Soft deprecate :class_name in multi_search

In favor of :collection option

Author: ellnix

README.md

@@ -265,12 +265,14 @@ Use `#each_result` to loop through pairs of your provided keys and the results:
 </ul>
 ```
 
-Records are loaded when the keys are models, or when `:class_name` option is passed:
+Records are loaded when the keys are models, or when `:collection` option is passed:
 
 ```ruby
 multi_search_results = MeiliSearch::Rails.multi_search(
-  'books' => { q: 'Harry', class_name: 'Book' },
-  'mangas' => { q: 'Attack', class_name: 'Manga' }
+  # Collection may be a relation
+  'books' => { q: 'Harry', collection: Book.all },
+  # or a model
+  'mangas' => { q: 'Attack', collection: Manga }
 )
 ```
 
@@ -280,8 +282,8 @@ The index to search is inferred from the model if the key is a model, if the key
 
 ```ruby
 multi_search_results = MeiliSearch::Rails.multi_search(
-  'western' => { q: 'Harry', class_name: 'Book', index_uid: 'books_production' },
-  'japanese' => { q: 'Attack', class_name: 'Manga', index_uid: 'mangas_production' }
+  'western' => { q: 'Harry', collection: Book, index_uid: 'books_production' },
+  'japanese' => { q: 'Attack', collection: Manga, index_uid: 'mangas_production' }
 )
 ```
 
@@ -292,9 +294,9 @@ You can search the same index multiple times by specifying `:index_uid`:
 ```ruby
 query = 'hero'
 multi_search_results = MeiliSearch::Rails.multi_search(
-  'Isekai Manga' => { q: query, class_name: 'Manga', filters: 'genre:isekai', index_uid: 'mangas_production' }
-  'Shounen Manga' => { q: query, class_name: 'Manga', filters: 'genre:shounen', index_uid: 'mangas_production' }
-  'Steampunk Manga' => { q: query, class_name: 'Manga', filters: 'genre:steampunk', index_uid: 'mangas_production' }
+  'Isekai Manga' => { q: query, collection: Manga, filters: 'genre:isekai', index_uid: 'mangas_production' }
+  'Shounen Manga' => { q: query, collection: Manga, filters: 'genre:shounen', index_uid: 'mangas_production' }
+  'Steampunk Manga' => { q: query, collection: Manga, filters: 'genre:steampunk', index_uid: 'mangas_production' }
 )
 ```
 

lib/meilisearch/rails/multi_search/result.rb

@@ -9,6 +9,10 @@ def initialize(searches, raw_results)
 
         searches.zip(raw_results['results']).each do |(target, search_options), result|
           results_class = if search_options[:class_name]
+                            MeiliSearch::Rails.logger.warn(
+                              '[meilisearch-rails] The :class_name option in multi search is deprecated, please use :collection instead.'
+                            )
+
                             search_options[:class_name].constantize
                           elsif target.instance_of?(Class)
                             target

spec/multi_search_spec.rb

@@ -91,6 +91,8 @@ def reset_indexes
 
       context 'when :class_name is also present' do
         it 'loads results from the correct models' do
+          allow(MeiliSearch::Rails.logger).to receive(:warn).and_return(nil)
+
           results = MeiliSearch::Rails.multi_search(
             'books' => { q: 'Steve', index_uid: Book.index.uid, class_name: 'Book' },
             'products' => { q: 'palm', limit: 1, index_uid: Product.index.uid, class_name: 'Product' },
@@ -122,6 +124,18 @@ def reset_indexes
     end
 
     context 'when class_name is specified' 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
+        results = MeiliSearch::Rails.multi_search(Book.index.uid => { q: 'Steve', class_name: 'Book' })
+        expect(results.to_h[Book.index.uid]).to contain_exactly(steve_jobs)
+        expect(logger).to have_received(:warn).with(a_string_matching(':class_name'))
+      end
+
       it 'returns ORM records' do
         results = MeiliSearch::Rails.multi_search(
           Book.index.uid => { q: 'Steve', class_name: 'Book' },
@@ -150,7 +164,7 @@ def reset_indexes
     it 'returns a mixture of ORM records and hashes' do
       results = MeiliSearch::Rails.multi_search(
         Book => { q: 'Steve' },
-        Product.index.uid => { q: 'palm', limit: 1, class_name: 'Product' },
+        Product.index.uid => { q: 'palm', limit: 1, collection: Product },
         Color.index.uid => { q: 'bl' }
       )
 
@@ -184,7 +198,7 @@ def reset_indexes
   context 'with collections' do
     it 'fetches items from the given collection' do
       results = MeiliSearch::Rails.multi_search(
-        Product.index.uid => { q: 'palm', class_name: 'Product', collection: Product.where('tags LIKE "%terrible%"') },
+        Product => { q: 'palm', collection: Product.where('tags LIKE "%terrible%"') },
         Color => { q: 'bl', collection: Color.where(short_name: 'bla') }
       )