From e3de01c9f61d026fa7c9638810f8878f100c2927 Mon Sep 17 00:00:00 2001
From: chengyongru <2755839590@qq.com>
Date: Sun, 19 Jul 2026 23:56:35 +0800
Subject: [PATCH] fix(webui): resolve build runner executable

---
 nanobot/webui/build.py    |  4 ++--
 tests/webui/test_build.py | 17 ++++++++++++++++-
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/nanobot/webui/build.py b/nanobot/webui/build.py
index 950cf1f0..6c53afc6 100644
--- a/nanobot/webui/build.py
+++ b/nanobot/webui/build.py
@@ -266,8 +266,8 @@ def ensure_webui_bundle(
 def pick_webui_build_runner() -> str | None:
     """Pick the frontend package manager used to build the WebUI."""
     for candidate in ("bun", "npm"):
-        if shutil.which(candidate):
-            return candidate
+        if executable := shutil.which(candidate):
+            return executable
     return None
 
 
diff --git a/tests/webui/test_build.py b/tests/webui/test_build.py
index 5b70d17b..ff811ca1 100644
--- a/tests/webui/test_build.py
+++ b/tests/webui/test_build.py
@@ -4,7 +4,11 @@ import os
 import tomllib
 from pathlib import Path
 
-from nanobot.webui.build import ensure_webui_bundle, inspect_webui_bundle
+from nanobot.webui.build import (
+    ensure_webui_bundle,
+    inspect_webui_bundle,
+    pick_webui_build_runner,
+)
 
 _MTIME_BASE_NS = 1_700_000_000_000_000_000
 _MTIME_STEP_NS = 5_000_000_000
@@ -119,6 +123,17 @@ def test_ensure_webui_bundle_auto_builds_stale_dist(tmp_path: Path) -> None:
     assert commands == [("bun", "install"), ("bun", "run", "build")]
 
 
+def test_pick_webui_build_runner_returns_resolved_executable(monkeypatch) -> None:
+    bun_shim = r"C:\tools\npm\bun.CMD"
+
+    monkeypatch.setattr(
+        "nanobot.webui.build.shutil.which",
+        lambda candidate: bun_shim if candidate == "bun" else None,
+    )
+
+    assert pick_webui_build_runner() == bun_shim
+
+
 def test_ensure_webui_bundle_warns_without_building(tmp_path: Path) -> None:
     source = tmp_path / "webui"
     dist = tmp_path / "nanobot" / "web" / "dist"