Keep filters in admin search

While this bug was already present in the general admin search, the
combination of both search and filters was very uncommon. I've only
found this combinations in the users section, where you've got the
"erased" filter, but in this case searching for erased users doesn't
really make sense since their username and email have been deleted and
so there's nothing to find.

So the hidden content seemed to be the only affected section. However,
we're adding the field to every section so we don't have to make sure we
add it when we need it (like we did in the SDGManagement section).

app/components/admin/search_component.html.erb

@@ -1,4 +1,5 @@
 <%= form_tag(url, options) do |f| %>
+  <%= hidden_current_filter_tag %>
   <%= text_field_tag :search, search_terms.to_s, placeholder: label, "aria-label": label %>
   <%= content %>
   <%= submit_tag t("admin.shared.search.search") %>

app/components/admin/search_component.rb

@@ -20,4 +20,14 @@ class Admin::SearchComponent < ApplicationComponent
     def options
       { method: :get, role: "search" }.merge(form_options)
     end
+
+    def hidden_current_filter_tag
+      hidden_field_tag(:filter, current_filter) if current_filter
+    end
+
+    def current_filter
+      if helpers.respond_to?(:current_filter)
+        helpers.current_filter
+      end
+    end
 end

app/components/sdg_management/relations/index_component.html.erb

@@ -1,6 +1,6 @@
 <%= header %>
 
-<%= render SDGManagement::Relations::SearchComponent.new(label: search_label, current_filter: current_filter) %>
+<%= render SDGManagement::Relations::SearchComponent.new(label: search_label) %>
 <%= render "shared/filter_subnav", i18n_namespace: "sdg_management.relations.index" %>
 
 <table>

app/components/sdg_management/relations/index_component.rb

@@ -1,7 +1,5 @@
 class SDGManagement::Relations::IndexComponent < ApplicationComponent
   include Header
-  delegate :valid_filters, :current_filter, to: :helpers
-
   attr_reader :records
 
   def initialize(records)

app/components/sdg_management/relations/search_component.html.erb

@@ -5,5 +5,4 @@
   <%= component.select_tag :target_code, target_options,
                            include_blank: target_blank_option,
                            "aria-label": target_label %>
-  <%= component.hidden_field_tag :filter, current_filter %>
 <% end %>

app/components/sdg_management/relations/search_component.rb

@@ -1,10 +1,9 @@
 class SDGManagement::Relations::SearchComponent < ApplicationComponent
   include SDG::OptionsForSelect
-  attr_reader :label, :current_filter
+  attr_reader :label
 
-  def initialize(label:, current_filter: nil)
+  def initialize(label:)
     @label = label
-    @current_filter = current_filter
   end
 
   private

spec/components/admin/search_component_spec.rb

@@ -0,0 +1,31 @@
+require "rails_helper"
+
+describe Admin::SearchComponent do
+  describe "#hidden_current_filter_tag" do
+    context "controller responds to current_filter", controller: ApplicationController do
+      it "is present when the controller has a current filter" do
+        allow(controller).to receive(:current_filter).and_return("all")
+
+        render_inline Admin::SearchComponent.new(label: "Search")
+
+        expect(page).to have_field "filter", type: :hidden, with: "all"
+      end
+
+      it "is not present when the controller has no current filter" do
+        render_inline Admin::SearchComponent.new(label: "Search")
+
+        expect(page).not_to have_field "filter", type: :hidden
+        expect(page).not_to have_field "filter"
+      end
+    end
+
+    context "controller does not respond to current_filter", controller: ActionController::Base do
+      it "is not present" do
+        render_inline Admin::SearchComponent.new(label: "Search")
+
+        expect(page).not_to have_field "filter", type: :hidden
+        expect(page).not_to have_field "filter"
+      end
+    end
+  end
+end

spec/system/admin/hidden_content_search_spec.rb

@@ -102,4 +102,24 @@ describe "Hidden content search", :admin do
     expect(page).not_to have_content "alien1"
     expect(page).not_to have_content "alien2"
   end
+
+  scenario "keeps filter parameters after searching" do
+    create(:user, :hidden, :with_confirmed_hide, username: "person1")
+    create(:user, :hidden, :with_confirmed_hide, username: "alien1")
+    create(:user, :hidden, username: "person2")
+    create(:user, :hidden, username: "alien2")
+
+    visit admin_hidden_users_path(filter: "with_confirmed_hide")
+
+    fill_in "search", with: "alien"
+    click_button "Search"
+
+    expect(page).not_to have_content "person1"
+    expect(page).to have_content "alien1"
+    expect(page).not_to have_content "person2"
+    expect(page).not_to have_content "alien2"
+
+    expect(page).to have_content "Confirmed"
+    expect(page).not_to have_link "Confirmed"
+  end
 end