fix(ext/node): support process.stdin.unref() (#22865)

This PR adds private `[REF]()` and `[UNREF]()` methods to Stdin class,
and call them from Node.js polyfill layer (`TTY` class). This enables
`process.stdin.unref()` and `process.stdin.ref()` for the case when
stdin is terminal.

closes #21796

ext/io/12_io.js

@@ -9,6 +9,7 @@ import { op_set_raw } from "ext:core/ops";
 const {
   Uint8Array,
   ArrayPrototypePush,
+  Symbol,
   TypedArrayPrototypeSubarray,
   TypedArrayPrototypeSet,
   TypedArrayPrototypeGetByteLength,
@@ -181,9 +182,14 @@ const STDIN_RID = 0;
 const STDOUT_RID = 1;
 const STDERR_RID = 2;
 
+const REF = Symbol("REF");
+const UNREF = Symbol("UNREF");
+
 class Stdin {
   #rid = STDIN_RID;
+  #ref = true;
   #readable;
+  #opPromise;
 
   constructor() {
   }
@@ -197,8 +203,14 @@ class Stdin {
     return this.#rid;
   }
 
-  read(p) {
-    return read(this.#rid, p);
+  async read(p) {
+    if (p.length === 0) return 0;
+    this.#opPromise = core.read(this.#rid, p);
+    if (!this.#ref) {
+      core.unrefOpPromise(this.#opPromise);
+    }
+    const nread = await this.#opPromise;
+    return nread === 0 ? null : nread;
   }
 
   readSync(p) {
@@ -224,6 +236,20 @@ class Stdin {
   isTerminal() {
     return core.isTerminal(this.#rid);
   }
+
+  [REF]() {
+    this.#ref = true;
+    if (this.#opPromise) {
+      core.refOpPromise(this.#opPromise);
+    }
+  }
+
+  [UNREF]() {
+    this.#ref = false;
+    if (this.#opPromise) {
+      core.unrefOpPromise(this.#opPromise);
+    }
+  }
 }
 
 class Stdout {
@@ -318,6 +344,7 @@ export {
   readAll,
   readAllSync,
   readSync,
+  REF,
   SeekMode,
   Stderr,
   stderr,
@@ -327,6 +354,7 @@ export {
   Stdout,
   stdout,
   STDOUT_RID,
+  UNREF,
   write,
   writeSync,
 };

ext/node/polyfills/tty.js

@@ -9,7 +9,10 @@ const {
 } = core;
 
 import { ERR_INVALID_FD } from "ext:deno_node/internal/errors.ts";
-import { LibuvStreamWrap } from "ext:deno_node/internal_binding/stream_wrap.ts";
+import {
+  kStreamBaseField,
+  LibuvStreamWrap,
+} from "ext:deno_node/internal_binding/stream_wrap.ts";
 import { providerType } from "ext:deno_node/internal_binding/async_wrap.ts";
 import { Socket } from "node:net";
 import { setReadStream } from "ext:deno_node/_process/streams.mjs";
@@ -36,6 +39,14 @@ class TTY extends LibuvStreamWrap {
   constructor(handle) {
     super(providerType.TTYWRAP, handle);
   }
+
+  ref() {
+    this[kStreamBaseField][io.REF]();
+  }
+
+  unref() {
+    this[kStreamBaseField][io.UNREF]();
+  }
 }
 
 export class ReadStream extends Socket {

tests/integration/run_tests.rs

@@ -5359,3 +5359,32 @@ fn code_cache_npm_with_require_test() {
     assert!(!output.stderr().contains("Updating V8 code cache"));
   }
 }
+
+#[test]
+fn node_process_stdin_unref_with_pty() {
+  TestContext::default()
+    .new_command()
+    .args_vec(["run", "--quiet", "run/node_process_stdin_unref_with_pty.js"])
+    .with_pty(|mut console| {
+      console.expect("START\r\n");
+      console.write_line("foo");
+      console.expect("foo\r\n");
+      console.write_line("bar");
+      console.expect("bar\r\n");
+      console.write_line("baz");
+      console.expect("baz\r\n");
+    });
+
+  TestContext::default()
+    .new_command()
+    .args_vec([
+      "run",
+      "--quiet",
+      "run/node_process_stdin_unref_with_pty.js",
+      "--unref",
+    ])
+    .with_pty(|mut console| {
+      // if process.stdin.unref is called, the program immediately ends by skipping reading from stdin.
+      console.expect("START\r\nEND\r\n");
+    });
+}

tests/testdata/run/node_process_stdin_unref_with_pty.js

@@ -0,0 +1,14 @@
+import process from "node:process";
+import util from "node:util";
+
+console.log("START");
+globalThis.addEventListener("unload", () => console.log("END"));
+
+const args = util.parseArgs({ options: { unref: { type: "boolean" } } });
+
+// call stdin.unref if --unref is passed
+if (args.values.unref) {
+  process.stdin.unref();
+}
+
+process.stdin.pipe(process.stdout);