Fix Style/FormatString offenses

`Kernel#format` is faster and will avoid to allocate an array compared
to `String#%`.

```
IPS:
       kernel_format:  3877614.2 i/s
      string_percent:  3531475.0 i/s - 1.10x  (± 0.00) slower

Memory:
       kernel_format:        160 allocated
      string_percent:        200 allocated - 1.25x more
```

8 files changed, 17 insertions, 23 deletions

diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index 2359f950..67e59726 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -187,18 +187,6 @@ Style/ExpandPathArguments:
     - 'axlsx.gemspec'
 
 # This cop supports safe autocorrection (--autocorrect).
-# Configuration parameters: EnforcedStyle.
-# SupportedStyles: format, sprintf, percent
-Style/FormatString:
-  Exclude:
-    - 'lib/axlsx/drawing/pic.rb'
-    - 'lib/axlsx/drawing/view_3D.rb'
-    - 'lib/axlsx/drawing/vml_drawing.rb'
-    - 'lib/axlsx/util/accessors.rb'
-    - 'lib/axlsx/util/validators.rb'
-    - 'lib/axlsx/workbook/worksheet/worksheet.rb'
-
-# This cop supports safe autocorrection (--autocorrect).
 # Configuration parameters: MaxUnannotatedPlaceholdersAllowed, AllowedMethods, AllowedPatterns.
 # SupportedStyles: annotated, template, unannotated
 Style/FormatStringToken:
diff --git a/lib/axlsx/drawing/pic.rb b/lib/axlsx/drawing/pic.rb
index 150d6dc5..c9efb378 100644
--- a/lib/axlsx/drawing/pic.rb
+++ b/lib/axlsx/drawing/pic.rb
@@ -124,7 +124,7 @@ module Axlsx
     # The part name for this image used in serialization and relationship building
     # @return [String]
     def pn
-      "#{IMAGE_PN % [(index + 1), extname]}"
+      format(IMAGE_PN, index + 1, extname)
     end
 
     # The relationship object for this pic.
diff --git a/lib/axlsx/drawing/view_3D.rb b/lib/axlsx/drawing/view_3D.rb
index 9b3489a3..5b29b296 100644
--- a/lib/axlsx/drawing/view_3D.rb
+++ b/lib/axlsx/drawing/view_3D.rb
@@ -111,7 +111,7 @@ module Axlsx
       val = Axlsx.instance_values_for(self)[name]
       return "" if val.nil?
 
-      "<%s:%s val='%s'/>" % [namespace, Axlsx::camel(name, false), val]
+      format("<%s:%s val='%s'/>", namespace, Axlsx::camel(name, false), val)
     end
   end
 end
diff --git a/lib/axlsx/drawing/vml_drawing.rb b/lib/axlsx/drawing/vml_drawing.rb
index 364ce19a..15698486 100644
--- a/lib/axlsx/drawing/vml_drawing.rb
+++ b/lib/axlsx/drawing/vml_drawing.rb
@@ -14,7 +14,7 @@ module Axlsx
     # The part name for this vml drawing
     # @return [String]
     def pn
-      "#{VML_DRAWING_PN}" % (@comments.worksheet.index + 1)
+      VML_DRAWING_PN % (@comments.worksheet.index + 1)
     end
 
     # serialize the vml_drawing to xml.
diff --git a/lib/axlsx/util/accessors.rb b/lib/axlsx/util/accessors.rb
index d653e32f..dfc3b1cd 100644
--- a/lib/axlsx/util/accessors.rb
+++ b/lib/axlsx/util/accessors.rb
@@ -56,7 +56,7 @@ module Axlsx
         symbols.each do |symbol|
           attr_reader symbol
 
