From bfcc0978824c742ee56481b617564f7a1c2d1825 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Julien=20Valverd=C3=A9?= <julien.valverde@mailo.com>
Date: Tue, 18 Feb 2025 15:25:46 +0100
Subject: [PATCH] usePromise

---
 packages/example/src/routes/promise.tsx | 46 +++++++--------
 packages/reffuse/src/Reffuse.ts         | 76 +++++++++++++++----------
 2 files changed, 64 insertions(+), 58 deletions(-)

diff --git a/packages/example/src/routes/promise.tsx b/packages/example/src/routes/promise.tsx
index 9d69d62..da200db 100644
--- a/packages/example/src/routes/promise.tsx
+++ b/packages/example/src/routes/promise.tsx
@@ -2,44 +2,36 @@ import { R } from "@/reffuse"
 import { HttpClient } from "@effect/platform"
 import { Text } from "@radix-ui/themes"
 import { createFileRoute } from "@tanstack/react-router"
-import { Console, Effect } from "effect"
-import { Suspense, use, useEffect, useMemo } from "react"
+import { Effect, Schema } from "effect"
+import { Suspense, use } from "react"
 
 
 export const Route = createFileRoute("/promise")({
     component: RouteComponent
 })
 
+
+const Result = Schema.Tuple(Schema.String)
+type Result = typeof Result.Type
+
 function RouteComponent() {
+    const promise = R.usePromise(HttpClient.HttpClient.pipe(
+        Effect.flatMap(client => client.get("https://www.uuidtools.com/api/generate/v4")),
+        HttpClient.withTracerPropagation(false),
+        Effect.flatMap(res => res.json),
+        Effect.flatMap(Schema.decodeUnknown(Result)),
+
+        Effect.scoped,
+    ))
+
     return (
         <Suspense fallback={<Text>Loading...</Text>}>
-            <AsyncComponent />
+            <AsyncComponent promise={promise} />
         </Suspense>
     )
 }
 
-function AsyncComponent() {
-
-    // const runPromise = R.useRunPromise()
-
-    // const promise = useMemo(() => HttpClient.HttpClient.pipe(
-    //     Effect.flatMap(client => client.get("https://www.uuidtools.com/api/generate/v4")),
-    //     HttpClient.withTracerPropagation(false),
-    //     Effect.flatMap(res => res.json),
-    //     Effect.tap(Console.log),
-
-    //     Effect.scoped,
-    //     runPromise,
-    // ), [runPromise])
-
-    const promise = useMemo(() => new Promise<string>((resolve => {
-        setTimeout(() => { resolve("prout") }, 500)
-    })), [])
-
-    console.log("React.use invoked with:", promise);
-    const value = use(promise)
-
-
-    return <div>Hello "/tests"!</div>
-
+function AsyncComponent({ promise }: { readonly promise: Promise<Result> }) {
+    const [uuid] = use(promise)
+    return <Text>{uuid}</Text>
 }
diff --git a/packages/reffuse/src/Reffuse.ts b/packages/reffuse/src/Reffuse.ts
index 4ec7386..cc1755f 100644
--- a/packages/reffuse/src/Reffuse.ts
+++ b/packages/reffuse/src/Reffuse.ts
@@ -284,43 +284,57 @@ export class Reffuse<R> {
         ])
     }
 
-    // useSuspense<A, E>(
-    //     effect: Effect.Effect<A, E, R>,
-    //     deps?: React.DependencyList,
-    //     options?: { readonly signal?: AbortSignal } & RenderOptions,
-    // ): A {
-    //     const runPromise = this.useRunPromise()
+    usePromise<A, E>(
+        effect: Effect.Effect<A, E, R>,
+        deps?: React.DependencyList,
+        options?: { readonly signal?: AbortSignal } & RenderOptions,
+    ): Promise<A> {
+        const runPromise = this.useRunPromise()
 
-    //     const promise = React.useMemo(() => runPromise(effect, options), [
-    //         ...options?.doNotReExecuteOnRuntimeOrContextChange ? [] : [runPromise],
-    //         ...(deps ?? []),
-    //     ])
-    //     return React.use(promise)
-    // }
+        return React.useMemo(() => runPromise(effect, options), [
+            ...options?.doNotReExecuteOnRuntimeOrContextChange ? [] : [runPromise],
+            ...(deps ?? []),
+        ])
+    }
 
-    // useSuspenseScoped<A, E>(
-    //     effect: Effect.Effect<A, E, R | Scope.Scope>,
-    //     deps?: React.DependencyList,
-    //     options?: { readonly signal?: AbortSignal } & RenderOptions & ScopeOptions,
-    // ): A {
-    //     const runSync = this.useRunSync()
-    //     const runPromise = this.useRunPromise()
+    usePromiseScoped<A, E>(
+        effect: Effect.Effect<A, E, R | Scope.Scope>,
+        deps?: React.DependencyList,
+        options?: { readonly signal?: AbortSignal } & RenderOptions & ScopeOptions,
+    ): Promise<A> {
+        const runSync = this.useRunSync()
+        const runPromise = this.useRunPromise()
 
-    //     const initialPromise = React.useMemo(() => runPromise(Effect.scoped(effect)), [])
-    //     const [promise, setPromise] = React.useState(initialPromise)
+        // Calculate an initial version of the value so that it can be accessed during the first render
+        const initialScope = React.useMemo(() => runSync(Scope.make(options?.finalizerExecutionStrategy)), [])
+        const initialValue = React.useMemo(() => runPromise(Effect.provideService(effect, Scope.Scope, initialScope), options), [])
 
-    //     React.useEffect(() => {
-    //         const scope = runSync(Scope.make())
-    //         setPromise(runPromise(Effect.provideService(effect, Scope.Scope, scope), options))
+        // Keep track of the state of the initial scope
+        const initialScopeClosed = React.useRef(false)
 
-    //         return () => { runPromise(Scope.close(scope, Exit.void)) }
-    //     }, [
-    //         ...options?.doNotReExecuteOnRuntimeOrContextChange ? [] : [runSync, runPromise],
-    //         ...(deps ?? []),
-    //     ])
+        const [value, setValue] = React.useState(initialValue)
 
-    //     return React.use(promise)
-    // }
+        React.useEffect(() => {
+            const closeInitialScopeIfNeeded = Scope.close(initialScope, Exit.void).pipe(
+                Effect.andThen(Effect.sync(() => { initialScopeClosed.current = true })),
+                Effect.when(() => !initialScopeClosed.current),
+            )
+
+            const scope = closeInitialScopeIfNeeded.pipe(
+                Effect.andThen(Scope.make(options?.finalizerExecutionStrategy)),
+                runSync,
+            )
+
+            setValue(runPromise(Effect.provideService(effect, Scope.Scope, initialScope), options))
+
+            return () => { runSync(Scope.close(scope, Exit.void)) }
+        }, [
+            ...options?.doNotReExecuteOnRuntimeOrContextChange ? [] : [runSync, runPromise],
+            ...(deps ?? []),
+        ])
+
+        return value
+    }
 
 
     useRef<A>(value: A): SubscriptionRef.SubscriptionRef<A> {