Added WASM support

Cargo.toml

@@ -29,6 +29,20 @@ bevy_simple_subsecond_system_macros = { path = "macros", version = "0.1.9" }
 crossbeam-channel = "0.5.15"
 send_wrapper = "0.6.0"
 
+[target.'cfg(target_arch = "wasm32")'.dependencies]
+dioxus-cli-config = { version = "0.7.0-alpha.1", features = ["web"] }
+serde_json = { version = "1.0" }
+
+[target.'cfg(target_arch = "wasm32")'.dependencies.web-sys]
+version = "0.3.77"
+features = [
+    "Window",
+    "Location",
+    "CloseEvent",
+    "MessageEvent",
+    "WebSocket"
+]
+
 [dev-dependencies]
 bevy = { version = "0.16.0", features = ["bevy_ui_debug", "track_location"] }
 

macros/src/lib.rs

@@ -132,20 +132,14 @@ pub fn hot(attr: TokenStream, item: TokenStream) -> TokenStream {
 
     if !hot_patch_signature && !rerun_on_hot_patch {
         let result = quote! {
-            #[cfg(any(target_family = "wasm", not(debug_assertions)))]
-            #vis fn #original_fn_name #impl_generics(#inputs) #where_clause #original_output {
-                #block
-            }
-
-
-            #[cfg(all(not(target_family = "wasm"), debug_assertions))]
+            #[cfg(debug_assertions)]
             #[allow(unused_mut)]
             #vis fn #original_fn_name #impl_generics(#inputs) #where_clause #original_output {
                 #hot_fn.call((#(#param_idents,)*))
             }
 
 
-            #[cfg(all(not(target_family = "wasm"), debug_assertions))]
+            #[cfg(debug_assertions)]
             #vis fn #hotpatched_fn #impl_generics(#inputs) #where_clause #original_output {
                 #block
             }
@@ -215,12 +209,8 @@ pub fn hot(attr: TokenStream, item: TokenStream) -> TokenStream {
     };
 
     let result = quote! {
-        #[cfg(any(target_family = "wasm", not(debug_assertions)))]
-        #vis fn #original_fn_name #impl_generics(#inputs) #where_clause #original_output {
-            #block
-        }
         // Outer entry point: stable ABI, hot-reload safe
-        #[cfg(all(not(target_family = "wasm"), debug_assertions))]
+        #[cfg(debug_assertions)]
         #vis fn #original_fn_name #impl_generics(world: &mut ::bevy_simple_subsecond_system::__macros_internal::World) #where_clause #original_output {
             use std::any::Any as _;
             let type_id = #hotpatched_fn #maybe_generics.type_id();
@@ -258,11 +248,11 @@ pub fn hot(attr: TokenStream, item: TokenStream) -> TokenStream {
         }
 
         // Hotpatched version with stable signature
-        #[cfg(all(not(target_family = "wasm"), debug_assertions))]
+        #[cfg(debug_assertions)]
         #hotpatched_fn_definition
 
         // Original function body moved into a standalone fn
-        #[cfg(all(not(target_family = "wasm"), debug_assertions))]
+        #[cfg(debug_assertions)]
         #vis fn #original_wrapper_fn #impl_generics(#inputs) #where_clause #original_output {
             #block
         }

src/hot_patched_app.rs

@@ -7,7 +7,7 @@ use bevy_app::{
 };
 use bevy_derive::{Deref, DerefMut};
 use bevy_ecs::prelude::*;
-#[cfg(all(not(target_family = "wasm"), debug_assertions))]
+#[cfg(debug_assertions)]
 use bevy_ecs::system::{Commands, Res};
 use bevy_ecs_macros::ScheduleLabel;
 use bevy_log::{debug, error};

src/lib.rs

@@ -4,15 +4,23 @@
 
 pub mod migration;
 
