Refactor Query

packages/effect-fc/src/Query.ts

@@ -20,14 +20,15 @@ extends Pipeable.Pipeable {
     readonly latestKey: Subscribable.Subscribable<Option.Option<K>>
     readonly fiber: Subscribable.Subscribable<Option.Option<Fiber.Fiber<A, E>>>
     readonly result: Subscribable.Subscribable<Result.Result<A, E, P>>
+    readonly latestFinalResult: Subscribable.Subscribable<Option.Option<Result.Final<A, E, P>>>
 
     readonly run: Effect.Effect<void>
     fetch(key: K): Effect.Effect<Result.Final<A, E, P>>
-    fetchSubscribable(key: K): Effect.Effect<Subscribable.Subscribable<Result.Result<A, E, P>>>
+    fetchSubscribable(key: K): Effect.Effect<Subscribable.Subscribable<Result.Result<A, E, P>>, never, Scope.Scope>
     readonly refetch: Effect.Effect<Result.Final<A, E, P>, Cause.NoSuchElementException>
-    readonly refetchSubscribable: Effect.Effect<Subscribable.Subscribable<Result.Result<A, E, P>>, Cause.NoSuchElementException>
+    readonly refetchSubscribable: Effect.Effect<Subscribable.Subscribable<Result.Result<A, E, P>>, Cause.NoSuchElementException, Scope.Scope>
     readonly refresh: Effect.Effect<Result.Final<A, E, P>, Cause.NoSuchElementException>
-    readonly refreshSubscribable: Effect.Effect<Subscribable.Subscribable<Result.Result<A, E, P>>, Cause.NoSuchElementException>
+    readonly refreshSubscribable: Effect.Effect<Subscribable.Subscribable<Result.Result<A, E, P>>, Cause.NoSuchElementException, Scope.Scope>
 }
 
 export declare namespace Query {
@@ -49,6 +50,7 @@ extends Pipeable.Class() implements Query<K, A, E, R, P> {
         readonly latestKey: SubscriptionRef.SubscriptionRef<Option.Option<K>>,
         readonly fiber: SubscriptionRef.SubscriptionRef<Option.Option<Fiber.Fiber<A, E>>>,
         readonly result: SubscriptionRef.SubscriptionRef<Result.Result<A, E, P>>,
+        readonly latestFinalResult: SubscriptionRef.SubscriptionRef<Option.Option<Result.Final<A, E, P>>>,
 
         readonly runSemaphore: Effect.Semaphore,
     ) {
@@ -56,13 +58,19 @@ extends Pipeable.Class() implements Query<K, A, E, R, P> {
     }
 
     get run(): Effect.Effect<void> {
-        return Stream.runForEach(this.key, key => this.interrupt.pipe(
+        return Effect.provide(
+            Stream.runForEach(this.key, key => this.interrupt.pipe(
                 Effect.andThen(SubscriptionRef.set(this.latestKey, Option.some(key))),
-            Effect.andThen(this.startCached(key, Result.initial(), false)),
+                Effect.andThen(this.latestFinalResult),
+                Effect.andThen(previous => this.startCached(key, Option.isSome(previous)
+                    ? Result.willFetch(previous.value) as Result.Final<A, E, P>
+                    : Result.initial()
+                )),
                 Effect.andThen(sub => Effect.forkScoped(this.watch(sub))),
-            Effect.provide(this.context),
                 this.runSemaphore.withPermits(1),
-        ))
+            )),
+            this.context,
+        )
     }
 
