packages/effect-fc-next/src/Component.ts

@@ -1,6 +1,6 @@
 /** biome-ignore-all lint/complexity/noBannedTypes: {} is the default type for React props */
 /** biome-ignore-all lint/complexity/useArrowFunction: necessary for class prototypes */
-import { Cause, Context, type Duration, Effect, Equal, Equivalence, Exit, Fiber, Function, HashMap, identity, Layer, Option, Pipeable, Predicate, Ref, Scheduler, Scope, Tracer } from "effect"
+import { Context, type Duration, Effect, Equivalence, Exit, Function, identity, Layer, Pipeable, Predicate, Scheduler, Scope, Tracer } from "effect"
 import * as React from "react"
 import * as ScopeRegistry from "./ScopeRegistry.js"
 
@@ -668,54 +668,26 @@ export const useScope = Effect.fnUntraced(function*(
     // biome-ignore lint/style/noNonNullAssertion: context initialization
     const contextRef = React.useRef<Context.Context<never>>(null!)
     contextRef.current = yield* Effect.context()
+    const registry = yield* ScopeRegistry.ScopeRegistry as unknown as Effect.Effect<ScopeRegistry.ScopeRegistryService>
 
-    const { key, scope } = React.useMemo(() => Effect.runSyncWith(contextRef.current)(Effect.Do.pipe(
-        Effect.bind("scopeRegistryRef", () => Effect.map(
-            ScopeRegistry.ScopeRegistry as unknown as Effect.Effect<ScopeRegistry.ScopeRegistry["Service"]>,
-            scopeRegistry => scopeRegistry.ref,
-        )),
-        Effect.let("key", () => Equal.byReference({})),
-        Effect.bind("scope", () => Scope.make(options?.finalizerExecutionStrategy ?? defaultOptions.finalizerExecutionStrategy)),
-        Effect.tap(({ scopeRegistryRef, key, scope }) =>
-            Ref.update(scopeRegistryRef, HashMap.set(key, Equal.byReference({
-                scope,
-                closeFiber: Option.none(),
-            })))
-        ),
+    const [key, scope] = React.useMemo(() => Effect.runSyncWith(contextRef.current)(Effect.gen(function*() {
+        const key = ScopeRegistry.makeKey()
+        const entry = yield* registry.register(key, {
+            finalizerExecutionStrategy: options?.finalizerExecutionStrategy ?? defaultOptions.finalizerExecutionStrategy,
+            finalizerExecutionDebounce: options?.finalizerExecutionDebounce ?? defaultOptions.finalizerExecutionDebounce,
+        })
+
+        return [key, entry.scope]
     // biome-ignore lint/correctness/useExhaustiveDependencies: use of React.DependencyList
-    )), deps)
+    })), deps)
 
     // biome-ignore lint/correctness/useExhaustiveDependencies: only reactive on "key"
-    React.useEffect(() => Effect.runSyncWith(contextRef.current)(
-        (ScopeRegistry.ScopeRegistry as unknown as Effect.Effect<ScopeRegistry.ScopeRegistry["Service"]>).pipe(
-            Effect.map(scopeRegistry => scopeRegistry.ref),
-            Effect.tap(ref => Ref.get(ref).pipe(
-                Effect.flatMap(map => Effect.fromOption(HashMap.get(map, key))),
-                Effect.flatMap(entry => Option.match(entry.closeFiber, {
-                    onSome: fiber => Effect.forkDetach(Fiber.interrupt(fiber)),
-                    onNone: () => Effect.void,
-                })),
-            )),
-            Effect.map(ref =>
-                () => Effect.runSyncWith(contextRef.current)(Effect.flatMap(
-                    Effect.sleep(options?.finalizerExecutionDebounce ?? defaultOptions.finalizerExecutionDebounce).pipe(
-                        Effect.andThen(Scope.close(scope, Exit.void)),
-                        Effect.onExit(exit => Exit.match(exit, {
-                            onSuccess: () => Ref.update(ref, HashMap.remove(key)),
-                            onFailure: cause => Cause.hasInterruptsOnly(cause)
-                                ? Effect.void
-                                : Ref.update(ref, HashMap.remove(key)),
-                        })),
-                        Effect.forkDetach,
-                    ),
-                    fiber => Ref.update(ref, HashMap.set(key, Equal.byReference({
-                        scope,
-                        closeFiber: Option.some(fiber),
-                    }))),
-                ))
-            ),
-        )
-    ), [key])
+    React.useEffect(() => {
+        Effect.runSyncWith(contextRef.current)(registry.commit(key))
+        return () => {
+            Effect.runSyncWith(contextRef.current)(registry.release(key))
+        }
+    }, [key])
 
     return scope
 })

packages/effect-fc-next/src/ReactRuntime.ts

@@ -17,7 +17,7 @@ export interface ReactRuntime<R, ER> {
 
 const ReactRuntimePrototype = Object.freeze({ [ReactRuntimeTypeId]: ReactRuntimeTypeId } as const)
 
