change return type of Fiber.joinAll to return an array (#2521)

Co-authored-by: Tim <hello@timsmart.co>

.changeset/warm-onions-kneel.md

@@ -0,0 +1,5 @@
+---
+"effect": patch
+---
+
+change return type of Fiber.joinAll to return an array

packages/effect/src/Fiber.ts

@@ -451,7 +451,7 @@ export const join: <A, E>(self: Fiber<A, E>) => Effect.Effect<A, E> = internal.j
  * @since 2.0.0
  * @category destructors
  */
-export const joinAll: <A, E>(fibers: Iterable<Fiber<A, E>>) => Effect.Effect<void, E> = fiberRuntime.fiberJoinAll
+export const joinAll: <A, E>(fibers: Iterable<Fiber<A, E>>) => Effect.Effect<Array<A>, E> = fiberRuntime.fiberJoinAll
 
 /**
  * Maps over the value the Fiber computes.

packages/effect/src/internal/fiberRuntime.ts

@@ -3263,8 +3263,8 @@ export const fiberInterruptFork = <A, E>(self: Fiber.Fiber<A, E>): Effect.Effect
   core.asUnit(forkDaemon(core.interruptFiber(self)))
 
 /* @internal */
-export const fiberJoinAll = <A, E>(fibers: Iterable<Fiber.Fiber<A, E>>): Effect.Effect<void, E> =>
-  core.asUnit(internalFiber.join(fiberAll(fibers)))
+export const fiberJoinAll = <A, E>(fibers: Iterable<Fiber.Fiber<A, E>>): Effect.Effect<Array<A>, E> =>
+  internalFiber.join(fiberAll(fibers))
 
 /* @internal */
 export const fiberScoped = <A, E>(self: Fiber.Fiber<A, E>): Effect.Effect<Fiber.Fiber<A, E>, never, Scope.Scope> =>

packages/effect/test/Fiber.test.ts

@@ -215,7 +215,9 @@ describe("Fiber", () => {
   it.effect("joinAll - stack safety", () =>
     Effect.gen(function*($) {
       const result = yield* $(Fiber.joinAll(fibers))
-      assert.isUndefined(result)
+      assert.isArray(result)
+      assert(result.length === fibers.length)
+      result.forEach((_) => assert.isUndefined(_))
     }), 10000)
   it.effect("all - stack safety", () =>
     Effect.gen(function*($) {