     get interrupt(): Effect.Effect<void, never, never> {
@@ -75,51 +83,112 @@ 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.startCached(key, Result.initial(), false), this.context)),
+            Effect.andThen(this.latestFinalResult),
+            Effect.andThen(previous => Effect.provide(
+                this.startCached(key, Option.isSome(previous)
+                    ? Result.willFetch(previous.value) as Result.Final<A, E, P>
+                    : Result.initial()
+                ),
+                this.context,
+            )),
             Effect.andThen(sub => this.watch(sub)),
         )
     }
-    fetchSubscribable(key: K): Effect.Effect<Subscribable.Subscribable<Result.Result<A, E, P>>> {
+
+    fetchSubscribable(key: K): Effect.Effect<
+        Subscribable.Subscribable<Result.Result<A, E, P>>,
+        never,
+        Scope.Scope
+    > {
         return this.interrupt.pipe(
             Effect.andThen(SubscriptionRef.set(this.latestKey, Option.some(key))),
-            Effect.andThen(Effect.provide(this.startCached(key, Result.initial(), false), this.context)),
+            Effect.andThen(this.latestFinalResult),
+            Effect.andThen(previous => Effect.provide(
+                this.startCached(key, Option.isSome(previous)
+                    ? Result.willFetch(previous.value) as Result.Final<A, E, P>
+                    : Result.initial()
+                ),
+                this.context,
+            )),
+            Effect.tap(sub => Effect.forkScoped(this.watch(sub))),
         )
     }
+
     get refetch(): Effect.Effect<Result.Final<A, E, P>, Cause.NoSuchElementException> {
         return this.interrupt.pipe(
-            Effect.andThen(this.latestKey),
-            Effect.andThen(identity),
-            Effect.andThen(key => Effect.provide(this.start(key, Result.initial(), false), this.context)),
+            Effect.andThen(Effect.Do),
+            Effect.bind("latestKey", () => Effect.andThen(this.latestKey, identity)),
+            Effect.bind("latestFinalResult", () => this.latestFinalResult),
+            Effect.andThen(({ latestKey, latestFinalResult }) => Effect.provide(
+                this.startCached(latestKey, Option.isSome(latestFinalResult)
+                    ? Result.willFetch(latestFinalResult.value) as Result.Final<A, E, P>
+                    : Result.initial()
+                ),
+                this.context,
+            )),
             Effect.andThen(sub => this.watch(sub)),
         )
     }
-    get refetchSubscribable(): Effect.Effect<Subscribable.Subscribable<Result.Result<A, E, P>>, Cause.NoSuchElementException> {
+
+    get refetchSubscribable(): Effect.Effect<
+        Subscribable.Subscribable<Result.Result<A, E, P>>,
+        Cause.NoSuchElementException,
+        Scope.Scope
+    > {
         return this.interrupt.pipe(
-            Effect.andThen(this.latestKey),
-            Effect.andThen(identity),
-            Effect.andThen(key => Effect.provide(this.start(key, Result.initial(), false), this.context)),
+            Effect.andThen(Effect.Do),
+            Effect.bind("latestKey", () => Effect.andThen(this.latestKey, identity)),
+            Effect.bind("latestFinalResult", () => this.latestFinalResult),
+            Effect.andThen(({ latestKey, latestFinalResult }) => Effect.provide(
+                this.startCached(latestKey, Option.isSome(latestFinalResult)
+                    ? Result.willFetch(latestFinalResult.value) as Result.Final<A, E, P>
+                    : Result.initial()
+                ),
+                this.context,
+            )),
+            Effect.tap(sub => Effect.forkScoped(this.watch(sub))),
         )
     }
+
     get refresh(): Effect.Effect<Result.Final<A, E, P>, Cause.NoSuchElementException> {
         return this.interrupt.pipe(
-            Effect.andThen(this.latestKey),
-            Effect.andThen(identity),
-            Effect.andThen(key => Effect.provide(this.start(key, Result.initial(), true), this.context)),
+            Effect.andThen(Effect.Do),
+            Effect.bind("latestKey", () => Effect.andThen(this.latestKey, identity)),
+            Effect.bind("latestFinalResult", () => this.latestFinalResult),
+            Effect.andThen(({ latestKey, latestFinalResult }) => Effect.provide(
+                this.startCached(latestKey, Option.isSome(latestFinalResult)
+                    ? Result.willRefresh(latestFinalResult.value) as Result.Final<A, E, P>
+                    : Result.initial()
+                ),
+                this.context,
+            )),
             Effect.andThen(sub => this.watch(sub)),
         )
     }
-    get refreshSubscribable(): Effect.Effect<Subscribable.Subscribable<Result.Result<A, E, P>>, Cause.NoSuchElementException> {
+
+    get refreshSubscribable(): Effect.Effect<
+        Subscribable.Subscribable<Result.Result<A, E, P>>,
+        Cause.NoSuchElementException,
+        Scope.Scope
+    > {
         return this.interrupt.pipe(
-            Effect.andThen(this.latestKey),
-            Effect.andThen(identity),
-            Effect.andThen(key => Effect.provide(this.start(key, Result.initial(), true), this.context)),
+            Effect.andThen(Effect.Do),
+            Effect.bind("latestKey", () => Effect.andThen(this.latestKey, identity)),
+            Effect.bind("latestFinalResult", () => this.latestFinalResult),
+            Effect.andThen(({ latestKey, latestFinalResult }) => Effect.provide(
+                this.startCached(latestKey, Option.isSome(latestFinalResult)
+                    ? Result.willRefresh(latestFinalResult.value) as Result.Final<A, E, P>
+                    : Result.initial()
+                ),
+                this.context,
+            )),
+            Effect.tap(sub => Effect.forkScoped(this.watch(sub))),
         )
     }
 
