Adopt JSON-API conventions for search results serialization

app/views/catalog/index.json.jbuilder

@@ -1,5 +1,21 @@
+json.links do
+  json.self url_for(search_state.to_h.merge(only_path: false))
+  json.prev url_for(search_state.to_h.merge(only_path: false, page: @response.prev_page.to_s)) if @response.prev_page
+  json.next url_for(search_state.to_h.merge(only_path: false, page: @response.next_page.to_s)) if @response.next_page
+  json.last url_for(search_state.to_h.merge(only_path: false, page: @response.total_pages.to_s))
+end
+
+json.data do
+  json.array! @presenter.documents do |document|
+    json.id document.id
+    json.attributes document
+    json.links do
+      json.self polymorphic_url(url_for_document(document))
+    end
+  end
+end
+
 json.response do
-  json.docs @presenter.documents
   json.facets @presenter.search_facets_as_json
   json.pages @presenter.pagination_info
 end

spec/features/search_spec.rb

@@ -116,4 +116,3 @@
     expect(page).to have_content "No results found for your search"
   end
 end
-

spec/views/catalog/index.json.jbuilder_spec.rb

@@ -1,30 +1,48 @@
 # frozen_string_literal: true
 RSpec.describe "catalog/index.json" do
-  let(:response) { instance_double(Blacklight::Solr::Response, documents: docs) }
-  let(:docs) { [{ id: '123', title_t: 'Book1' }, { id: '456', title_t: 'Book2' }] }
+  let(:response) { instance_double(Blacklight::Solr::Response, documents: docs, prev_page: nil, next_page: 2, total_pages: 3) }
+  let(:docs) { [SolrDocument.new(id: '123', title_t: 'Book1'), SolrDocument.new(id: '456', title_t: 'Book2')] }
   let(:facets) { double("facets") }
-  let(:config) { instance_double(Blacklight::Configuration) }
+  let(:config) { Blacklight::Configuration.new }
   let(:presenter) { Blacklight::JsonPresenter.new(response, facets, config) }
 
   it "renders index json" do
+    allow(view).to receive(:blacklight_config).and_return(config)
     allow(presenter).to receive(:pagination_info).and_return({ current_page: 1, next_page: 2,
                                                                prev_page: nil })
     allow(presenter).to receive(:search_facets_as_json).and_return(
           [{ name: "format", label: "Format",
              items: [{ value: 'Book', hits: 30, label: 'Book' }] }])
     assign :presenter, presenter
+    assign :response, response
     render template: "catalog/index.json", format: :json
-    hash = JSON.parse(rendered)
-    expect(hash).to eq('response' => { 'docs' => [{ 'id' => '123', 'title_t' => 'Book1' },
-                                                  { 'id' => '456', 'title_t' => 'Book2' }],
-                                       'facets' => [{ 'name' => "format", 'label' => "Format",
-                                                      'items' => [
-                                                        { 'value' => 'Book',
-                                                          'hits' => 30,
-                                                          'label' => 'Book' }] }],
-                                       'pages' => { 'current_page' =>  1,
-                                                    'next_page' => 2,
-                                                    'prev_page' => nil } }
-                      )
+    hash = JSON.parse(rendered).with_indifferent_access
+    expect(hash).to include(links: hash_including(self: 'http://test.host/', next: 'http://test.host/?page=2', last: 'http://test.host/?page=3'))
+    expect(hash).to include(response: hash_including(facets: [
+      { 
+        'name' => "format", 'label' => "Format",
+        'items' => [
+          { 'value' => 'Book',
+            'hits' => 30,
+            'label' => 'Book' }] 
+      }]))
+    expect(hash).to include(response: hash_including(pages: 
+      { 
+        'current_page' =>  1,
+        'next_page' => 2,
+        'prev_page' => nil 
+      }))
+    expect(hash).to include(data: [
+      {
+        id: '123',
+        attributes: { 'id' => '123', 'title_t' => 'Book1' },
+        links: { self: 'http://test.host/catalog/123' }
+      },
+      {
+        id: '456',
+        attributes: { 'id' => '456', 'title_t' => 'Book2' },
+        links: { self: 'http://test.host/catalog/456' }
+      },
+    ])
   end
 end