Make search redaction more robust

Instead of stubbing out the policy framework, stub out the results
given to us by our subclasses. This allows us to test the redaction
logic itself. In so doing, we find a few mistakes.

By applying redaction only to a few known classes, it turns out we're
skipping it in a number of desirable cases. It's better to apply it
unconditionally, providing a fallback for cases where a plain array has
been returned to us.

app/services/search_service.rb

@@ -3,11 +3,6 @@
 class SearchService
   include Gitlab::Allowable
 
-  REDACTABLE_RESULTS = [
-    ActiveRecord::Relation,
-    Gitlab::Search::FoundBlob
-  ].freeze
-
   SEARCH_TERM_LIMIT = 64
   SEARCH_CHAR_LIMIT = 4096
 
@@ -68,10 +63,6 @@ class SearchService
     @search_objects ||= redact_unauthorized_results(search_results.objects(scope, params[:page]))
   end
 
-  def redactable_results
-    REDACTABLE_RESULTS
-  end
-
   private
 
   def visible_result?(object)
@@ -80,12 +71,9 @@ class SearchService
     Ability.allowed?(current_user, :"read_#{object.to_ability_name}", object)
   end
 
-  def redact_unauthorized_results(results)
-    return results unless redactable_results.any? { |redactable| results.is_a?(redactable) }
-
-    permitted_results = results.select do |object|
-      visible_result?(object)
-    end
+  def redact_unauthorized_results(results_collection)
+    results = results_collection.to_a
+    permitted_results = results.select { |object| visible_result?(object) }
 
     filtered_results = (results - permitted_results).each_with_object({}) do |object, memo|
       memo[object.id] = { ability: :"read_#{object.to_ability_name}", id: object.id, class_name: object.class.name }
@@ -93,13 +81,13 @@ class SearchService
 
     log_redacted_search_results(filtered_results.values) if filtered_results.any?
 
-    return results.id_not_in(filtered_results.keys) if results.is_a?(ActiveRecord::Relation)
+    return results_collection.id_not_in(filtered_results.keys) if results_collection.is_a?(ActiveRecord::Relation)
 
     Kaminari.paginate_array(
       permitted_results,
-      total_count: results.total_count,
-      limit: results.limit_value,
-      offset: results.offset_value
+      total_count: results_collection.total_count,
+      limit: results_collection.limit_value,
+      offset: results_collection.offset_value
     )
   end
 

changelogs/unreleased/201886-refactor-search-service-redaction.yml

+---
+title: Make search redaction more robust
+merge_request: 29166
+author:
+type: changed

ee/app/services/ee/search_service.rb

@@ -2,21 +2,12 @@
 
 module EE
   module SearchService
-    EE_REDACTABLE_RESULTS = [
-      Kaminari::PaginatableArray,
-      Elasticsearch::Model::Response::Records
-    ].freeze
-
     # This is a proper method instead of a `delegate` in order to
     # avoid adding unnecessary methods to Search::SnippetService
     def use_elasticsearch?
       search_service.use_elasticsearch?
     end
 
-    def redactable_results
-      super + EE_REDACTABLE_RESULTS
-    end
-
     def valid_query_length?
       return true if use_elasticsearch?
 

ee/lib/gitlab/elastic/group_search_results.rb

@@ -18,15 +18,6 @@ module Gitlab
         @group = group
       end
 
-      def objects(scope, page = nil)
-        case scope
-        when 'users'
-          users.page(page).per(per_page)
-        else
-          super
-        end
-      end
-
       def generic_search_results
         @generic_search_results ||= Gitlab::GroupSearchResults.new(current_user, limit_projects, group, query, default_project_filter: default_project_filter)
       end

ee/lib/gitlab/elastic/project_search_results.rb

@@ -19,23 +19,6 @@ module Gitlab
         @public_and_internal_projects = false
       end
 