     startCached(
         key: K,
-        initial: Result.Result<A, E, P>,
-        refresh: boolean,
+        initial: Result.Initial | Result.Final<A, E, P>,
     ): Effect.Effect<
         Subscribable.Subscribable<Result.Result<A, E, P>>,
         never,
@@ -127,43 +196,35 @@ extends Pipeable.Class() implements Query<K, A, E, R, P> {
     > {
         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({
+                ? Effect.succeed(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),
+                    get changes() { return Stream.make(entry.result as Result.Result<A, E, P>) },
+                }))
+                : this.start(key, Result.willRefresh(entry.result) as Result.Final<A, E, P>),
+            onNone: () => this.start(key, initial),
         }))
     }
 
     start(
         key: K,
-        initial: Result.Result<A, E, P>,
-        refresh: boolean,
+        initial: Result.Initial | Result.Final<A, E, P>,
     ): Effect.Effect<
         Subscribable.Subscribable<Result.Result<A, E, P>>,
         never,
         Scope.Scope | QueryClient.QueryClient | R
     > {
-        return this.result.pipe(
-            Effect.map(previous => Result.isFinal(previous) ? previous : undefined),
-            Effect.andThen(previous => Result.unsafeForkEffect(
+        return Result.unsafeForkEffect(
             Effect.onExit(this.f(key), exit => Effect.andThen(
                 Exit.isSuccess(exit)
-                        ? this.updateCacheEntry(key, Result.succeed(exit.value))
+                    ? this.updateCacheEntry(key, Result.fromExit(exit))
                     : Effect.void,
                 SubscriptionRef.set(this.fiber, Option.none()),
             )),
             {
                 initial,
                 initialProgress: this.initialProgress,
-                    refresh: refresh && previous,
-                    previous,
             } as Result.unsafeForkEffect.Options<A, E, P>,
-            )),
+        ).pipe(
             Effect.tap(([, fiber]) => SubscriptionRef.set(this.fiber, Option.some(fiber))),
             Effect.map(([sub]) => sub),
         )
@@ -172,14 +233,14 @@ extends Pipeable.Class() implements Query<K, A, E, R, P> {
     watch(
         sub: Subscribable.Subscribable<Result.Result<A, E, P>>
     ): Effect.Effect<Result.Final<A, E, P>> {
-        return Effect.andThen(
-            sub.get,
-            initial => Stream.runFoldEffect(
+        return sub.get.pipe(
+            Effect.andThen(initial => Stream.runFoldEffect(
                 Stream.filter(sub.changes, Predicate.not(Result.isInitial)),
                 initial,
                 (_, result) => Effect.as(SubscriptionRef.set(this.result, result), result),
-            ),
-        ) as Effect.Effect<Result.Final<A, E, P>>
+            ) as Effect.Effect<Result.Final<A, E, P>>),
+            Effect.tap(result => SubscriptionRef.set(this.latestFinalResult, Option.some(result))),
+        )
     }
 
