Edit file File name : features.rb Content :require 'set' module Sass # Provides `Sass.has_feature?` which allows for simple feature detection # by providing a feature name. module Features # This is the set of features that can be detected. # # When this is updated, the documentation of `feature-exists()` should be # updated as well. KNOWN_FEATURES = Set[*%w( global-variable-shadowing extend-selector-pseudoclass units-level-3 at-error custom-property )] # Check if a feature exists by name. This is used to implement # the Sass function `feature-exists($feature)` # # @param feature_name [String] The case sensitive name of the feature to # check if it exists in this version of Sass. # @return [Boolean] whether the feature of that name exists. def has_feature?(feature_name) KNOWN_FEATURES.include?(feature_name) end # Add a feature to Sass. Plugins can use this to easily expose their # availability to end users. Plugins must prefix their feature # names with a dash to distinguish them from official features. # # @example # Sass.add_feature("-import-globbing") # Sass.add_feature("-math-cos") # # # @param feature_name [String] The case sensitive name of the feature to # to add to Sass. Must begin with a dash. def add_feature(feature_name) unless feature_name[0] == ?- raise ArgumentError.new("Plugin feature names must begin with a dash") end KNOWN_FEATURES << feature_name end end extend Features end Save