Accept SHA256 as identifier for API playlists/show

app/controllers/api/sounds_controller.rb

@@ -12,7 +12,10 @@ module API
     private
 
     def set_sound
-      @sound = Sound.find(params[:id])
+      @sound = case params[:id]
+        when /\A\d+\z/  then Sound.find(params[:id])
+        when /\A\h+\z/  then Sound.find_by_sha256!(params[:id])
+      end
     end
   end
 end

spec/integration/api/sounds_spec.rb

@@ -4,7 +4,8 @@ describe 'API sounds' do
   describe 'sound show' do
     let(:sound)           { create :sound }
     let(:request_method)  { :get }
-    let(:request_show)    { send request_method, api_sound_path(sound) }
+    let(:request_path)    { api_sound_path(sound) }
+    let(:request_show)    { send request_method, request_path }
     subject               { response }
 
     before { request_show }
@@ -28,5 +29,11 @@ describe 'API sounds' do
         expect(response.body).to be_empty
       end
     end
+
+    context 'when sound is requested by SHA256 digest' do
+      let(:request_path) { api_sound_path id: sound.sha256 }
+
+      it { is_expected.to have_http_status 200 }
+    end
   end
 end