fix(ext/node): homedir() getpwuid/SHGetKnownFolderPath fallback (#23841)

**Unix**: Returns the value of the HOME environment variable if it is
set even if it is an empty string. Otherwise, it tries to determine the
home directory by invoking the
[getpwuid_r](https://linux.die.net/man/3/getpwuid_r) function with the
UID of the current user.

**Windows**: Returns the value of the USERPROFILE environment variable
if it is set and it is not an empty string. Otherwise, it tries to
determine the home directory by invoking the
[SHGetKnownFolderPath](https://learn.microsoft.com/en-us/windows/win32/api/shlobj_core/nf-shlobj_core-shgetknownfolderpath)
function with
[FOLDERID_Profile](https://learn.microsoft.com/en-us/windows/win32/shell/knownfolderid).

Fixes https://github.com/denoland/deno/issues/23824

Cargo.lock

@@ -1680,6 +1680,7 @@ dependencies = [
  "faster-hex",
  "h2 0.3.26",
  "hkdf",
+ "home",
  "http 0.2.12",
  "idna 0.3.0",
  "indexmap",

ext/node/Cargo.toml

@@ -36,6 +36,7 @@ errno = "0.2.8"
 faster-hex.workspace = true
 h2 = { version = "0.3.26", features = ["unstable"] }
 hkdf.workspace = true
+home = "0.5.9"
 http_v02.workspace = true
 idna = "0.3.0"
 indexmap.workspace = true

ext/node/lib.rs

@@ -309,6 +309,7 @@ deno_core::extension!(deno_node,
     ops::os::op_node_os_username<P>,
     ops::os::op_geteuid<P>,
     ops::os::op_cpus<P>,
+    ops::os::op_homedir<P>,
     op_node_build_os,
     op_node_is_promise_rejected,
     op_npm_process_state,

ext/node/ops/os/mod.rs

@@ -88,3 +88,17 @@ where
 
   cpus::cpu_info().ok_or_else(|| type_error("Failed to get cpu info"))
 }
+
+#[op2]
+#[string]
+pub fn op_homedir<P>(state: &mut OpState) -> Result<Option<String>, AnyError>
+where
+  P: NodePermissions + 'static,
+{
+  {
+    let permissions = state.borrow_mut::<P>();
+    permissions.check_sys("homedir", "node:os.homedir()")?;
+  }
+
+  Ok(home::home_dir().map(|path| path.to_string_lossy().to_string()))
+}

ext/node/polyfills/os.ts

@@ -25,6 +25,7 @@
 
 import {
   op_cpus,
+  op_homedir,
   op_node_os_get_priority,
   op_node_os_set_priority,
   op_node_os_username,
@@ -32,7 +33,7 @@ import {
 
 import { validateIntegerRange } from "ext:deno_node/_utils.ts";
 import process from "node:process";
-import { isWindows, osType } from "ext:deno_node/_util/os.ts";
+import { isWindows } from "ext:deno_node/_util/os.ts";
 import { ERR_OS_NO_HOMEDIR } from "ext:deno_node/internal/errors.ts";
 import { os } from "ext:deno_node/internal_binding/constants.ts";
 import { osUptime } from "ext:runtime/30_os.js";
@@ -173,21 +174,7 @@ export function getPriority(pid = 0): number {
 
 /** Returns the string path of the current user's home directory. */
 export function homedir(): string | null {
-  // Note: Node/libuv calls getpwuid() / GetUserProfileDirectory() when the
-  // environment variable isn't set but that's the (very uncommon) fallback
-  // path. IMO, it's okay to punt on that for now.
-  switch (osType) {
-    case "windows":
-      return Deno.env.get("USERPROFILE") || null;
-    case "linux":
-    case "android":
-    case "darwin":
-    case "freebsd":
-    case "openbsd":
-      return Deno.env.get("HOME") || null;
-    default:
-      throw Error("unreachable");
-  }
+  return op_homedir();
 }
 
 /** Returns the host name of the operating system as a string. */

runtime/permissions/lib.rs

@@ -913,7 +913,7 @@ impl Descriptor for SysDescriptor {
 pub fn parse_sys_kind(kind: &str) -> Result<&str, AnyError> {
   match kind {
     "hostname" | "osRelease" | "osUptime" | "loadavg" | "networkInterfaces"
-    | "systemMemoryInfo" | "uid" | "gid" | "cpus" => Ok(kind),
+    | "systemMemoryInfo" | "uid" | "gid" | "cpus" | "homedir" => Ok(kind),
     _ => Err(type_error(format!("unknown system info kind \"{kind}\""))),
   }
 }

tests/unit_node/os_test.ts

@@ -47,6 +47,14 @@ Deno.test({
   },
 });
 
+Deno.test({
+  name: "home directory when HOME is not set",
+  fn() {
+    Deno.env.delete("HOME");
+    assertEquals(typeof os.homedir(), "string");
+  },
+});
+
 Deno.test({
   name: "tmp directory is a string",
   fn() {