     getCacheEntry(
@@ -239,6 +300,7 @@ export const make = Effect.fnUntraced(function* <K extends Query.AnyKey, A, E =
         yield* SubscriptionRef.make(Option.none<K>()),
         yield* SubscriptionRef.make(Option.none<Fiber.Fiber<A, E>>()),
         yield* SubscriptionRef.make(Result.initial<A, E, P>()),
+        yield* SubscriptionRef.make(Option.none<Result.Final<A, E, P>>()),
 
         yield* Effect.makeSemaphore(1),
     )

packages/effect-fc/src/Result.ts

@@ -1,18 +1,17 @@
-import { Cause, Context, Data, Effect, Equal, Exit, type Fiber, Hash, Layer, Match, Option, Pipeable, Predicate, PubSub, pipe, Ref, type Scope, Stream, Subscribable } from "effect"
+import { Cause, Context, Data, Effect, Equal, Exit, type Fiber, Hash, Layer, Match, Pipeable, Predicate, PubSub, pipe, Ref, type Scope, Stream, Subscribable } from "effect"
 
 
 export const ResultTypeId: unique symbol = Symbol.for("@effect-fc/Result/Result")
 export type ResultTypeId = typeof ResultTypeId
 
 export type Result<A, E = never, P = never> = (
-    // biome-ignore lint/complexity/noBannedTypes: "{}" is relevant here
-    | (Initial & ({} | WillFetch))
+    | Initial
     | Running<P>
     | Final<A, E, P>
 )
 
 // biome-ignore lint/complexity/noBannedTypes: "{}" is relevant here
-export type Final<A, E = never, P = never> = (Success<A> | Failure<A, E>) & ({} | Flags<P>)
+export type Final<A, E = never, P = never> = (Success<A> | Failure<E>) & ({} | Flags<P>)
 export type Flags<P = never> = WillFetch | WillRefresh | Refreshing<P>
 
 export declare namespace Result {
@@ -43,10 +42,9 @@ export interface Success<A> extends Result.Prototype {
     readonly value: A
 }
 
-export interface Failure<A, E = never> extends Result.Prototype {
+export interface Failure<E = never> extends Result.Prototype {
     readonly _tag: "Failure"
     readonly cause: Cause.Cause<E>
-    readonly previousSuccess: Option.Option<Success<A>>
 }
 
 export interface WillFetch {
@@ -76,7 +74,7 @@ const ResultPrototype = Object.freeze({
             Match.tag("Initial", () => true),
             Match.tag("Running", self => Equal.equals(self.progress, (that as Running<any>).progress)),
             Match.tag("Success", self => Equal.equals(self.value, (that as Success<any>).value)),
-            Match.tag("Failure", self => Equal.equals(self.cause, (that as Failure<any, any>).cause)),
+            Match.tag("Failure", self => Equal.equals(self.cause, (that as Failure<any>).cause)),
             Match.exhaustive,
         )
     },
@@ -105,7 +103,7 @@ export const isFinal = (u: unknown): u is Final<unknown, unknown, unknown> => is
 export const isInitial = (u: unknown): u is Initial => isResult(u) && u._tag === "Initial"
 export const isRunning = (u: unknown): u is Running<unknown> => isResult(u) && u._tag === "Running"
 export const isSuccess = (u: unknown): u is Success<unknown> => isResult(u) && u._tag === "Success"
-export const isFailure = (u: unknown): u is Failure<unknown, unknown> => isResult(u) && u._tag === "Failure"
+export const isFailure = (u: unknown): u is Failure<unknown> => isResult(u) && u._tag === "Failure"
 export const hasFlag = (u: unknown): u is Flags => isResult(u) && Predicate.hasProperty(u, "_flag")
 export const hasWillFetchFlag = (u: unknown): u is WillFetch => isResult(u) && Predicate.hasProperty(u, "_flag") && u._flag === "WillFetch"
 export const hasWillRefreshFlag = (u: unknown): u is WillRefresh => isResult(u) && Predicate.hasProperty(u, "_flag") && u._flag === "WillRefresh"
@@ -117,17 +115,9 @@ export const initial: {
 } = (): Initial => Object.setPrototypeOf({ _tag: "Initial" }, ResultPrototype)
 export const running = <P = never>(progress?: P): Running<P> => Object.setPrototypeOf({ _tag: "Running", progress }, ResultPrototype)
 export const succeed = <A>(value: A): Success<A> => Object.setPrototypeOf({ _tag: "Success", value }, ResultPrototype)
+export const fail = <E>(cause: Cause.Cause<E> ): Failure<E> => Object.setPrototypeOf({ _tag: "Failure", cause }, ResultPrototype)
 
