test: use bare 'bash' for detection to match test invocation

On Windows, subprocess.run(['bash', ...]) uses CreateProcess which
searches System32 before PATH — finding WSL bash even when
shutil.which('bash') returns Git-for-Windows. Probe with bare 'bash'
(same as test helpers) so the detection matches actual test behavior.

Author: mnriem

tests/conftest.py

@@ -14,42 +14,47 @@
 def _has_working_bash() -> bool:
     """Check whether a functional native bash is available.
 
+    On Windows, ``subprocess.run(["bash", ...])`` uses CreateProcess,
+    which searches System32 *before* PATH — so it may find the WSL
+    launcher even when Git-for-Windows bash appears first in PATH via
+    ``shutil.which``.  We therefore probe with bare ``"bash"`` (the
+    same way test helpers invoke it) to get an accurate result.
+
     On Windows, only Git-for-Windows bash (MSYS2/MINGW) is accepted.
-    The WSL launcher (System32\\bash.exe) is rejected because it runs in
-    a separate Linux filesystem and cannot handle native Windows paths
-    used by the test fixtures.
+    The WSL launcher is rejected because it runs in a separate Linux
+    filesystem and cannot handle native Windows paths used by the
+    test fixtures.
 
     Set SPECKIT_TEST_BASH=1 to force-enable bash tests regardless.
     """
     if os.environ.get("SPECKIT_TEST_BASH") == "1":
         return True
-    bash_path = shutil.which("bash")
-    if bash_path is None:
+    if shutil.which("bash") is None:
         return False
-    # On Windows, reject the WSL launcher early (avoids WSL init prompts
-    # and the 5 s timeout) and only accept MSYS/MINGW/CYGWIN bash.
-    if sys.platform == "win32":
-        if "system32" in bash_path.lower():
+    # Probe with bare "bash" — same as the test helpers — so that
+    # Windows CreateProcess resolution order is respected.
+    try:
+        r = subprocess.run(
+            ["bash", "-c", "echo ok"],
+            capture_output=True, text=True, timeout=5,
+        )
+        if r.returncode != 0 or "ok" not in r.stdout:
             return False
+    except (OSError, subprocess.TimeoutExpired):
+        return False
+    # On Windows, verify we have MSYS/MINGW bash (Git for Windows),
+    # not the WSL launcher which can't handle native paths.
+    if sys.platform == "win32":
         try:
             u = subprocess.run(
-                [bash_path, "-c", "uname -s"],
+                ["bash", "-c", "uname -s"],
                 capture_output=True, text=True, timeout=5,
             )
             kernel = u.stdout.strip().upper()
             if not any(k in kernel for k in ("MSYS", "MINGW", "CYGWIN")):
                 return False
         except (OSError, subprocess.TimeoutExpired):
             return False
-    try:
-        r = subprocess.run(
-            [bash_path, "-c", "echo ok"],
-            capture_output=True, text=True, timeout=5,
-        )
-        if r.returncode != 0 or "ok" not in r.stdout:
-            return False
-    except (OSError, subprocess.TimeoutExpired):
-        return False
     return True