Add undo to activity in history

app/assets/stylesheets/history.sass

@@ -9,3 +9,9 @@
 
 .no-activities
   @extend .text-center
+
+.activity-card
+  display: flex
+
+.activity-text
+  flex: 1

app/controllers/activities_controller.rb

@@ -11,6 +11,15 @@ def create
     end
   end
 
+  def destroy
+    activity = Activity.find(params[:id])
+    if activity.destroy
+      redirect_to dashboard_path, notice: "Undone #{activity.name} successfully"
+    else
+      redirect_to dashboard_path, alert: activity.errors.full_messages.join(', ')
+    end
+  end
+
   private
 
   def activity_params

app/views/dashboard/_history.html.slim

@@ -2,9 +2,12 @@
   - if @activities.empty?
     .no-activities There is nothing done yet. Try sumbitting done activity.
   - @activities.each do |activity|
-    .activity.card.card-inverse.card-info
-		  .card-block
-		    .card-text
-		      = "#{activity.user.name} has done "
-		      em = "\"#{activity.name}\" "
-		      = activity_time_tag(activity.created_at)
+    .activity.card.card-inverse.card-info class="activity_#{activity.id}"
+      .card-block
+        .activity-card.card-text
+          .activity-text
+            = "#{activity.user.name} has done "
+            em = "\"#{activity.name}\" "
+            = activity_time_tag(activity.created_at)
+          .activity-undo
+            = button_to 'Undo', activity_path(id: activity.id), method: :delete, class: 'btn btn-warning btn-sm form-inline'

spec/features/dashboard_spec.rb

@@ -3,6 +3,7 @@
   let(:user) { room.users.first }
   let!(:room_activity) { create :room_activity, room: room }
   let(:room_activity_name) { room_activity.name }
+  let(:undone_activity) { room.activities.last }
 
   background do
     sign_in user
@@ -23,4 +24,14 @@
       expect(page).to have_content "#{user.name} has done \"#{room_activity.name}\""
     end
   end
+
+  scenario 'User undoes activity' do
+    click_on 'History'
+
+    expect {
+      within ".activity_#{undone_activity.id}" do
+        click_button 'Undo'
+      end
+    }.to change { Activity.count }.by(-1)
+  end
 end