+ def process(tree, params)
+ last_visited = {}
+ darknodes = []
+
+ tree.delete_if do |x|
+ sep = { node: :whitespace, raw: "\n" }
+ if last_visited[:node] == :whitespace
+ # Try to maintain indentation
+ sep[:raw] += last_visited[:raw].sub(/[^\n]*\z|.*\n/m, "")
+ end
+ last_visited = x
+
+ if is_supports_block(x)
+ # Re-parse the block as a list of rules
+ s = Crass::Parser.stringify(x[:block])
+ x[:block] = Crass::Parser.parse_rules(s, params)
+
+ block = process(x[:block], params)
+ unless block.empty?
+ block << { node: :whitespace, raw: "\n" }
+ darknodes << [sep, x.merge({ block: block })]
+ end
+
+ Crass::Parser.stringify(x[:block]).strip.empty?
+ elsif is_media_dark(x)
+ if params[:alternate]
+ x = prune_media_dark(x)
+ end
+ darknodes << [sep, x]
+ end
+ end
+
+ # Combine consecutive equivalent media queries into a single query
+ result = darknodes.slice_when do |a,b|
+ !equiv_query(a[1], b[1])
+ end.each.map do |x|
+ case x[0][1]
+ when Hash
+ g = x.map{ |sep, node| node[:block] }.flatten
+ [ x[0][0], x[0][1].merge({ block: simplify_whitespace(g) }) ]
+ else
+ x
+ end
+ end.flatten
+
+ simplify_whitespace(result)
+ end
+