-export const fail = <E, A = never>(
-    cause: Cause.Cause<E>,
-    previousSuccess?: Success<NoInfer<A>>,
-): Failure<A, E> => Object.setPrototypeOf({
-    _tag: "Failure",
-    cause,
-    previousSuccess: Option.fromNullable(previousSuccess),
-}, ResultPrototype)
-
-export const willFetch = <R extends Initial | Final<any, any, any>>(
+export const willFetch = <R extends Final<any, any, any>>(
     result: R
 ): Omit<R, keyof Flags.Keys> & WillFetch => Object.setPrototypeOf(
     Object.assign({}, result, { _flag: "WillFetch" }),
@@ -149,16 +139,18 @@ export const refreshing = <R extends Final<any, any, any>, P = never>(
     Object.getPrototypeOf(result),
 )
 
-export const fromExit = <A, E>(
-    exit: Exit.Exit<A, E>,
-    previousSuccess?: Success<NoInfer<A>>,
-): Success<A> | Failure<A, E> => exit._tag === "Success"
-    ? succeed(exit.value)
-    : fail(exit.cause, previousSuccess)
+export const fromExit: {
+    <A, E>(exit: Exit.Success<A, E>): Success<A>
+    <A, E>(exit: Exit.Failure<A, E>): Failure<E>
+    <A, E>(exit: Exit.Exit<A, E>): Success<A> | Failure<E>
+} = exit => (exit._tag === "Success" ? succeed(exit.value) : fail(exit.cause)) as any
 
-export const toExit = <A, E, P>(
-    self: Result<A, E, P>
-): Exit.Exit<A, E | Cause.NoSuchElementException> => {
+export const toExit: {
+    <A>(self: Success<A>): Exit.Success<A, never>
+    <E>(self: Failure<E>): Exit.Failure<never, E>
+    <A, E, P>(self: Final<A, E, P>): Exit.Exit<A, E>
+    <A, E, P>(self: Result<A, E, P>): Exit.Exit<A, E | Cause.NoSuchElementException>
+} = <A, E, P>(self: Result<A, E, P>): any => {
     switch (self._tag) {
         case "Success":
             return Exit.succeed(self.value)
@@ -218,8 +210,7 @@ export namespace unsafeForkEffect {
     export type OutputContext<A, E, R, P> = Exclude<R, State<A, E, P> | Progress<P> | Progress<never>>
 
     export interface Options<A, E, P> {
-        // biome-ignore lint/complexity/noBannedTypes: "{}" is relevant here
-        readonly initial?: (Initial | Success<A> | Failure<A, E>) & ({} | WillFetch | WillRefresh)
+        readonly initial?: Initial | Final<A, E, P>
         readonly initialProgress?: P
     }
 }
@@ -242,10 +233,7 @@ export const unsafeForkEffect = <A, E, R, P = never>(
         ).pipe(
             Effect.andThen(effect),
             Effect.onExit(exit => Effect.andThen(
-                state.set(fromExit(
-                    exit,
-                    isSuccess(options?.initial) ? options.initial : undefined),
-                ),
+                state.set(fromExit(exit)),
                 Effect.forkScoped(PubSub.shutdown(pubsub)),
             )),
         )),