[Sass] Allow interpolation in url().

doc-src/SASS_CHANGELOG.md

@@ -9,6 +9,8 @@
 
 * Variables are now allowed as arguments to `url()`.
 
+* `#{}` interpolation is now allowed within `url()`.
+
 ## 3.0.0.beta.3
 
 [Tagged on GitHub](http://github.com/nex3/haml/commit/3.0.0.beta.3).

lib/sass/script/css_lexer.rb

@@ -5,7 +5,12 @@ module Sass
         important || super
       end
 
-      def string(*args)
+      def string(re, *args)
+        if re == :uri
+          return unless uri = scan(URI)
+          return [:string, Script::String.new(uri)]
+        end
+
         return unless scan(STRING)
         [:string, Script::String.new((@scanner[1] || @scanner[2]).gsub(/\\(['"])/, '\1'), :string)]
       end

lib/sass/script/lexer.rb

@@ -120,6 +120,8 @@ module Sass
         [:single, false] => string_re("'", "'"),
         [:double, true] => string_re('', '"'),
         [:single, true] => string_re('', "'"),
+        [:uri, false] => /url\(#{W}(#{URLCHAR}*?)(#{W}\)|(?=#\{))/,
+        [:uri, true] => /(#{URLCHAR}*?)(#{W}\)|(?=#\{))/,
       }
 
       # @param str [String, StringScanner] The source text to lex
@@ -216,8 +218,8 @@ module Sass
         end
 
         variable || string(:double, false) || string(:single, false) || number ||
-          color || bool || raw(URI) || raw(UNICODERANGE) || special_fun ||
+          color || bool || string(:uri, false) || raw(UNICODERANGE) ||
-          ident_op || ident || op
+          special_fun || ident_op || ident || op
       end
 
       def variable
@@ -243,7 +245,13 @@ module Sass
       def string(re, open)
         return unless scan(STRING_REGULAR_EXPRESSIONS[[re, open]])
         @interpolation_stack << re if @scanner[2].empty? # Started an interpolated section
-        [:string, Script::String.new(@scanner[1].gsub(/\\(['"]|\#\{)/, '\1'), :string)]
+        str =
+          if re == :uri
+            Script::String.new("#{'url(' unless open}#{@scanner[1]}#{')' unless @scanner[2].empty?}")
+          else
+            Script::String.new(@scanner[1].gsub(/\\(['"]|\#\{)/, '\1'), :string)
+          end
+        [:string, str]
       end
 
       def number

lib/sass/scss/rx.rb

@@ -65,7 +65,8 @@ module Sass
       NAME     = /#{NMCHAR}+/
       NUM      = /[0-9]+|[0-9]*.[0-9]+/
       STRING   = /#{STRING1}|#{STRING2}/
-      URL      = /((?:[!#%&*-~]|#{NONASCII}|#{ESCAPE})*)/
+      URLCHAR  = /[!#%&*-~]|#{NONASCII}|#{ESCAPE}/
+      URL      = /(#{URLCHAR}*)/
       W        = /[ \t\r\n\f]*/
 
       # This is more liberal than the spec's definition,

test/sass/script_test.rb

@@ -150,6 +150,12 @@ SASS
     assert_equal "url(foo bar)", resolve("url(foo    bar)")
   end
 
+  def test_url_with_interpolation
+    assert_equal "url(http://sass-lang.com/images/foo-bar)", resolve("url(http://sass-lang.com/images/\#{foo-bar})")
+    assert_equal 'url("http://sass-lang.com/images/foo-bar")', resolve("url('http://sass-lang.com/images/\#{foo-bar}')")
+    assert_equal 'url("http://sass-lang.com/images/foo-bar")', resolve('url("http://sass-lang.com/images/#{foo-bar}")')
+  end
+
   def test_hyphenated_variables
     assert_equal("a-b", resolve("$a-b", {}, env("a-b" => Sass::Script::String.new("a-b"))))
   end