-          module_eval(SETTER % [symbol, validator, symbol], __FILE__, __LINE__)
+          module_eval(format(SETTER, symbol, validator, symbol), __FILE__, __LINE__)
         end
       end
     end
diff --git a/lib/axlsx/util/validators.rb b/lib/axlsx/util/validators.rb
index 48c12c13..1357f4f3 100644
--- a/lib/axlsx/util/validators.rb
+++ b/lib/axlsx/util/validators.rb
@@ -10,7 +10,7 @@ module Axlsx
     # @raise [ArgumentError] Raised if the value provided is not in the list of choices.
     # @return [Boolean] true if validation succeeds.
     def self.validate(name, choices, v)
-      raise ArgumentError, (ERR_RESTRICTION % [v.to_s, name, choices.inspect]) unless choices.include?(v)
+      raise ArgumentError, format(ERR_RESTRICTION, v.to_s, name, choices.inspect) unless choices.include?(v)
 
       true
     end
@@ -31,7 +31,7 @@ module Axlsx
                else
                  min < value && value < max
                end
-      raise ArgumentError, (ERR_RANGE % [value.inspect, min.to_s, max.to_s, inclusive]) unless passes
+      raise ArgumentError, format(ERR_RANGE, value.inspect, min.to_s, max.to_s, inclusive) unless passes
     end
   end
 
@@ -41,7 +41,7 @@ module Axlsx
     # @param [Regexp] regex The regular expression to evaluate
     # @param [Any] v The value to validate.
     def self.validate(name, regex, v)
-      raise ArgumentError, (ERR_REGEX % [v.inspect, regex.to_s]) unless v.respond_to?(:to_s) && regex.match?(v.to_s)
+      raise ArgumentError, format(ERR_REGEX, v.inspect, regex.to_s) unless v.respond_to?(:to_s) && regex.match?(v.to_s)
     end
   end
 
@@ -56,14 +56,14 @@ module Axlsx
     # @see validate_boolean
     def self.validate(name, types, v, other = false)
       if other.is_a?(Proc) && !other.call(v)
-        raise ArgumentError, (ERR_TYPE % [v.inspect, name, types.inspect])
+        raise ArgumentError, format(ERR_TYPE, v.inspect, name, types.inspect)
       end
 
       v_class = v.is_a?(Class) ? v : v.class
       Array(types).each do |t|
         return if v_class <= t
       end
-      raise ArgumentError, (ERR_TYPE % [v.inspect, name, types.inspect])
+      raise ArgumentError, format(ERR_TYPE, v.inspect, name, types.inspect)
     end
   end
 
diff --git a/lib/axlsx/workbook/worksheet/worksheet.rb b/lib/axlsx/workbook/worksheet/worksheet.rb
index 29a22db1..07221b3f 100644
--- a/lib/axlsx/workbook/worksheet/worksheet.rb
+++ b/lib/axlsx/workbook/worksheet/worksheet.rb
@@ -675,9 +675,9 @@ module Axlsx
         if parts.size > 2
           raise ArgumentError, (ERR_CELL_REFERENCE_INVALID % cell_def)
         elsif parts.first.nil?
-          raise ArgumentError, (ERR_CELL_REFERENCE_MISSING_CELL % [cell_def.split(":").first, cell_def])
+          raise ArgumentError, format(ERR_CELL_REFERENCE_MISSING_CELL, cell_def.split(":").first, cell_def)
         elsif parts.last.nil?
-          raise ArgumentError, (ERR_CELL_REFERENCE_MISSING_CELL % [cell_def.split(":").last, cell_def])
+          raise ArgumentError, format(ERR_CELL_REFERENCE_MISSING_CELL, cell_def.split(":").last, cell_def)
         end
 
         range(*parts)
diff --git a/test/drawing/tc_vml_drawing.rb b/test/drawing/tc_vml_drawing.rb
index fa939f56..e089457e 100644
--- a/test/drawing/tc_vml_drawing.rb
+++ b/test/drawing/tc_vml_drawing.rb
@@ -16,6 +16,12 @@ class TestVmlDrawing < Test::Unit::TestCase
     assert_raise(ArgumentError) { Axlsx::VmlDrawing.new }
   end
 
+  def test_pn
+    str = @vml_drawing.pn
+
+    assert_equal("drawings/vmlDrawing1.vml", str)
+  end
+
   def test_to_xml_string
     str = @vml_drawing.to_xml_string
     doc = Nokogiri::XML(str)