-#[cfg(all(not(target_family = "wasm"), debug_assertions))]
+#[cfg(debug_assertions)]
 use __macros_internal::__HotPatchedSystems as HotPatchedSystems;
 use bevy_app::{App, Last, Plugin, PostStartup, PreUpdate};
 use bevy_ecs::prelude::*;
 pub use bevy_simple_subsecond_system_macros::*;
 pub use dioxus_devtools;
-#[cfg(all(not(target_family = "wasm"), debug_assertions))]
+#[cfg(debug_assertions)]
 use dioxus_devtools::{subsecond::apply_patch, *};
 
+#[cfg(target_arch = "wasm32")]
+use web_sys::{
+    CloseEvent, MessageEvent, WebSocket,
+    js_sys::JsString,
+    wasm_bindgen::{JsCast, JsValue, closure::Closure},
+    window,
+};
+
 pub mod hot_patched_app;
 
 /// Everything you need to use hotpatching
@@ -51,20 +59,15 @@ impl Plugin for SimpleSubsecondPlugin {
             )
                 .chain(),
         );
-        #[cfg(target_family = "wasm")]
-        {
-            bevy_log::warn!(
-                "Hotpatching is not supported on Wasm yet. Disabling SimpleSubsecondPlugin."
-            );
-            return;
-        }
         #[cfg(not(debug_assertions))]
         {
             return;
         }
-        #[cfg(all(not(target_family = "wasm"), debug_assertions))]
+        #[cfg(debug_assertions)]
         {
             let (sender, receiver) = crossbeam_channel::bounded::<HotPatched>(1);
+
+            #[cfg(not(target_arch = "wasm32"))]
             connect(move |msg| {
                 if let DevserverMsg::HotReload(hot_reload_msg) = msg {
                     if let Some(jumptable) = hot_reload_msg.jump_table {
@@ -76,6 +79,59 @@ impl Plugin for SimpleSubsecondPlugin {
                 }
             });
 
+            #[cfg(target_arch = "wasm32")]
+            {
+                let location = web_sys::window().unwrap().location();
+                let url = format!(
+                    "{protocol}//{host}/_dioxus?build_id={build_id}",
+                    protocol = match location.protocol().unwrap() {
+                        prot if prot == "https:" => "wss:",
+                        _ => "ws:",
+                    },
+                    host = location.host().unwrap(),
+                    build_id = dioxus_cli_config::build_id(),
+                );
+
+                let ws = WebSocket::new(&url).unwrap();
+
+                ws.set_onmessage(Some(
+                    Closure::<dyn FnMut(MessageEvent)>::new(move |e: MessageEvent| {
+                        let Ok(text) = e.data().dyn_into::<JsString>() else {
+                            return;
+                        };
+
+                        // The devserver messages have some &'static strs in them, so we need to leak the source string
+                        let string: String = text.into();
+                        let string = Box::leak(string.into_boxed_str());
+
+                        match serde_json::from_str::<DevserverMsg>(string) {
+                            Ok(DevserverMsg::HotReload(hr)) => {
+                                if let Some(jumptable) = hr.jump_table {
+                                    // SAFETY: This is not unsafe, but anything using the updated jump table is.
+                                    // The table must be built carefully
+                                    unsafe { apply_patch(jumptable).unwrap() };
+                                    sender.send(HotPatched).unwrap();
+                                }
+                            }
+                            Ok(_) => {
+                                // Other devserver messages not used
+                            }
+                            Err(e) => web_sys::console::error_1(
+                                &format!("Error parsing devserver message: {}", e).into(),
+                            ),
+                            e => {
+                                web_sys::console::error_1(
+                                    &format!("Error parsing devserver message: {:?}", e).into(),
+                                );
+                            }
+                        }
+                    })
+                    .into_js_value()
+                    .as_ref()
+                    .unchecked_ref(),
+                ));
+            }
+
             app.init_resource::<HotPatchedSystems>();
 
             app.add_event::<HotPatched>().add_systems(