Deprecate the subject selector operator.

Closes #1126

doc-src/SASS_CHANGELOG.md

@@ -191,6 +191,9 @@ adding multiple suffixes to the same parent selector. For example:
   invalid according to the CSS string grammar. To include a newline in a string,
   use "\a" or "\a " as in CSS.
 
+* The subject selector operator, `!`, is deprecated and will produce a warning
+  if used. The `:has()` selector should be used instead.
+
 ## 3.3.10 (Unreleased)
 
 * Properly encode URLs in sourcemaps.

lib/sass/scss/css_parser.rb

@@ -31,29 +31,8 @@ def nested_properties!(node)
 
       def ruleset
         start_pos = source_position
-        rules, source_range = selector_sequence
-        return unless rules
-        block(node(Sass::Tree::RuleNode.new([rules], source_range), start_pos), :ruleset)
-      end
-
-      def selector_sequence
-        start_pos = source_position
-        if (sel = tok(STATIC_SELECTOR, true))
-          return sel, range(start_pos)
-        end
-
-        sel = selector_string
-        return unless sel
-
-        ws = ''
-        while tok(/,/)
-          ws << str {ss}
-          if (v = selector_string)
-            sel << ',' << ws << v
-            ws = ''
-          end
-        end
-        return sel, range(start_pos)
+        return unless (selector = selector_comma_sequence)
+        block(node(Sass::Tree::RuleNode.new(selector, range(start_pos)), start_pos), :ruleset)
       end
 
       @sass_script_parser = Class.new(Sass::Script::CssParser)

lib/sass/scss/static_parser.rb

@@ -107,6 +107,7 @@ def selector_string
       end
 
       def selector
+        start_pos = source_position
         # The combinator here allows the "> E" hack
         val = combinator || simple_selector_sequence
         return unless val
@@ -119,7 +120,19 @@ def selector
           res << val
           res << "\n" if str {ss}.include?("\n")
         end
-        Selector::Sequence.new(res.compact)
+        seq = Selector::Sequence.new(res.compact)
+
+        if seq.members.any? {|sseq| sseq.is_a?(Selector::SimpleSequence) && sseq.subject?}
+          location = " of #{@filename}" if @filename
+          Sass::Util.sass_warn <<MESSAGE
+DEPRECATION WARNING on line #{start_pos.line}, column #{start_pos.offset}#{location}:
+The subject selector operator "!" is deprecated and will be removed in a future release.
+This operator has been replaced by ":has()" in the CSS spec.
+For example: #{seq.subjectless}
+MESSAGE
+        end
+
+        seq
       end
 
       def combinator

lib/sass/selector/sequence.rb

@@ -167,6 +167,35 @@ def add_sources!(sources)
         members.map! {|m| m.is_a?(SimpleSequence) ? m.with_more_sources(sources) : m}
       end
 
+      # Converts the subject operator "!", if it exists, into a ":has()"
+      # selector.
+      #
+      # @retur [Sequence]
+      def subjectless
+        pre_subject = []
+        has = []
+        subject = nil
+        members.each do |sseq_or_op|
+          if subject
+            has << sseq_or_op
+          elsif sseq_or_op.is_a?(String) || !sseq_or_op.subject?
+            pre_subject << sseq_or_op
+          else
+            subject = sseq_or_op.dup
+            subject.members = sseq_or_op.members.dup
+            subject.subject = false
+            has = []
+          end
+        end
+
+        return self unless subject
+
+        unless has.empty?
+          subject.members << Pseudo.new(:class, 'has', nil, CommaSequence.new([Sequence.new(has)]))
+        end
+        Sequence.new(pre_subject + [subject])
+      end
+
       private
 
       # Conceptually, this expands "parenthesized selectors". That is, if we

lib/sass/selector/simple_sequence.rb

@@ -277,7 +277,9 @@ def to_s
       #
       # @return [String]
       def inspect
-        members.map {|m| m.inspect}.join
+        res = members.map {|m| m.inspect}.join
+        res << '!' if subject?
+        res
       end
 
       # Return a copy of this simple sequence with `sources` merged into the

lib/sass/tree/rule_node.rb

@@ -60,15 +60,20 @@ class RuleNode < Node
     # @return [String]
     attr_accessor :stack_trace
 
-    # @param rule [Array<String, Sass::Script::Tree::Node>]
+    # @param rule [Array<String, Sass::Script::Tree::Node>, Sass::Selector::CommaSequence]
+    #   The CSS rule, either unparsed or parsed.
     # @param selector_source_range [Sass::Source::Range]
-    #   The CSS rule. See \{#rule}
     def initialize(rule, selector_source_range = nil)
-      merged = Sass::Util.merge_adjacent_strings(rule)
-      @rule = Sass::Util.strip_string_array(merged)
+      if rule.is_a?(Sass::Selector::CommaSequence)
+        @rule = [rule.to_s]
+        @parsed_rules = rule
+      else
+        merged = Sass::Util.merge_adjacent_strings(rule)
+        @rule = Sass::Util.strip_string_array(merged)
+        try_to_parse_non_interpolated_rules
+      end
       @selector_source_range = selector_source_range
       @tabs = 0
-      try_to_parse_non_interpolated_rules
       super()
     end
 
