Default the state filters on the publications page

When visiting the root page, with no filters set, default the state
 filters so that only editions in the "pre-published" states are shown,
 as these are the editions that users of Mainstream Publisher mostly
 care about.

Uses the presence of the title filter as a proxy for whether any filters
 have been set, since that filter is always present when the
 'update filter' button is clicked (even if no title text has been
 supplied, in which case it will have an empty value).

app/controllers/root_controller.rb

@@ -15,10 +15,16 @@ class RootController < ApplicationController
     archived
   ].freeze
 
+  DEFAULT_FILTER_STATES = %w[draft amends_needed in_review fact_check fact_check_received ready].freeze
+
   def index
     filter_params_hash = filter_params.to_h
     states_filter_params = filter_params_hash[:states_filter]
-    sanitised_states_filter_params = states_filter_params&.select { |fp| PERMITTED_FILTER_STATES.include?(fp) }
+    if user_has_submitted_filters?
+      sanitised_states_filter_params = states_filter_params&.select { |fp| PERMITTED_FILTER_STATES.include?(fp) }
+    else
+      sanitised_states_filter_params = DEFAULT_FILTER_STATES
+    end
     assignee_filter = filter_params_hash[:assignee_filter]
     format_filter = filter_params_hash[:format_filter]
     title_filter = filter_params_hash[:title_filter]
@@ -33,6 +39,10 @@ def index
 
 private
 
+  def user_has_submitted_filters?
+    filter_params.to_h[:title_filter]
+  end
+
   def filter_params
     params.permit(:page, :assignee_filter, :format_filter, :title_filter, states_filter: [])
   end

test/functional/root_controller_test.rb

@@ -13,6 +13,26 @@ class RootControllerTest < ActionController::TestCase
       assert_template "root/index"
     end
 
+    should "default the state filters when no filters are specified" do
+      get :index
+
+      # These filters should be 'checked'
+      assert_select "input.govuk-checkboxes__input[value='draft'][checked]"
+      assert_select "input.govuk-checkboxes__input[value='amends_needed'][checked]"
+      assert_select "input.govuk-checkboxes__input[value='in_review'][checked]"
+      assert_select "input.govuk-checkboxes__input[value='fact_check'][checked]"
+      assert_select "input.govuk-checkboxes__input[value='fact_check_received'][checked]"
+      assert_select "input.govuk-checkboxes__input[value='ready'][checked]"
+
+      # These filters should NOT be 'checked'
+      assert_select "input.govuk-checkboxes__input[value='scheduled_for_publishing']"
+      assert_select "input.govuk-checkboxes__input[value='scheduled_for_publishing'][checked]", false
+      assert_select "input.govuk-checkboxes__input[value='published']"
+      assert_select "input.govuk-checkboxes__input[value='published'][checked]", false
+      assert_select "input.govuk-checkboxes__input[value='archived']"
+      assert_select "input.govuk-checkboxes__input[value='archived'][checked]", false
+    end
+
     should "filter publications by state" do
       FactoryBot.create(:guide_edition, state: "draft")
       FactoryBot.create(:guide_edition, state: "published")
@@ -59,7 +79,7 @@ class RootControllerTest < ActionController::TestCase
         .with(has_entry(:states_filter, %w[draft]))
         .returns(stub(editions: Kaminari.paginate_array([]).page(1), available_users: []))
 
-      get :index, params: { states_filter: %w[draft not_a_real_state] }
+      get :index, params: { title_filter: "", states_filter: %w[draft not_a_real_state] }
     end
 
     should "show the first page of publications when no page is specified" do