add aria-sort on sortable column

app/models/procedure_presentation.rb

@@ -340,6 +340,22 @@ class ProcedurePresentation < ApplicationRecord
     end
   end
 
+  def sortable?(field)
+    sort['table'] == field['table'] && sort['column'] == field['column']
+  end
+
+  def aria_sort(order, field)
+    if sortable?(field)
+      if order == 'asc'
+        { "aria-sort": "ascending" }
+      elsif order == 'desc'
+        { "aria-sort": "descending" }
+      end
+    else
+      {}
+    end
+  end
+
   private
 
   def field_id(field)

app/views/instructeurs/procedures/_header_field.html.haml

@@ -1,6 +1,7 @@
-%th{ class: classname }
+%th{ @procedure_presentation.aria_sort(@procedure_presentation.sort['order'], field), class: classname }
+
   = link_to update_sort_instructeur_procedure_path(@procedure, table: field['table'], column: field['column'], order: @procedure_presentation.opposite_order_for(field['table'], field['column'])) do
-    - if @procedure_presentation.sort['table'] == field['table'] && @procedure_presentation.sort['column'] == field['column']
+    - if @procedure_presentation.sortable?(field)
       - if @procedure_presentation.sort['order'] == 'asc'
         #{field['label']} ↑
       - else