fix(node): Implement `fs.lchown` (and `process.getegid`) (#24418)

Closes https://github.com/denoland/deno/issues/21260.
Part of https://github.com/denoland/deno/issues/18218.

Implements `node:fs.lchown`, and enables the node_compat test for it.
The test uses `process.getegid`, which we didn't have implemented, so I
went ahead and implemented that as well to get the test working.

1 files changed, 43 insertions, 0 deletions

diff --git a/ext/fs/std_fs.rs b/ext/fs/std_fs.rs
index c501b8928..7903700c3 100644
--- a/ext/fs/std_fs.rs
+++ b/ext/fs/std_fs.rs
@@ -303,6 +303,24 @@ impl FileSystem for RealFs {
     .await?
   }
 
+  fn lchown_sync(
+    &self,
+    path: &Path,
+    uid: Option<u32>,
+    gid: Option<u32>,
+  ) -> FsResult<()> {
+    lchown(path, uid, gid)
+  }
+
+  async fn lchown_async(
+    &self,
+    path: PathBuf,
+    uid: Option<u32>,
+    gid: Option<u32>,
+  ) -> FsResult<()> {
+    spawn_blocking(move || lchown(&path, uid, gid)).await?
+  }
+
   fn write_file_sync(
     &self,
     path: &Path,
@@ -431,6 +449,31 @@ fn chown(_path: &Path, _uid: Option<u32>, _gid: Option<u32>) -> FsResult<()> {
   Err(FsError::NotSupported)
 }
 
+#[cfg(unix)]
+fn lchown(path: &Path, uid: Option<u32>, gid: Option<u32>) -> FsResult<()> {
+  use std::os::unix::ffi::OsStrExt;
+  let c_path = std::ffi::CString::new(path.as_os_str().as_bytes()).unwrap();
+  // -1 = leave unchanged
+  let uid = uid
+    .map(|uid| uid as libc::uid_t)
+    .unwrap_or(-1i32 as libc::uid_t);
+  let gid = gid
+    .map(|gid| gid as libc::gid_t)
+    .unwrap_or(-1i32 as libc::gid_t);
+  // SAFETY: `c_path` is a valid C string and lives throughout this function call.
+  let result = unsafe { libc::lchown(c_path.as_ptr(), uid, gid) };
+  if result != 0 {
+    return Err(io::Error::last_os_error().into());
+  }
+  Ok(())
+}
+
+// TODO: implement lchown for Windows
+#[cfg(not(unix))]
+fn lchown(_path: &Path, _uid: Option<u32>, _gid: Option<u32>) -> FsResult<()> {
+  Err(FsError::NotSupported)
+}
+
 fn remove(path: &Path, recursive: bool) -> FsResult<()> {
   // TODO: this is racy. This should open fds, and then `unlink` those.
   let metadata = fs::symlink_metadata(path)?;