Add controller concern for paginated collections

We had similar code in a few places to redirect to the last page if
the given page number is out of range. This unifies the handling in a
new controller concern and adds usage of it in all snippet listings.

app/controllers/concerns/issuable_collections.rb

@@ -2,6 +2,7 @@
 
 module IssuableCollections
   extend ActiveSupport::Concern
+  include PaginatedCollection
   include SortingHelper
   include SortingPreference
   include Gitlab::IssuableMetadata
@@ -17,8 +18,11 @@ module IssuableCollections
   def set_issuables_index
     @issuables = issuables_collection
 
+    unless pagination_disabled?
       set_pagination
-    return if redirect_out_of_range(@total_pages)
+
+      return if redirect_out_of_range(@issuables, @total_pages)
+    end
 
     if params[:label_name].present? && @project
       labels_params = { project_id: @project.id, title: params[:label_name] }
@@ -38,12 +42,10 @@ module IssuableCollections
   end
 
   def set_pagination
-    return if pagination_disabled?
-
     @issuables          = @issuables.page(params[:page])
     @issuables          = per_page_for_relative_position if params[:sort] == 'relative_position'
     @issuable_meta_data = issuable_meta_data(@issuables, collection_type, current_user)
-    @total_pages        = issuable_page_count
+    @total_pages        = issuable_page_count(@issuables)
   end
   # rubocop:enable Gitlab/ModuleWithInstanceVariables
 
@@ -57,20 +59,8 @@ module IssuableCollections
   end
   # rubocop: enable CodeReuse/ActiveRecord
 
-  def redirect_out_of_range(total_pages)
-    return false if total_pages.nil? || total_pages.zero?
-
-    out_of_range = @issuables.current_page > total_pages # rubocop:disable Gitlab/ModuleWithInstanceVariables
-
-    if out_of_range
-      redirect_to(url_for(safe_params.merge(page: total_pages, only_path: true)))
-    end
-
-    out_of_range
-  end
-
-  def issuable_page_count
-    page_count_for_relation(@issuables, finder.row_count) # rubocop:disable Gitlab/ModuleWithInstanceVariables
+  def issuable_page_count(relation)
+    page_count_for_relation(relation, finder.row_count)
   end
 
   def page_count_for_relation(relation, row_count)

app/controllers/concerns/paginated_collection.rb

+# frozen_string_literal: true
+
+module PaginatedCollection
+  extend ActiveSupport::Concern
+
+  private
+
+  def redirect_out_of_range(collection, total_pages = collection.total_pages)
+    return false if total_pages.zero?
+
+    out_of_range = collection.current_page > total_pages
+
+    if out_of_range
+      redirect_to(url_for(safe_params.merge(page: total_pages, only_path: true)))
+    end
+
+    out_of_range
+  end
+end

app/controllers/dashboard/snippets_controller.rb

 # frozen_string_literal: true
 
 class Dashboard::SnippetsController < Dashboard::ApplicationController
+  include PaginatedCollection
   include Gitlab::NoteableMetadata
 
   skip_cross_project_access_check :index
@@ -11,6 +12,8 @@ class Dashboard::SnippetsController < Dashboard::ApplicationController
       .page(params[:page])
       .inc_author
 
+    return if redirect_out_of_range(@snippets)
+
     @noteable_meta_data = noteable_meta_data(@snippets, 'Snippet')
   end
 end

app/controllers/dashboard/todos_controller.rb

@@ -2,6 +2,7 @@
 
 class Dashboard::TodosController < Dashboard::ApplicationController
   include ActionView::Helpers::NumberHelper
+  include PaginatedCollection
 
   before_action :authorize_read_project!, only: :index
   before_action :authorize_read_group!, only: :index
@@ -12,7 +13,7 @@ class Dashboard::TodosController < Dashboard::ApplicationController
     @todos = @todos.page(params[:page])
     @todos = @todos.with_entity_associations
 
-    return if redirect_out_of_range(@todos)
+    return if redirect_out_of_range(@todos, todos_page_count(@todos))
   end
 
   def destroy
@@ -82,28 +83,15 @@ class Dashboard::TodosController < Dashboard::ApplicationController
     }
   end
 
-  def todo_params
-    params.permit(:action_id, :author_id, :project_id, :type, :sort, :state, :group_id)
-  end
-
-  # rubocop: disable CodeReuse/ActiveRecord
-  def redirect_out_of_range(todos)
-    total_pages =
-      if todo_params.except(:sort, :page).empty?
+  def todos_page_count(todos)
+    if todo_params.except(:sort, :page).empty? # rubocop: disable CodeReuse/ActiveRecord
       (current_user.todos_pending_count.to_f / todos.limit_value).ceil
     else
       todos.total_pages
     end
-
-    return false if total_pages.zero?
-
-    out_of_range = todos.current_page > total_pages
-
-    if out_of_range
-      redirect_to url_for(safe_params.merge(page: total_pages, only_path: true))
   end
 
