Support Windows symlink downloads

src/bin/dosh-client.rs

@@ -3654,24 +3654,67 @@ fn download_symlink(
 
 #[cfg(unix)]
 fn create_local_symlink(path: &Path, target: &str, overwrite: bool) -> Result<()> {
-    if let Ok(metadata) = fs::symlink_metadata(path) {
+    prepare_local_symlink_destination(path, overwrite)?;
-        anyhow::ensure!(overwrite, "destination exists: {}", path.display());
-        anyhow::ensure!(
-            !metadata.is_dir(),
-            "destination is a directory: {}",
-            path.display()
-        );
-        fs::remove_file(path).with_context(|| format!("remove {}", path.display()))?;
-    }
     std::os::unix::fs::symlink(target, path)
         .with_context(|| format!("symlink {} -> {}", path.display(), target))
 }
 
-#[cfg(not(unix))]
+#[cfg(windows)]
+fn create_local_symlink(path: &Path, target: &str, overwrite: bool) -> Result<()> {
+    prepare_local_symlink_destination(path, overwrite)?;
+    if local_symlink_target_is_dir(path, target) {
+        std::os::windows::fs::symlink_dir(target, path)
+            .with_context(|| format!("directory symlink {} -> {}", path.display(), target))
+    } else {
+        std::os::windows::fs::symlink_file(target, path)
+            .with_context(|| format!("file symlink {} -> {}", path.display(), target))
+    }
+}
+
+#[cfg(not(any(unix, windows)))]
 fn create_local_symlink(_path: &Path, _target: &str, _overwrite: bool) -> Result<()> {
     bail!("symlink creation is not supported on this client platform")
 }
 
+fn prepare_local_symlink_destination(path: &Path, overwrite: bool) -> Result<()> {
+    let Ok(metadata) = fs::symlink_metadata(path) else {
+        return Ok(());
+    };
+    anyhow::ensure!(overwrite, "destination exists: {}", path.display());
+    anyhow::ensure!(
+        !metadata.is_dir(),
+        "destination is a directory: {}",
+        path.display()
+    );
+    match fs::remove_file(path) {
+        Ok(()) => Ok(()),
+        Err(file_err) if metadata.file_type().is_symlink() => {
+            fs::remove_dir(path).map_err(|_| file_err)?;
+            Ok(())
+        }
+        Err(err) => Err(err),
+    }
+    .with_context(|| format!("remove {}", path.display()))
+}
+
+#[cfg_attr(not(any(test, windows)), allow(dead_code))]
+fn local_symlink_target_is_dir(link_path: &Path, target: &str) -> bool {
+    if target.ends_with('/') || target.ends_with('\\') {
+        return true;
+    }
+    let target_path = Path::new(target);
+    let resolved = if target_path.is_absolute() {
+        target_path.to_path_buf()
+    } else {
+        link_path
+            .parent()
+            .filter(|parent| !parent.as_os_str().is_empty())
+            .unwrap_or_else(|| Path::new("."))
+            .join(target_path)
+    };
+    fs::metadata(resolved).is_ok_and(|metadata| metadata.is_dir())
+}
+
 fn hash_prefix(file: &mut fs::File, bytes: u64, hasher: &mut Sha256) -> Result<()> {
     file.seek(std::io::SeekFrom::Start(0))?;
     let mut remaining = bytes;
@@ -10034,13 +10077,13 @@ mod tests {
         clear_cached_credentials, effective_update_artifact_tag, ensure_tui_safe_status_overlay,
         expand_ssh_path_tokens, input_contains_focus_in, input_matches_escape,
         is_local_status_target, is_resume_response_for_client, latest_release_download_url,
-        load_first_native_identity_with_prompt, native_proxy_udp_warning,
+        load_first_native_identity_with_prompt, local_symlink_target_is_dir,
-        newest_client_trace_path_from, parse_dynamic_forward, parse_escape_key,
+        native_proxy_udp_warning, newest_client_trace_path_from, parse_dynamic_forward,
-        parse_local_forward, parse_remote_forward, parse_single_remote_path, parse_ssh_config,
+        parse_escape_key, parse_local_forward, parse_remote_forward, parse_single_remote_path,
-        parse_trace_line, parse_trace_options, parse_trace_report_options, parse_trace_summary,
+        parse_ssh_config, parse_trace_line, parse_trace_options, parse_trace_report_options,
-        parse_update_options, post_submit_hold_duration, queue_or_send_stream_data,
+        parse_trace_summary, parse_update_options, post_submit_hold_duration,
-        queue_pending_user_input, queue_stale_pending_user_input, raw_contains_host_table,
+        queue_or_send_stream_data, queue_pending_user_input, queue_stale_pending_user_input,
-        recv_response_until, refresh_live_addr, release_tag_download_url,
+        raw_contains_host_table, recv_response_until, refresh_live_addr, release_tag_download_url,
         release_tag_from_effective_url, release_version_from_tag, render_frame_bytes,
         render_status_clear, render_status_overlay, requested_env, resolve_forward_agent_endpoint,
         resolved_startup_command, retire_stream_state, retransmit_stream_closes,
@@ -10124,6 +10167,25 @@ mod tests {
         );
     }
 
+    #[test]
+    fn symlink_target_dir_inference_uses_existing_relative_target() {
+        let dir = tempfile::tempdir().unwrap();
+        fs::create_dir(dir.path().join("target-dir")).unwrap();
+        let link = dir.path().join("link");
+
+        assert!(local_symlink_target_is_dir(&link, "target-dir"));
+        assert!(!local_symlink_target_is_dir(&link, "missing-file"));
+    }
+
+    #[test]
+    fn symlink_target_dir_inference_honors_trailing_separator() {
+        let dir = tempfile::tempdir().unwrap();
+        let link = dir.path().join("link");
+
+        assert!(local_symlink_target_is_dir(&link, "missing-dir/"));
+        assert!(local_symlink_target_is_dir(&link, "missing-dir\\"));
+    }
+
     #[test]
     fn cleanup_stream_state_removes_all_per_stream_state_only_for_target() {
         let stream_id = 42;