From 7a966ec353402af6876b4e821aadcdd1f8077fc7 Mon Sep 17 00:00:00 2001
From: samzong <samzong.lu@gmail.com>
Date: Tue, 4 Aug 2026 13:14:33 -0400
Subject: [PATCH] fix(sdk): resolve home via platform APIs

Use os.homedir() in TypeScript and HOME/USERPROFILE fallback in Rust so
host path expansion works on Windows without relying on HOME alone.

## Considered and deferred

- testdata/cases [BOT-SCOPE]: Default-home / Windows USERPROFILE path is not covered by golden cases; fixtures inject home explicitly and adding cases is outside this commit's file set.
- rust/src/lib.rs:1471 [BOT-NIT]: HOME/USERPROFILE env fallback is shallower than Go os.UserHomeDir (go/kitup.go:1262) and Python Path.home (python/src/kitup/hosts.py:64); Rust std has no home API and a new crate is out of scope.
- ts/src/index.ts:419 [BOT-NIT]: os.homedir() can throw when home is unresolvable vs previous empty-string fallback; empty home previously produced wrong ~/ expansion, so throw is acceptable platform behavior.

Signed-off-by: samzong <samzong.lu@gmail.com>
---
 rust/src/lib.rs | 6 +++++-
 ts/src/index.ts | 5 +++--
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/rust/src/lib.rs b/rust/src/lib.rs
index 162cccd..11c560e 100644
--- a/rust/src/lib.rs
+++ b/rust/src/lib.rs
@@ -1467,7 +1467,11 @@ fn expand_host_path(path: &str, home: &Path, cwd: &Path) -> PathBuf {
 fn defaults(options: &BaseOptions) -> io::Result<(PathBuf, PathBuf)> {
     let home = match &options.home {
         Some(home) => home.clone(),
-        None => PathBuf::from(std::env::var("HOME").unwrap_or_default()),
+        None => PathBuf::from(
+            std::env::var("HOME")
+                .or_else(|_| std::env::var("USERPROFILE"))
+                .unwrap_or_default(),
+        ),
     };
     let cwd = match &options.cwd {
         Some(cwd) => cwd.clone(),
diff --git a/ts/src/index.ts b/ts/src/index.ts
index 71b69da..dc0ff21 100644
--- a/ts/src/index.ts
+++ b/ts/src/index.ts
@@ -10,6 +10,7 @@ import {
   stat,
   writeFile,
 } from "node:fs/promises";
+import { homedir } from "node:os";
 import { dirname, join, relative, resolve, sep } from "node:path";
 import { fileURLToPath } from "node:url";
 import { defaultHostsSpecJson } from "./hosts.generated.js";
@@ -415,7 +416,7 @@ export async function detectHosts(
   options: BaseOptions & { scope?: Scope } = {},
 ): Promise<Host[]> {
   const spec = await loadHostSpec(options.hostsFile);
-  const home = options.home ?? process.env.HOME ?? "";
+  const home = options.home ?? homedir();
   const cwd = options.cwd ?? process.cwd();
   const detected: Host[] = [];
 
@@ -678,7 +679,7 @@ export async function resolveInstallTargets(
   detectedHostIds: string[];
 }> {
   const spec = await loadHostSpec(options.hostsFile);
-  const home = options.home ?? process.env.HOME ?? "";
+  const home = options.home ?? homedir();
   const cwd = options.cwd ?? process.cwd();
   const agents = options.agents ?? defaultAgents;
   const resolved =