fix(ext/node): only set our end of child process pipe to nonblocking mode (#26495)

Fixes playwright on linux, as reported in
https://github.com/denoland/deno/issues/16899#issuecomment-2378268454.

The issue was that we were opening the socket in nonblocking mode, which
meant that subprocesses trying to use it would get a `EWOULDBLOCK` error
(unexpectedly). The fix here is to only set nonblocking mode on our end
(which we need to use asynchronously)

1 files changed, 16 insertions, 4 deletions

diff --git a/tests/specs/node/child_process_extra_pipes/main.ts b/tests/specs/node/child_process_extra_pipes/main.ts
index a3683fe9e..2837cdc53 100644
--- a/tests/specs/node/child_process_extra_pipes/main.ts
+++ b/tests/specs/node/child_process_extra_pipes/main.ts
@@ -1,5 +1,4 @@
 import child_process from "node:child_process";
-import { Buffer } from "node:buffer";
 import console from "node:console";
 
 const child = child_process.spawn("./test-pipe/target/debug/test-pipe", [], {
@@ -8,19 +7,32 @@ const child = child_process.spawn("./test-pipe/target/debug/test-pipe", [], {
 
 const extra = child.stdio[4];
 
-const p = Promise.withResolvers();
+if (!extra) {
+  throw new Error("no extra pipe");
+}
+
+const p = Promise.withResolvers<void>();
+
+let got = "";
 
 child.on("close", () => {
   console.log("child closed");
-  p.resolve();
+  console.log("got:", got);
+  if (got === "hello world") {
+    p.resolve();
+  } else {
+    p.reject(new Error(`wanted "hello world", got "${got}"`));
+  }
 });
 
 extra.on("data", (d) => {
-  console.log("data:", d.toString().trim());
+  got += d.toString();
 });
 
 extra.on("close", () => {
   console.log("pipe closed");
 });
 
+extra.write("start");
+
 await p.promise;