Drop support for Ruby 2.3

Ruby 2.3 reached EOL on March 31, 2019:
https://www.ruby-lang.org/en/news/2019/03/31/support-of-ruby-2-3-has-ended/

While here, run a RuboCop auto-correct as we're now requiring Ruby 2.4+.

.rubocop.yml

@@ -1,6 +1,6 @@
 AllCops:
   DisplayCopNames: true
-  TargetRubyVersion: 2.3 # Oldest version of Ruby we support
+  TargetRubyVersion: 2.4 # Oldest version of Ruby we support
 
 AccessModifierIndentation:
   EnforcedStyle: outdent

.travis.yml

@@ -11,11 +11,9 @@ env:
     - "JRUBY_OPTS=--dev"
 
 rvm:
-  - 2.3.8
-  - 2.4.5
+  - 2.4.6
   - 2.5.5
-  - 2.6.2
-  - jruby-9.1.17.0
+  - 2.6.3
   - jruby-9.2.6.0
 
 before_install:

CHANGELOG.md

@@ -1,5 +1,9 @@
 # SCSS-Lint Changelog
 
+## master (unreleased)
+
+* Drop support for Ruby 2.3 or older
+
 ## 0.57.1
 
 * Relax Sass gem dependency to allow 3.6.x

README.md

@@ -51,7 +51,7 @@ support on the issue tracker.
 
 ## Requirements
 
-* Ruby 2.3+
+* Ruby 2.4+
 * Sass 3.5.5+
 * Files you wish to lint must be written in SCSS (not Sass) syntax
 

lib/scss_lint/linter/chained_classes.rb

@@ -6,7 +6,7 @@ class Linter::ChainedClasses < Linter
     def visit_sequence(sequence)
       line_offset = 0
       sequence.members.each do |member|
-        line_offset += 1 if member =~ /\n/
+        line_offset += 1 if member =~ /\n/ # rubocop:disable Performance/RegexpMatch
         next unless chained_class?(member)
         add_lint(member.line + line_offset,
                  'Prefer using a distinct class over chained classes ' \

lib/scss_lint/linter/disable_linter_reason.rb

@@ -7,7 +7,7 @@ def visit_comment(node)
       # No lint if the first line of the comment is not a command (because then
       # either this comment has no commands, or the first line serves as a the
       # reason for a command on a later line).
-      if comment_lines(node).first.match(COMMAND_REGEX)
+      if comment_lines(node).first.match?(COMMAND_REGEX)
         visit_command_comment(node)
       else
         @previous_comment = node
@@ -21,7 +21,7 @@ def visit_command_comment(node)
       end
 
       # Not a "disable linter reason" if the last line of the previous comment is a command.
-      if comment_lines(@previous_comment).last.match(COMMAND_REGEX)
+      if comment_lines(@previous_comment).last.match?(COMMAND_REGEX)
         report_lint(node)
         return
       end

lib/scss_lint/linter/hex_validation.rb

@@ -16,7 +16,7 @@ def visit_script_string(node)
     HEX_REGEX = /(#(\h{3}|\h{6}|\h{8}))(?!\h)/
 
     def check_hex(hex, node)
-      return if HEX_REGEX.match(hex)
+      return if HEX_REGEX.match?(hex)
       add_lint(node, "Colors must have either three or six digits: `#{hex}`")
     end
   end

lib/scss_lint/linter/indentation.rb

@@ -98,7 +98,7 @@ def visit_atroot(node, &block)
 
     def visit_import(node)
       previous_node(node)
-      return unless engine.lines[node.line - 1] =~ /@import/
+      return unless engine.lines[node.line - 1].match?(/@import/)
       check_indentation(node)
     end
 

lib/scss_lint/linter/space_around_operator.rb

@@ -13,7 +13,7 @@ def visit_script_operation(node)
       # (only selectors?), the source ranges are offset by two (probably not
       # accounting for the `#{`. Slide everything to the left by 2, and maybe
       # things will look sane this time.
-      unless operation_sources.operator_source =~ Sass::Script::Lexer::REGULAR_EXPRESSIONS[:op]
+      unless operation_sources.operator_source.match?(Sass::Script::Lexer::REGULAR_EXPRESSIONS[:op])
         operation_sources.adjust_for_interpolation
         operation_sources.adjust_sources
       end

