Recover usage of Todos counter cache20842-todos-queries-cache

We’re being kept up to date the counter data but we’re not using it.
The only thing which is not real if is the number of projects that the 
user read changes the number of todos can be stale for some time.

The counters will be sync just after the user receives a new todo or mark any as done

5 files changed, 44 insertions, 9 deletions

diff --git a/app/controllers/dashboard/todos_controller.rb b/app/controllers/dashboard/todos_controller.rb
index 19a76a5b5d8..1243bb96d4d 100644
--- a/app/controllers/dashboard/todos_controller.rb
+++ b/app/controllers/dashboard/todos_controller.rb
@@ -37,8 +37,8 @@ class Dashboard::TodosController < Dashboard::ApplicationController
 
   def todos_counts
     {
-      count: TodosFinder.new(current_user, state: :pending).execute.count,
-      done_count: TodosFinder.new(current_user, state: :done).execute.count
+      count: current_user.todos_pending_count,
+      done_count: current_user.todos_done_count
     }
   end
 end
diff --git a/app/helpers/todos_helper.rb b/app/helpers/todos_helper.rb
index e3a208f826a..0465327060e 100644
--- a/app/helpers/todos_helper.rb
+++ b/app/helpers/todos_helper.rb
@@ -1,10 +1,10 @@
 module TodosHelper
   def todos_pending_count
-    @todos_pending_count ||= TodosFinder.new(current_user, state: :pending).execute.count
+    @todos_pending_count ||= current_user.todos_pending_count
   end
 
   def todos_done_count
-    @todos_done_count ||= TodosFinder.new(current_user, state: :done).execute.count
+    @todos_done_count ||= current_user.todos_done_count
   end
 
   def todo_action_name(todo)
diff --git a/app/services/todo_service.rb b/app/services/todo_service.rb
index 6b48d68cccb..eb833dd82ac 100644
--- a/app/services/todo_service.rb
+++ b/app/services/todo_service.rb
@@ -144,8 +144,9 @@ class TodoService
   def mark_todos_as_done(todos, current_user)
     todos = current_user.todos.where(id: todos.map(&:id)) unless todos.respond_to?(:update_all)
 
-    todos.update_all(state: :done)
+    marked_todos = todos.update_all(state: :done)
     current_user.update_todos_count_cache
+    marked_todos
   end
 
   # When user marks an issue as todo
diff --git a/lib/api/todos.rb b/lib/api/todos.rb
index a90a667fafe..19df13d8aac 100644
--- a/lib/api/todos.rb
+++ b/lib/api/todos.rb
@@ -61,9 +61,9 @@ module API
       #
       delete ':id' do
         todo = current_user.todos.find(params[:id])
-        todo.done
+        TodoService.new.mark_todos_as_done([todo], current_user)
 
-        present todo, with: Entities::Todo, current_user: current_user
+        present todo.reload, with: Entities::Todo, current_user: current_user
       end
 
       # Mark all todos as done
@@ -74,8 +74,6 @@ module API
       delete do
         todos = find_todos
         TodoService.new.mark_todos_as_done(todos, current_user)
-
-        todos.length
       end
     end
   end
diff --git a/spec/services/todo_service_spec.rb b/spec/services/todo_service_spec.rb
index 34d8ea9090e..6c3cbeae13c 100644
--- a/spec/services/todo_service_spec.rb
+++ b/spec/services/todo_service_spec.rb
@@ -472,6 +472,42 @@ describe TodoService, services: true do
     expect(john_doe.todos_pending_count).to eq(1)
   end
 
+  describe '#mark_todos_as_done' do
+    let(:issue) { create(:issue, project: project, author: author, assignee: john_doe) }
+
+    it 'marks a relation of todos as done' do
+      create(:todo, :mentioned, user: john_doe, target: issue, project: project)
+
+      todos = TodosFinder.new(john_doe, {}).execute
+      expect { TodoService.new.mark_todos_as_done(todos, john_doe) }
+       .to change { john_doe.todos.done.count }.from(0).to(1)
+    end
+
+    it 'marks an array of todos as done' do
+      todo = create(:todo, :mentioned, user: john_doe, target: issue, project: project)
+
+      expect { TodoService.new.mark_todos_as_done([todo], john_doe) }
+        .to change { todo.reload.state }.from('pending').to('done')
+    end
+
+    it 'returns the number of updated todos' do # Needed on API
+      todo = create(:todo, :mentioned, user: john_doe, target: issue, project: project)
+
+      expect(TodoService.new.mark_todos_as_done([todo], john_doe)).to eq(1)
+    end
+
+    it 'caches the number of todos of a user', :caching do
+      create(:todo, :mentioned, user: john_doe, target: issue, project: project)
+      todo = create(:todo, :mentioned, user: john_doe, target: issue, project: project)
+      TodoService.new.mark_todos_as_done([todo], john_doe)
+
+      expect_any_instance_of(TodosFinder).not_to receive(:execute)
+
+      expect(john_doe.todos_done_count).to eq(1)
+      expect(john_doe.todos_pending_count).to eq(1)
+    end
+  end
+
   def should_create_todo(attributes = {})
     attributes.reverse_merge!(
       project: project,