Merge branch 'ajk-13984-connections' into 'master'

Add connection redaction and connection extension methods

See merge request gitlab-org/gitlab!47967

lib/gitlab/graphql/connection_collection_methods.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Graphql
+    module ConnectionCollectionMethods
+      extend ActiveSupport::Concern
+
+      included do
+        delegate :to_a, :size, :include?, :empty?, to: :nodes
+      end
+    end
+  end
+end

lib/gitlab/graphql/connection_redaction.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Graphql
+    module ConnectionRedaction
+      class RedactionState
+        attr_reader :redactor
+        attr_reader :redacted_nodes
+
+        def redactor=(redactor)
+          @redactor = redactor
+          @redacted_nodes = nil
+        end
+
+        def redacted(&block)
+          @redacted_nodes ||= redactor.present? ? redactor.redact(yield) : yield
+        end
+      end
+
+      delegate :redactor=, to: :redaction_state
+
+      def nodes
+        redaction_state.redacted { super.to_a }
+      end
+
+      private
+
+      def redaction_state
+        @redaction_state ||= RedactionState.new
+      end
+    end
+  end
+end

lib/gitlab/graphql/pagination/array_connection.rb

+# frozen_string_literal: true
+
+# We use the Keyset / Stable cursor connection by default for ActiveRecord::Relation.
+# However, there are times when that may not be powerful enough (yet), and we
+# want to use standard offset pagination.
+module Gitlab
+  module Graphql
+    module Pagination
+      class ArrayConnection < ::GraphQL::Pagination::ArrayConnection
+        prepend ::Gitlab::Graphql::ConnectionRedaction
+        include ::Gitlab::Graphql::ConnectionCollectionMethods
+      end
+    end
+  end
+end

lib/gitlab/graphql/pagination/connections.rb

@@ -12,6 +12,10 @@ module Gitlab
           schema.connections.add(
             Gitlab::Graphql::ExternallyPaginatedArray,
             Gitlab::Graphql::Pagination::ExternallyPaginatedArrayConnection)
+
+          schema.connections.add(
+            Array,
+            Gitlab::Graphql::Pagination::ArrayConnection)
         end
       end
     end

lib/gitlab/graphql/pagination/externally_paginated_array_connection.rb

@@ -5,6 +5,9 @@ module Gitlab
   module Graphql
     module Pagination
       class ExternallyPaginatedArrayConnection < GraphQL::Pagination::ArrayConnection
+        include ::Gitlab::Graphql::ConnectionCollectionMethods
+        prepend ::Gitlab::Graphql::ConnectionRedaction
+
         def start_cursor
           items.previous_cursor
         end

lib/gitlab/graphql/pagination/keyset/connection.rb

@@ -31,6 +31,8 @@ module Gitlab
       module Keyset
         class Connection < GraphQL::Pagination::ActiveRecordRelationConnection
           include Gitlab::Utils::StrongMemoize
+          include ::Gitlab::Graphql::ConnectionCollectionMethods
+          prepend ::Gitlab::Graphql::ConnectionRedaction
 
           # rubocop: disable Naming/PredicateName
           # https://relay.dev/graphql/connections.htm#sec-undefined.PageInfo.Fields

lib/gitlab/graphql/pagination/offset_active_record_relation_connection.rb

@@ -7,6 +7,8 @@ module Gitlab
   module Graphql
     module Pagination
       class OffsetActiveRecordRelationConnection < GraphQL::Pagination::ActiveRecordRelationConnection
+        prepend ::Gitlab::Graphql::ConnectionRedaction
+        include ::Gitlab::Graphql::ConnectionCollectionMethods
       end
     end
   end

spec/lib/gitlab/graphql/pagination/array_connection_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe ::Gitlab::Graphql::Pagination::ArrayConnection do
+  let(:nodes) { (1..10) }
+
+  subject(:connection) { described_class.new(nodes, max_page_size: 100) }
+
+  it_behaves_like 'a connection with collection methods'
+
+  it_behaves_like 'a redactable connection' do
+    let(:unwanted) { 5 }
+  end
+end

spec/lib/gitlab/graphql/pagination/externally_paginated_array_connection_spec.rb

@@ -13,6 +13,12 @@ RSpec.describe Gitlab::Graphql::Pagination::ExternallyPaginatedArrayConnection d
     described_class.new(all_nodes, { max_page_size: values.size }.merge(arguments))
   end
 
