sass/sass-spec — pull request #35 by benesch (2014-08-13 16:39:36+00:00)
Title: add tests for CSS native filter functions

Add tests to verify that attempts to use native CSS filter functions,
like `grayscale(20%)`, are properly passed through to CSS unchanged,
rather than interpreted as the Sass function `grayscale` that operates
on colors.

Fixes compatibility with Ruby Sass.

Original issue reported in sass/libsass#151. These tests pass with
sass/libsass#467.