Merge branch 'placeholder'

lib/sass/scss/css_parser.rb

@@ -18,6 +18,7 @@ def parse_selector_string
 
       private
 
+      def placeholder_selector; nil; end
       def parent_selector; nil; end
       def interpolation; nil; end
       def interp_string; tok(STRING); end

lib/sass/scss/parser.rb

@@ -509,12 +509,14 @@ def combinator
       def simple_selector_sequence
         # This allows for stuff like http://www.w3.org/TR/css3-animations/#keyframes-
         return expr unless e = element_name || id_selector || class_selector ||
-          attrib || negation || pseudo || parent_selector || interpolation_selector
+          placeholder_selector || attrib || negation || pseudo || parent_selector ||
+          interpolation_selector
         res = [e]
 
         # The tok(/\*/) allows the "E*" hack
-        while v = id_selector || class_selector || attrib || negation || pseudo ||
-            interpolation_selector || (tok(/\*/) && Selector::Universal.new(nil))
+        while v = id_selector || class_selector || placeholder_selector || attrib ||
+            negation || pseudo || interpolation_selector ||
+            (tok(/\*/) && Selector::Universal.new(nil))
           res << v
         end
 
@@ -554,6 +556,12 @@ def id_selector
         Selector::Id.new(merge(expr!(:interp_name)))
       end
 
+      def placeholder_selector
+        return unless tok(/%/)
+        @expected = "placeholder name"
+        Selector::Placeholder.new(merge(expr!(:interp_ident)))
+      end
+
       def element_name
         return unless name = interp_ident || tok(/\*/) || (tok?(/\|/) && "")
         if tok(/\|/)

lib/sass/selector.rb

@@ -81,6 +81,27 @@ def unify(sels)
       end
     end
 
+    # A placeholder selector (e.g. `%foo`).
+    # This exists to be replaced via `@extend`.
+    # Rulesets using this selector will not be printed, but can be extended.
+    # Otherwise, this acts just like a class selector.
+    class Placeholder < Simple
+      # The placeholder name.
+      #
+      # @return [Array<String, Sass::Script::Node>]
+      attr_reader :name
+
+      # @param name [Array<String, Sass::Script::Node>] The placeholder name
+      def initialize(name)
+        @name = name
+      end
+
+      # @see Selector#to_a
+      def to_a
+        ["%", *@name]
+      end
+    end
+
     # A universal selector (`*` in CSS).
     class Universal < Simple
       # The selector namespace.

lib/sass/selector/abstract_sequence.rb

@@ -57,6 +57,13 @@ def eql?(other)
         other.class == self.class && other.hash == self.hash && _eql?(other)
       end
       alias_method :==, :eql?
+
+      # Whether or not this selector sequence contains a placeholder selector.
+      # Checks recursively.
+      def has_placeholder?
+        @has_placeholder ||=
+          members.any? {|m| m.is_a?(AbstractSequence) ? m.has_placeholder? : m.is_a?(Placeholder)}
+      end
     end
   end
 end

lib/sass/tree/rule_node.rb

@@ -122,6 +122,11 @@ def debug_info
        :line => self.line}
     end
 
+    # A rule node is invisible if it has only placeholder selectors.
+    def invisible?
+      resolved_rules.members.all? {|seq| seq.has_placeholder?}
+    end
+
     private
 
     def try_to_parse_non_interpolated_rules

lib/sass/tree/visitors/cssize.rb

@@ -76,6 +76,8 @@ def visit_extend(node)
       sseq = seq.members.first
       if !sseq.is_a?(Sass::Selector::SimpleSequence)
         raise Sass::SyntaxError.new("Can't extend #{seq.to_a.join}: invalid selector")
+      elsif sseq.members.any? {|ss| ss.is_a?(Sass::Selector::Parent)}
+        raise Sass::SyntaxError.new("Can't extend #{seq.to_a.join}: can't extend parent selectors")
       end
 
       sel = sseq.members

lib/sass/tree/visitors/perform.rb

@@ -87,7 +87,7 @@ def visit_each(node)
   # Runs SassScript interpolation in the selector,
   # and then parses the result into a {Sass::Selector::CommaSequence}.
   def visit_extend(node)
-    parser = Sass::SCSS::CssParser.new(run_interp(node.selector), node.filename, node.line)
+    parser = Sass::SCSS::StaticParser.new(run_interp(node.selector), node.filename, node.line)
     node.resolved_selector = parser.parse_selector
     node
   end

lib/sass/tree/visitors/to_css.rb

@@ -131,10 +131,11 @@ def visit_rule(node)
       per_rule_indent, total_indent = [:nested, :expanded].include?(node.style) ? [rule_indent, ''] : ['', rule_indent]
 
       joined_rules = node.resolved_rules.members.map do |seq|
+        next if seq.has_placeholder?
         rule_part = seq.to_a.join
         rule_part.gsub!(/\s*([^,])\s*\n\s*/m, '\1 ') if node.style == :compressed
         rule_part
-      end.join(rule_separator)
+      end.compact.join(rule_separator)
 
       joined_rules.sub!(/\A\s*/, per_rule_indent)
       joined_rules.gsub!(/\s*\n\s*/, "#{line_separator}#{per_rule_indent}")

