test: split compiled classes string into array for technically correct assertion

src/renderer/services/utils.spec.ts

@@ -59,7 +59,7 @@ describe('Frontend Utils', function () {
 
           expect(compiled).to.be.a('string', 'class util does not return a string');
           expectedClasses.forEach((className) => {
-            expect(compiled).to.contain(className, 'class util does not add all classes');
+            expect(compiled.split(' ')).to.include(className, 'class util does not add all classes');
           });
         })
       );