增加导出export的merge选项支持，如果相邻行相同，则合并该列各行单元格

lib/tallty_import_export/export.rb

@@ -81,11 +81,34 @@ module TalltyImportExport
 
         sheet.add_row headers.map{|header| header[:name]}, style: title2, height: 39
 
+        last_row = nil
+        merge_column_hash = {}
+        first_content_row_index = respond_to?(:first_header) ? 2 : 1
+
         each_method = records.is_a?(Array) ? :each : :each
         records.send(each_method).with_index do |record, index|
           row = []
-          headers.each{ |header| row.push(handle_data(record, header, index)) }
+          headers.each_with_index do |header, col_index|
+            _data = handle_data(record, header, index)
+            if header[:merge].present? && last_row.present? && _data == last_row[index]
+              merge_index = merge_column_hash[col_index] || []
+              merge_index << index + first_content_row_index
+              merge_index << index + first_content_row_index + 1
+            end
+            row.push(_data)
+          end
           sheet.add_row row, style: title3, height: @row_height, types: headers.map{|header| header[:format]&.to_sym}
+          last_row = row
+        end
+        # 需要根据column进行多行的内容合并
+        if merge_column_hash.present?
+          merge_column_hash.each do |col_index, row_arr|
+            split_arr(row_arr).each do |arr|
+              sheet.merge_cells(
+                Axlsx::cell_r(arr.first, col_index) + ':' + Axlsx::cell_r(arr.last, col_index)
+              )
+            end
+          end
         end
         sheet.column_widths(*headers.map{|header| header[:width] || @width})
       end
@@ -146,5 +169,28 @@ module TalltyImportExport
         data
       end
     end
+
+    private
+
+    def split_arr continuous_arr
+      continuous_arr.sort.each_with_index.reduce([]) do |arr, (i, _index)|
+        if arr.last.nil?
+          arr << i
+        elsif i - arr.last > 2
+          arr << nil
+          arr << i
+        else
+          if arr[-2].blank?
+            arr << i
+          elsif arr[-1] - arr[-2] == i - arr[-1]
+            arr << i
+          else
+            arr << nil
+            arr << i
+          end
+        end
+        arr
+      end.split
+    end
   end
 end