+  it_behaves_like 'a connection with collection methods'
+
+  it_behaves_like 'a redactable connection' do
+    let(:unwanted) { 3 }
+  end
+
   describe '#nodes' do
     let(:paged_nodes) { connection.nodes }
 

spec/lib/gitlab/graphql/pagination/keyset/connection_spec.rb

@@ -21,6 +21,13 @@ RSpec.describe Gitlab::Graphql::Pagination::Keyset::Connection do
     Gitlab::Json.parse(Base64Bp.urlsafe_decode64(cursor))
   end
 
+  it_behaves_like 'a connection with collection methods'
+
+  it_behaves_like 'a redactable connection' do
+    let_it_be(:projects) { create_list(:project, 2) }
+    let(:unwanted) { projects.second }
+  end
+
   describe '#cursor_for' do
     let(:project) { create(:project) }
     let(:cursor)  { connection.cursor_for(project) }

spec/lib/gitlab/graphql/pagination/offset_active_record_relation_connection_spec.rb

@@ -6,4 +6,15 @@ RSpec.describe Gitlab::Graphql::Pagination::OffsetActiveRecordRelationConnection
   it 'subclasses from GraphQL::Relay::RelationConnection' do
     expect(described_class.superclass).to eq GraphQL::Pagination::ActiveRecordRelationConnection
   end
+
+  it_behaves_like 'a connection with collection methods' do
+    let(:connection) { described_class.new(Project.all) }
+  end
+
+  it_behaves_like 'a redactable connection' do
+    let_it_be(:users) { create_list(:user, 2) }
+
+    let(:connection) { described_class.new(User.all, max_page_size: 10) }
+    let(:unwanted) { users.second }
+  end
 end

spec/support/shared_examples/graphql/connection_redaction_shared_examples.rb

+# frozen_string_literal: true
+
+# requires:
+#  - `connection` (no-empty, containing `unwanted` and at least one more item)
+#  - `unwanted` (single item in collection)
+RSpec.shared_examples 'a redactable connection' do
+  context 'no redactor set' do
+    it 'contains the unwanted item' do
+      expect(connection.nodes).to include(unwanted)
+    end
+
+    it 'does not redact more than once' do
+      connection.nodes
+      r_state = connection.send(:redaction_state)
+
+      expect(r_state.redacted { raise 'Should not be called!' }).to be_present
+    end
+  end
+
+  let_it_be(:constant_redactor) do
+    Class.new do
+      def initialize(remove)
+        @remove = remove
+      end
+
+      def redact(items)
+        items - @remove
+      end
+    end
+  end
+
+  context 'redactor is set' do
+    let(:redactor) do
+      constant_redactor.new([unwanted])
+    end
+
+    before do
+      connection.redactor = redactor
+    end
+
+    it 'does not contain the unwanted item' do
+      expect(connection.nodes).not_to include(unwanted)
+      expect(connection.nodes).not_to be_empty
+    end
+
+    it 'does not redact more than once' do
+      expect(redactor).to receive(:redact).once.and_call_original
+
+      connection.nodes
+      connection.nodes
+      connection.nodes
+    end
+  end
+end

spec/support/shared_examples/graphql/connection_shared_examples.rb

+# frozen_string_literal: true
+
+RSpec.shared_examples 'a connection with collection methods' do
+  %i[to_a size include? empty?].each do |method_name|
+    it "responds to #{method_name}" do
+      expect(connection).to respond_to(method_name)
+    end
+  end
+end