fix: stabilize v2 runtime behavior

packages/cli/test/fixture/standalone-owner.ts

@@ -0,0 +1,15 @@
+import { Effect } from "effect"
+import path from "node:path"
+import { Standalone } from "../../src/services/standalone"
+
+process.argv[1] = path.join(import.meta.dir, "../../src/index.ts")
+
+await Effect.runPromise(
+  Effect.scoped(
+    Effect.gen(function* () {
+      const transport = yield* Standalone.transport()
+      console.log(`${transport.pid} ${transport.url}`)
+      return yield* Effect.never
+    }),
+  ),
+)

packages/cli/test/standalone.test.ts

@@ -0,0 +1,65 @@
+import { expect, test } from "bun:test"
+import path from "node:path"
+
+test("standalone server exits when its owner is killed", async () => {
+  const owner = Bun.spawn([process.execPath, path.join(import.meta.dir, "fixture/standalone-owner.ts")], {
+    cwd: path.join(import.meta.dir, ".."),
+    env: process.env,
+    stdin: "ignore",
+    stdout: "pipe",
+    stderr: "pipe",
+  })
+  const line = await Promise.race([readLine(owner.stdout), Bun.sleep(10_000).then(() => undefined)])
+  const [rawPID, url] = line?.split(" ") ?? []
+  const pid = Number(rawPID)
+
+  try {
+    expect(pid).toBeGreaterThan(0)
+    expect(url).toStartWith("http://127.0.0.1:")
+    expect(running(pid)).toBe(true)
+
+    owner.kill("SIGKILL")
+    await owner.exited
+
+    expect(await waitForExit(pid)).toBe(true)
+  } finally {
+    owner.kill("SIGKILL")
+    if (running(pid)) process.kill(pid, "SIGKILL")
+  }
+})
+
+async function readLine(stream: ReadableStream<Uint8Array>) {
+  const reader = stream.getReader()
+  const decoder = new TextDecoder()
+  const chunks: string[] = []
+  while (true) {
+    const result = await reader.read()
+    if (result.done) break
+    chunks.push(decoder.decode(result.value, { stream: true }))
+    const output = chunks.join("")
+    const newline = output.indexOf("\n")
+    if (newline !== -1) {
+      reader.releaseLock()
+      return output.slice(0, newline)
+    }
+  }
+  reader.releaseLock()
+  return chunks.join("") + decoder.decode()
+}
+
+async function waitForExit(pid: number, attempts = 100): Promise<boolean> {
+  if (!running(pid)) return true
+  if (attempts === 0) return false
+  await Bun.sleep(50)
+  return waitForExit(pid, attempts - 1)
+}
+
+function running(pid: number) {
+  if (!Number.isSafeInteger(pid) || pid <= 0) return false
+  try {
+    process.kill(pid, 0)
+    return true
+  } catch {
+    return false
+  }
+}