From 59d813aa4973d1115cfc70cc3667508335f49693 Mon Sep 17 00:00:00 2001
From: Tim <hello@timsmart.co>
Date: Sat, 26 Oct 2024 22:06:42 +1300
Subject: [PATCH] ensure fiber refs are not inherited by ManagedRuntime (#3845)

---
 .changeset/twelve-seals-move.md               |  5 +++
 .../effect/src/internal/managedRuntime.ts     | 15 +++++---
 packages/effect/test/ManagedRuntime.test.ts   | 38 +++++++++++--------
 3 files changed, 37 insertions(+), 21 deletions(-)
 create mode 100644 .changeset/twelve-seals-move.md

diff --git a/.changeset/twelve-seals-move.md b/.changeset/twelve-seals-move.md
new file mode 100644
index 0000000000..e85d69a7df
--- /dev/null
+++ b/.changeset/twelve-seals-move.md
@@ -0,0 +1,5 @@
+---
+"effect": patch
+---
+
+ensure fiber refs are not inherited by ManagedRuntime
diff --git a/packages/effect/src/internal/managedRuntime.ts b/packages/effect/src/internal/managedRuntime.ts
index 4a27cf77f9..ed41588834 100644
--- a/packages/effect/src/internal/managedRuntime.ts
+++ b/packages/effect/src/internal/managedRuntime.ts
@@ -1,3 +1,4 @@
+import type { Mutable } from "effect/Types"
 import type * as Effect from "../Effect.js"
 import * as Effectable from "../Effectable.js"
 import type { Exit } from "../Exit.js"
@@ -8,7 +9,6 @@ import { pipeArguments } from "../Pipeable.js"
 import { hasProperty } from "../Predicate.js"
 import type * as Runtime from "../Runtime.js"
 import * as Scope from "../Scope.js"
-import * as effect from "./core-effect.js"
 import * as core from "./core.js"
 import * as fiberRuntime from "./fiberRuntime.js"
 import * as internalLayer from "./layer.js"
@@ -56,8 +56,9 @@ export const make = <R, ER>(
 ): M.ManagedRuntime<R, ER> => {
   memoMap = memoMap ?? internalLayer.unsafeMakeMemoMap()
   const scope = internalRuntime.unsafeRunSyncEffect(fiberRuntime.scopeMake())
-  const runtimeEffect = internalRuntime.unsafeRunSyncEffect(
-    effect.memoize(
+  let buildFiber: Fiber.RuntimeFiber<Runtime.Runtime<R>, ER> | undefined
+  const runtimeEffect = core.suspend(() => {
+    buildFiber ??= internalRuntime.unsafeForkEffect(
       core.tap(
         Scope.extend(
           internalLayer.toRuntimeWithMemoMap(layer, memoMap),
@@ -66,9 +67,11 @@ export const make = <R, ER>(
         (rt) => {
           self.cachedRuntime = rt
         }
-      )
+      ),
+      { scope }
     )
-  )
+    return core.flatten(buildFiber.await)
+  })
   const self: ManagedRuntimeImpl<R, ER> = Object.assign(Object.create(ManagedRuntimeProto), {
     memoMap,
     scope,
@@ -83,7 +86,7 @@ export const make = <R, ER>(
       return internalRuntime.unsafeRunPromiseEffect(self.disposeEffect)
     },
     disposeEffect: core.suspend(() => {
-      ;(self as any).runtime = core.die("ManagedRuntime disposed")
+      ;(self as Mutable<ManagedRuntimeImpl<R, ER>>).runtimeEffect = core.die("ManagedRuntime disposed")
       self.cachedRuntime = undefined
       return Scope.close(self.scope, core.exitVoid)
     }),
diff --git a/packages/effect/test/ManagedRuntime.test.ts b/packages/effect/test/ManagedRuntime.test.ts
index defe8e4445..07aa4315ff 100644
--- a/packages/effect/test/ManagedRuntime.test.ts
+++ b/packages/effect/test/ManagedRuntime.test.ts
@@ -1,10 +1,9 @@
-import { ManagedRuntime } from "effect"
+import { FiberRefs, List, ManagedRuntime } from "effect"
 import * as Context from "effect/Context"
 import * as Effect from "effect/Effect"
 import * as FiberRef from "effect/FiberRef"
 import * as Layer from "effect/Layer"
-import * as it from "effect/test/utils/extend"
-import { assert, describe, test } from "vitest"
+import { assert, describe, it, test } from "effect/test/utils/extend"
 
 describe.concurrent("ManagedRuntime", () => {
   test("memoizes the layer build", async () => {
@@ -50,16 +49,25 @@ describe.concurrent("ManagedRuntime", () => {
     assert.strictEqual(count, 1)
   })
 
-  it.effect(
-    "is subtype of effect",
-    () =>
-      Effect.gen(function*() {
-        const tag = Context.GenericTag<string>("string")
-        const layer = Layer.succeed(tag, "test")
-        const managedRuntime = ManagedRuntime.make(layer)
-        const runtime = yield* managedRuntime
-        const result = Context.get(runtime.context, tag)
-        assert.strictEqual(result, "test")
-      })
-  )
+  it.effect("is subtype of effect", () =>
+    Effect.gen(function*() {
+      const tag = Context.GenericTag<string>("string")
+      const layer = Layer.succeed(tag, "test")
+      const managedRuntime = ManagedRuntime.make(layer)
+      const runtime = yield* managedRuntime
+      const result = Context.get(runtime.context, tag)
+      assert.strictEqual(result, "test")
+    }))
+
+  it.effect("does not inherit fiber refs", () =>
+    Effect.gen(function*() {
+      const tag = Context.GenericTag<string>("string")
+      const layer = Layer.succeed(tag, "test")
+      const managedRuntime = ManagedRuntime.make(layer)
+      const runtime = yield* managedRuntime.runtimeEffect.pipe(
+        Effect.withLogSpan("test")
+      )
+      const result = FiberRefs.getOrDefault(runtime.fiberRefs, FiberRef.currentLogSpan)
+      assert.deepStrictEqual(result, List.empty())
+    }))
 })