cpython/Lib/idlelib/idle_test/test_undo.py
Miss Islington (bot) 433f016718
[3.15] gh-155648: In IDLE tests, call unittest.main without exit arg (GH-156249) (#156251)
DevDanzin bug 73: In idlelib.idle_test, test_xyz.py files should end with

if __name__ == '__main__':
    unittest.main(verbosity=2)

The default exit is True. This need not and should not be added.
5 files add the confusing equivalent exit=2 ("why the weird value?"),

4 files add exit=False. This is nonsensical when there is nothing more to run;
main will immediately exit anyway. When running a test file from an IDLE editor,
this argument has no visible effect. However, a Claude-based
bug finder claims that in other circumstances (such as a program running
the test in a shell), the good test may falsely fail. Even if this is
not true, it can only confuse a reader.

(The only place in idlelib for exit=False is in idlelib/abc.py files where the unittest
is followed by an htest. The default exit=True exits the process, skipping the htest.)

As part of editing the discussion of this in idle_test/htest.py, I clarified other things.

(cherry picked from commit c20318bf09)

Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>
2026-10-09 13:30:07 -04:00

135 lines
4.1 KiB
Python

"Test undo, coverage 77%."
# Only test UndoDelegator so far.
from idlelib.undo import UndoDelegator
import unittest
from test.support import requires
requires('gui')
from unittest.mock import Mock
from tkinter import Text, Tk
from idlelib.percolator import Percolator
class UndoDelegatorTest(unittest.TestCase):
@classmethod
def setUpClass(cls):
cls.root = Tk()
cls.text = Text(cls.root)
cls.percolator = Percolator(cls.text)
@classmethod
def tearDownClass(cls):
cls.percolator.redir.close()
del cls.percolator, cls.text
cls.root.destroy()
del cls.root
def setUp(self):
self.delegator = UndoDelegator()
self.delegator.bell = Mock()
self.percolator.insertfilter(self.delegator)
def tearDown(self):
self.percolator.removefilter(self.delegator)
self.text.delete('1.0', 'end')
self.delegator.resetcache()
def test_undo_event(self):
text = self.text
text.insert('insert', 'foobar')
text.insert('insert', 'h')
text.event_generate('<<undo>>')
self.assertEqual(text.get('1.0', 'end'), '\n')
text.insert('insert', 'foo')
text.insert('insert', 'bar')
text.delete('1.2', '1.4')
text.insert('insert', 'hello')
text.event_generate('<<undo>>')
self.assertEqual(text.get('1.0', '1.4'), 'foar')
text.event_generate('<<undo>>')
self.assertEqual(text.get('1.0', '1.6'), 'foobar')
text.event_generate('<<undo>>')
self.assertEqual(text.get('1.0', '1.3'), 'foo')
text.event_generate('<<undo>>')
self.delegator.undo_event('event')
self.assertTrue(self.delegator.bell.called)
def test_redo_event(self):
text = self.text
text.insert('insert', 'foo')
text.insert('insert', 'bar')
text.delete('1.0', '1.3')
text.event_generate('<<undo>>')
text.event_generate('<<redo>>')
self.assertEqual(text.get('1.0', '1.3'), 'bar')
text.event_generate('<<redo>>')
self.assertTrue(self.delegator.bell.called)
def test_dump_event(self):
"""
Dump_event cannot be tested directly without changing
environment variables. So, test statements in dump_event
indirectly
"""
text = self.text
d = self.delegator
text.insert('insert', 'foo')
text.insert('insert', 'bar')
text.delete('1.2', '1.4')
self.assertTupleEqual((d.pointer, d.can_merge), (3, True))
text.event_generate('<<undo>>')
self.assertTupleEqual((d.pointer, d.can_merge), (2, False))
def test_get_set_saved(self):
# test the getter method get_saved
# test the setter method set_saved
# indirectly test check_saved
d = self.delegator
self.assertTrue(d.get_saved())
self.text.insert('insert', 'a')
self.assertFalse(d.get_saved())
d.saved_change_hook = Mock()
d.set_saved(True)
self.assertEqual(d.pointer, d.saved)
self.assertTrue(d.saved_change_hook.called)
d.set_saved(False)
self.assertEqual(d.saved, -1)
self.assertTrue(d.saved_change_hook.called)
def test_undo_start_stop(self):
# test the undo_block_start and undo_block_stop methods
text = self.text
text.insert('insert', 'foo')
self.delegator.undo_block_start()
text.insert('insert', 'bar')
text.insert('insert', 'bar')
self.delegator.undo_block_stop()
self.assertEqual(text.get('1.0', '1.3'), 'foo')
# test another code path
self.delegator.undo_block_start()
text.insert('insert', 'bar')
self.delegator.undo_block_stop()
self.assertEqual(text.get('1.0', '1.3'), 'foo')
def test_addcmd(self):
text = self.text
# when number of undo operations exceeds max_undo
self.delegator.max_undo = max_undo = 10
for i in range(max_undo + 10):
text.insert('insert', 'foo')
self.assertLessEqual(len(self.delegator.undolist), max_undo)
if __name__ == '__main__':
unittest.main(verbosity=2)