Change UX to transform from fields_to_hide to fields_to_show

Fill `params[:fields_to_show]` with its default value

app/controllers/admin/reports_controller.rb

@@ -46,6 +46,7 @@ module Admin
 
       # Initialize data
       params[:display_summary_row] = true if request.get?
+      params[:fields_to_show] = @report.columns.keys if request.get?
 
       @data = Reporting::FrontendData.new(spree_current_user)
     end

app/views/admin/reports/_rendering_options.html.haml

@@ -19,9 +19,9 @@
 
 - if @report.available_headers.present?
   .row
-    .alpha.two.columns= label_tag nil, t(:report_hide_columns)
+    .alpha.two.columns= label_tag nil, t(:report_columns)
     .omega.fourteen.columns
-      = select_tag(:fields_to_hide, options_for_select(@report.available_headers, params[:fields_to_hide]),
+      = select_tag(:fields_to_show, options_for_select(@report.available_headers, params[:fields_to_show]),
                   class: "select2 fullwidth", multiple: true)
 
 .row.rendering-options

config/locales/en.yml

@@ -2625,7 +2625,7 @@ See the %{link} to find out more about %{sitename}'s features and to start using
   report_payment_totals: 'Payment Totals'
   report_all: 'all'
   report_order_cycle: "Order Cycle"
-  report_hide_columns: Columns to Hide
+  report_columns: Columns
   report_enterprises: "Enterprises"
   report_enterprise_fee: "Fees Names"
   report_users: "Users"

spec/controllers/admin/reports_controller_spec.rb

@@ -250,6 +250,7 @@ describe Admin::ReportsController, type: :controller do
         .and_return(report = double(:report))
       allow(report).to receive(:table_headers).and_return []
       allow(report).to receive(:table_rows).and_return []
+      allow(report).to receive(:columns).and_return({})
       spree_get :show, report_type: :products_and_inventory, test: "foo"
       expect(assigns(:report)).to eq(report)
     end
@@ -300,6 +301,7 @@ describe Admin::ReportsController, type: :controller do
         .and_return(report = double(:report))
       allow(report).to receive(:table_headers).and_return []
       allow(report).to receive(:table_rows).and_return []
+      allow(report).to receive(:columns).and_return({})
       spree_get :show, report_type: :customers, test: "foo"
       expect(assigns(:report)).to eq(report)
     end