Add destroy functionality to save_multiple

app/controllers/projects/variables_controller.rb

@@ -39,6 +39,7 @@ class Projects::VariablesController < Projects::ApplicationController
         return head :bad_request unless @variables.all?(&:valid?)
 
         @variables.each(&:save)
+        @variables_destroy.each(&:destroy)
         head :ok
       end
     end
@@ -75,10 +76,16 @@ class Projects::VariablesController < Projects::ApplicationController
   end
 
   def variables
-    @variables = variables_params[:variables].map do |variable_hash|
+    destroy, edit = variables_params[:variables].partition { |hash| hash[:_destroy] == 'true' }
+    @variables = initialize_or_update_variables_from_hash(edit)
+    @variables_destroy = initialize_or_update_variables_from_hash(destroy)
+  end
+
+  def initialize_or_update_variables_from_hash(hash)
+    hash.map do |variable_hash|
       variable = project.variables.where(key: variable_hash[:key])
         .first_or_initialize(variable_hash).present(current_user: current_user)
-      variable.assign_attributes(variable_hash) unless variable.new_record?
+      variable.assign_attributes(variable_hash.except(:_destroy)) unless variable.new_record?
       variable
     end
   end

spec/controllers/projects/variables_controller_spec.rb

@@ -110,5 +110,25 @@ describe Projects::VariablesController do
         expect(response).to have_gitlab_http_status(:ok)
       end
     end
+
+    context 'with a deleted variable' do
+      subject do
+        post :save_multiple,
+          namespace_id: project.namespace.to_param, project_id: project,
+          variables: [{ key: variable.key, value: variable.value, _destroy: 'true' }],
+          format: :json
+      end
+
+      it 'destroys the variable' do
+        expect { subject }.to change { project.variables.count }.by(-1)
+        expect { variable.reload }.to raise_error ActiveRecord::RecordNotFound
+      end
+
+      it 'returns a successful response' do
+        subject
+
+        expect(response).to have_gitlab_http_status(:ok)
+      end
+    end
   end
 end