Add 'inline-base' asset function for base64 inlining assets

lib/roger_sassc/sassc/asset_functions.rb

@@ -1,4 +1,6 @@
 require "sassc"
+require "base64"
+require "mime/types"
 require "digest"
 
 module RogerSassc
@@ -21,6 +23,20 @@ def asset_path(path)
         ::SassC::Script::String.new("url(#{finger_printed_path})", :identifier)
       end
 
+      def inline_base64(path)
+        file = find_file(path)
+
+        if File.exist?(file)
+          encoded_file = Base64.encode64(File.open(file, "rb").read)
+          mime_type = MIME::Types.type_for(File.basename(file)).first
+          base64_string = "data:#{mime_type};base64,#{encoded_file}"
+        else
+          base64_string = path.value
+        end
+
+        ::SassC::Script::String.new("url(\"#{base64_string}\")", :identifier)
+      end
+
       private
 
       # Translate the given path to a path on disk

roger_sassc.gemspec

@@ -19,6 +19,7 @@ Gem::Specification.new do |spec|
 
   spec.add_dependency "sassc", "~> 1.2.0"
   spec.add_dependency "roger", "~> 1.0"
+  spec.add_dependency "mime-types", ["~> 2.2"]
   spec.add_dependency "rack"
 
   spec.add_development_dependency "rake", "~> 10.0"

test/asset_functions_test.rb

@@ -48,6 +48,13 @@ def test_asset_path_fingerprinting_absolute_path
       # rubocop:enable LineLength
     end
 
+    def test_inline_base_absolute_path
+      scss_path = "test/fixtures/asset_functions/inline_base_absolute_path.scss"
+      engine = get_engine_for(scss_path)
+
+      assert_match 'background-image: url("data:image/svg+xml;base64,', engine.render
+    end
+
     private
 
     def get_engine_for(scss_path)

test/fixtures/asset_functions/inline_base_absolute_path.scss

@@ -0,0 +1,3 @@
+div {
+  background-image: inline-base64('/images/logo.svg');
+}