[oden] Tolerate bad scripts on hot reload

When the script changes from under us it might be bugged for some
reason; just let that be for now, ignore the load, and hopefully the
engineer will fix it, eventually.

src/lib.rs

@@ -768,8 +768,8 @@ fn main_thread(event_loop: EventLoopProxy<OdenEvent>, state: State, reciever: Re
 
     let (script_reload_send, script_reload_recv) = channel();
 
-    let mut script = script::ScriptContext::new(script_reload_send.clone());
-    script.init();
+    let mut script = script::ScriptContext::new(None, script_reload_send.clone())
+        .expect("Unable to create initial script context");
 
     const SPF: f64 = 1.0 / 60.0;
     loop {
@@ -823,11 +823,10 @@ fn main_thread(event_loop: EventLoopProxy<OdenEvent>, state: State, reciever: Re
             if reload_script {
                 eprintln!("RELOADING SCRIPT");
                 let suspend_state = script.suspend();
-                script = script::ScriptContext::new(script_reload_send.clone());
-                script.init();
-                if let Some(s) = suspend_state {
-                    script.resume(&s);
-                }
+                match script::ScriptContext::new(suspend_state, script_reload_send.clone()) {
+                    Ok(new_script) => script = new_script,
+                    Err(e) => eprintln!("WARNING: Script reload aborted, load failure: {e:?}"),
+                };
             }
         }
 

src/script.rs

@@ -55,11 +55,9 @@ impl ModuleLoader for Loader {
 
 pub struct ScriptContext {
     context: Context,
-    init: Value,
     update: Value,
     draw: Value,
     suspend: Value,
-    resume: Value,
 
     state: Value,
 
@@ -71,7 +69,7 @@ pub struct ScriptContext {
 }
 
 impl ScriptContext {
-    pub fn new(reload_trigger: Sender<()>) -> Self {
+    pub fn new(suspend_state: Option<Vec<u8>>, reload_trigger: Sender<()>) -> Result<Self> {
         let mut runtime = Runtime::new();
         runtime.set_module_loader(Loader::new(reload_trigger));
 
@@ -82,41 +80,31 @@ impl ScriptContext {
 
         let (gfx_send, gfx_receive) = channel();
 
-        let gfx = graphics::GraphicsAPI::define(&context, gfx_send.clone())
-            .expect("Graphics module should load without error");
-        let _io = io::IoAPI::define(&context).expect("IO module should load without error");
-        let time = time::TimeAPI::define(&context).expect("Time module should load without error");
-        let input =
-            input::InputAPI::define(&context).expect("Input module should load without error");
+        let gfx = graphics::GraphicsAPI::define(&context, gfx_send.clone())?;
+        let _io = io::IoAPI::define(&context)?;
+        let time = time::TimeAPI::define(&context)?;
+        let input = input::InputAPI::define(&context)?;
 
-        let module = context
-            .import_module("./main.ts", "")
-            .expect("Unable to load main");
+        let module = context.import_module("./main.ts", "")?;
 
-        let init = module
-            .get_export(&context, "init")
-            .expect("Unable to fetch init");
-        let suspend = module
-            .get_export(&context, "suspend")
-            .expect("Unable to fetch suspend");
-        let resume = module
-            .get_export(&context, "resume")
-            .expect("Unable to fetch suspend");
-        let update = module
-            .get_export(&context, "update")
-            .expect("Unable to fetch update");
-        let draw = module
-            .get_export(&context, "draw")
-            .expect("Unable to fetch draw");
+        let init = module.get_export(&context, "init")?;
+        let suspend = module.get_export(&context, "suspend")?;
+        let resume = module.get_export(&context, "resume")?;
+        let update = module.get_export(&context, "update")?;
+        let draw = module.get_export(&context, "draw")?;
 
-        let state = context.undefined();
+        let mut state = init.call(&context, &[])?;
+        if let Some(buffer) = suspend_state {
+            if !resume.is_undefined() {
+                let serialized_state = context.deserialize(&buffer)?;
+                state = resume.call(&context, &[&serialized_state, &state])?;
+            }
+        }
 
-        ScriptContext {
+        Ok(ScriptContext {
             context,
 
-            init,
             suspend,
-            resume,
             update,
             draw,
 
@@ -127,7 +115,7 @@ impl ScriptContext {
 
             time,
             input,
-        }
+        })
     }
 
     /// Allow the script to save its state before we destroy it and re-create
@@ -149,36 +137,10 @@ impl ScriptContext {
         }
     }
 
-    /// Allow the script to restore its state after being destroyed and
-    /// re-created.
-    pub fn resume(&mut self, state: &[u8]) {
-        let _span = span!("script resume");
-        if !self.resume.is_undefined() {
-            let suspend_state = self
-                .context
-                .deserialize(state)
-                .expect("Unable to deserialize state");
-            let prev_state = self.state.clone();
-            self.state = self
-                .resume
-                .call(&self.context, &[&suspend_state, &prev_state])
-                .expect("Exception in resume");
-        }
-    }
-
     // TODO: The script could really be on a background thread you know.
     //       We would want a bi-directional gate for frames to not let the
     //       game thread go to fast probably? And to discard whole frames &c.
 
-    pub fn init(&mut self) {
-        let _span = span!("script init");
-
-        self.state = self
-            .init
-            .call(&self.context, &[])
-            .expect("Exception in init");
-    }
-
     pub fn input(&mut self, event: &WindowEvent) -> bool {
         match event {
             WindowEvent::KeyboardInput { input, .. } => self.input.handle_keyboard_input(input),