test/sass/conversion_test.rb

@@ -1177,6 +1177,36 @@ def test_empty_content
 SCSS
   end
 
+  def test_placeholder_conversion
+    assert_renders(<<SASS, <<SCSS)
+#content a%foo.bar
+  color: blue
+SASS
+#content a%foo.bar {
+  color: blue; }
+SCSS
+  end
+
+  def test_placeholder_interoplation_conversion
+    assert_renders(<<SASS, <<SCSS)
+$foo: foo
+
+%\#{$foo}
+  color: blue
+
+.bar
+  @extend %foo
+SASS
+$foo: foo;
+
+%\#{$foo} {
+  color: blue; }
+
+.bar {
+  @extend %foo; }
+SCSS
+  end
+
   private
 
   def assert_sass_to_sass(sass, options = {})

test/sass/engine_test.rb

@@ -39,6 +39,9 @@ class SassEngineTest < Test::Unit::TestCase
     "a\n  b: c;" => 'Invalid CSS after "c": expected expression (e.g. 1px, bold), was ";"',
     ".foo ^bar\n  a: b" => ['Invalid CSS after ".foo ": expected selector, was "^bar"', 1],
     "a\n  @extend .foo ^bar" => 'Invalid CSS after ".foo ": expected selector, was "^bar"',
+    "a\n  @extend .foo .bar" => "Can't extend .foo .bar: can't extend nested selectors",
+    "a\n  @extend >" => "Can't extend >: invalid selector",
+    "a\n  @extend &.foo" => "Can't extend &.foo: can't extend parent selectors",
     "a: b" => 'Properties are only allowed within rules, directives, mixin includes, or other properties.',
     ":a b" => 'Properties are only allowed within rules, directives, mixin includes, or other properties.',
     "$" => 'Invalid variable: "$".',
@@ -64,7 +67,7 @@ class SassEngineTest < Test::Unit::TestCase
     "@mixin foo\n  @import foo" => "Import directives may not be used within control directives or mixins.",
     "@import foo;" => "Invalid @import: expected end of line, was \";\".",
     '$foo: "bar" "baz" !' => %Q{Invalid CSS after ""bar" "baz" ": expected expression (e.g. 1px, bold), was "!"},
-    '$foo: "bar" "baz" $' => %Q{Invalid CSS after ""bar" "baz" ": expected expression (e.g. 1px, bold), was "$"},
+    '$foo: "bar" "baz" $' => %Q{Invalid CSS after ""bar" "baz" ": expected expression (e.g. 1px, bold), was "$"}, #'
     "=foo\n  :color red\n.bar\n  +bang" => "Undefined mixin 'bang'.",
     "=foo\n  :color red\n.bar\n  +bang_bop" => "Undefined mixin 'bang_bop'.",
     "=foo\n  :color red\n.bar\n  +bang-bop" => "Undefined mixin 'bang-bop'.",
@@ -141,6 +144,7 @@ class SassEngineTest < Test::Unit::TestCase
     "@mixin foo\n  @extend .bar\n@include foo" => ["Extend directives may only be used within rules.", 2],
     "foo\n  &a\n    b: c" => ["Invalid CSS after \"&\": expected \"{\", was \"a\"\n\n\"a\" may only be used at the beginning of a selector.", 2],
     "foo\n  &1\n    b: c" => ["Invalid CSS after \"&\": expected \"{\", was \"1\"\n\n\"1\" may only be used at the beginning of a selector.", 2],
+    "foo %\n  a: b" => ['Invalid CSS after "foo %": expected placeholder name, was ""', 1],
     "=foo\n  @content error" => "Invalid content directive. Trailing characters found: \"error\".",
     "=foo\n  @content\n    b: c" => "Illegal nesting: Nothing may be nested beneath @content directives.",
     "@content" => '@content may only be used within a mixin.',

test/sass/extend_test.rb

@@ -1339,6 +1339,71 @@ def test_control_flow_while
 SCSS
   end
 
+  def test_basic_placeholder_selector
+    assert_equal <<CSS, render(<<SCSS)
+.bar {
+  color: blue; }
+CSS
+%foo {color: blue}
+.bar {@extend %foo}
+SCSS
+  end
+
+  def test_unused_placeholder_selector
+    assert_equal <<CSS, render(<<SCSS)
+.baz {
+  color: blue; }
+CSS
+%foo {color: blue}
+%bar {color: red}
+.baz {@extend %foo}
+SCSS
+  end
+
+  def test_placeholder_descendant_selector
+    assert_equal <<CSS, render(<<SCSS)
+#context .bar a {
+  color: blue; }
+CSS
+#context %foo a {color: blue}
+.bar {@extend %foo}
+SCSS
+  end
+
+  def test_placeholder_selector_with_multiple_extenders
+    assert_equal <<CSS, render(<<SCSS)
+.bar, .baz {
+  color: blue; }
+CSS
+%foo {color: blue}
+.bar {@extend %foo}
+.baz {@extend %foo}
+SCSS
+  end
+
+  def test_placeholder_selector_as_modifier
+    assert_equal <<CSS, render(<<SCSS)
+a.baz.bar {
+  color: blue; }
+CSS
+a%foo.baz {color: blue}
+.bar {@extend %foo}
+div {@extend %foo}
+SCSS
+  end
+
+  def test_placeholder_interpolation
+    assert_equal <<CSS, render(<<SCSS)
+.bar {
+  color: blue; }
+CSS
+$foo: foo;
+
+%\#{$foo} {color: blue}
+.bar {@extend %foo}
+SCSS
+  end
+
   private
 
   def render(sass, options = {})