From 595bcc89fc8c0e0891193180df27939c2d1ccd2d Mon Sep 17 00:00:00 2001
From: Sanjay Santhanam <51058514+Sanjays2402@users.noreply.github.com>
Date: Sat, 2 May 2026 16:48:10 -0700
Subject: [PATCH] test(update): patch isatty on real streams to fix xdist-flaky
 --yes tests

Two CI tests for the new `--yes` update flag (#18261) flaked under
`pytest-xdist` on Linux/Python 3.11 even though they passed every
local run on macOS/Python 3.14.4:

  FAILED tests/hermes_cli/test_update_yes_flag.py
    ::TestUpdateYesConfigMigration::test_no_yes_flag_still_prompts_in_tty
      `AssertionError: assert <MagicMock 'input'>.called is False`
  FAILED tests/hermes_cli/test_update_yes_flag.py
    ::TestUpdateYesStashRestore::test_yes_restores_stash_without_prompting
      `AssertionError: assert <MagicMock '_restore_stashed_changes'>.called is False`

Captured stdout for the first failure shows `cmd_update` taking the
"Non-interactive session \u2014 skipping config migration prompt." branch
\u2014 i.e. the `sys.stdin.isatty() and sys.stdout.isatty()` check at
`hermes_cli/main.py:7118` evaluated to `False` despite the test doing:

    with patch("hermes_cli.main.sys") as mock_sys:
        mock_sys.stdin.isatty.return_value = True
        mock_sys.stdout.isatty.return_value = True

The whole-module mock is fragile under xdist worker reuse: a sibling
test that imports `hermes_cli.main` first can leave another `sys`
reference resolved inside the function (re-import in a helper, etc.),
and the wholesale module replacement never gets consulted.

Switch to `patch.object(_sys.stdin, "isatty", return_value=True)` (and
the same for `stdout`). That patches the *attribute on the real stream
object* \u2014 every call site, no matter how it reached `sys.stdin`,
hits the patched method. Same fix applied to the stash-restore test
(it took the "non-TTY \u2192 skip restore prompt" branch for the same reason).

Validation:

    $ pytest tests/hermes_cli/test_update_yes_flag.py -q
    3 passed in 5.47s

No production code change. Fixes the two failures observed on `main`
(run 25250051126):

`tests/hermes_cli/test_update_yes_flag.py::TestUpdateYesConfigMigration::test_no_yes_flag_still_prompts_in_tty`
`tests/hermes_cli/test_update_yes_flag.py::TestUpdateYesStashRestore::test_yes_restores_stash_without_prompting`

Refs: #18261 (added the `--yes` flag + these tests).
---
 tests/hermes_cli/test_update_yes_flag.py | 28 +++++++++++++++++++-----
 1 file changed, 22 insertions(+), 6 deletions(-)

diff --git a/tests/hermes_cli/test_update_yes_flag.py b/tests/hermes_cli/test_update_yes_flag.py
index e36cc5142e..66060b10aa 100644
--- a/tests/hermes_cli/test_update_yes_flag.py
+++ b/tests/hermes_cli/test_update_yes_flag.py
@@ -113,11 +113,18 @@ class TestUpdateYesConfigMigration:
 
         args = SimpleNamespace(yes=False)
 
-        with patch("builtins.input", return_value="n") as mock_input, patch(
-            "hermes_cli.main.sys"
-        ) as mock_sys:
-            mock_sys.stdin.isatty.return_value = True
-            mock_sys.stdout.isatty.return_value = True
+        # Patch ``sys.stdin.isatty`` and ``sys.stdout.isatty`` directly on the
+        # real ``sys`` module instead of replacing ``hermes_cli.main.sys`` with
+        # a MagicMock. The MagicMock approach was flaky under ``pytest-xdist``
+        # — a sibling test that imported ``hermes_cli.main`` first could leave
+        # a different ``sys`` reference resolved inside the function and the
+        # mock would never be consulted, with CI then taking the
+        # "Non-interactive session" branch instead of prompting.
+        import sys as _sys
+
+        with patch("builtins.input", return_value="n") as mock_input, patch.object(
+            _sys.stdin, "isatty", return_value=True
+        ), patch.object(_sys.stdout, "isatty", return_value=True):
             cmd_update(args)
             # The user was actually prompted.
             assert mock_input.called
@@ -156,7 +163,16 @@ class TestUpdateYesStashRestore:
 
         args = SimpleNamespace(yes=True)
 
-        cmd_update(args)
+        # Force a TTY-shaped session so the autostash-restore branch is
+        # reachable in CI workers regardless of inherited stdio (matches the
+        # isatty patching strategy in ``test_no_yes_flag_still_prompts_in_tty``
+        # — ``patch.object`` on the real streams is robust under xdist).
+        import sys as _sys
+
+        with patch.object(_sys.stdin, "isatty", return_value=True), patch.object(
+            _sys.stdout, "isatty", return_value=True
+        ):
+            cmd_update(args)
 
         # _restore_stashed_changes was called, and called with prompt_user=False
         # every time (so the user never sees "Restore local changes now?").