add empty scss test case

Author: adamgruber

test/__snapshots__/test.js.snap

@@ -41,6 +41,8 @@ Object {
 }
 `;
 
+exports[`sass-extract-js should handle file with no variables 1`] = `Object {}`;
+
 exports[`sass-extract-js should handle imports 1`] = `
 Object {
   "importedVar": true,

test/sass/test-empty.scss

@@ -0,0 +1,3 @@
+html {
+  background-color: #fff;
+}

test/test.js

@@ -7,6 +7,7 @@ const testfiles = {
   camel: path.resolve(__dirname, './sass/test-opts-camel.scss'),
   sassOpts: path.resolve(__dirname, './sass/test-opts-sass.scss'),
   import: path.resolve(__dirname, './sass/test-import.scss'),
+  empty: path.resolve(__dirname, './sass/test-empty.scss'),
 };
 
 const getVars = (file, compileOpts = {}) =>
@@ -25,6 +26,10 @@ describe('sass-extract-js', () => {
     expect(getVars(testfiles.import)).toMatchSnapshot();
   });
 
+  it('should handle file with no variables', () => {
+    expect(getVars(testfiles.empty)).toMatchSnapshot();
+  });
+
   it('should pass sass options through', () => {
     const opts = {
       includePaths: [path.join(__dirname, 'sass', 'nested')],