Deprecate flattened access on multi search results

Update #each to mimmick #each_result, not #each_hit

Author: ellnix

lib/meilisearch/rails/multi_search/result.rb

@@ -23,17 +23,41 @@ def initialize(searches, raw_results)
       include Enumerable
 
       def each_hit(&block)
-        @results.each do |_index_target, results|
+        MeiliSearch::Rails.logger.warn(
+          <<~DEPRECATION
+            [meilisearch-rails] Flattening multi search results is deprecated.
+            If you do not want the results to be grouped, please use federated search instead.
+          DEPRECATION
+        )
+
+        @results.each_value do |results|
           results.each(&block)
         end
       end
-      alias each each_hit
+
+      def each(&block)
+        MeiliSearch::Rails.logger.info(
+          <<~INFO
+            [meilisearch-rails] #each on a multi search now iterates through grouped results.
+            If you do not want the results to be grouped, please use federated search instead.
+            To quickly go back to the old deprecated behavior, use `#each_hit`.
+          INFO
+        )
+
+        @results.each(&block)
+      end
 
       def each_result(&block)
         @results.each(&block)
       end
 
       def to_a
+        MeiliSearch::Rails.logger.warn(
+          <<~DEPRECATION
+            [meilisearch-rails] Flattening multi search results is deprecated.
+            If you do not want the results to be grouped, please use federated search instead.
+          DEPRECATION
+        )
         @results.values.flatten(1)
       end
       alias to_ary to_a

spec/multi_search/result_spec.rb

@@ -60,7 +60,57 @@
       )
     end
 
+    describe '#each' do
+      let(:logger) { instance_double('Logger', info: nil) }
+
+      before do
+        allow(MeiliSearch::Rails).to receive(:logger).and_return(logger)
+      end
+
+      it 'has the same behavior as #each_result' do
+        expect(result.each).to be_an(Enumerator)
+        expect(result.each).to contain_exactly(
+          ['books_index', contain_exactly(
+            a_hash_including('author' => 'Walter Isaacson', 'name' => 'Steve Jobs')
+          )],
+          ['products_index', contain_exactly(
+            a_hash_including('name' => 'palm pixi plus')
+          )],
+          ['color_index', contain_exactly(
+            a_hash_including('name' => 'blue', 'short_name' => 'blu'),
+            a_hash_including('name' => 'black', 'short_name' => 'bla')
+          )]
+        )
+      end
+
+      it 'warns about changed behavior' do
+        result.each(&:to_s)
+
+        expect(logger).to have_received(:info).with(a_string_including('#each on a multi search now iterates through grouped results.'))
+      end
+    end
+
+    describe '#each_hit' do
+      let(:logger) { instance_double('Logger', warn: nil) }
+
+      before do
+        allow(MeiliSearch::Rails).to receive(:logger).and_return(logger)
+      end
+
+      it 'warns about deprecation' do
+        result.each_hit(&:to_s)
+
+        expect(logger).to have_received(:warn).with(a_string_including('Flattening multi search'))
+      end
+    end
+
     describe '#to_a' do
+      let(:logger) { instance_double('Logger', warn: nil) }
+
+      before do
+        allow(MeiliSearch::Rails).to receive(:logger).and_return(logger)
+      end
+
       it 'returns the hits' do
         expect(result.to_a).to contain_exactly(
           a_hash_including('author' => 'Walter Isaacson', 'name' => 'Steve Jobs'),
@@ -73,6 +123,12 @@
       it 'aliases as #to_ary' do
         expect(result.method(:to_ary).original_name).to eq :to_a
       end
+
+      it 'warns about deprecation' do
+        result.to_a
+
+        expect(logger).to have_received(:warn).with(a_string_including('Flattening multi search'))
+      end
     end
 
     describe '#to_h' do