fix: implement child_process IPC (#21490)

This PR implements the Node child_process IPC functionality in Deno on
Unix systems.

For `fd > 2` a duplex unix pipe is set up between the parent and child
processes. Currently implements data passing via the channel in the JSON
serialization format.

1 files changed, 9 insertions, 0 deletions

diff --git a/ext/node/polyfills/child_process.ts b/ext/node/polyfills/child_process.ts
index 94a108447..c7d007f46 100644
--- a/ext/node/polyfills/child_process.ts
+++ b/ext/node/polyfills/child_process.ts
@@ -10,6 +10,7 @@ import {
   ChildProcess,
   ChildProcessOptions,
   normalizeSpawnArguments,
+  setupChannel,
   type SpawnOptions,
   spawnSync as _spawnSync,
   type SpawnSyncOptions,
@@ -821,6 +822,14 @@ export function execFileSync(
   return ret.stdout as string | Buffer;
 }
 
+function setupChildProcessIpcChannel(fd: number) {
+  if (typeof fd != "number" || fd < 0) return;
+  setupChannel(process, fd);
+}
+
+globalThis.__bootstrap.internals.__setupChildProcessIpcChannel =
+  setupChildProcessIpcChannel;
+
 export default {
   fork,
   spawn,