Marks pending tasks for an user as done when he edit an issue

app/services/issuable_base_service.rb

@@ -54,7 +54,7 @@ class IssuableBaseService < BaseService
     if params.present? && issuable.update_attributes(params.merge(updated_by: current_user))
       issuable.reset_events_cache
       handle_common_system_notes(issuable, old_labels: old_labels)
-      handle_changes(issuable)
+      handle_changes(issuable, old_labels: old_labels)
       issuable.create_new_cross_references!(current_user)
       execute_hooks(issuable, 'update')
     end

app/services/issues/update_service.rb

@@ -4,7 +4,11 @@ module Issues
       update(issue)
     end
 
-    def handle_changes(issue)
+    def handle_changes(issue, options = {})
+      if have_changes?(issue, options)
+        task_service.mark_as_done(issue, current_user)
+      end
+
       if issue.previous_changes.include?('milestone_id')
         create_milestone_note(issue)
       end
@@ -23,5 +27,22 @@ module Issues
     def close_service
       Issues::CloseService
     end
+
+    private
+
+    def have_changes?(issue, options = {})
+      valid_attrs = [:title, :description, :assignee_id, :milestone_id]
+
+      attrs_changed = valid_attrs.any? do |attr|
+        issue.previous_changes.include?(attr.to_s)
+      end
+
+      old_labels = options[:old_labels]
+      labels_changed = old_labels && issue.labels != old_labels
+
+      if attrs_changed || labels_changed
+        task_service.mark_as_done(issue, current_user)
+      end
+    end
   end
 end

app/services/merge_requests/update_service.rb

@@ -14,7 +14,7 @@ module MergeRequests
       update(merge_request)
     end
 
-    def handle_changes(merge_request)
+    def handle_changes(merge_request, options = {})
       if merge_request.previous_changes.include?('target_branch')
         create_branch_change_note(merge_request, 'target',
                                   merge_request.previous_changes['target_branch'].first,

app/services/task_service.rb

@@ -26,6 +26,15 @@ class TaskService
     end
   end
 
+  # When we mark a task as done we should:
+  #
+  #  * mark all pending tasks related to the target for the user as done
+  #
+  def mark_as_done(target, user)
+    pending_tasks = pending_tasks_for(user, target.project, target)
+    pending_tasks.update_all(state: :done)
+  end
+
   private
 
   def create_task(project, target, author, user, action)
@@ -40,4 +49,8 @@ class TaskService
 
     Task.create(attributes)
   end
+
+  def pending_tasks_for(user, project, target)
+    user.tasks.pending.where(project: project, target: target)
+  end
 end

spec/factories/tasks.rb

@@ -19,5 +19,15 @@ FactoryGirl.define do
     project
     author
     user
+
+    factory :pending_assigned_task, traits: [:assgined, :pending]
+
+    trait :assgined do
+      action { Task::ASSIGNED }
+    end
+
+    trait :pending do
+      state { :pending }
+    end
   end
 end

spec/services/issues/update_service_spec.rb

@@ -78,8 +78,43 @@ describe Issues::UpdateService, services: true do
         expect(note).not_to be_nil
         expect(note.note).to eq 'Title changed from **Old title** to **New title**'
       end
+    end
+
+    context 'task queue' do
+      let!(:pending_task) do
+        create(:pending_assigned_task, user: user, project: project, target: issue, author: user2)
+      end
+
+      context 'when the title change' do
+        before do
+          update_issue({ title: 'New title' })
+        end
+
+        it 'marks pending tasks as done' do
+          expect(pending_task.reload.done?).to eq true
+        end
+      end
+
+      context 'when the description change' do
+        before do
+          update_issue({ description: 'Also please fix' })
+        end
+
+        it 'marks pending tasks as done' do
+          expect(pending_task.reload.done?).to eq true
+        end
+      end
+
+      context 'when is reassigned' do
+        before do
+          update_issue({ assignee: user2 })
+        end
+
+        it 'marks previous assignee pending tasks as done' do
+          expect(pending_task.reload.done?).to eq true
+        end
 
-      it 'creates a pending task if being reassigned' do
+        it 'creates a pending task for new assignee' do
           attributes = {
             project: project,
             author: user,
@@ -93,6 +128,27 @@ describe Issues::UpdateService, services: true do
         end
       end
 
+      context 'when the milestone change' do
+        before do
+          update_issue({ milestone: create(:milestone) })
+        end
+
+        it 'marks pending tasks as done' do
+          expect(pending_task.reload.done?).to eq true
+        end
+      end
+
+      context 'when the labels change' do
+        before do
+          update_issue({ label_ids: [label.id] })
+        end
+
+        it 'marks pending tasks as done' do
+          expect(pending_task.reload.done?).to eq true
+        end
+      end
+    end
+
     context 'when Issue has tasks' do
       before { update_issue({ description: "- [ ] Task 1\n- [ ] Task 2" }) }
 
@@ -157,6 +213,5 @@ describe Issues::UpdateService, services: true do
         end
       end
     end
-
   end
 end

spec/services/task_service_spec.rb

@@ -45,6 +45,23 @@ describe TaskService, services: true do
         is_expected_to_not_create_task { service.reassigned_issue(assigned_issue, author) }
       end
     end
+
+    describe '#mark_as_done' do
+      let!(:first_pending_task) do
+        create(:pending_assigned_task, user: john_doe, project: project, target: assigned_issue, author: author)
+      end
+
+      let!(:second_pending_task) do
+        create(:pending_assigned_task, user: john_doe, project: project, target: assigned_issue, author: author)
+      end
+
+      it 'marks related pending tasks to the target for the user as done' do
+        service.mark_as_done(assigned_issue, john_doe)
+
+        expect(first_pending_task.reload.done?).to eq true
+        expect(second_pending_task.reload.done?).to eq true
+      end
+    end
   end
 
   def is_expected_to_create_pending_task(attributes = {})