Remove DownloadManager.dummy_mode

[qstokkink]

In #7466 it was uncovered that dummy_mode of DownloadManager is uncovered.

The dummy_mode code being uncovered suggests that the corresponding code is dead code and can be removed. However, we should check that this is indeed the case.

If the code related to dummy_mode is indeed dead code, we can remove it.

[drew2a]

How the dummy_mode is used in our test infrastructure

The dummy_mode is equivalent to the gui_test_mode.

tribler/src/tribler/core/components/libtorrent/libtorrent_component.py

Line 30 in 8c2f12c

dummy_mode=config.gui_test_mode)

The gui_test_mode is used in test_gui.py while performing GUI tests

tribler/src/tribler/gui/tests/test_gui.py

Line 59 in 8c2f12c

core_args=[str(RUN_TRIBLER_PY.absolute()), '--core', '--gui-test-mode'],

Therefore it is used in guitest workflow: https://github.com/Tribler/tribler/blob/main/.github/workflows/guitest.yml

What is the dummy_mode

The following lines are affected by dummy_mode:

tribler/src/tribler/core/components/libtorrent/download_manager/download_manager.py

Line 128 in 8c2f12c

self.dht_readiness_timeout = self.config.dht_readiness_timeout if not self.dummy_mode else 0

tribler/src/tribler/core/components/libtorrent/download_manager/download_manager.py

Lines 198 to 205 in 8c2f12c

	# If libtorrent session has pending disk io, wait until timeout (default: 30 seconds) to let it finish.
	# In between ask for session stats to check if state is clean for shutdown.
	# In dummy mode, we immediately shut down the download manager.
	while not self.dummy_mode and not self.is_shutdown_ready() and timeout >= 1:
	self.notify_shutdown_state("Waiting for LibTorrent to finish...")
	self.post_session_stats()
	timeout -= 1
	await asyncio.sleep(1)

tribler/src/tribler/core/components/libtorrent/download_manager/download_manager.py

Lines 252 to 259 in 8c2f12c

	if self.dummy_mode:
	from unittest.mock import Mock
	ltsession = Mock()
	ltsession.pop_alerts = lambda: {}
	ltsession.listen_port = lambda: 123
	ltsession.get_settings = lambda: {"peer_fingerprint": "000"}
	else:
	ltsession = lt.session(lt.fingerprint(*fingerprint), flags=0) if hops == 0 else lt.session(flags=0)

tribler/src/tribler/core/components/libtorrent/download_manager/download_manager.py

Lines 324 to 328 in 8c2f12c

	if self.config.dht and not self.dummy_mode:
	ltsession.start_dht()
	for router in DEFAULT_DHT_ROUTERS:
	ltsession.add_dht_router(*router)
	ltsession.start_lsd()

tribler/src/tribler/core/components/libtorrent/download_manager/download_manager.py

Lines 634 to 636 in 8c2f12c

	if not self.dummy_mode:
	self._logger.info('Dummy mode is disabled. Starting handle.')
	await self.start_handle(download, atp)

tribler/src/tribler/core/components/libtorrent/download_manager/download.py

Line 112 in 8c2f12c

self.checkpoint_disabled = checkpoint_disabled or self.dummy

[qstokkink]

Working from the results of this analysis, I think dummy_mode should be removed because it is only used for tests. My reasoning is that the system under test is changing its behavior to fit the tests. Instead, the tests should configure the system to test certain behavior.

[qstokkink]

This appears to have been resolved in #7466