-export const preludeLayer: Layer.Layer<ScopeRegistry.ScopeRegistry> = ScopeRegistry.ScopeRegistry.layer
+export const preludeLayer: Layer.Layer<ScopeRegistry.ScopeRegistry> = ScopeRegistry.layer
 
 export const isReactRuntime = (u: unknown): u is ReactRuntime<unknown, unknown> => Predicate.hasProperty(u, ReactRuntimeTypeId)
 

packages/effect-fc-next/src/ScopeRegistry.ts

@@ -1,4 +1,185 @@
-import { Context, Effect, type Fiber, HashMap, Layer, type Option, Ref, type Scope } from "effect"
+import { type Cause, Context, DateTime, type Duration, Effect, Equal, Exit, HashMap, Layer, Option, Scope, Semaphore, Stream, SubscriptionRef } from "effect"
+
+
+export interface ScopeRegistryService {
+    readonly ref: SubscriptionRef.SubscriptionRef<HashMap.HashMap<ScopeRegistryService.Key, ScopeRegistryService.Entry>>
+
+    register(
+        key: ScopeRegistryService.Key,
+        options: ScopeRegistryService.RegisterOptions,
+    ): Effect.Effect<ScopeRegistryService.Entry>
+    commit(key: ScopeRegistryService.Key): Effect.Effect<ScopeRegistryService.Entry, Cause.NoSuchElementError>
+    release(key: ScopeRegistryService.Key): Effect.Effect<ScopeRegistryService.Entry, Cause.NoSuchElementError>
+
+    readonly run: Effect.Effect<void>
+    readonly dispose: Effect.Effect<void>
+}
+
+export declare namespace ScopeRegistryService {
+    export type Key = object
+
+    export interface RegisterOptions {
+        readonly finalizerExecutionStrategy: "sequential" | "parallel"
+        readonly finalizerExecutionDebounce: Duration.Input
+    }
+
+    export interface Entry {
+        readonly scope: Scope.Closeable
+        readonly leases: number
+        readonly expiresAt: Option.Option<DateTime.Utc>
+        readonly finalizerExecutionDebounce: Duration.Input
+    }
+}
+
+export const makeKey = (): ScopeRegistryService.Key => Equal.byReference({})
+
+
+export class ScopeRegistryServiceImpl implements ScopeRegistryService {
+    constructor(
+        readonly ref: SubscriptionRef.SubscriptionRef<HashMap.HashMap<ScopeRegistryService.Key, ScopeRegistryService.Entry>>,
+        readonly runSemaphore: Semaphore.Semaphore,
+    ) {}
+
+
+    register(
+        key: ScopeRegistryService.Key,
+        options: ScopeRegistryService.RegisterOptions,
+    ): Effect.Effect<ScopeRegistryService.Entry> {
+        return Effect.gen({ self: this }, function*() {
+            const now = yield* DateTime.now
+            const entry = Equal.byReference<ScopeRegistryService.Entry>({
+                scope: yield* Scope.make(options.finalizerExecutionStrategy),
+                leases: 0,
+                expiresAt: Option.some(DateTime.addDuration(now, options.finalizerExecutionDebounce)),
+                finalizerExecutionDebounce: options.finalizerExecutionDebounce,
+            })
+
+            yield* SubscriptionRef.update(this.ref, HashMap.set(key, entry))
+
+            return entry
+        })
+    }
+
+    commit(key: ScopeRegistryService.Key): Effect.Effect<ScopeRegistryService.Entry, Cause.NoSuchElementError> {
+        return this.updateEntry(key, entry => Equal.byReference({
+            ...entry,
+            leases: entry.leases + 1,
+            expiresAt: Option.none(),
+        }))
+    }
+
+    release(key: ScopeRegistryService.Key): Effect.Effect<ScopeRegistryService.Entry, Cause.NoSuchElementError> {
+        return Effect.flatMap(DateTime.now, now => this.updateEntry(key, entry => {
+            if (entry.leases === 0)
+                return entry
+
+            const leases = entry.leases - 1
+            return Equal.byReference({
+                ...entry,
+                leases,
+                expiresAt: leases === 0
