Add federated search

lib/meilisearch/multi_search.rb

@@ -2,10 +2,15 @@
 
 module MeiliSearch
   module MultiSearch
-    def multi_search(data)
+    # Performs search on one or more indexes
+    #
+    # @param [Hash] federation_options
+    #   - `limit`: number of results in the merged list
+    #   - `offset`: number of results to skip in the merged list
+    def multi_search(data, federation_options = nil)
       body = Utils.transform_attributes(data)
 
-      http_post '/multi-search', queries: body
+      http_post '/multi-search', queries: body, federation: federation_options
     end
   end
 end

spec/meilisearch/client/multi_search_spec.rb

@@ -16,4 +16,37 @@
     expect(response['results'][0]['estimatedTotalHits']).to eq(0)
     expect(response['results'][1]['estimatedTotalHits']).to eq(0)
   end
+
+  it 'does a federated search with two different indexes' do
+    client.index('books').add_documents(
+      [
+        { id: 1, title: 'Harry Potter and the Philosophers Stone' },
+        { id: 2, title: 'War and Peace' }
+      ]
+    )
+
+    client.index('movies').add_documents(
+      [
+        { id: 1, title: 'Harry Potter and the Philosophers Stone' },
+        { id: 2, title: 'Lord of the Rings' }
+      ]
+    ).await
+
+    response = client.multi_search([
+                                     { index_uid: 'books', q: 'Harry Potter' },
+                                     { index_uid: 'movies', q: 'Harry Potter' }
+                                   ],
+                                   {
+                                     limit: 20,
+                                     offset: 0
+                                   })
+
+    expect(response).to have_key('hits')
+    expect(response['hits'].first).to have_key('_federation')
+    expect(response['hits'].first['_federation']).to have_key('indexUid')
+    expect(response).to have_key('estimatedTotalHits')
+    expect(response).not_to have_key('results')
+    expect(response['limit']).to eq(20)
+    expect(response['offset']).to eq(0)
+  end
 end