Add sort filters to search page

By default the results returned are "best match" and the sort option
in the filter is automatically selected.

When the results are sorted by "most recent" we want to sort using
the `public_updated_at` (the equivalent field in Solr is
`metadata_modified`) and ordered by desc. This is passed as the
`sort` parameter in the Solr query.

app/controllers/solr_search_controller.rb

@@ -1,7 +1,9 @@
 class SolrSearchController < ApplicationController
   before_action :search_for_dataset, only: [:search]
 
-  def search; end
+  def search
+    @sort = params["sort"]
+  end
 
 private
 

app/services/search/solr.rb

@@ -3,17 +3,21 @@ class Solr
     def self.search(params)
       query_param = params.fetch("q", "").squish
       page = params["page"]
+      sort_param = params["sort"]
       page && page.to_i.positive? ? page.to_i : 1
 
       solr_client = client
 
       query = "*:*" if query_param.empty?
 
+      sort_query = "metadata_modified desc" if sort_param == "recent"
+
       solr_client.get "select", params: {
         q: query,
         start: page,
         rows: 20,
         fl: field_list,
+        sort: sort_query,
       }
     end
 

app/views/solr_search/search.html.erb

@@ -25,6 +25,7 @@
 
       <div class="govuk-grid-row dgu-filters">
         <div class="govuk-grid-column-two-thirds dgu-results">
+          <%= render '/search/sort' if @num_results > 1 %>
           <span class="dgu-results__summary">
             <span class="govuk-body-s govuk-!-font-weight-bold"><%= number_with_delimiter(@num_results) %></span>
             <%= t('.result').pluralize(@num_results) %> <%= t('.found') %>

spec/features/solr_search_page_spec.rb

@@ -3,43 +3,66 @@
 RSpec.describe "Solr Search page", type: :feature do
   let(:results) { File.read(Rails.root.join("spec/fixtures/solr_response.json").to_s) }
 
-  before do
-    allow(Search::Solr).to receive(:search).and_return(JSON.parse(results))
-  end
+  describe "Default search page behaviour" do
+    before do
+      allow(Search::Solr).to receive(:search).and_return(JSON.parse(results))
+    end
 
-  scenario "Displays search heading" do
-    visit "/search/solr"
-    expect(page).to have_css("h1", text: "Search results")
-  end
+    scenario "Displays search heading" do
+      visit "/search/solr"
+      expect(page).to have_css("h1", text: "Search results")
+    end
 
-  scenario "Displays search box" do
-    visit "/search/solr"
-    expect(page).to have_content("Search data.gov.uk")
-  end
+    scenario "Displays search box" do
+      visit "/search/solr"
+      expect(page).to have_content("Search data.gov.uk")
+    end
 
-  scenario "Displays search results" do
-    visit "/search/solr"
-    expect(page).to have_content("2 results found")
-  end
+    scenario "Displays search results" do
+      visit "/search/solr"
+      expect(page).to have_content("2 results found")
+    end
 
-  scenario "Displays the title for each search result" do
-    visit "/search/solr"
-    expect(page).to have_css("h2", text: "A very interesting dataset")
-    expect(page).to have_css("h2", text: "A dataset with additional inspire metadata")
-  end
+    scenario "Displays the title for each search result" do
+      visit "/search/solr"
+      expect(page).to have_css("h2", text: "A very interesting dataset")
+      expect(page).to have_css("h2", text: "A dataset with additional inspire metadata")
+    end
 
-  scenario "Displays the publisher for each search result" do
-    visit "/search/solr"
-    results = all(".published_by")
-    expect(results.length).to be(2)
-    expect(results[0]).to have_content "Ministry of Housing, Communities and Local Government"
-    expect(results[1]).to have_content "Mole Valley District Council"
+    scenario "Displays the publisher for each search result" do
+      visit "/search/solr"
+      results = all(".published_by")
+      expect(results.length).to be(2)
+      expect(results[0]).to have_content "Ministry of Housing, Communities and Local Government"
+      expect(results[1]).to have_content "Mole Valley District Council"
+    end
+
+    scenario "Displays the last updated for each search result" do
+      visit "/search/solr"
+      expect(page).to have_content("Last updated", count: 2)
+      expect(page).to have_content("30 June 2017")
+      expect(page).to have_content("17 August 2018")
+    end
+
+    scenario "Results are sorted by best match" do
+      visit "/search/solr"
+      expect(page).to have_select("sort", selected: "Best match")
+    end
   end
 
-  scenario "Displays the last updated for each search result" do
-    visit "/search/solr"
-    expect(page).to have_content("Last updated", count: 2)
-    expect(page).to have_content("30 June 2017")
-    expect(page).to have_content("17 August 2018")
+  describe "When a user filters the results" do
+    before do
+      allow(Search::Solr).to receive(:search).and_return(JSON.parse(results))
+    end
+
+    scenario "Results are sorted by best match" do
+      filtered_solr_search_for("Best match")
+      expect(page).to have_select("sort", selected: "Best match")
+    end
+
+    scenario "Results are sorted by most recent" do
+      filtered_solr_search_for("Most recent")
+      expect(page).to have_select("sort", selected: "Most recent")
+    end
   end
 end