fix(bun): call close hooks on server shutdown

The bun preset delegates shutdown to srvx, which closes the server on
SIGINT/SIGTERM without calling Nitro's runtime `close` hook. Cleanup
handlers registered via the `close` hook were silently skipped in
production.

Wrap `server.close()` to run the `close` hooks after the server closes,
mirroring the node preset fix in #4522. `deno_server` has the same gap.

Author: hamodywe

src/presets/bun/runtime/bun.ts

@@ -3,7 +3,7 @@ import type { ServerRequest } from "srvx";
 import { serve } from "srvx/bun";
 import wsAdapter from "crossws/adapters/bun";
 
-import { useNitroApp } from "nitro/app";
+import { useNitroApp, useNitroHooks } from "nitro/app";
 import { startScheduleRunner } from "#nitro/runtime/task";
 import { trapUnhandledErrors } from "#nitro/runtime/error/hooks";
 import { resolveWebsocketHooks } from "#nitro/runtime/app";
@@ -41,6 +41,22 @@ const server = serve({
   plugins: [...tracingSrvxPlugins],
 });
 
+// Run `close` hooks on server shutdown (srvx closes the server on `SIGINT`/`SIGTERM`)
+const closeServer = server.close.bind(server);
+let closeHooksCalled = false;
+server.close = async (closeActiveConnections?: boolean) => {
+  try {
+    await closeServer(closeActiveConnections);
+  } finally {
+    if (!closeHooksCalled) {
+      closeHooksCalled = true;
+      await useNitroHooks()
+        .callHook("close")
+        ?.catch((error) => console.error("[close]", error));
+    }
+  }
+};
+
 trapUnhandledErrors();
 
 // Scheduled tasks

test/fixture/server/plugins/close.ts

@@ -0,0 +1,9 @@
+import { definePlugin } from "nitro";
+
+export default definePlugin((nitroApp) => {
+  nitroApp.hooks.hook("close", () => {
+    if (globalThis.process?.env?.NITRO_TEST_CLOSE_HOOK) {
+      console.log("[fixture] close hook called");
+    }
+  });
+});

test/presets/bun.test.ts

@@ -1,7 +1,8 @@
 import { execa, execaCommandSync } from "execa";
+import { isWindows } from "std-env";
 import { getRandomPort, waitForPort } from "get-port-please";
 import { resolve } from "pathe";
-import { describe } from "vitest";
+import { describe, it, expect } from "vitest";
 import { setupTest, testNitro } from "../tests.ts";
 
 const hasBun = execaCommandSync("bun --version", { stdio: "ignore", reject: false }).exitCode === 0;
@@ -26,4 +27,52 @@ describe.runIf(hasBun)("nitro:preset:bun", async () => {
       return res;
     };
   });
+  it.skipIf(isWindows)(
+    "calls the `close` hook on shutdown",
+    async () => {
+      const port = await getRandomPort();
+      const entryPath = resolve(ctx.outDir, "server/index.mjs");
+      // srvx graceful shutdown is disabled when the CI/TEST env vars are set,
+      // so drop them for this child to exercise the real SIGTERM path.
+      const env: Record<string, string | undefined> = {
+        ...process.env,
+        PORT: String(port),
+        NITRO_HOST: "127.0.0.1",
+        NITRO_TEST_CLOSE_HOOK: "true",
+      };
+      delete env.CI;
+      delete env.TEST;
+      const child = execa("bun", [entryPath], {
+        env,
+        extendEnv: false,
+        reject: false,
+      });
+
+      let output = "";
+      child.stdout!.on("data", (data) => (output += data));
+      child.stderr!.on("data", (data) => (output += data));
+
+      await waitForPort(port, { delay: 1000, retries: 20, host: "127.0.0.1" });
+
+      child.kill("SIGTERM");
+      await new Promise<void>((r) => {
+        const timeout = setTimeout(r, 10_000);
+        child.on("close", () => {
+          clearTimeout(timeout);
+          r();
+        });
+        child.stdout!.on("data", (data) => {
+          if (String(data).includes("[fixture] close hook called")) {
+            clearTimeout(timeout);
+            r();
+          }
+        });
+      });
+      child.kill("SIGKILL");
+
+      expect(output).toContain("[fixture] close hook called");
+      expect(output).not.toContain("unhandledRejection");
+    },
+    40_000
+  );
 });