Navigation bar issuables counters reflects dashboard issuables counters

app/helpers/issuables_helper.rb

@@ -141,8 +141,19 @@ module IssuablesHelper
     html.html_safe
   end
 
+  def cached_assigned_issuables_count(assignee, issuable_type, state)
+    cache_key = "#{assignee.id}_#{issuable_type}_#{state}"
+    Rails.cache.fetch(cache_key, expires_in: 2.minutes) do
+      assigned_issuables_count(assignee, issuable_type, state)
+    end
+  end
+
   private
 
+  def assigned_issuables_count(assignee, issuable_type, state)
+    assignee.send("assigned_#{issuable_type}").send(state).count
+  end
+
   def sidebar_gutter_collapsed?
     cookies[:collapsed_gutter] == 'true'
   end

app/views/layouts/nav/_dashboard.html.haml

@@ -26,12 +26,12 @@
       = link_to assigned_issues_dashboard_path, title: 'Issues', class: 'dashboard-shortcuts-issues' do
         %span
           Issues
-          %span.count= number_with_delimiter(current_user.assigned_issues.opened.count)
+          %span.count= number_with_delimiter(cached_assigned_issuables_count(current_user, :issues, :opened))
     = nav_link(path: 'dashboard#merge_requests') do
       = link_to assigned_mrs_dashboard_path, title: 'Merge Requests', class: 'dashboard-shortcuts-merge_requests' do
         %span
           Merge Requests
-          %span.count= number_with_delimiter(current_user.assigned_merge_requests.opened.count)
+          %span.count= number_with_delimiter(cached_assigned_issuables_count(current_user, :merge_requests, :opened))
     = nav_link(controller: 'dashboard/snippets') do
       = link_to dashboard_snippets_path, title: 'Snippets' do
         %span

changelogs/unreleased/fix_navigation_bar_issuables_counters.yml

+---
+title: Navigation bar issuables counters reflects dashboard issuables counters
+merge_request: 
+author: Lucas Deschamps

spec/features/dashboard/issuables_counter_spec.rb

+require 'spec_helper'
+
+describe 'Navigation bar counter', feature: true, js: true, caching: true do
+  let(:user) { create(:user) }
+  let(:project) { create(:project, namespace: user.namespace) }
+
+  before do
+    login_as(user)
+    visit issues_dashboard_path
+  end
+
+  it 'reflects dashboard issues count' do
+    create(:issue, project: project, assignee: user)
+    visit issues_dashboard_path
+
+    dashboard_count = find('li.active span.badge')
+    nav_count = find('.dashboard-shortcuts-issues span.count')
+
+    expect(dashboard_count).to have_content('0')
+    expect(nav_count).to have_content('0')
+  end
+
+  it 'reflects dashboard merge requests count' do
+    create(:merge_request, assignee: user)
+    visit merge_requests_dashboard_path
+
+    dashboard_count = find('li.active span.badge')
+    nav_count = find('.dashboard-shortcuts-merge_requests span.count')
+
+    expect(dashboard_count).to have_content('0')
+    expect(nav_count).to have_content('0')
+  end
+end