// MixedScheduler.starve() — called once when first task is scheduled
private starve(depth = 0) {
  if (depth >= this.maxNextTickBeforeTimer) {
    setTimeout(() => this.starveInternal(0), 0)       // timer queue
  } else {
    Promise.resolve(void 0).then(() => this.starveInternal(depth + 1)) // microtask queue
  }
}

// MixedScheduler.starveInternal() — drains ALL accumulated tasks in one call
private starveInternal(depth: number) {
  const tasks = this.tasks.buckets
  this.tasks.buckets = []
  for (const [_, toRun] of tasks) {
    for (let i = 0; i < toRun.length; i++) {
      toRun[i]()  // ← Every fiber continuation runs in the SAME ALS context
    }
  }
  // ...
}

export const toWebHandlerRuntime = <R>(runtime: Runtime.Runtime<R>) => {
  const httpRuntime: Types.Mutable<Runtime.Runtime<R>> = Runtime.make(runtime)
  const run = Runtime.runFork(httpRuntime)
  return <E>(self: Default<E, R | Scope.Scope>, middleware?) => {
    return (request: Request, context?): Promise<Response> =>
      new Promise((resolve) => {
        // Per-request Effect context is correctly set via contextMap:
        const contextMap = new Map<string, any>(runtime.context.unsafeMap)
        const httpServerRequest = ServerRequest.fromWeb(request)
        contextMap.set(ServerRequest.HttpServerRequest.key, httpServerRequest)
        httpRuntime.context = Context.unsafeMake(contextMap)

        // But the fiber is forked without any ALS propagation:
        const fiber = run(httpApp as any)  // ← ALS context is NOT captured or restored
      })
  }
}

// RPC handler — runs inside an Effect fiber
const handler = Effect.gen(function*() {
  // This calls auth() from @clerk/nextjs/server, which reads from ALS
  const { userId } = yield* Effect.tryPromise({
    try: async () => auth(),  // ← may read WRONG user's session
    catch: () => new UnauthorizedError({ message: "Auth failed" })
  })
  return yield* repository.getUser(userId)
})

import { AsyncLocalStorage } from "node:async_hooks"
import { Effect, Layer } from "effect"
import { RpcServer, RpcSerialization, Rpc, RpcGroup } from "@effect/rpc"
import { HttpServer } from "@effect/platform"
import * as S from "effect/Schema"

// Simulate a framework's ALS (like Next.js / Clerk)
const requestStore = new AsyncLocalStorage<{ userId: string }>()

class GetUser extends Rpc.make("GetUser", {
  success: S.Struct({ userId: S.String, alsUserId: S.String }),
  failure: S.Never,
  payload: {}
}) {}

const MyRpc = RpcGroup.make("MyRpc").add(GetUser)

const MyRpcLive = MyRpc.toLayer(
  RpcGroup.toHandlers(MyRpc, {
    GetUser: () =>
      Effect.gen(function*() {
        // Simulate calling an ALS-dependent API inside an Effect fiber
        const alsResult = yield* Effect.tryPromise({
          try: async () => {
            const store = requestStore.getStore()
            return store?.userId ?? "NONE"
          },
          catch: () => { throw new Error("impossible") }
        })
        return { userId: "from-effect-context", alsUserId: alsResult }
      })
  })
)

const RpcLayer = MyRpcLive.pipe(
  Layer.provideMerge(RpcSerialization.layerJson),
  Layer.provideMerge(HttpServer.layerContext)
)

const { handler } = RpcServer.toWebHandler(MyRpc, { layer: RpcLayer })

// Simulate two concurrent requests with different ALS contexts
async function main() {
  const results = await Promise.all([
    requestStore.run({ userId: "user-A" }, () => handler(makeRpcRequest("GetUser"))),
    requestStore.run({ userId: "user-B" }, () => handler(makeRpcRequest("GetUser"))),
  ])

  // Parse responses and check if alsUserId matches the expected user
  // Under the bug: both responses may show "user-A" (or one shows the other's)
  for (const res of results) {
    console.log(await res.json())
  }
}

// In the route handler — OUTSIDE the Effect fiber (ALS is correct here)
export const POST = async (request: Request) => {
  const { userId } = await auth()  // ← Safe: still in Next.js ALS context

  // Inject into request headers or use the `context` parameter
  const headers = new Headers(request.headers)
  headers.set("x-clerk-auth-user-id", userId ?? "")
  const enrichedRequest = new Request(request.url, {
    method: request.method,
    headers,
    body: request.body,
    duplex: "half" as any,
  })

  return webHandler(enrichedRequest)
}

// In Effect handlers — read from HttpServerRequest headers instead of calling auth()
const getAuthenticatedUserId = Effect.gen(function*() {
  const req = yield* HttpServerRequest.HttpServerRequest
  const userId = req.headers["x-clerk-auth-user-id"]
  if (!userId) return yield* Effect.fail(new UnauthorizedError({ message: "Auth required" }))
  return userId
})

// In MixedScheduler or the fiber runtime
import { AsyncLocalStorage } from "node:async_hooks"

scheduleTask(task: Task, priority: number) {
  // Capture current ALS context
  const snapshot = AsyncLocalStorage.snapshot()
  this.tasks.scheduleTask(() => snapshot(task), priority)
  // ...
}