Pass new and previous session to using_session block if it accepts

.rubocop.yml

@@ -11,6 +11,11 @@ AllCops:
 
 #################### Lint ################################
 
+Layout/SpaceAroundMethodCallOperator:
+  Enabled: true
+Style/ExponentialNotation:
+  Enabled: true
+
 Layout/LineLength:
   Description: 'Limit lines to 80 characters.'
   StyleGuide: 'https://github.com/bbatsov/ruby-style-guide#80-character-limits'

lib/capybara.rb

@@ -350,7 +350,8 @@ module Capybara
     #
     # Yield a block using a specific session name or {Capybara::Session} instance.
     #
-    def using_session(name_or_session)
+    def using_session(name_or_session, &block)
+      previous_session = current_session
       previous_session_info = {
         specified_session: specified_session,
         session_name: session_name,
@@ -363,7 +364,12 @@ module Capybara
       else
         self.session_name = name_or_session
       end
-      yield
+
+      if block.arity.zero?
+        yield
+      else
+        yield current_session, previous_session
+      end
     ensure
       self.session_name, self.specified_session = previous_session_info.values_at(:session_name, :specified_session)
       self.current_driver, self.app = previous_session_info.values_at(:current_driver, :app) if threadsafe

lib/capybara/spec/session/has_current_path_spec.rb

@@ -128,11 +128,11 @@ Capybara::SpecHelper.spec '#has_no_current_path?' do
     # Without ignore_query option
     expect do
       expect(@session).not_to have_current_path('/with_js')
-    end. not_to raise_exception
+    end.not_to raise_exception
 
     # With ignore_query option
     expect do
       expect(@session).not_to have_current_path('/with_js', ignore_query: true)
-    end. not_to raise_exception
+    end.not_to raise_exception
   end
 end

spec/dsl_spec.rb

@@ -238,6 +238,15 @@ RSpec.describe Capybara::DSL do
       end
       expect(Capybara.current_session).to eq(original_session)
     end
+
+    it 'should pass the new session if block accepts' do
+      original_session = Capybara.current_session
+      Capybara.using_session(:administrator) do |admin_session, prev_session|
+        expect(admin_session).to be(Capybara.current_session)
+        expect(prev_session).to be(original_session)
+        expect(prev_session).not_to be(admin_session)
+      end
+    end
   end
 
   describe '#session_name' do