Reintroduce Ruby 2.6 compatibility

The main reason is to allow JRuby 9.3, which is still supported.

5 files changed, 26 insertions, 10 deletions

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index f2c7a3d4..b63ec71d 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -18,11 +18,11 @@ jobs:
       fail-fast: false
       matrix:
         include:
+          - ruby: 2.6
           - ruby: 2.7
           - ruby: "3.0" ### must be quoted otherwise will be treated as "3" which resolves to latest 3.x version
           - ruby: 3.1
           - ruby: 3.2
-          - ruby: jruby-9.2
           - ruby: jruby-9.3
           - ruby: jruby-9.4
           - ruby: head
diff --git a/.rubocop.yml b/.rubocop.yml
index 95d93f14..32a50a30 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -4,7 +4,7 @@ AllCops:
   DisabledByDefault: true
   NewCops: enable
   SuggestExtensions: false
-  TargetRubyVersion: 2.7
+  TargetRubyVersion: 2.6
   Exclude:
     - 'docs/**/*'
     - 'examples/**/*'
diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index 59777b4c..67848b74 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -1,6 +1,6 @@
 # This configuration was generated by
 # `rubocop --auto-gen-config --no-offense-counts --no-auto-gen-timestamp`
-# using RuboCop version 1.50.0.
+# using RuboCop version 1.50.2.
 # The point is for the user to remove these configuration records
 # one by one as the offenses are removed from the code base.
 # Note that changes in the inspected code, or installation of new
@@ -65,11 +65,6 @@ Style/CaseLikeIf:
     - 'lib/axlsx/workbook/worksheet/merged_cells.rb'
 
 # This cop supports safe autocorrection (--autocorrect).
-Style/CharacterLiteral:
-  Exclude:
-    - 'lib/axlsx/workbook/worksheet/cell.rb'
-
-# This cop supports safe autocorrection (--autocorrect).
 # Configuration parameters: EnforcedStyle.
 # SupportedStyles: is_a?, kind_of?
 Style/ClassCheck:
@@ -246,6 +241,12 @@ Style/HashEachMethods:
 Style/HashSyntax:
   Enabled: false
 
+# This cop supports unsafe autocorrection (--autocorrect-all).
+Style/HashTransformKeys:
+  Exclude:
+    - 'lib/axlsx/workbook/worksheet/cell_serializer.rb'
+    - 'lib/axlsx/workbook/worksheet/rich_text_run.rb'
+
 # This cop supports safe autocorrection (--autocorrect).
 # Configuration parameters: AllowIfModifier.
 Style/IfInsideElse:
@@ -603,6 +604,16 @@ Style/Semicolon:
 Style/SingleLineMethods:
   Enabled: false
 
+# This cop supports unsafe autocorrection (--autocorrect-all).
+Style/SlicingWithRange:
+  Exclude:
+    - 'lib/axlsx.rb'
+    - 'lib/axlsx/drawing/area_chart.rb'
+    - 'lib/axlsx/drawing/line_chart.rb'
+    - 'lib/axlsx/util/simple_typed_list.rb'
+    - 'lib/axlsx/workbook/worksheet/pivot_table.rb'
+    - 'lib/axlsx/workbook/worksheet/worksheet.rb'
+
 # This cop supports safe autocorrection (--autocorrect).
 # Configuration parameters: AllowModifier.
 Style/SoleNestedConditional:
@@ -696,6 +707,11 @@ Style/TrivialAccessors:
     - 'lib/axlsx/workbook/worksheet/worksheet_hyperlink.rb'
 
 # This cop supports safe autocorrection (--autocorrect).
+Style/UnpackFirst:
+  Exclude:
+    - 'lib/axlsx/workbook/worksheet/sheet_protection.rb'
+
+# This cop supports safe autocorrection (--autocorrect).
 Style/WhileUntilDo:
   Exclude:
     - 'lib/axlsx.rb'
diff --git a/CHANGELOG.md b/CHANGELOG.md
index adf5206d..ec38447e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,7 +1,7 @@
 CHANGELOG
 ---------
 - **Unreleased**: 4.0.0
-  - Drop support for Ruby versions < 2.7
+  - Drop support for Ruby versions < 2.6
 
 - **April.23.23**: 3.4.1
   - [PR #209](https://github.com/caxlsx/caxlsx/pull/209) - Revert characters other than `=` being considered as formulas.
diff --git a/axlsx.gemspec b/axlsx.gemspec
index 369413ce..a15f4129 100644
--- a/axlsx.gemspec
+++ b/axlsx.gemspec
@@ -22,6 +22,6 @@ Gem::Specification.new do |s|
   s.add_development_dependency 'yard', "~> 0.9.8"
   s.add_development_dependency 'kramdown', '~> 2.3'
   s.add_development_dependency 'timecop', "~> 0.9.0"
-  s.required_ruby_version = '>= 2.7'
+  s.required_ruby_version = '>= 2.6'
   s.require_path = 'lib'
 end