test: use common.PIPE in fs.cp socket tests

The socket was created under a nested tmpdir using an absolute path,
which can exceed the 104-byte sun_path limit on macOS when the
checkout lives in a long directory. common.PIPE uses a path relative
to the cwd, as the other pipe tests do.

Fixes: #66324
Assisted-by: a closed-source coding agent
Signed-off-by: Maksim Romanov <romanov.maxim.98@gmail.com>
PR-URL: #66329
Reviewed-By: Filip Skokan <panva.ip@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Chemi Atlow <chemi@atlow.co.il>

Author: maksim-romanov

test/parallel/test-fs-cp-async-socket.mjs

@@ -2,9 +2,8 @@
 
 import * as common from '../common/index.mjs';
 import assert from 'node:assert';
-import { cp, mkdirSync } from 'node:fs';
+import { cp } from 'node:fs';
 import { createServer } from 'node:net';
-import { join } from 'node:path';
 import { nextdir } from '../common/fs.js';
 import tmpdir from '../common/tmpdir.js';
 
@@ -21,13 +20,10 @@ if (common.isInsideDirWithUnusualChars) {
 tmpdir.refresh();
 
 {
-  const src = nextdir();
-  mkdirSync(src);
   const dest = nextdir();
-  const sock = join(src, `${process.pid}.sock`);
   const server = createServer();
-  server.listen(sock);
-  cp(sock, dest, common.mustCall((err) => {
+  server.listen(common.PIPE);
+  cp(common.PIPE, dest, common.mustCall((err) => {
     assert.strictEqual(err.code, 'ERR_FS_CP_SOCKET');
     server.close();
   }));

test/parallel/test-fs-cp-sync-copy-socket-error.mjs

@@ -2,9 +2,8 @@
 import * as common from '../common/index.mjs';
 import { nextdir } from '../common/fs.js';
 import assert from 'node:assert';
-import { cpSync, mkdirSync } from 'node:fs';
+import { cpSync } from 'node:fs';
 import { createServer } from 'node:net';
-import { join } from 'node:path';
 import tmpdir from '../common/tmpdir.js';
 
 const isWindows = process.platform === 'win32';
@@ -20,14 +19,11 @@ if (common.isInsideDirWithUnusualChars) {
 tmpdir.refresh();
 
 {
-  const src = nextdir();
-  mkdirSync(src);
   const dest = nextdir();
-  const sock = join(src, `${process.pid}.sock`);
   const server = createServer();
-  server.listen(sock);
+  server.listen(common.PIPE);
   assert.throws(
-    () => cpSync(sock, dest),
+    () => cpSync(common.PIPE, dest),
     { code: 'ERR_FS_CP_SOCKET' }
   );
   server.close();