Drop support for the reference combinator. (#2317)

Closes #303

doc-src/SASS_CHANGELOG.md

@@ -7,21 +7,23 @@
 
 ### Backwards Incompatibilities -- Must Read!
 
-Certain ways of using `#{}` without quotes in property and variable values,
-which were deprecated in version 3.4.20, have been removed entirely in order to
-simplify the feature.
+* Certain ways of using `#{}` without quotes in property and variable values,
+  which were deprecated in version 3.4.20, have been removed entirely in order
+  to simplify the feature.
 
-Previously, `#{}` behaved unpredictably. If it was used near operators, it would
-cause those operators to become part of an unquoted string instead of having
-their normal meaning. This wan't an especially useful feature, and it made it
-hard to reason about some code that included `#{}`.
+  Previously, `#{}` behaved unpredictably. If it was used near operators, it
+  would cause those operators to become part of an unquoted string instead of
+  having their normal meaning. This wan't an especially useful feature, and it
+  made it hard to reason about some code that included `#{}`.
 
-Now `#{}` just returns an unquoted string that acts like any other unquoted
-string. For example, `foo + #{$var}` does the same thing as `foo + $var`,
-instead of doing the same thing as `unquote("foo + #{$var}")`.
+  Now `#{}` just returns an unquoted string that acts like any other unquoted
+  string. For example, `foo + #{$var}` does the same thing as `foo + $var`,
+  instead of doing the same thing as `unquote("foo + #{$var}")`.
 
-For more details, see [this blog post][interp-blog] and
-[the GitHub issue in which it was planned][interp-issue].
+  For more details, see [this blog post][interp-blog] and
+  [the GitHub issue in which it was planned][interp-issue].
+
+* The reference combinator, `/foo/` is no longer supported.
 
 ## 3.5.0
 

lib/sass/scss/static_parser.rb

@@ -135,23 +135,7 @@ def selector
       end
 
       def combinator
-        tok(PLUS) || tok(GREATER) || tok(TILDE) || reference_combinator
-      end
-
-      def reference_combinator
-        return unless tok(%r{/})
-        res = '/'
-        ns, name = expr!(:qualified_name)
-        res << ns << '|' if ns
-        res << name << tok!(%r{/})
-
-        location = " of #{@filename}" if @filename
-        Sass::Util.sass_warn <<MESSAGE
-DEPRECATION WARNING on line #{@line}, column #{@offset}#{location}:
-The reference combinator #{res} is deprecated and will be removed in a future release.
-MESSAGE
-
-        res
+        tok(PLUS) || tok(GREATER) || tok(TILDE)
       end
 
       def simple_selector_sequence

test/sass/engine_test.rb

@@ -2862,7 +2862,7 @@ def test_selector_compression
   end
 
   def test_comment_like_selector
-    assert_raise_message(Sass::SyntaxError, 'Invalid CSS after "/": expected identifier, was " foo"') {render(<<SASS)}
+    assert_raise_message(Sass::SyntaxError, 'Invalid CSS after "": expected selector, was "/ foo"') {render(<<SASS)}
 / foo
   a: b
 SASS

test/sass/extend_test.rb

@@ -644,12 +644,6 @@ def test_nested_extender_doesnt_find_common_selectors_around_sibling_selector
     assert_extends 'a ~ b c .c1', 'b c .c2 {@extend .c1}', 'a ~ b c .c1, a ~ b c .c2'
   end
 
-  def test_nested_extender_doesnt_find_common_selectors_around_reference_selector
-    silence_warnings {assert_extends 'a /for/ b c .c1', 'a c .c2 {@extend .c1}', 'a /for/ b c .c1, a /for/ b a c .c2, a a /for/ b c .c2'}
-    silence_warnings {assert_extends 'a /for/ b c .c1', 'a b .c2 {@extend .c1}', 'a /for/ b c .c1, a a /for/ b c .c2'}
-    silence_warnings {assert_extends 'a /for/ b c .c1', 'b c .c2 {@extend .c1}', 'a /for/ b c .c1, a /for/ b c .c2'}
-  end
-
   def test_nested_extender_with_early_child_selectors_doesnt_subseq_them
     assert_extends('.bip > .bap .foo', '.grip > .bap .bar {@extend .foo}',
       '.bip > .bap .foo, .bip > .bap .grip > .bap .bar, .grip > .bap .bip > .bap .bar')

test/sass/scss/css_test.rb

@@ -805,11 +805,8 @@ def test_summarized_selectors_with_element
     assert_selector_parses('E > F')
     assert_selector_parses('E + F')
     assert_selector_parses('E ~ F')
-    silence_warnings {assert_selector_parses('E /foo/ F')}
     silence_warnings {assert_selector_parses('E! > F')}
 
-    silence_warnings {assert_selector_parses('E /ns|foo/ F')}
-
     # From http://dev.w3.org/csswg/css-scoping-1/
     assert_selector_parses('E:host(s)')
     assert_selector_parses('E:host-context(s)')
@@ -1167,7 +1164,7 @@ def test_very_long_comment_doesnt_take_forever
 
   def test_long_unclosed_comment_doesnt_take_forever
     assert_raise_message(Sass::SyntaxError,
-      'Invalid CSS after "/*": expected "/", was "//*************..."') {render(<<SCSS)}
+      'Invalid CSS after "": expected selector or at-rule, was "/*"') {render(<<SCSS)}
 /*
 //**************************************************************************
 SCSS

test/sass/scss/scss_test.rb

@@ -2173,18 +2173,6 @@ def test_selector_interpolation_at_dashes
 SCSS
   end
 
-  def test_selector_interpolation_in_reference_combinator
-    silence_warnings {assert_equal <<CSS, render(<<SCSS)}
-.foo /a/ .bar /b|c/ .baz {
-  a: b; }
-CSS
-$a: a;
-$b: b;
-$c: c;
-.foo /\#{$a}/ .bar /\#{$b}|\#{$c}/ .baz {a: b}
-SCSS
-  end
-
   def test_parent_selector_with_parent_and_subject
     silence_warnings {assert_equal <<CSS, render(<<SCSS)}
 bar foo.baz! .bip {
@@ -3825,27 +3813,6 @@ def test_import_comments_in_imports
 SCSS
   end
 
-  def test_reference_combinator_with_parent_ref
-    silence_warnings {assert_equal <<CSS, render(<<SCSS)}
-a /foo/ b {
-  c: d; }
-CSS
-a {& /foo/ b {c: d}}
-SCSS
-  end
-
-  def test_reference_combinator_warning
-    assert_warning(<<WARNING) {assert_equal <<CSS, render(<<SCSS)}
-DEPRECATION WARNING on line 1, column 8 of test_reference_combinator_warning_inline.scss:
-The reference combinator /foo/ is deprecated and will be removed in a future release.
-WARNING
-a /foo/ b {
-  c: d; }
-CSS
-a {& /foo/ b {c: d}}
-SCSS
-  end
-
   def test_newline_selector_rendered_multiple_times
     assert_equal <<CSS, render(<<SCSS)
 form input,