-      def objects(scope, page = nil)
-        case scope
-        when 'notes'
-          notes.page(page).per(per_page).records
-        when 'blobs'
-          blobs(page: page, per_page: per_page)
-        when 'wiki_blobs'
-          wiki_blobs(page: page, per_page: per_page)
-        when 'commits'
-          commits(page: page, per_page: per_page)
-        when 'users'
-          users.page(page).per(per_page)
-        else
-          super
-        end
-      end
-
       def generic_search_results
         @generic_search_results ||= Gitlab::ProjectSearchResults.new(current_user, project, query, repository_ref)
       end

spec/services/search_service_spec.rb

@@ -3,16 +3,16 @@
 require 'spec_helper'
 
 describe SearchService do
-  let(:user) { create(:user) }
+  let_it_be(:user) { create(:user) }
 
-  let(:accessible_group) { create(:group, :private) }
-  let(:inaccessible_group) { create(:group, :private) }
-  let!(:group_member) { create(:group_member, group: accessible_group, user: user) }
+  let_it_be(:accessible_group) { create(:group, :private) }
+  let_it_be(:inaccessible_group) { create(:group, :private) }
+  let_it_be(:group_member) { create(:group_member, group: accessible_group, user: user) }
 
-  let!(:accessible_project) { create(:project, :private, name: 'accessible_project') }
-  let(:note) { create(:note_on_issue, project: accessible_project) }
+  let_it_be(:accessible_project) { create(:project, :repository, :private, name: 'accessible_project') }
+  let_it_be(:note) { create(:note_on_issue, project: accessible_project) }
 
-  let!(:inaccessible_project) { create(:project, :private, name: 'inaccessible_project') }
+  let_it_be(:inaccessible_project) { create(:project, :repository, :private, name: 'inaccessible_project') }
 
   let(:snippet) { create(:snippet, author: user) }
   let(:group_project) { create(:project, group: accessible_group, name: 'group_project') }
@@ -298,67 +298,129 @@ describe SearchService do
     end
 
     context 'redacting search results' do
-      shared_examples 'it redacts incorrect results' do
-        before do
-          allow(Ability).to receive(:allowed?).and_return(allowed)
-        end
+      let(:search) { 'anything' }
 
-        context 'when allowed' do
-          let(:allowed) { true }
+      subject(:result) { search_service.search_objects }
 
-          it 'does nothing' do
-            expect(results).not_to be_empty
-            expect(results).to all(be_an(model_class))
-          end
+      def found_blob(project)
+        Gitlab::Search::FoundBlob.new(project: project)
       end
 
-        context 'when disallowed' do
-          let(:allowed) { false }
+      def found_wiki_page(project)
+        Gitlab::Search::FoundWikiPage.new(found_blob(project))
+      end
 
-          it 'does nothing' do
-            expect(results).to be_empty
+      before do
+        expect(search_service)
+          .to receive(:search_results)
+          .and_return(double('search results', objects: unredacted_results))
       end
+
+      def ar_relation(klass, *objects)
+        klass.id_in(objects.map(&:id))
       end
+
+      def kaminari_array(*objects)
+        Kaminari.paginate_array(objects).page(1).per(20)
       end
 
       context 'issues' do
-        let(:issue) { create(:issue, project: accessible_project) }
+        let(:readable) { create(:issue, project: accessible_project) }
+        let(:unreadable) { create(:issue, project: inaccessible_project) }
+        let(:unredacted_results) { ar_relation(Issue, readable, unreadable) }
         let(:scope) { 'issues' }
-        let(:model_class) { Issue }
-        let(:ability) { :read_issue }
-        let(:search) { issue.title }
-        let(:results) { subject.search_objects }
 
