fix: guard missing env vars in authenticate(), drain queues post-yield

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/test_server.py

@@ -1,4 +1,5 @@
 import json
+import os
 import queue
 import threading
 from unittest.mock import MagicMock, patch
@@ -21,6 +22,12 @@ def reset_state():
     yield
     server._auth_state = original_state
     server._client = original_client
+    for q in (server._mfa_input_queue, server._login_result_queue):
+        while not q.empty():
+            try:
+                q.get_nowait()
+            except queue.Empty:
+                break
 
 
 def test_check_auth_unauthenticated():
@@ -34,19 +41,23 @@ def test_check_auth_authenticated():
 
 
 def test_authenticate_success():
-    with patch("server.Garmin") as mock_garmin_cls:
-        mock_garmin_cls.return_value = MagicMock()
-        # mock login() returns immediately, thread puts success in queue
-        result = server.authenticate()
-        assert result == "Authenticated successfully."
-        assert server._auth_state == "authenticated"
+    env = {"GARMIN_EMAIL": "test@example.com", "GARMIN_PASSWORD": "secret"}
+    with patch.dict("os.environ", env):
+        with patch("server.Garmin") as mock_garmin_cls:
+            mock_garmin_cls.return_value = MagicMock()
+            # mock login() returns immediately, thread puts success in queue
+            result = server.authenticate()
+            assert result == "Authenticated successfully."
+            assert server._auth_state == "authenticated"
 
 
 def test_authenticate_mfa_required():
-    with patch("server.Garmin") as mock_garmin_cls:
-        mock_garmin_cls.return_value = MagicMock()
-        with patch.object(server._login_result_queue, "get", side_effect=queue.Empty):
-            result = server.authenticate()
+    env = {"GARMIN_EMAIL": "test@example.com", "GARMIN_PASSWORD": "secret"}
+    with patch.dict("os.environ", env):
+        with patch("server.Garmin") as mock_garmin_cls:
+            mock_garmin_cls.return_value = MagicMock()
+            with patch.object(server._login_result_queue, "get", side_effect=queue.Empty):
+                result = server.authenticate()
         assert "MFA required" in result
         assert server._auth_state == "mfa_pending"
 
@@ -64,3 +75,12 @@ def test_complete_mfa_not_in_progress():
     server._auth_state = "unauthenticated"
     result = server.complete_mfa("123456")
     assert result == "No MFA in progress. Call authenticate() first."
+
+
+def test_authenticate_missing_credentials():
+    with patch.dict("os.environ", {}, clear=False):
+        # Ensure the env vars are absent
+        os.environ.pop("GARMIN_EMAIL", None)
+        os.environ.pop("GARMIN_PASSWORD", None)
+        result = server.authenticate()
+    assert result == "GARMIN_EMAIL and GARMIN_PASSWORD environment variables are required."