1 files changed, 4 insertions, 4 deletions
diff --git a/lib/axlsx/workbook/worksheet/worksheet.rb b/lib/axlsx/workbook/worksheet/worksheet.rb
index 90461c66..29a22db1 100644
--- a/lib/axlsx/workbook/worksheet/worksheet.rb
+++ b/lib/axlsx/workbook/worksheet/worksheet.rb
@@ -584,7 +584,7 @@ module Axlsx
     # @param [String|Array] cell_refs Cell references
     # @param [Hash] styles
     def add_style(cell_refs, *styles)
-      if !cell_refs.is_a?(Array)
+      unless cell_refs.is_a?(Array)
         cell_refs = [cell_refs]
       end
 
@@ -613,7 +613,7 @@ module Axlsx
         border_edges = options
       end
 
-      if !cell_refs.is_a?(Array)
+      unless cell_refs.is_a?(Array)
         cell_refs = [cell_refs]
       end
 
@@ -753,7 +753,7 @@ module Axlsx
     def validate_sheet_name(name)
       DataTypeValidator.validate :worksheet_name, String, name
       # ignore first character (BOM) after encoding to utf16 because Excel does so, too.
-      raise ArgumentError, (ERR_SHEET_NAME_EMPTY) if name.empty?
+      raise ArgumentError, ERR_SHEET_NAME_EMPTY if name.empty?
 
       character_length = name.encode("utf-16")[1..-1].encode("utf-16").bytesize / 2
       raise ArgumentError, (ERR_SHEET_NAME_TOO_LONG % name) if character_length > WORKSHEET_MAX_NAME_LENGTH
@@ -850,7 +850,7 @@ module Axlsx
     end
 
     def add_autofilter_defined_name_to_workbook
-      return if !auto_filter.range
+      return unless auto_filter.range
 
       workbook.add_defined_name auto_filter.defined_name, name: '_xlnm._FilterDatabase', local_sheet_id: index, hidden: 1
     end