1 files changed, 28 insertions, 0 deletions
diff --git a/app/tests/test_backends_envs.py b/app/tests/test_backends_envs.py
index 8b17458..2f0f910 100644
--- a/app/tests/test_backends_envs.py
+++ b/app/tests/test_backends_envs.py
@@ -154,6 +154,34 @@ class PipInstallTests(unittest.TestCase):
         self.assertEqual(rc, 1)
         run.assert_not_called()
 
+    def test_upgrade_adds_the_u_flag(self):
+        calls = []
+
+        def fake_run(argv, **kwargs):
+            calls.append(list(argv))
+            return 0
+
+        with patch.object(envs, "env_exists", return_value=True), \
+                patch.object(envs.common, "run_console_subprocess",
+                             side_effect=fake_run):
+            self.assertEqual(envs.pip_install(["qwen-tts"], upgrade=True), 0)
+        self.assertIn("-U", calls[0])
+        # -U sits before the packages; nothing else about the argv changes.
+        self.assertLess(calls[0].index("-U"), calls[0].index("qwen-tts"))
+
+    def test_no_upgrade_flag_by_default(self):
+        calls = []
+
+        def fake_run(argv, **kwargs):
+            calls.append(list(argv))
+            return 0
+
+        with patch.object(envs, "env_exists", return_value=True), \
+                patch.object(envs.common, "run_console_subprocess",
+                             side_effect=fake_run):
+            self.assertEqual(envs.pip_install(["qwen-tts"]), 0)
+        self.assertNotIn("-U", calls[0])
+
 
 class PipUninstallTests(unittest.TestCase):
     def test_missing_env_is_success_without_running_pip(self):