I discovered this issue in some code I'm working on, and constructed this sample to match the issue I observed:

impl SomeType {
    fn method(&mut self) {
        self.array[array_index as usize]
            .as_mut()
            .expect("thing must exist")
            .extra_info = Some(ExtraInfo {
            parent,
            count: count as u16,
            children: children.into_boxed_slice(),
        });
    }
}

The fields of ExtraInfo should not be wrapping to the same indent level as the method chain. I can imagine a few ways to format this better, and don't feel strongly about which one, just that this definitely isn't the right formatting.