Add failing test for calc result

Author: jsakas

lib/CSSStyleDeclaration.test.js

@@ -523,5 +523,8 @@ describe('CSSStyleDeclaration', () => {
     const style = new CSSStyleDeclaration();
     style.setProperty('width', 'calc(100% - 100px)');
     expect(style.getPropertyValue('width')).toEqual('calc(100% - 100px)');
+
+    style.setProperty('width', 'calc(100px * 2)');
+    expect(style.getPropertyValue('width')).toEqual('calc(200px)');
   });
 });