packages/effect-fc/src/Query.ts

@@ -1,4 +1,4 @@
-import { type Cause, type Context, DateTime, Duration, Effect, Exit, Fiber, HashMap, identity, Option, Pipeable, Predicate, type Scope, Stream, type Subscribable, SubscriptionRef } from "effect"
+import { type Cause, type Context, DateTime, type Duration, Effect, Exit, Fiber, HashMap, identity, Option, Pipeable, Predicate, type Scope, Stream, Subscribable, SubscriptionRef } from "effect"
 import * as QueryClient from "./QueryClient.js"
 import * as Result from "./Result.js"
 
@@ -58,7 +58,7 @@ extends Pipeable.Class() implements Query<K, A, E, R, P> {
     get run(): Effect.Effect<void> {
         return Stream.runForEach(this.key, key => this.interrupt.pipe(
             Effect.andThen(SubscriptionRef.set(this.latestKey, Option.some(key))),
-            Effect.andThen(this.start(key, Result.initial(), false)),
+            Effect.andThen(this.startCached(key, Result.initial(), false)),
             Effect.andThen(sub => Effect.forkScoped(this.watch(sub))),
             Effect.provide(this.context),
             this.runSemaphore.withPermits(1),
@@ -75,14 +75,14 @@ extends Pipeable.Class() implements Query<K, A, E, R, P> {
     fetch(key: K): Effect.Effect<Result.Final<A, E, P>> {
         return this.interrupt.pipe(
             Effect.andThen(SubscriptionRef.set(this.latestKey, Option.some(key))),
-            Effect.andThen(Effect.provide(this.start(key, Result.initial(), false), this.context)),
+            Effect.andThen(Effect.provide(this.startCached(key, Result.initial(), false), this.context)),
             Effect.andThen(sub => this.watch(sub)),
         )
     }
     fetchSubscribable(key: K): Effect.Effect<Subscribable.Subscribable<Result.Result<A, E, P>>> {
         return this.interrupt.pipe(
             Effect.andThen(SubscriptionRef.set(this.latestKey, Option.some(key))),
-            Effect.andThen(Effect.provide(this.start(key, Result.initial(), false), this.context)),
+            Effect.andThen(Effect.provide(this.startCached(key, Result.initial(), false), this.context)),
         )
     }
     get refetch(): Effect.Effect<Result.Final<A, E, P>, Cause.NoSuchElementException> {
@@ -118,24 +118,25 @@ extends Pipeable.Class() implements Query<K, A, E, R, P> {
 
     startCached(
         key: K,
+        initial: Result.Result<A, E, P>,
         refresh: boolean,
     ): Effect.Effect<
         Subscribable.Subscribable<Result.Result<A, E, P>>,
         never,
         Scope.Scope | QueryClient.QueryClient | R
     > {
-        return this.getCacheEntry(key).pipe(
-            Effect.andThen(Option.match({
-                onSome: entry => Effect.andThen(
-                    DateTime.now,
-                    now => Duration.lessThan(DateTime.distanceDuration(entry.createdAt, now), this.staleTime)
-                        ? Result.optimistic(entry.result) as Result.Result<A, E, P>
-                        : Result.initial<A, E, P>(),
-                ),
-                onNone: () => Effect.succeed(Result.initial<A, E, P>()),
-            })),
-            Effect.andThen(initial => this.start(key, initial, refresh)),
-        )
+        return Effect.andThen(this.getCacheEntry(key), Option.match({
+            onSome: entry => QueryClient.isQueryClientCacheEntryStale(entry, this.staleTime)
+                ? Effect.map(
+                    SubscriptionRef.set(this.result, entry.result as Result.Result<A, E, P>),
+                    () => Subscribable.make({
+                        get: Effect.succeed(entry.result as Result.Result<A, E, P>),
+                        get changes() { return Stream.empty },
+                    }),
+                )
+                : this.start(key, Result.optimistic(entry.result) as Result.Result<A, E, P>, false),
+            onNone: () => this.start(key, initial, refresh),
+        }))
     }
 
     start(

packages/effect-fc/src/QueryClient.ts

@@ -1,4 +1,4 @@
-import { type DateTime, type Duration, Effect, Equal, Equivalence, Hash, HashMap, Pipeable, Predicate, type Scope, SubscriptionRef } from "effect"
+import { DateTime, Duration, Effect, Equal, Equivalence, Hash, HashMap, Pipeable, Predicate, type Scope, SubscriptionRef } from "effect"
 import type * as Query from "./Query.js"
 import type * as Result from "./Result.js"
 
@@ -105,3 +105,11 @@ implements Pipeable.Pipeable {
 }
 
 export const isQueryClientCacheEntry = (u: unknown): u is QueryClientCacheEntry => Predicate.hasProperty(u, QueryClientCacheEntryTypeId)
+
+export const isQueryClientCacheEntryStale = (
+    self: QueryClientCacheEntry,
+    staleTime: Duration.DurationInput,
+): Effect.Effect<boolean> => Effect.andThen(
+    DateTime.now,
+    now => Duration.lessThan(DateTime.distanceDuration(self.createdAt, now), staleTime),
+)