Skip to content

gh-140482: Avoid changing terminal settings in test_pty #142202

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
colesbury merged 3 commits into from
Dec 3, 2025
Merged

gh-140482: Avoid changing terminal settings in test_pty #142202

Changes from 1 commit
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
b30dc28
gh-140482: Avoid changing terminal settings in test_pty
colesbury Dec 2, 2025
f5cc4a2
Fix lint
colesbury Dec 2, 2025
d89f1b7
Fix hang on macOS
colesbury Dec 2, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Next Next commit
gh-140482: Avoid changing terminal settings in test_pty 
The previous test_spawn_doesnt_hang test had a few problems:

* It would cause ENV CHANGED failures if other tests were running
  concurrently due to stty changes
* Typing while the test was running could cause it to fail
  • Loading branch information
@colesbury
colesbury committed Dec 2, 2025
commit b30dc28ef575f45f80d61d8a97c40ad5f5307c3d
34 changes: 14 additions & 20 deletions Lib/test/test_pty.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -299,26 +299,20 @@ def test_master_read(self):

@warnings_helper.ignore_fork_in_thread_deprecation_warnings()
def test_spawn_doesnt_hang(self):
self.addCleanup(unlink, TESTFN)
with open(TESTFN, 'wb') as f:
STDOUT_FILENO = 1
dup_stdout = os.dup(STDOUT_FILENO)
os.dup2(f.fileno(), STDOUT_FILENO)
buf = b''
def master_read(fd):
nonlocal buf
data = os.read(fd, 1024)
buf += data
return data
try:
pty.spawn([sys.executable, '-c', 'print("hi there")'],
master_read)
finally:
os.dup2(dup_stdout, STDOUT_FILENO)
os.close(dup_stdout)
self.assertEqual(buf, b'hi there\r\n')
with open(TESTFN, 'rb') as f:
self.assertEqual(f.read(), b'hi there\r\n')
# gh-140482: Do the test in a pty.fork() child to avoid messing
# with the interactive test runner's terminal settings.
pid, fd = pty.fork()
if pid == pty.CHILD:
pty.spawn([sys.executable, '-c', 'print("hi there")'])
os._exit(0)

try:
(pid, status) = os.waitpid(pid, 0)
self.assertEqual(status, 0)
data = os.read(fd, 1024)
self.assertEqual(data, b"hi there\r\n")
finally:
os.close(fd)

class SmallPtyTests(unittest.TestCase):
"""These tests don't spawn children or hang."""
Expand Down
Loading