Add tests for `TimelineController`

app/helpers/application_helper/title_methods.rb

@@ -61,6 +61,6 @@ module ApplicationHelper::TitleMethods
   end
 
   def list_title(list)
-    generate_title list.name
+    generate_title list.display_name
   end
 end

spec/controllers/timeline_controller_spec.rb

@@ -0,0 +1,125 @@
+# frozen_string_literal: true
+
+require "rails_helper"
+
+describe TimelineController do
+  let(:user) { FactoryBot.create(:user) }
+
+  let!(:followed_users) { FactoryBot.create_list(:user, 3) }
+  let!(:followed_user_answers) { followed_users.map { |u| FactoryBot.create_list(:answer, 5, user: u) }.flatten }
+
+  let!(:unfollowed_users) { FactoryBot.create_list(:user, 3) }
+  let!(:unfollowed_user_answers) { unfollowed_users.map { |u| FactoryBot.create_list(:answer, 5, user: u) }.flatten }
+
+  let!(:listed_users) { [followed_users[0], unfollowed_users[0], unfollowed_users[1]] }
+  let!(:listed_user_answers) { listed_users.map(&:answers).flatten }
+  let(:list) { FactoryBot.create(:list, user: user, members: listed_users, display_name: "Test List") }
+
+  before do
+    sign_in(user)
+
+    followed_users.each { |u| user.follow(u) }
+    stub_const("APP_CONFIG", {
+                 "site_name"      => "Specspring",
+                 "hostname"       => "test.host",
+                 "https"          => false,
+                 "items_per_page" => 10
+               })
+  end
+
+  shared_examples_for "paginates" do |answer_set, last_page_start_index = 5, expected_last_page_size = 5, should_test_single_page = true|
+    context "can't display all answers on one page" do
+      let(:last_id) { nil }
+
+      it { should have_http_status(200) }
+
+      it "paginates" do
+        subject
+        expect(assigns(:more_data_available)).to eq(true)
+        expect(assigns(:timeline).length).to eq(10)
+      end
+    end
+
+    context "fetching the last page" do
+      let(:last_id) do
+        if answer_set.is_a?(Symbol)
+          public_send(answer_set).sort_by(&:id)[last_page_start_index].id
+        else
+          answer_set.sort_by(&:id)[last_page_start_index].id
+        end
+      end
+
+      it "loads the last page" do
+        subject
+        expect(assigns(:more_data_available)).to eq(false)
+        expect(assigns(:timeline).length).to eq(expected_last_page_size)
+      end
+    end
+
+    if should_test_single_page
+      context "can display all answers on one page" do
+        before do
+          if answer_set.is_a?(Symbol)
+            public_send(answer_set).last(6).each(&:destroy!)
+          else
+            answer_set.last(6).each(&:destroy!)
+          end
+        end
+
+        it { should have_http_status(200) }
+
+        it "does not paginate" do
+          subject
+          expect(assigns(:more_data_available)).to eq(false)
+          expect(assigns(:timeline).length).to eq(9)
+        end
+      end
+    end
+  end
+
+  shared_examples_for "assigns title" do |expected_prefix|
+    it "assigns the list and title to an instance variable" do
+      subject
+      expect(assigns(:title)).to eq("#{expected_prefix} | Specspring")
+    end
+  end
+
+  describe "#index" do
+    subject { get :index, params: params }
+
+    let(:params) { { last_id: last_id } }
+    let(:last_id) { nil }
+
+    it { should have_http_status(200) }
+    it_behaves_like "paginates", :followed_user_answers
+  end
+
+  describe "#list" do
+    subject { get :list, params: params }
+
+    context "viewing a list" do
+      let(:params) { { list_name: list.name, last_id: last_id } }
+      let(:last_id) { nil }
+
+      it_behaves_like "paginates", :listed_user_answers
+      it_behaves_like "assigns title", "Test List"
+
+      it "assigns the list to an instance variable" do
+        subject
+        expect(assigns(:list)).to eq(list)
+      end
+    end
+  end
+
+  describe "#public" do
+    subject { get :public, params: params }
+
+    context "viewing public timeline" do
+      let(:params) { { last_id: last_id } }
+      let(:last_id) { nil }
+
+      it_behaves_like "paginates", Answer.all.order(created_at: :desc), 10, 10, false
+      it_behaves_like "assigns title", "Public Timeline"
+    end
+  end
+end