Use `Redactor` to hide cross project information

Since the redactor can be run on multiple documents at once and
query results are stored in the request store.

lib/banzai/filter/cross_project_issuable_information_filter.rb

-module Banzai
-  module Filter
-    # HTML filter that removes sensitive information from cross project
-    # issue references.
-    #
-    # The link to the issue or merge request is preserved only the IID is shown,
-    # but all other info is removed.
-    class CrossProjectIssuableInformationFilter < HTML::Pipeline::Filter
-      def call
-        return doc if can_read_cross_project?
-
-        extractor = Banzai::IssuableExtractor.new(project, current_user)
-        issuables = extractor.extract([doc])
-
-        issuables.each do |node, issuable|
-          next if issuable.project == project
-
-          node['class'] = node['class'].gsub('has-tooltip', '')
-          node['title'] = nil
-        end
-
-        doc
-      end
-
-      private
-
-      def project
-        context[:project]
-      end
-
-      def can_read_cross_project?
-        Ability.allowed?(current_user, :read_cross_project)
-      end
-
-      def current_user
-        context[:current_user]
-      end
-    end
-  end
-end

lib/banzai/pipeline/post_process_pipeline.rb

@@ -6,7 +6,6 @@ module Banzai
           Filter::RedactorFilter,
           Filter::RelativeLinkFilter,
           Filter::IssuableStateFilter,
-          Filter::CrossProjectIssuableInformationFilter,
           Filter::AbsoluteLinkFilter
         ]
       end

lib/banzai/redactor.rb

@@ -19,8 +19,9 @@ module Banzai
     #
     # Returns the documents passed as the first argument.
     def redact(documents)
-      all_document_nodes = document_nodes(documents)
+      redact_cross_project_references(documents) unless can_read_cross_project?
 
+      all_document_nodes = document_nodes(documents)
       redact_document_nodes(all_document_nodes)
     end
 
@@ -51,6 +52,18 @@ module Banzai
       metadata
     end
 
+    def redact_cross_project_references(documents)
+      extractor = Banzai::IssuableExtractor.new(project, user)
+      issuables = extractor.extract(documents)
+
+      issuables.each do |node, issuable|
+        next if issuable.project == project
+
+        node['class'] = node['class'].gsub('has-tooltip', '')
+        node['title'] = nil
+      end
+    end
+
     # Returns the nodes visible to the current user.
     #
     # nodes - The input nodes to check.
@@ -78,5 +91,11 @@ module Banzai
         { document: document, nodes: Querying.css(document, 'a.gfm[data-reference-type]') }
       end
     end
+
+    private
+
+    def can_read_cross_project?
+      Ability.allowed?(user, :read_cross_project)
+    end
   end
 end

spec/lib/banzai/filter/cross_project_issuable_information_filter_spec.rb

-require 'spec_helper'
-
-describe Banzai::Filter::CrossProjectIssuableInformationFilter do
-  include ActionView::Helpers::UrlHelper
-  include FilterSpecHelper
-
-  let(:user) { create(:user) }
-  let(:project) { create(:project, :public) }
-  let(:context) { { project: project, current_user: user } }
-  let(:other_project) { create(:project, :public) }
-
-  def create_link(issuable)
-    type = issuable.class.name.underscore.downcase
-    link_to(issuable.to_reference, '',
-            class: 'gfm has-tooltip',
-            title: issuable.title,
-            data: {
-              reference_type: type,
-              "#{type}": issuable.id
-            })
-  end
-
-  context 'when the user cannot read cross project' do
-    before do
-      allow(Ability).to receive(:allowed?) { false }
-    end
-
-    it 'skips links to issues within the same project' do
-      issue = create(:issue, project: project)
-      link = create_link(issue)
-      doc = filter(link, context)
-
-      result = doc.css('a').last
-
-      expect(result['class']).to include('has-tooltip')
-      expect(result['title']).to eq(issue.title)
-    end
-
-    it 'removes info from a cross project reference' do
-      issue = create(:issue, project: other_project)
-      link = create_link(issue)
-      doc = filter(link, context)
-
-      result = doc.css('a').last
-
-      expect(result['class']).not_to include('has-tooltip')
-      expect(result['title']).to be_empty
-    end
-  end
-end

spec/lib/banzai/filter/redactor_filter_spec.rb

@@ -6,7 +6,7 @@ describe Banzai::Filter::RedactorFilter do
 
   it 'ignores non-GFM links' do
     html = %(See <a href="https://google.com/">Google</a>)
-    doc = filter(html, current_user: double)
+    doc = filter(html, current_user: build(:user))
 
     expect(doc.css('a').length).to eq 1
   end

spec/lib/banzai/redactor_spec.rb

@@ -88,6 +88,55 @@ describe Banzai::Redactor do
     end
   end
 
+  context 'when the user cannot read cross project' do
+    include ActionView::Helpers::UrlHelper
+    let(:project) { create(:project) }
+    let(:other_project) { create(:project, :public) }
+
+    def create_link(issuable)
+      type = issuable.class.name.underscore.downcase
+      link_to(issuable.to_reference, '',
+              class: 'gfm has-tooltip',
+              title: issuable.title,
+              data: {
+                reference_type: type,
+                "#{type}": issuable.id
+              })
+    end
+
+    before do
+      project.add_developer(user)
+
+      allow(Ability).to receive(:allowed?).and_call_original
+      allow(Ability).to receive(:allowed?).with(user, :read_cross_project, :global) { false }
+      allow(Ability).to receive(:allowed?).with(user, :read_cross_project) { false }
+    end
+
+    it 'skips links to issues within the same project' do
+      issue = create(:issue, project: project)
+      link = create_link(issue)
+      doc = Nokogiri::HTML.fragment(link)
+
+      redactor.redact([doc])
+      result = doc.css('a').last
+
+      expect(result['class']).to include('has-tooltip')
+      expect(result['title']).to eq(issue.title)
+    end
+
+    it 'removes info from a cross project reference' do
+      issue = create(:issue, project: other_project)
+      link = create_link(issue)
+      doc = Nokogiri::HTML.fragment(link)
+
+      redactor.redact([doc])
+      result = doc.css('a').last
+
+      expect(result['class']).not_to include('has-tooltip')
+      expect(result['title']).to be_empty
+    end
+  end
+
   describe '#redact_nodes' do
     it 'redacts an Array of nodes' do
       doc = Nokogiri::HTML.fragment('<a href="foo">foo</a>')