id: user.id)
+          link = reference_link(user: user.id, reference_filter: Gitlab::Markdown::UserReferenceFilter.name)
           doc = filter(link)
 
           expect(doc.css('a').length).to eq 1
         end
       end
     end
+  end
 end

spec/lib/gitlab/markdown/reference_gatherer_filter_spec.rb

+require 'spec_helper'
+
+module Gitlab::Markdown
+  describe ReferenceGathererFilter do
+    include ActionView::Helpers::UrlHelper
+    include FilterSpecHelper
+
+    def reference_link(data)
+      link_to('text', '', class: 'gfm', data: data)
+    end
+
+    context "for issue references" do
+
+      context 'with data-project' do
+        it 'removes unpermitted Project references' do
+          user = create(:user)
+          project = create(:empty_project)
+          issue = create(:issue, project: project)
+
+          link = reference_link(project: project.id, issue: issue.id, reference_filter: Gitlab::Markdown::IssueReferenceFilter.name)
+          result = pipeline_result(link, current_user: user)
+
+          expect(result[:references][:issue]).to be_empty
+        end
+
+        it 'allows permitted Project references' do
+          user = create(:user)
+          project = create(:empty_project)
+          issue = create(:issue, project: project)
+          project.team << [user, :master]
+
+          link = reference_link(project: project.id, issue: issue.id, reference_filter: Gitlab::Markdown::IssueReferenceFilter.name)
+          result = pipeline_result(link, current_user: user)
+
+          expect(result[:references][:issue]).to eq([issue])
+        end
+
+        it 'handles invalid Project references' do
+          link = reference_link(project: 12345, issue: 12345, reference_filter: Gitlab::Markdown::IssueReferenceFilter.name)
+
+          expect { pipeline_result(link) }.not_to raise_error
+        end
+      end
+    end
+
+    context "for user references" do
+
+      context 'with data-group' do
+        it 'removes unpermitted Group references' do
+          user = create(:user)
+          group = create(:group)
+
+          link = reference_link(group: group.id, reference_filter: Gitlab::Markdown::UserReferenceFilter.name)
+          result = pipeline_result(link, current_user: user)
+
+          expect(result[:references][:user]).to be_empty
+        end
+
+        it 'allows permitted Group references' do
+          user = create(:user)
+          group = create(:group)
+          group.add_developer(user)
+
+          link = reference_link(group: group.id, reference_filter: Gitlab::Markdown::UserReferenceFilter.name)
+          result = pipeline_result(link, current_user: user)
+
+          expect(result[:references][:user]).to eq([user])
+        end
+
+        it 'handles invalid Group references' do
+          link = reference_link(group: 12345, reference_filter: Gitlab::Markdown::UserReferenceFilter.name)
+
+          expect { pipeline_result(link) }.not_to raise_error
+        end
+      end
+
+      context 'with data-user' do
+        it 'allows any User reference' do
+          user = create(:user)
+
+          link = reference_link(user: user.id, reference_filter: Gitlab::Markdown::UserReferenceFilter.name)
+          result = pipeline_result(link)
+
+          expect(result[:references][:user]).to eq([user])
+        end
+      end
+    end
+  end
+end

spec/lib/gitlab/markdown/snippet_reference_filter_spec.rb

@@ -4,7 +4,7 @@ module Gitlab::Markdown
   describe SnippetReferenceFilter do
     include FilterSpecHelper
 
-    let(:project)   { create(:empty_project) }
+    let(:project)   { create(:empty_project, :public) }
     let(:snippet)   { create(:project_snippet, project: project) }
     let(:reference) { snippet.to_reference }
 
@@ -55,12 +55,20 @@ module Gitlab::Markdown
         expect(doc.css('a').first.attr('class')).to eq 'gfm gfm-snippet'
       end
 
-      it 'includes a data-project-id attribute' do
+      it 'includes a data-project attribute' do
         doc = filter("Snippet #{reference}")
         link = doc.css('a').first
 
-        expect(link).to have_attribute('data-project-id')
-        expect(link.attr('data-project-id')).to eq project.id.to_s
+        expect(link).to have_attribute('data-project')
+        expect(link.attr('data-project')).to eq project.id.to_s
+      end
+
+      it 'includes a data-snippet attribute' do
+        doc = filter("See #{reference}")
+        link = doc.css('a').first
+
+        expect(link).to have_attribute('data-snippet')
+        expect(link.attr('data-snippet')).to eq snippet.id.to_s
       end
 
       it 'supports an :only_path context' do
@@ -72,14 +80,14 @@ module Gitlab::Markdown
       end
 
       it 'adds to the results hash' do
-        result = pipeline_result("Snippet #{reference}")
+        result = reference_pipeline_result("Snippet #{reference}")
         expect(result[:references][:snippet]).to eq [snippet]
       end
     end
 
     context 'cross-project reference' do
       let(:namespace) { create(:namespace, name: 'cross-reference') }
-      let(:project2)  { create(:empty_project, namespace: namespace) }
+      let(:project2)  { create(:empty_project, :public, namespace: namespace) }
       let(:snippet)   { create(:project_snippet, project: project2) }
       let(:reference) { snippet.to_reference(project) }
 
