When using JSDoc, it's common to do this sort of thing:
const x = /** @type {Foo} */ (a.b).c();
This tells TypeScript that a.b is of type Foo. Prettier will preserve those parentheses when processing JS files, but for whatever reason it fails to do so inside .svelte files, instead turning it into this:
const x = /** @type {Foo} */ a.b.c();