From 0718ba48bd99a18b45992d2d428a0bade3e70481 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Julien=20Valverd=C3=A9?= <julien.valverde@mailo.com>
Date: Sat, 8 Nov 2025 01:35:58 +0100
Subject: [PATCH] Fix ErrorObserver

---
 packages/effect-fc/src/Async.ts         |  5 ++---
 packages/effect-fc/src/Component.ts     | 10 ++++------
 packages/effect-fc/src/ErrorObserver.ts | 21 ++++++++++++++++++---
 3 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/packages/effect-fc/src/Async.ts b/packages/effect-fc/src/Async.ts
index 0a63777..a0dba11 100644
--- a/packages/effect-fc/src/Async.ts
+++ b/packages/effect-fc/src/Async.ts
@@ -2,7 +2,6 @@
 import { Effect, Function, Predicate, Runtime, Scope } from "effect"
 import * as React from "react"
 import * as Component from "./Component.js"
-import * as ErrorObserver from "./ErrorObserver.js"
 
 
 export const TypeId: unique symbol = Symbol.for("@effect-fc/Async/Async")
@@ -32,10 +31,10 @@ const SuspenseProto = Object.freeze({
 
         return ({ fallback, name, ...props }: Async.Props) => {
             const promise = Runtime.runPromise(runtimeRef.current)(
-                ErrorObserver.handle(Effect.andThen(
+                Effect.andThen(
                     Component.useScope([], this),
                     scope => Effect.provideService(this.body(props as P), Scope.Scope, scope),
-                ))
+                )
             )
 
             return React.createElement(
diff --git a/packages/effect-fc/src/Component.ts b/packages/effect-fc/src/Component.ts
index 921ccff..38d8bd0 100644
--- a/packages/effect-fc/src/Component.ts
+++ b/packages/effect-fc/src/Component.ts
@@ -2,7 +2,6 @@
 /** biome-ignore-all lint/complexity/useArrowFunction: necessary for class prototypes */
 import { Context, type Duration, Effect, Effectable, Equivalence, ExecutionStrategy, Exit, Fiber, Function, HashMap, Layer, ManagedRuntime, Option, Predicate, Ref, Runtime, Scope, Tracer, type Utils } from "effect"
 import * as React from "react"
-import * as ErrorObserver from "./ErrorObserver.js"
 import { Memoized } from "./index.js"
 
 
@@ -76,10 +75,10 @@ const ComponentProto = Object.freeze({
         runtimeRef: React.RefObject<Runtime.Runtime<Exclude<R, Scope.Scope>>>,
     ) {
         return (props: P) => Runtime.runSync(runtimeRef.current)(
-            ErrorObserver.handle(Effect.andThen(
+            Effect.andThen(
                 useScope([], this),
                 scope => Effect.provideService(this.body(props), Scope.Scope, scope),
-            ))
+            )
         )
     },
 } as const)
@@ -548,15 +547,14 @@ const runReactEffect = <E, R>(
         () => {
             switch (options?.finalizerExecutionMode ?? "fork") {
                 case "sync":
-                    Runtime.runSync(runtime)(ErrorObserver.handle(Scope.close(scope, Exit.void)))
+                    Runtime.runSync(runtime)(Scope.close(scope, Exit.void))
                     break
                 case "fork":
-                    Runtime.runFork(runtime)(ErrorObserver.handle(Scope.close(scope, Exit.void)))
+                    Runtime.runFork(runtime)(Scope.close(scope, Exit.void))
                     break
             }
         }
     ),
-    ErrorObserver.handle,
     Runtime.runSync(runtime),
 )
 
diff --git a/packages/effect-fc/src/ErrorObserver.ts b/packages/effect-fc/src/ErrorObserver.ts
index cbb1cbe..243242f 100644
--- a/packages/effect-fc/src/ErrorObserver.ts
+++ b/packages/effect-fc/src/ErrorObserver.ts
@@ -1,4 +1,4 @@
-import { type Cause, Context, Effect, Layer, Option, Pipeable, Predicate, PubSub, type Queue, type Scope } from "effect"
+import { type Cause, Context, Effect, Exit, Layer, Option, Pipeable, Predicate, PubSub, type Queue, type Scope, Supervisor } from "effect"
 
 
 export const TypeId: unique symbol = Symbol.for("@effect-fc/ErrorObserver/ErrorObserver")
@@ -29,12 +29,27 @@ extends Pipeable.Class() implements ErrorObserver<E> {
     }
 }
 
+class ErrorObserverSupervisorImpl extends Supervisor.AbstractSupervisor<void> {
+    readonly value = Effect.void
+    constructor(readonly pubsub: PubSub.PubSub<Cause.Cause<never>>) {
+        super()
+    }
+
+    onEnd<A, E>(_value: Exit.Exit<A, E>): void {
+        if (Exit.isFailure(_value))
+            Effect.runSync(PubSub.publish(this.pubsub, _value.cause as Cause.Cause<never>))
+    }
+}
+
 
 export const isErrorObserver = (u: unknown): u is ErrorObserver<unknown> => Predicate.hasProperty(u, TypeId)
 
-export const layer: Layer.Layer<ErrorObserver> = Layer.effect(ErrorObserver(), Effect.andThen(
+export const layer: Layer.Layer<ErrorObserver> = Layer.unwrapEffect(Effect.map(
     PubSub.unbounded<Cause.Cause<never>>(),
-    pubsub => new ErrorObserverImpl(pubsub),
+    pubsub => Layer.merge(
+        Supervisor.addSupervisor(new ErrorObserverSupervisorImpl(pubsub)),
+        Layer.succeed(ErrorObserver(), new ErrorObserverImpl(pubsub)),
+    ),
 ))
 
 export const handle = <A, E, R>(effect: Effect.Effect<A, E, R>): Effect.Effect<A, E, R> => Effect.andThen(