+                    ? Option.some(DateTime.addDuration(now, entry.finalizerExecutionDebounce))
+                    : Option.none(),
+            })
+        }))
+    }
+
+    get run(): Effect.Effect<void> {
+        return this.runSemaphore.withPermits(1)(SubscriptionRef.changes(this.ref).pipe(
+            Stream.switchMap(entries => Option.match(this.getNextExpiration(entries), {
+                onNone: () => Stream.never,
+                onSome: expiresAt => Stream.fromEffect(DateTime.now.pipe(
+                    Effect.flatMap(now => DateTime.isLessThan(now, expiresAt)
+                        ? Effect.sleep(DateTime.distance(now, expiresAt))
+                        : Effect.void),
+                    Effect.andThen(Effect.uninterruptible(this.closeExpired)),
+                )),
+            })),
+            Stream.runDrain,
+        ))
+    }
+
+    get dispose(): Effect.Effect<void> {
+        return SubscriptionRef.getAndSet(
+            this.ref,
+            HashMap.empty<ScopeRegistryService.Key, ScopeRegistryService.Entry>(),
+        ).pipe(
+            Effect.flatMap(entries => Effect.forEach(
+                HashMap.values(entries),
+                entry => Scope.close(entry.scope, Exit.void),
+            )),
+            Effect.asVoid,
+        )
+    }
+
+
+    updateEntry(
+        key: ScopeRegistryService.Key,
+        f: (entry: ScopeRegistryService.Entry) => ScopeRegistryService.Entry,
+    ): Effect.Effect<ScopeRegistryService.Entry, Cause.NoSuchElementError> {
+        return SubscriptionRef.modify(this.ref, entries => {
+            const current = HashMap.get(entries, key)
+
+            if (current._tag === "None")
+                return [Option.none(), entries]
+
+            const entry = f(current.value)
+            return [Option.some(entry), HashMap.set(entries, key, entry)]
+        }).pipe(Effect.flatMap(Effect.fromOption))
+    }
+
+    get closeExpired(): Effect.Effect<void> {
+        return Effect.flatMap(DateTime.now, now => SubscriptionRef.modify(
+            this.ref,
+            entries => {
+                const expired: ScopeRegistryService.Entry[] = []
+                const remaining = HashMap.filter(entries, entry => {
+                    const shouldClose = entry.leases === 0 && Option.exists(
+                        entry.expiresAt,
+                        expiresAt => DateTime.isLessThanOrEqualTo(expiresAt, now),
+                    )
+
+                    if (shouldClose)
+                        expired.push(entry)
+
+                    return !shouldClose
+                })
+
+                return [expired, remaining]
+            },
+        )).pipe(
+            Effect.flatMap(entries => Effect.forEach(
+                entries,
+                entry => Scope.close(entry.scope, Exit.void),
+            )),
+            Effect.asVoid,
+        )
+    }
+
+    getNextExpiration(
+        entries: HashMap.HashMap<ScopeRegistryService.Key, ScopeRegistryService.Entry>,
+    ): Option.Option<DateTime.Utc> {
+        let earliest: DateTime.Utc | undefined
+
+        for (const entry of HashMap.values(entries)) {
+            if (
+                entry.leases === 0 &&
+                entry.expiresAt._tag === "Some" &&
+                (!earliest || DateTime.isLessThan(entry.expiresAt.value, earliest))
+            )
+                earliest = entry.expiresAt.value
+        }
+
+        return Option.fromNullishOr(earliest)
+    }
+}
+
+export const make: Effect.Effect<ScopeRegistryService> = Effect.gen(function*() {
+    return new ScopeRegistryServiceImpl(
+        yield* SubscriptionRef.make(HashMap.empty<ScopeRegistryService.Key, ScopeRegistryService.Entry>()),
+        yield* Semaphore.make(1),
+    )
+})
 