-    out_of_range
+  def todo_params
+    params.permit(:action_id, :author_id, :project_id, :type, :sort, :state, :group_id)
   end
-  # rubocop: enable CodeReuse/ActiveRecord
 end

app/controllers/explore/snippets_controller.rb

 # frozen_string_literal: true
 
 class Explore::SnippetsController < Explore::ApplicationController
+  include PaginatedCollection
   include Gitlab::NoteableMetadata
 
   def index
@@ -9,6 +10,8 @@ class Explore::SnippetsController < Explore::ApplicationController
       .page(params[:page])
       .inc_author
 
+    return if redirect_out_of_range(@snippets)
+
     @noteable_meta_data = noteable_meta_data(@snippets, 'Snippet')
   end
 end

app/controllers/projects/snippets_controller.rb

@@ -6,6 +6,7 @@ class Projects::SnippetsController < Projects::ApplicationController
   include SpammableActions
   include SnippetsActions
   include RendersBlob
+  include PaginatedCollection
   include Gitlab::NoteableMetadata
 
   skip_before_action :verify_authenticity_token,
@@ -34,9 +35,7 @@ class Projects::SnippetsController < Projects::ApplicationController
       .page(params[:page])
       .inc_author
 
-    if @snippets.out_of_range? && @snippets.total_pages != 0
-      return redirect_to project_snippets_path(@project, page: @snippets.total_pages)
-    end
+    return if redirect_out_of_range(@snippets)
 
     @noteable_meta_data = noteable_meta_data(@snippets, 'Snippet')
   end

app/controllers/snippets_controller.rb

@@ -7,6 +7,7 @@ class SnippetsController < ApplicationController
   include SnippetsActions
   include RendersBlob
   include PreviewMarkdown
+  include PaginatedCollection
   include Gitlab::NoteableMetadata
 
   skip_before_action :verify_authenticity_token,
@@ -37,6 +38,8 @@ class SnippetsController < ApplicationController
         .page(params[:page])
         .inc_author
 
+      return if redirect_out_of_range(@snippets)
+
       @noteable_meta_data = noteable_meta_data(@snippets, 'Snippet')
 
       render 'index'

spec/controllers/dashboard/snippets_controller_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Dashboard::SnippetsController do
+  let(:user) { create(:user) }
+
+  before do
+    sign_in(user)
+  end
+
+  describe 'GET #index' do
+    it_behaves_like 'paginated collection' do
+      let(:collection) { Snippet.all }
+
+      before do
+        create(:personal_snippet, :public, author: user)
+      end
+    end
+  end
+end

spec/controllers/dashboard/todos_controller_spec.rb

@@ -82,35 +82,15 @@ describe Dashboard::TodosController do
       end
     end
 
-    context 'when using pagination' do
-      let(:last_page) { user.todos.page.total_pages }
+    it_behaves_like 'paginated collection' do
       let!(:issues) { create_list(:issue, 3, project: project, assignees: [user]) }
+      let(:collection) { user.todos }
 
       before do
         issues.each { |issue| todo_service.new_issue(issue, user) }
         allow(Kaminari.config).to receive(:default_per_page).and_return(2)
       end
 
-      it 'redirects to last_page if page number is larger than number of pages' do
-        get :index, params: { page: (last_page + 1).to_param }
-
-        expect(response).to redirect_to(dashboard_todos_path(page: last_page))
-      end
-
-      it 'goes to the correct page' do
-        get :index, params: { page: last_page }
-
-        expect(assigns(:todos).current_page).to eq(last_page)
-        expect(response).to have_gitlab_http_status(200)
-      end
-
-      it 'does not redirect to external sites when provided a host field' do
-        external_host = "www.example.com"
-        get :index, params: { page: (last_page + 1).to_param, host: external_host }
-
-        expect(response).to redirect_to(dashboard_todos_path(page: last_page))
-      end
-
       context 'when providing no filters' do
         it 'does not perform a query to get the page count, but gets that from the user' do
           allow(controller).to receive(:current_user).and_return(user)

spec/controllers/explore/snippets_controller_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Explore::SnippetsController do
+  describe 'GET #index' do
+    it_behaves_like 'paginated collection' do
+      let(:collection) { Snippet.all }
+
+      before do
+        create(:personal_snippet, :public)
+      end
+    end
+  end
+end

