[Specs] Fix search related specs

lib/cocoapods/sources_manager.rb

@@ -113,6 +113,10 @@ module Pod
         @updated_search_index
       end
 
+      # Allows to clear the search index.
+      #
+      attr_writer :updated_search_index
+
       # @return [Pathname] The path where the search index should be stored.
       #
       def search_index_path

spec/functional/command/search_spec.rb

@@ -8,6 +8,7 @@ module Pod
     before do
       @test_source = Source.new(fixture('spec-repos/test_repo'))
       Source::Aggregate.any_instance.stubs(:all).returns([@test_source])
+      SourcesManager.updated_search_index = nil
     end
 
     it "runs with correct parameters" do

spec/unit/sources_manager_spec.rb

@@ -54,7 +54,7 @@ module Pod
         Source::Aggregate.any_instance.stubs(:all).returns([@test_source])
         Source::Aggregate.any_instance.expects(:generate_search_index).returns({'BananaLib' => {}})
         Source::Aggregate.any_instance.expects(:update_search_index).never
-        SourcesManager.instance_variable_set("@updated_search_index", nil)
+        SourcesManager.updated_search_index = nil
         sets = SourcesManager.search_by_name('BananaLib', true)
       end
 
@@ -63,7 +63,7 @@ module Pod
         Source::Aggregate.any_instance.stubs(:all).returns([@test_source])
         Source::Aggregate.any_instance.expects(:generate_search_index).never
         Source::Aggregate.any_instance.expects(:update_search_index).returns({'BananaLib' => {}})
-        SourcesManager.instance_variable_set("@updated_search_index", nil)
+        SourcesManager.updated_search_index = nil
         sets = SourcesManager.search_by_name('BananaLib', true)
       end