-        it_behaves_like 'it redacts incorrect results'
+        it 'redacts the inaccessible issue' do
+          expect(result).to contain_exactly(readable)
+        end
       end
 
       context 'notes' do
-        let(:note) { create(:note_on_commit, project: accessible_project) }
+        let(:readable) { create(:note_on_commit, project: accessible_project) }
+        let(:unreadable) { create(:note_on_commit, project: inaccessible_project) }
+        let(:unredacted_results) { ar_relation(Note, readable, unreadable) }
         let(:scope) { 'notes' }
-        let(:model_class) { Note }
-        let(:ability) { :read_note }
-        let(:search) { note.note }
-        let(:results) do
-          described_class.new(
-            user,
-            project_id: accessible_project.id,
-            scope: scope,
-            search: note.note
-          ).search_objects
-        end
 
-        it_behaves_like 'it redacts incorrect results'
+        it 'redacts the inaccessible note' do
+          expect(result).to contain_exactly(readable)
+        end
       end
 
       context 'merge_requests' do
+        let(:readable) { create(:merge_request, source_project: accessible_project, author: user) }
+        let(:unreadable) { create(:merge_request, source_project: inaccessible_project) }
+        let(:unredacted_results) { ar_relation(MergeRequest, readable, unreadable) }
         let(:scope) { 'merge_requests' }
-        let(:model_class) { MergeRequest }
-        let(:ability) { :read_merge_request }
-        let(:merge_request) { create(:merge_request, source_project: accessible_project, author: user) }
-        let(:search) { merge_request.title }
-        let(:results) { subject.search_objects }
 
-        it_behaves_like 'it redacts incorrect results'
+        it 'redacts the inaccessible merge request' do
+          expect(result).to contain_exactly(readable)
+        end
+      end
+
+      context 'project repository blobs' do
+        let(:readable) { found_blob(accessible_project) }
+        let(:unreadable) { found_blob(inaccessible_project) }
+        let(:unredacted_results) { kaminari_array(readable, unreadable) }
+        let(:scope) { 'blobs' }
+
+        it 'redacts the inaccessible blob' do
+          expect(result).to contain_exactly(readable)
+        end
+      end
+
+      context 'project wiki blobs' do
+        let(:readable) { found_wiki_page(accessible_project) }
+        let(:unreadable) { found_wiki_page(inaccessible_project) }
+        let(:unredacted_results) { kaminari_array(readable, unreadable) }
+        let(:scope) { 'wiki_blobs' }
+
+        it 'redacts the inaccessible blob' do
+          expect(result).to contain_exactly(readable)
+        end
+      end
+
+      context 'project snippets' do
+        let(:readable) { create(:project_snippet, project: accessible_project) }
+        let(:unreadable) { create(:project_snippet, project: inaccessible_project) }
+        let(:unredacted_results) { ar_relation(ProjectSnippet, readable, unreadable) }
+        let(:scope) { 'snippet_blobs' }
+
+        it 'redacts the inaccessible snippet' do
+          expect(result).to contain_exactly(readable)
+        end
+      end
+
+      context 'personal snippets' do
+        let(:readable) { create(:personal_snippet, :private, author: user) }
+        let(:unreadable) { create(:personal_snippet, :private) }
+        let(:unredacted_results) { ar_relation(PersonalSnippet, readable, unreadable) }
+        let(:scope) { 'snippet_blobs' }
+
+        it 'redacts the inaccessible snippet' do
+          expect(result).to contain_exactly(readable)
+        end
+      end
+
+      context 'commits' do
+        let(:readable) { accessible_project.commit }
+        let(:unreadable) { inaccessible_project.commit }
+        let(:unredacted_results) { kaminari_array(readable, unreadable) }
+        let(:scope) { 'commits' }
+
+        it 'redacts the inaccessible commit' do
+          expect(result).to contain_exactly(readable)
+        end
+      end
+
+      context 'users' do
+        let(:other_user) { create(:user) }
+        let(:unredacted_results) { ar_relation(User, user, other_user) }
+        let(:scope) { 'users' }
+
+        it 'passes the users through' do
+          # Users are always visible to everyone
+          expect(result).to contain_exactly(user, other_user)
+        end
       end
     end
   end