spec/controllers/projects/issues_controller_spec.rb

@@ -71,61 +71,27 @@ describe Projects::IssuesController do
       end
     end
 
-    context 'with page param' do
-      let(:last_page) { project.issues.page.total_pages }
+    it_behaves_like 'paginated collection' do
       let!(:issue_list) { create_list(:issue, 2, project: project) }
-
-      before do
-        sign_in(user)
-        project.add_developer(user)
-        allow(Kaminari.config).to receive(:default_per_page).and_return(1)
-      end
-
-      it 'redirects to last_page if page number is larger than number of pages' do
-        get :index,
-          params: {
-            namespace_id: project.namespace.to_param,
-            project_id: project,
-            page: (last_page + 1).to_param
-          }
-
-        expect(response).to redirect_to(namespace_project_issues_path(page: last_page, state: controller.params[:state], scope: controller.params[:scope]))
-      end
-
-      it 'redirects to specified page' do
-        get :index,
-          params: {
+      let(:collection) { project.issues }
+      let(:params) do
+        {
           namespace_id: project.namespace.to_param,
           project_id: project,
-            page: last_page.to_param
+          state: 'opened'
         }
-
-        expect(assigns(:issues).current_page).to eq(last_page)
-        expect(response).to have_gitlab_http_status(200)
       end
 
-      it 'does not redirect to external sites when provided a host field' do
-        external_host = "www.example.com"
-        get :index,
-          params: {
-            namespace_id: project.namespace.to_param,
-            project_id: project,
-            page: (last_page + 1).to_param,
-            host: external_host
-          }
-
-        expect(response).to redirect_to(namespace_project_issues_path(page: last_page, state: controller.params[:state], scope: controller.params[:scope]))
+      before do
+        sign_in(user)
+        project.add_developer(user)
+        allow(Kaminari.config).to receive(:default_per_page).and_return(1)
       end
 
       it 'does not use pagination if disabled' do
         allow(controller).to receive(:pagination_disabled?).and_return(true)
 
-        get :index,
-          params: {
-            namespace_id: project.namespace.to_param,
-            project_id: project,
-            page: (last_page + 1).to_param
-          }
+        get :index, params: params.merge(page: last_page + 1)
 
         expect(response).to have_gitlab_http_status(200)
         expect(assigns(:issues).size).to eq(2)

spec/controllers/projects/snippets_controller_spec.rb

@@ -13,31 +13,17 @@ describe Projects::SnippetsController do
   end
 
   describe 'GET #index' do
-    context 'when page param' do
-      let(:last_page) { project.snippets.page.total_pages }
-      let!(:project_snippet) { create(:project_snippet, :public, project: project, author: user) }
-
-      it 'redirects to last_page if page number is larger than number of pages' do
-        get :index,
-          params: {
+    it_behaves_like 'paginated collection' do
+      let(:collection) { project.snippets }
+      let(:params) do
+        {
           namespace_id: project.namespace,
-            project_id: project,
-            page: (last_page + 1).to_param
+          project_id: project
         }
-
-        expect(response).to redirect_to(namespace_project_snippets_path(page: last_page))
       end
 
-      it 'redirects to specified page' do
-        get :index,
-          params: {
-            namespace_id: project.namespace,
-            project_id: project,
-            page: last_page.to_param
-          }
-
-        expect(assigns(:snippets).current_page).to eq(last_page)
-        expect(response).to have_gitlab_http_status(200)
+      before do
+        create(:project_snippet, :public, project: project, author: user)
       end
     end
 

spec/controllers/snippets_controller_spec.rb

@@ -9,6 +9,15 @@ describe SnippetsController do
     let(:user) { create(:user) }
 
     context 'when username parameter is present' do
+      it_behaves_like 'paginated collection' do
+        let(:collection) { Snippet.all }
+        let(:params) { { username: user.username } }
+
+        before do
+          create(:personal_snippet, :public, author: user)
+        end
+      end
+
       it 'renders snippets of a user when username is present' do
         get :index, params: { username: user.username }
 

spec/support/shared_examples/controllers/paginated_collection_shared_examples.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+shared_examples 'paginated collection' do
+  let(:collection) { nil }
+  let(:last_page) { collection.page.total_pages }
+  let(:action) { :index }
+  let(:params) { {} }
+
+  it 'renders a page number that is not ouf of range' do
+    get action, params: params.merge(page: last_page)
+
+    expect(response).to have_gitlab_http_status(200)
+  end
+
+  it 'redirects to last_page if page number is larger than number of pages' do
+    get action, params: params.merge(page: last_page + 1)
+
+    expect(response).to redirect_to(params.merge(page: last_page))
+  end
+
+  it 'does not redirect to external sites when provided a host field' do
+    external_host = 'www.example.com'
+
+    get action, params: params.merge(page: last_page + 1, host: external_host)
+
+    expect(response).to redirect_to(params.merge(page: last_page))
+  end
+end