Add pagination and sorting

for jira issue controller

app/finders/projects/integrations/jira/issues_finder.rb

@@ -7,14 +7,19 @@ module Jira
       RequestError = Class.new(StandardError)
 
       class IssuesFinder
-        attr_reader :issues, :total_count
+        attr_reader :issues, :total_count, :per_page
+
+        class << self
+          def valid_params
+            @valid_params ||= %i[page per_page search state]
+          end
+        end
 
         def initialize(project, params = {})
           @project = project
           @jira_service = project.jira_service
-          @page = params[:page].presence || 1
-          @params = params
-          @params = @params.reverse_merge(map_sort_values(@params.delete(:sort)))
+          @params = params.merge(map_sort_values(params[:sort]))
+          set_pagination
         end
 
         def execute
@@ -35,7 +40,9 @@ def execute
         # rubocop: disable CodeReuse/ServiceClass
         def fetch_issues(project_key)
           jql = ::Jira::JqlBuilderService.new(project_key, params).execute
-          response = ::Jira::Requests::Issues::ListService.new(jira_service, { jql: jql, page: page }).execute
+          response = ::Jira::Requests::Issues::ListService
+                       .new(jira_service, { jql: jql, page: page, per_page: per_page })
+                       .execute
 
           if response.success?
             @total_count = response.payload[:total_count]
@@ -54,6 +61,11 @@ def map_sort_values(sort)
             { sort: ::Jira::JqlBuilderService::DEFAULT_SORT, sort_direction: ::Jira::JqlBuilderService::DEFAULT_SORT_DIRECTION }
           end
         end
+
+        def set_pagination
+          @page = (params[:page].presence || 1).to_i
+          @per_page = (params[:per_page].presence || ::Jira::Requests::Issues::ListService::PER_PAGE).to_i
+        end
       end
     end
   end

ee/app/controllers/projects/integrations/jira/issues_controller.rb

@@ -5,6 +5,8 @@ module Integrations
     module Jira
       class IssuesController < Projects::ApplicationController
         include RecordUserLastActivity
+        include SortingHelper
+        include SortingPreference
 
         before_action :check_feature_enabled!
 
@@ -27,9 +29,42 @@ def index
         private
 
         def issues_json
-          jira_issues = ::Projects::Integrations::Jira::IssuesFinder.new(project, {}).execute
+          jira_issues = finder.execute
+          jira_issues = Kaminari.paginate_array(jira_issues, limit: finder.per_page, total_count: finder.total_count)
 
-          ::Integrations::Jira::IssueSerializer.new.represent(jira_issues, project: project)
+          ::Integrations::Jira::IssueSerializer.new
+            .with_pagination(request, response)
+            .represent(jira_issues, project: project)
+        end
+
+        def finder
+          @finder ||= finder_type.new(project, finder_options)
+        end
+
+        def finder_type
+          ::Projects::Integrations::Jira::IssuesFinder
+        end
+
+        def finder_options
+          params[:state] = default_state if params[:state].blank?
+          options = { sort: set_sort_order }
+
+          # Used by view to highlight active option
+          @sort = options[:sort]
+
+          params.permit(finder_type.valid_params).merge(options)
+        end
+
+        def default_state
+          'opened'
+        end
+
+        def default_sort_order
+          case params[:state]
+          when 'opened', 'all' then sort_value_created_date
+          when 'closed'        then sort_value_recently_updated
+          else sort_value_created_date
+          end
         end
 
         protected

ee/app/serializers/integrations/jira/issue_serializer.rb

@@ -3,6 +3,8 @@
 module Integrations
   module Jira
     class IssueSerializer < BaseSerializer
+      include WithPagination
+
       entity ::Integrations::Jira::IssueEntity
     end
   end

ee/spec/controllers/projects/integrations/jira/issues_controller_spec.rb

@@ -53,7 +53,7 @@
       let(:jira_issues) { [] }
 
       it 'returns a list of serialized jira issues' do
-        expect_next_instance_of(Projects::Integrations::Jira::IssuesFinder, project, {}) do |finder|
+        expect_next_instance_of(Projects::Integrations::Jira::IssuesFinder) do |finder|
           expect(finder).to receive(:execute).and_return(jira_issues)
         end
 
@@ -83,6 +83,59 @@
         expect(response).to have_gitlab_http_status(:bad_request)
         expect(json_response['errors']).to eq ['Request error']
       end
+
+      it 'sets pagination headers' do
+        expect_next_instance_of(Projects::Integrations::Jira::IssuesFinder) do |finder|
+          expect(finder).to receive(:execute).and_return(jira_issues)
+        end
+
+        get :index, params: { namespace_id: project.namespace, project_id: project }, format: :json
+
+        expect(response).to include_pagination_headers
+        expect(response.headers['X-Page']).to eq '1'
+        expect(response.headers['X-Per-Page']).to eq Jira::Requests::Issues::ListService::PER_PAGE.to_s
+        expect(response.headers['X-Total']).to eq '0'
+      end
+
+      context 'when parameters are passed' do
+        shared_examples 'proper parameter values' do
+          it 'properly set the values' do
+            expect_next_instance_of(Projects::Integrations::Jira::IssuesFinder, project, expected_params) do |finder|
+              expect(finder).to receive(:execute).and_return(jira_issues)
+            end
+
+            get :index, params: { namespace_id: project.namespace, project_id: project }.merge(params), format: :json
+          end
+        end
+
+        context 'when there are no params' do
+          it_behaves_like 'proper parameter values' do
+            let(:params) { {} }
+            let(:expected_params) { { 'state' => 'opened', 'sort' => 'created_date' } }
+          end
+        end
+
+        context 'when pagination params' do
+          it_behaves_like 'proper parameter values' do
+            let(:params) { { 'page' => '12', 'per_page' => '20' } }
+            let(:expected_params) { { 'page' => '12', 'per_page' => '20', 'state' => 'opened', 'sort' => 'created_date' } }
+          end
+        end
+
+        context 'when state is closed' do
+          it_behaves_like 'proper parameter values' do
+            let(:params) { { 'state' => 'closed' } }
+            let(:expected_params) { { 'state' => 'closed', 'sort' => 'updated_desc' } }
+          end
+        end
+
+        context 'when invalid params' do
+          it_behaves_like 'proper parameter values' do
+            let(:params) { { 'invalid' => '12' } }
+            let(:expected_params) { { 'state' => 'opened', 'sort' => 'created_date' } }
+          end
+        end
+      end
     end
   end
 

spec/finders/projects/integrations/jira/issues_finder_spec.rb

@@ -99,6 +99,18 @@
             subject
           end
         end
+
+        context 'when pagination params used' do
+          let(:params) { { page: '10', per_page: '20' } }
+
+          it 'passes them to JqlBuilderService ' do
+            expect(::Jira::JqlBuilderService).to receive(:new)
+              .with(jira_service.project_key, include({ page: '10', per_page: '20' }))
+              .and_call_original
+
+            subject
+          end
+        end
       end
     end
   end