there are always StringFragments

src/compiler/utils.ts

@@ -236,7 +236,12 @@ export const getStringParts = (node: SyntaxNode, input: string) => {
     }
   })
 
-  return { parts, hasInterpolation: parts.length > 0 }
+  // hasInterpolation means the string has interpolation ($var) or escape sequences (\n)
+  // A simple string like 'hello' has one StringFragment but no interpolation
+  const hasInterpolation = parts.some(
+    (p) => p.type.id === terms.Interpolation || p.type.id === terms.EscapeSeq
+  )
+  return { parts, hasInterpolation }
 }
 
 export const getDotGetParts = (node: SyntaxNode, input: string) => {