fix tests

src/effects.js

@@ -181,7 +181,7 @@ export const apply_side_effects = (prev, next, ui) => {
     next.eval_modules_state != null
   ) {
     const s = next.eval_modules_state
-    s.promise.__original_then(result => {
+    s.promise.then(result => {
       exec('eval_modules_finished', 
         next, /* becomes prev_state */
         result, 

src/eval.js

@@ -515,7 +515,8 @@ export const eval_modules = (
   }
 
   if(is_async) {
-    return result.__original_then(make_result)
+    // convert app_window.Promise to host Promise
+    return Promise.resolve(result).then(make_result)
   } else {
     return make_result(result)
   }

src/runtime/record_io.js

@@ -75,7 +75,7 @@ const make_patched_method = (window, original, name, use_context) => {
           ? new original(...args)
           : original.apply(this, args)
 
-        if(value instanceof cxt.window.Promise) {
+        if(value?.[Symbol.toStringTag] == 'Promise') {
           // TODO use __original_then, not finally which calls
           // patched 'then'?
           value = value.finally(() => {

src/runtime/runtime.js

@@ -262,7 +262,7 @@ const __await_start = (cxt, promise) => {
   const children_copy = cxt.children
   const result = {children_copy, promise}
 
-  if(promise instanceof cxt.window.Promise) {
+  if(promise?.[Symbol.toStringTag] == 'Promise') {
     result.promise = promise.then(
       (value) => {
         result.status = {ok: true, value}