Remove unnecessary query from labels filter

app/finders/labels_finder.rb

@@ -71,7 +71,7 @@ class LabelsFinder < UnionFinder
   end
 
   def projects?
-    params[:project_ids].present?
+    params[:project_ids]
   end
 
   def only_group_labels?

app/helpers/issuables_helper.rb

@@ -304,6 +304,12 @@ module IssuablesHelper
     issuable.model_name.human.downcase
   end
 
+  def selected_labels
+    Array(params[:label_name]).map do |label_name|
+      Label.new(title: label_name)
+    end
+  end
+
   private
 
   def sidebar_gutter_collapsed?

app/views/shared/issuable/_filter.html.haml

@@ -22,7 +22,7 @@
           = render "shared/issuable/milestone_dropdown", selected: finder.milestones.try(:first), name: :milestone_title, show_any: true, show_upcoming: true, show_started: true
 
         .filter-item.inline.labels-filter
-          = render "shared/issuable/label_dropdown", selected: finder.labels.select(:title).uniq, use_id: false, selected_toggle: params[:label_name], data_options: { field_name: "label_name[]" }
+          = render "shared/issuable/label_dropdown", selected: selected_labels, use_id: false, selected_toggle: params[:label_name], data_options: { field_name: "label_name[]" }
 
         - if issuable_filter_present?
           .filter-item.inline.reset-filters

changelogs/unreleased/issue_37143_2.yml

+---
+title: Remove unecessary query from labels filter
+merge_request:
+author:
+type: performance

spec/helpers/issuables_helper_spec.rb

@@ -192,4 +192,33 @@ describe IssuablesHelper do
       expect(JSON.parse(helper.issuable_initial_data(issue))).to eq(expected_data)
     end
   end
+
+  describe '#selected_labels' do
+    context 'if label_name param is a string' do
+      it 'returns a new label with title' do
+        allow(helper).to receive(:params)
+          .and_return(ActionController::Parameters.new(label_name: 'test label'))
+
+        labels = helper.selected_labels
+
+        expect(labels).to be_an(Array)
+        expect(labels.size).to eq(1)
+        expect(labels.first.title).to eq('test label')
+      end
+    end
+
+    context 'if label_name param is an array' do
+      it 'returns a new label with title for each element' do
+        allow(helper).to receive(:params)
+          .and_return(ActionController::Parameters.new(label_name: ['test label 1', 'test label 2']))
+
+        labels = helper.selected_labels
+
+        expect(labels).to be_an(Array)
+        expect(labels.size).to eq(2)
+        expect(labels.first.title).to eq('test label 1')
+        expect(labels.second.title).to eq('test label 2')
+      end
+    end
+  end
 end