add lectureSearch resolver to GraphQL (#740)

* add `lectureSearch` resolver to graphql
* add empty line 3:)

app/graphql/resolvers/search_lectures.rb

@@ -0,0 +1,11 @@
+class Resolvers::SearchLectures < GraphQL::Schema::Resolver
+  type [Types::LectureType], null: false
+
+  argument :query, String, required: true
+  argument :page, Integer, required: false
+
+  def resolve(query:, page: 1)
+    results = Frontend::Event.query(query).page(page)
+    @events = results.records.includes(recordings: :conference)
+  end
+end

app/graphql/types/query_type.rb

@@ -42,6 +42,8 @@ def lecture_by_slug(slug:)
       Frontend::Event.find_by(slug: slug)
     end
 
+    field :lecture_search, resolver: Resolvers::SearchLectures
+
     field :lectures_related_to, LectureType.connection_type, null: true do
       description 'A list of related lectures, ordered by decreasing relevance.'
       argument :guid, ID, required: true

test/integration/graphql/lecture_test.rb

@@ -71,4 +71,58 @@ class LectureGraphQLApiTest < ActionDispatch::IntegrationTest
 
   end
 
+  unless ENV['SKIP_ELASTICSEARCH']
+    test 'search for lectures' do
+      query_string = <<-GRAPHQL
+      query($query: String!) {
+        lectureSearch(query: $query) {
+          title
+           images {
+             thumbUrl
+             posterUrl
+          }
+        }
+      }
+      GRAPHQL
+      result = MediaBackendSchema.execute(query_string, variables: { query: "not-existing" })
+      assert_empty result['data']['lectureSearch']
+    end
+
+    test 'search for lectures return multiple results' do
+      Event.__elasticsearch__.create_index! force: true
+      create_list(:event, 26, title: 'fake-event')
+      Event.import
+      Event.__elasticsearch__.refresh_index!
+
+      query_string = <<-GRAPHQL
+      query($query: String!) {
+        lectureSearch(query: $query) {
+          title
+           images {
+             thumbUrl
+             posterUrl
+          }
+        }
+      }
+      GRAPHQL
+      result = MediaBackendSchema.execute(query_string, variables: { query: "fake-event" })
+      assert_nil result['errors']
+      assert_equal 25, result['data']['lectureSearch'].count
+      query_string = <<-GRAPHQL
+      query($query: String!, $page: Int!) {
+        lectureSearch(query: $query, page: $page) {
+          title
+           images {
+             thumbUrl
+             posterUrl
+          }
+        }
+      }
+      GRAPHQL
+      result = MediaBackendSchema.execute(query_string, variables: { query: "fake-event", page: 2 })
+      assert_nil result['errors']
+      assert_equal 1, result['data']['lectureSearch'].count
+    end
+  end
+
 end