Assert that launch never returns for better compiler errors (#2517)

* assert that launch never returns for better compiler errors

* fix static generation launch function

* fix web renderer

packages/fullstack/src/launch.rs

@@ -6,6 +6,39 @@ use dioxus_lib::prelude::{Element, VirtualDom};
 
 pub use crate::Config;
 
+fn virtual_dom_factory(
+    root: fn() -> Element,
+    contexts: Vec<Box<dyn Fn() -> Box<dyn Any> + Send + Sync>>,
+) -> impl Fn() -> VirtualDom + 'static {
+    move || {
+        let mut vdom = VirtualDom::new(root);
+        for context in &contexts {
+            vdom.insert_any_root_context(context());
+        }
+        vdom
+    }
+}
+
+#[cfg(feature = "server")]
+/// Launch a fullstack app with the given root component, contexts, and config.
+#[allow(unused)]
+pub fn launch(
+    root: fn() -> Element,
+    contexts: Vec<Box<dyn Fn() -> Box<dyn Any> + Send + Sync>>,
+    platform_config: Config,
+) -> ! {
+    let factory = virtual_dom_factory(root, contexts);
+    #[cfg(all(feature = "server", not(target_arch = "wasm32")))]
+    tokio::runtime::Runtime::new()
+        .unwrap()
+        .block_on(async move {
+            platform_config.launch_server(factory).await;
+        });
+
+    unreachable!("Launching a fullstack app should never return")
+}
+
+#[cfg(all(not(feature = "server"), feature = "web"))]
 /// Launch a fullstack app with the given root component, contexts, and config.
 #[allow(unused)]
 pub fn launch(
@@ -13,40 +46,36 @@ pub fn launch(
     contexts: Vec<Box<dyn Fn() -> Box<dyn Any> + Send + Sync>>,
     platform_config: Config,
 ) {
-    let virtual_dom_factory = move || {
-        let mut vdom = VirtualDom::new(root);
-        for context in &contexts {
-            vdom.insert_any_root_context(context());
-        }
-        vdom
-    };
+    let factory = virtual_dom_factory(root, contexts);
+    let cfg = platform_config.web_cfg.hydrate(true);
+    dioxus_web::launch::launch_virtual_dom(factory(), cfg)
+}
 
-    #[cfg(all(feature = "server", not(target_arch = "wasm32")))]
-    tokio::runtime::Runtime::new()
-        .unwrap()
-        .block_on(async move {
-            platform_config.launch_server(virtual_dom_factory).await;
-        });
+#[cfg(all(not(any(feature = "server", feature = "web")), feature = "desktop"))]
+/// Launch a fullstack app with the given root component, contexts, and config.
+#[allow(unused)]
+pub fn launch(
+    root: fn() -> Element,
+    contexts: Vec<Box<dyn Fn() -> Box<dyn Any> + Send + Sync>>,
+    platform_config: Config,
+) -> ! {
+    let factory = virtual_dom_factory(root, contexts);
+    let cfg = platform_config.desktop_cfg;
+    dioxus_desktop::launch::launch_virtual_dom(factory(), cfg)
+}
 
-    #[cfg(not(feature = "server"))]
-    {
-        #[cfg(feature = "web")]
-        {
-            // TODO: this should pull the props from the document
-            let cfg = platform_config.web_cfg.hydrate(true);
-            dioxus_web::launch::launch_virtual_dom(virtual_dom_factory(), cfg);
-        }
-
-        #[cfg(feature = "desktop")]
-        {
-            let cfg = platform_config.desktop_cfg;
-            dioxus_desktop::launch::launch_virtual_dom(virtual_dom_factory(), cfg)
-        }
-
-        #[cfg(feature = "mobile")]
-        {
-            let cfg = platform_config.mobile_cfg;
-            dioxus_mobile::launch::launch_virtual_dom(virtual_dom_factory(), cfg)
-        }
-    }
+#[cfg(all(
+    not(any(feature = "server", feature = "web", feature = "desktop")),
+    feature = "mobile"
+))]
+/// Launch a fullstack app with the given root component, contexts, and config.
+#[allow(unused)]
+pub fn launch(
+    root: fn() -> Element,
+    contexts: Vec<Box<dyn Fn() -> Box<dyn Any> + Send + Sync>>,
+    platform_config: Config,
+) {
+    let factory = virtual_dom_factory(root, contexts);
+    let cfg = platform_config.mobile_cfg;
+    dioxus_mobile::launch::launch_virtual_dom(factory(), cfg)
 }