@@ -130,7 +135,7 @@ def try_to_parse_non_interpolated_rules
       if @rule.all? {|t| t.kind_of?(String)}
         # We don't use real filename/line info because we don't have it yet.
         # When we get it, we'll set it on the parsed rules if possible.
-        parser = Sass::SCSS::StaticParser.new(@rule.join.strip, '', nil, 1)
+        parser = Sass::SCSS::StaticParser.new(@rule.join.strip, nil, nil, 1)
         # rubocop:disable RescueModifier
         @parsed_rules = parser.parse_selector rescue nil
         # rubocop:enable RescueModifier

test/sass/css2sass_test.rb

@@ -238,7 +238,7 @@ def test_pseudo_classes_are_escaped
   end
 
   def test_subject
-    assert_equal(<<SASS, css2sass(<<CSS))
+    silence_warnings {assert_equal(<<SASS, css2sass(<<CSS))}
 .foo
   .bar!
     .baz

test/sass/extend_test.rb

@@ -1202,15 +1202,15 @@ def test_extend_within_and_without_nested_directives
   end
 
   def test_extend_with_subject_transfers_subject_to_extender
-    assert_equal(<<CSS, render(<<SCSS))
+    silence_warnings {assert_equal(<<CSS, render(<<SCSS))}
 foo bar! baz, foo .bip .bap! baz, .bip foo .bap! baz {
   a: b; }
 CSS
 foo bar! baz {a: b}
 .bip .bap {@extend bar}
 SCSS
 
-    assert_equal(<<CSS, render(<<SCSS))
+    silence_warnings {assert_equal(<<CSS, render(<<SCSS))}
 foo.x bar.y! baz.z, foo.x .bip bar.bap! baz.z, .bip foo.x bar.bap! baz.z {
   a: b; }
 CSS
@@ -1220,7 +1220,7 @@ def test_extend_with_subject_transfers_subject_to_extender
   end
 
   def test_extend_with_subject_retains_subject_on_target
-    assert_equal(<<CSS, render(<<SCSS))
+    silence_warnings {assert_equal(<<CSS, render(<<SCSS))}
 .foo! .bar, .foo! .bip .bap, .bip .foo! .bap {
   a: b; }
 CSS
@@ -1230,7 +1230,7 @@ def test_extend_with_subject_retains_subject_on_target
   end
 
   def test_extend_with_subject_transfers_subject_to_target
-    assert_equal(<<CSS, render(<<SCSS))
+    silence_warnings {assert_equal(<<CSS, render(<<SCSS))}
 a.foo .bar, .bip a.bap! .bar {
   a: b; }
 CSS
@@ -1240,7 +1240,7 @@ def test_extend_with_subject_transfers_subject_to_target
   end
 
   def test_extend_with_subject_retains_subject_on_extender
-    assert_equal(<<CSS, render(<<SCSS))
+    silence_warnings {assert_equal(<<CSS, render(<<SCSS))}
 .foo .bar, .foo .bip! .bap, .bip! .foo .bap {
   a: b; }
 CSS
@@ -1250,7 +1250,7 @@ def test_extend_with_subject_retains_subject_on_extender
   end
 
   def test_extend_with_subject_fails_with_conflicting_subject
-    assert_equal(<<CSS, render(<<SCSS))
+    silence_warnings {assert_equal(<<CSS, render(<<SCSS))}
 x! .bar {
   a: b; }
 CSS

test/sass/scss/css_test.rb

@@ -760,7 +760,7 @@ def test_summarized_selectors_with_element
     assert_selector_parses('E + F')
     assert_selector_parses('E ~ F')
     assert_selector_parses('E /foo/ F')
-    assert_selector_parses('E! > F')
+    silence_warnings {assert_selector_parses('E! > F')}
 
     assert_selector_parses('E /ns|foo/ F')
 
@@ -978,6 +978,29 @@ def test_spaceless_combo_selectors
     assert_equal "E + F {\n  a: b; }\n", render("E+F { a: b;} ")
   end
 
+  def test_subject_selector_deprecation
+    assert_warning(<<WARNING) {render(".foo .bar! .baz {a: b}")}
+DEPRECATION WARNING on line 1, column 1:
+The subject selector operator "!" is deprecated and will be removed in a future release.
+This operator has been replaced by ":has()" in the CSS spec.
+For example: .foo .bar:has(.baz)
+WARNING
+
+    assert_warning(<<WARNING) {render(".foo .bar! > .baz {a: b}")}
+DEPRECATION WARNING on line 1, column 1:
+The subject selector operator "!" is deprecated and will be removed in a future release.
+This operator has been replaced by ":has()" in the CSS spec.
+For example: .foo .bar:has(> .baz)
+WARNING
+
+    assert_warning(<<WARNING) {render(".foo .bar! {a: b}")}
+DEPRECATION WARNING on line 1, column 1:
+The subject selector operator "!" is deprecated and will be removed in a future release.
+This operator has been replaced by ":has()" in the CSS spec.
+For example: .foo .bar
+WARNING
+  end
+
   ## Errors
 
   def test_invalid_directives

test/sass/scss/scss_test.rb

@@ -651,7 +651,7 @@ def test_parent_selectors
   end
 
   def test_parent_selector_with_subject
-    assert_equal <<CSS, render(<<SCSS)
+    silence_warnings {assert_equal <<CSS, render(<<SCSS)}
 bar foo.baz! .bip {
   a: b; }
 
@@ -2055,7 +2055,7 @@ def test_selector_interpolation_in_reference_combinator
   end
 
   def test_parent_selector_with_parent_and_subject
-    assert_equal <<CSS, render(<<SCSS)
+    silence_warnings {assert_equal <<CSS, render(<<SCSS)}
 bar foo.baz! .bip {
   c: d; }
 CSS