 
 /**
@@ -7,20 +188,14 @@ import { Context, Effect, type Fiber, HashMap, Layer, type Option, Ref, type Sco
  * This service is used internally by the `Component.useScope` hook to manage the lifecycle of component scopes,
  * including tracking active scopes and coordinating their cleanup when components unmount or dependencies change.
  */
-export class ScopeRegistry extends Context.Service<ScopeRegistry, {
-    readonly ref: Ref.Ref<HashMap.HashMap<object, ScopeRegistry.Entry>>
-}>()(
-    "@effect-fc/ScopeRegistry/ScopeRegistry"
-) {
-    static readonly layer = Layer.effect(ScopeRegistry, Effect.map(
-        Ref.make(HashMap.empty<object, ScopeRegistry.Entry>()),
-        ref => ({ ref }),
-    ))
-}
+export class ScopeRegistry extends Context.Service<ScopeRegistry, ScopeRegistryService>()(
+    "@effect-view/ScopeRegistry/ScopeRegistry"
+) {}
 
-export declare namespace ScopeRegistry {
-    export interface Entry {
-        readonly scope: Scope.Closeable
-        readonly closeFiber: Option.Option<Fiber.Fiber<void>>
-    }
-}
+export const layer = Layer.effect(ScopeRegistry, Effect.tap(
+    make,
+    registry => Effect.andThen(
+        Effect.addFinalizer(() => registry.dispose),
+        Effect.forkScoped(registry.run),
+    ),
+))

packages/effect-fc-next/test/Component.test.tsx

@@ -1,5 +1,5 @@
 import { act, fireEvent, render, screen, waitFor } from "@testing-library/react"
-import { Context, Effect, HashMap, Layer, Ref } from "effect"
+import { Context, Effect, HashMap, Layer, SubscriptionRef } from "effect"
 import * as React from "react"
 import { afterEach, describe, expect, it, vi } from "vitest"
 import * as Component from "../src/Component.js"
@@ -362,7 +362,7 @@ describe("Component", () => {
         await runtime.runtime.dispose()
     })
 
-    it.fails("does not commit effects or retain registered scopes for a discarded Suspense render", async () => {
+    it("does not commit effects or retain registered scopes for a discarded Suspense render", async () => {
         const setup = vi.fn()
         const runtime = ReactRuntime.make(Layer.empty)
         const effectRuntime = await runtime.runtime.context()
@@ -391,7 +391,7 @@ describe("Component", () => {
         try {
             await screen.findByText("fallback")
             expect(setup).not.toHaveBeenCalled()
-            expect(HashMap.size(Effect.runSync(Ref.get(scopeRegistry.ref)))).toBe(0)
+            await waitFor(() => expect(HashMap.size(Effect.runSync(SubscriptionRef.get(scopeRegistry.ref)))).toBe(0))
         }
         finally {
             view.unmount()
@@ -399,7 +399,45 @@ describe("Component", () => {
         }
     })
 
-    it.fails("clears ScopeRegistry after a suspended render retries, commits, and unmounts", async () => {
+    it("keeps committed scopes alive without heartbeats", async () => {
+        const acquisitions = vi.fn()
+        const releases = vi.fn()
+        const runtime = ReactRuntime.make(Layer.empty)
+        const effectRuntime = await runtime.runtime.context()
+        const scopeRegistry = Context.get(effectRuntime, ScopeRegistry.ScopeRegistry)
+
+        const Probe = Component.makeUntraced("CommittedScopeProbe")(function*() {
+            yield* Component.useOnMount(() => Effect.gen(function*() {
+                yield* Effect.sync(acquisitions)
+                yield* Effect.addFinalizer(() => Effect.sync(releases))
+            }))
+
+            return <div>committed</div>
+        }).pipe(
+            Component.withOptions({ finalizerExecutionDebounce: "10 millis" }),
+            Component.withContext(runtime.context),
+        )
+
+        const view = render(
+            <runtime.context.Provider value={effectRuntime}>
+                <Probe />
+            </runtime.context.Provider>
+        )
+
+        await screen.findByText("committed")
+        await waitFor(() => expect(releases).toHaveBeenCalledTimes(acquisitions.mock.calls.length - 1))
+        await new Promise(resolve => setTimeout(resolve, 30))
+
+        expect(HashMap.size(Effect.runSync(SubscriptionRef.get(scopeRegistry.ref)))).toBe(1)
+        expect(releases).toHaveBeenCalledTimes(acquisitions.mock.calls.length - 1)
+
+        view.unmount()
+        await waitFor(() => expect(releases).toHaveBeenCalledTimes(acquisitions.mock.calls.length))
+        await waitFor(() => expect(HashMap.size(Effect.runSync(SubscriptionRef.get(scopeRegistry.ref)))).toBe(0))
+        await runtime.runtime.dispose()
+    })
+
+    it("clears ScopeRegistry after a suspended render retries, commits, and unmounts", async () => {
         const lifecycle = vi.fn<(message: string) => void>()
         const runtime = ReactRuntime.make(Layer.empty)
         const effectRuntime = await runtime.runtime.context()
@@ -441,7 +479,7 @@ describe("Component", () => {
             await waitFor(() => expect(lifecycle).toHaveBeenCalledWith("mount"))
 
             view.unmount()
-            await waitFor(() => expect(HashMap.size(Effect.runSync(Ref.get(scopeRegistry.ref)))).toBe(0))
+            await waitFor(() => expect(HashMap.size(Effect.runSync(SubscriptionRef.get(scopeRegistry.ref)))).toBe(0))
             expect(lifecycle.mock.calls.filter(([message]) => message === "mount")).toHaveLength(2)
             expect(lifecycle.mock.calls.filter(([message]) => message === "cleanup")).toHaveLength(2)
         }