@@ -102,7 +110,7 @@ module Gitlab::Markdown
       end
 
       it 'adds to the results hash' do
-        result = pipeline_result("Snippet #{reference}")
+        result = reference_pipeline_result("Snippet #{reference}")
         expect(result[:references][:snippet]).to eq [snippet]
       end
     end

spec/lib/gitlab/markdown/user_reference_filter_spec.rb

@@ -4,7 +4,7 @@ module Gitlab::Markdown
   describe UserReferenceFilter do
     include FilterSpecHelper
 
-    let(:project)   { create(:empty_project) }
+    let(:project)   { create(:empty_project, :public) }
     let(:user)      { create(:user) }
     let(:reference) { user.to_reference }
 
@@ -39,7 +39,7 @@ module Gitlab::Markdown
       end
 
       it 'adds to the results hash' do
-        result = pipeline_result("Hey #{reference}")
+        result = reference_pipeline_result("Hey #{reference}")
         expect(result[:references][:user]).to eq [project.creator]
       end
     end
@@ -64,16 +64,16 @@ module Gitlab::Markdown
         expect(doc.css('a').length).to eq 1
       end
 
-      it 'includes a data-user-id attribute' do
+      it 'includes a data-user attribute' do
         doc = filter("Hey #{reference}")
         link = doc.css('a').first
 
-        expect(link).to have_attribute('data-user-id')
-        expect(link.attr('data-user-id')).to eq user.namespace.owner_id.to_s
+        expect(link).to have_attribute('data-user')
+        expect(link.attr('data-user')).to eq user.namespace.owner_id.to_s
       end
 
       it 'adds to the results hash' do
-        result = pipeline_result("Hey #{reference}")
+        result = reference_pipeline_result("Hey #{reference}")
         expect(result[:references][:user]).to eq [user]
       end
     end
@@ -87,16 +87,16 @@ module Gitlab::Markdown
         expect(doc.css('a').first.attr('href')).to eq urls.group_url(group)
       end
 
-      it 'includes a data-group-id attribute' do
+      it 'includes a data-group attribute' do
         doc = filter("Hey #{reference}")
         link = doc.css('a').first
 
-        expect(link).to have_attribute('data-group-id')
-        expect(link.attr('data-group-id')).to eq group.id.to_s
+        expect(link).to have_attribute('data-group')
+        expect(link.attr('data-group')).to eq group.id.to_s
       end
 
       it 'adds to the results hash' do
-        result = pipeline_result("Hey #{reference}")
+        result = reference_pipeline_result("Hey #{reference}")
         expect(result[:references][:user]).to eq group.users
       end
     end

spec/lib/gitlab/reference_extractor_spec.rb

@@ -2,7 +2,7 @@ require 'spec_helper'
 
 describe Gitlab::ReferenceExtractor do
   let(:project) { create(:project) }
-  subject { Gitlab::ReferenceExtractor.new(project, project.creator) }
+  subject { Gitlab::ReferenceExtractor.new(project, project.owner) }
 
   it 'accesses valid user objects' do
     @u_foo = create(:user, username: 'foo')
@@ -102,7 +102,7 @@ describe Gitlab::ReferenceExtractor do
     let(:issue) { create(:issue, project: other_project) }
 
     before do
-      other_project.team << [project.creator, :developer]
+      other_project.team << [project.owner, :developer]
     end
 
     it 'handles project issue references' do

spec/support/filter_spec_helper.rb

@@ -29,12 +29,19 @@ module FilterSpecHelper
   #
   # Returns the Hash
   def pipeline_result(body, contexts = {})
-    contexts.reverse_merge!(project: project)
+    contexts.reverse_merge!(project: project) if defined?(project)
 
     pipeline = HTML::Pipeline.new([described_class], contexts)
     pipeline.call(body)
   end
 
+  def reference_pipeline_result(body, contexts = {})
+    contexts.reverse_merge!(project: project) if defined?(project)
+
+    pipeline = HTML::Pipeline.new([described_class, Gitlab::Markdown::ReferenceGathererFilter], contexts)
+    pipeline.call(body)
+  end
+
   # Modify a String reference to make it invalid
   #
   # Commit SHAs get reversed, IDs get incremented by 1, all other Strings get