lib/scss_lint/linter/space_between_parens.rb

@@ -90,7 +90,7 @@ def feel_for_enclosing_parens(node) # rubocop:disable Metrics/AbcSize, Metrics/C
       # those parens may be part of a parent function call. We don't care about
       # such parens. This depends on whether the preceding character is part of
       # a function name.
-      return original_source if character_at(range.start_pos, left_offset - 1) =~ /[A-Za-z0-9_]/
+      return original_source if character_at(range.start_pos, left_offset - 1).match?(/[A-Za-z0-9_]/)
 
       range.start_pos.offset += left_offset
       range.end_pos.offset += right_offset

lib/scss_lint/linter/string_quotes.rb

@@ -66,7 +66,7 @@ def check_single_quotes(node, string)
         if string =~ /(?<! \\) \\'/x && string !~ /"/
           add_lint(node, 'Use double-quoted strings when writing single ' \
                          'quotes to avoid having to escape the single quotes')
-        elsif string =~ /(?<! \\) \\"/x
+        elsif string.match?(/(?<! \\) \\"/x)
           add_lint(node, "Don't escape double quotes in single-quoted strings")
         end
       elsif string !~ /"/

lib/scss_lint/linter/trailing_semicolon.rb

@@ -45,7 +45,7 @@ def visit_mixin(node)
 
     def visit_import(node)
       # Ignore all but the last import for comma-separated @imports
-      return if source_from_range(node.source_range) =~ /,\s*$/
+      return if source_from_range(node.source_range).match?(/,\s*$/)
       check_semicolon(node)
     end
 

lib/scss_lint/linter/trailing_whitespace.rb

@@ -5,7 +5,7 @@ class Linter::TrailingWhitespace < Linter
 
     def visit_root(_node)
       engine.lines.each_with_index do |line, index|
-        next unless line =~ /[ \t]+$/
+        next unless line.match?(/[ \t]+$/)
 
         add_lint(index + 1, 'Line contains trailing whitespace')
       end

lib/scss_lint/linter/unnecessary_mantissa.rb

@@ -8,7 +8,7 @@ class Linter::UnnecessaryMantissa < Linter
 
     def visit_script_string(node)
       return unless node.type == :identifier
-      return if node.value =~ /^'|"/
+      return if node.value.match?(/^'|"/)
       return if url_literal?(node)
 
       node.value.scan(REAL_NUMBER_REGEX) do |number, integer, mantissa, units|

lib/scss_lint/linter/url_quotes.rb

@@ -20,8 +20,8 @@ def visit_prop(node)
   private
 
     def check(node, string)
-      return unless string =~ /^\s*url\(\s*[^"']/
-      return if string =~ /^\s*url\(\s*data:/ # Ignore data URIs
+      return unless string.match?(/^\s*url\(\s*[^"']/)
+      return if string.match?(/^\s*url\(\s*data:/) # Ignore data URIs
 
       add_lint(node, 'URLs should be enclosed in quotes')
     end

lib/scss_lint/linter/vendor_prefix.rb

@@ -27,7 +27,7 @@ def check_node(node)
   private
 
     def check_identifier(node, identifier)
-      return unless identifier =~ /^[_-]/
+      return unless identifier.match?(/^[_-]/)
 
       # Strip vendor prefix to check against identifiers.
       # (Also strip closing parentheticals from values like linear-gradient.)

scss_lint.gemspec

@@ -23,7 +23,7 @@ Gem::Specification.new do |s|
 
   s.test_files       = Dir['spec/**/*']
 
-  s.required_ruby_version = '>= 2.3'
+  s.required_ruby_version = '>= 2.4'
 
   s.add_dependency 'rake', '>= 0.9', '< 13'
   s.add_dependency 'sass', '~> 3.5', '>= 3.5.5'