Conservatively process control commands

lib/scss_lint/engine.rb

@@ -8,7 +8,7 @@ class FileEncodingError < StandardError; end
   class Engine
     ENGINE_OPTIONS = { cache: false, syntax: :scss }
 
-    attr_reader :contents, :filename, :lines, :tree
+    attr_reader :contents, :filename, :lines, :tree, :any_control_commands
 
     # Creates a parsed representation of an SCSS document from the given string
     # or file.
@@ -27,7 +27,8 @@ def initialize(options = {})
       # Need `to_a` for Ruby 1.9.3.
       @lines = @contents.force_encoding('UTF-8').lines.to_a
       @tree = @engine.to_tree
-    rescue Encoding::UndefinedConversionError, Sass::SyntaxError => error
+      find_any_control_commands
+    rescue Encoding::UndefinedConversionError, Sass::SyntaxError, ArgumentError => error
       if error.is_a?(Encoding::UndefinedConversionError) ||
          error.message.match(/invalid.*(byte sequence|character)/i)
         raise FileEncodingError,
@@ -52,5 +53,10 @@ def build_from_string(scss)
       @engine = Sass::Engine.new(scss, ENGINE_OPTIONS)
       @contents = scss
     end
+
+    def find_any_control_commands
+      @any_control_commands =
+        @lines.any? { |line| line['scss-lint:disable'] || line['scss-line:enable'] }
+    end
   end
 end

lib/scss_lint/linter.rb

@@ -127,9 +127,9 @@ def visit(node)
         visit_selector(node.parsed_rules)
       end
 
-      @comment_processor.before_node_visit(node)
+      @comment_processor.before_node_visit(node) if @engine.any_control_commands
       super
-      @comment_processor.after_node_visit(node)
+      @comment_processor.after_node_visit(node) if @engine.any_control_commands
     end
 
     # Redefine so we can set the `node_parent` of each node