Extract setting icon and direction to methods

app/helpers/budget_investments_helper.rb

@@ -5,13 +5,10 @@ module BudgetInvestmentsHelper
 
   def link_to_investments_sorted_by(column)
     sort_by = column.downcase
-    default_direction = "desc"
     current_direction = params[:direction].downcase if params[:direction]
 
-    direction = current_direction == default_direction ? "asc" : default_direction
-
-    icon = direction == default_direction ? "icon-arrow-top" : "icon-arrow-down"
-    icon = sort_by == params[:sort_by] ? icon : ""
+    direction = set_direction(current_direction)
+    icon = set_sorting_icon(direction, sort_by)
 
     translation = t("admin.budget_investments.index.sort_by.#{sort_by}")
 
@@ -21,6 +18,15 @@ module BudgetInvestmentsHelper
     )
   end
 
+  def set_sorting_icon(direction, sort_by)
+    icon = direction == "desc" ? "icon-arrow-top" : "icon-arrow-down"
+    icon = sort_by == params[:sort_by] ? icon : ""
+  end
+
+  def set_direction(current_direction)
+    current_direction == "desc" ? "asc" : "desc"
+  end
+
   def investments_minimal_view_path
     budget_investments_path(id: @heading.group.to_param,
                             heading_id: @heading.to_param,

spec/helpers/budget_investments_helper_spec.rb

@@ -0,0 +1,47 @@
+require 'rails_helper'
+
+RSpec.describe BudgetInvestmentsHelper, type: :helper do
+
+  describe "#set_direction" do
+
+    it "returns ASC if current_direction is DESC" do
+      expect(set_direction("desc")).to eq "asc"
+    end
+
+    it "returns DESC if current_direction is ASC" do
+      expect(set_direction("asc")).to eq "desc"
+    end
+
+    it "returns DESC if current_direction is nil" do
+      expect(set_direction(nil)).to eq "desc"
+    end
+  end
+
+  describe "#set_sorting_icon" do
+    let(:sort_by) { "title" }
+    let(:params)  { { sort_by: sort_by } }
+
+    it "returns arrow down if current direction is ASC" do
+      expect(set_sorting_icon("asc", sort_by)).to eq "icon-arrow-down"
+    end
+
+    it "returns arrow top if current direction is DESC" do
+      expect(set_sorting_icon("desc", sort_by)).to eq "icon-arrow-top"
+    end
+
+    it "returns arrow down if sort_by present, but no direction" do
+      expect(set_sorting_icon(nil, sort_by)).to eq "icon-arrow-down"
+    end
+
+    it "returns no icon if sort_by and direction is missing" do
+      params[:sort_by] = nil
+      expect(set_sorting_icon(nil, sort_by)).to eq ""
+    end
+
+    it "returns no icon if sort_by is incorrect" do
+      params[:sort_by] = "random"
+      expect(set_sorting_icon("asc", sort_by)).to eq ""
+    end
+  end
+
+end