Support either include_paths or exclude_paths.

Author: fhwang

lib/cc/engine/csslint.rb

@@ -48,14 +48,31 @@ def results
         @results ||= Nokogiri::XML(csslint_xml)
       end
 
+      def build_files_with_exclusions(exclusions)
+        files = Dir.glob("**/*.css")
+        files.reject { |f| exclusions.include?(f) }
+      end
+
+      def build_files_with_inclusions(inclusions)
+        inclusions.map do |include_path|
+          if include_path =~ %r{/$}
+            Dir.glob("#{include_path}/**/*.css")
+          else
+            include_path
+          end
+        end.flatten
+      end
+
       def csslint_xml
-        exclusions = @engine_config['exclude_paths'] || []
-        final_files = files.reject { |f| exclusions.include?(f) }
-        `csslint --format=checkstyle-xml #{final_files.join(" ")}`
+        `csslint --format=checkstyle-xml #{files_to_inspect.join(" ")}`
       end
 
-      def files
-        Dir.glob("**/*.css")
+      def files_to_inspect
+        if includes = @engine_config["include_paths"]
+          build_files_with_inclusions(includes)
+        else
+          build_files_with_exclusions(@engine_config["exclude_paths"] || [])
+        end
       end
     end
   end

spec/cc/engine/csslint_spec.rb

@@ -35,6 +35,44 @@ module Engine
               output(/Don't use IDs in selectors./).to_stdout
           end
         end
+
+        describe "with include_paths" do
+          let(:engine_config) {
+            {"include_paths" => %w(included.css included_dir/)}
+          }
+
+          before do
+            create_source_file("included.css", id_selector_content)
+            create_source_file(
+              "included_dir/file.css", "p { color: blue !important; }"
+            )
+            create_source_file(
+              "included_dir/sub/sub/subdir/file.css", "img { }"
+            )
+            create_source_file("not_included.css", "a { outline: none; }")
+          end
+
+          it "includes all mentioned files" do
+            expect{ lint.run }.to \
+              output(/Don't use IDs in selectors./).to_stdout
+          end
+
+          it "expands directories" do
+            expect{ lint.run }.to output(/Use of !important/).to_stdout
+            expect{ lint.run }.to output(/Rule is empty/).to_stdout
+          end
+
+          it "excludes any unmentioned files" do
+            expect{ lint.run }.not_to \
+              output(/Outlines should only be modified using :focus/).to_stdout
+          end
+
+          it "shouldn't call a top-level Dir.glob ever" do
+            expect(Dir).not_to receive(:glob).with("**/*.css")
+            expect{ lint.run }.to \
+              output(/Don't use IDs in selectors./).to_stdout
+          end
+        end
       end
 
       def create_source_file(path, content)