view! compile error when passing empty Children through component

[zdenek-crha]

Describe the bug

When component prop struct contains only Children struct and view! macro is used to render it without child node(s), then compilation fails with an argument of type AppProps<'_, _> is missing.

To Reproduce

use sycamore::prelude::*;

#[derive(Prop)]
pub struct AppProps<'cx, G: Html> {
    children: Children<'cx, G>,
}

#[component]
pub fn App<'cx, G: Html>(cx: Scope<'cx>, props: AppProps<'cx, G>) -> View<G> {
    let children = props.children.call(cx);
    view! { cx, (children) }
}

pub fn main() {
    sycamore::render(|cx| view! { cx,
        App { }
    });
}

Expected behavior

Code compiles without issue and AppProps contains Children struct instance that has no child nodes.

Environment

• Sycamore: 0.8.2

Additional context

This seems to be an edge-case in view! macro building the AppProps struct from component attributes and children. It manifests only in the case described above. Any of the following changes will make it compile:

• add attribute to App component when rendering (requires adding field to AppProps struct)
• add child node to App component rendering (even empty string "" will help)

[lukechu10]

This issue was actually solved way back with #548, I just didn't realize it 😅