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, 22 insertions, 3 deletions

diff --git a/tests/specs/node/child_process_extra_pipes/test-pipe/src/main.rs b/tests/specs/node/child_process_extra_pipes/test-pipe/src/main.rs
index 192f82731..acc034830 100644
--- a/tests/specs/node/child_process_extra_pipes/test-pipe/src/main.rs
+++ b/tests/specs/node/child_process_extra_pipes/test-pipe/src/main.rs
@@ -1,12 +1,31 @@
+use std::fs::File;
 use std::io::prelude::*;
 use std::os::fd::FromRawFd;
-use std::os::unix::net::UnixStream;
 
 fn main() {
   #[cfg(unix)]
   {
-    let mut stream = unsafe { UnixStream::from_raw_fd(4) };
+    let mut pipe = unsafe { File::from_raw_fd(4) };
 
-    stream.write_all(b"hello world\n").unwrap();
+    let mut read = 0;
+    let mut buf = [0u8; 1024];
+    loop {
+      if read > 4 {
+        assert_eq!(&buf[..5], b"start");
+        break;
+      }
+      match pipe.read(&mut buf) {
+        Ok(n) => {
+          read += n;
+        }
+        Ok(0) => {
+          return;
+        }
+        Err(e) => {
+          eprintln!("GOT ERROR: {e:?}");
+        }
+      }
+    }
+    pipe.write_all(b"hello world").unwrap();
   }
 }