enable multiprocessing on other platforms

tests/integration/test_checker.py

@@ -266,17 +266,12 @@ def test_report_order(results, expected_order):
     # tuples to create the expected result lists from the indexes
     expected_results = [results[index] for index in expected_order]
 
-    file_checker = mock.Mock(spec=["results", "display_name"])
-    file_checker.results = results
-    file_checker.display_name = "placeholder"
-
     style_guide = mock.MagicMock(spec=["options", "processing_file"])
 
     # Create a placeholder manager without arguments or plugins
     # Just add one custom file checker which just provides the results
-    manager = checker.Manager(style_guide, finder.Checkers([], [], []))
-    manager.checkers = manager._all_checkers = [file_checker]
-
+    manager = checker.Manager(style_guide, finder.Checkers([], [], []), [])
+    manager.results = [("placeholder", results, {})]
     # _handle_results is the first place which gets the sorted result
     # Should something non-private be mocked instead?
     handler = mock.Mock(side_effect=count_side_effect)
@@ -295,9 +290,9 @@ def test_acquire_when_multiprocessing_pool_can_initialize():
     This simulates the behaviour on most common platforms.
     """
     with mock.patch("multiprocessing.Pool") as pool:
-        result = checker._try_initialize_processpool(2)
+        result = checker._try_initialize_processpool(2, [])
 
-    pool.assert_called_once_with(2, checker._pool_init)
+    pool.assert_called_once_with(2, checker._mp_init, initargs=([],))
     assert result is pool.return_value
 
 
@@ -314,9 +309,9 @@ def test_acquire_when_multiprocessing_pool_can_not_initialize():
     https://github.com/python/cpython/blob/4e02981de0952f54bf87967f8e10d169d6946b40/Lib/multiprocessing/synchronize.py#L30-L33
     """
     with mock.patch("multiprocessing.Pool", side_effect=ImportError) as pool:
-        result = checker._try_initialize_processpool(2)
+        result = checker._try_initialize_processpool(2, [])
 
-    pool.assert_called_once_with(2, checker._pool_init)
+    pool.assert_called_once_with(2, checker._mp_init, initargs=([],))
     assert result is None
 
 

tests/unit/test_checker_manager.py

@@ -20,9 +20,9 @@ def style_guide_mock():
 def _parallel_checker_manager():
     """Call Manager.run() and return the number of calls to `run_serial`."""
     style_guide = style_guide_mock()
-    manager = checker.Manager(style_guide, finder.Checkers([], [], []))
-    # multiple checkers is needed for parallel mode
-    manager.checkers = [mock.Mock(), mock.Mock()]
+    manager = checker.Manager(style_guide, finder.Checkers([], [], []), [])
+    # multiple files is needed for parallel mode
+    manager.filenames = ("file1", "file2")
     return manager
 
 
@@ -36,8 +36,7 @@ def test_oserrors_cause_serial_fall_back():
     assert serial.call_count == 1
 
 
-@mock.patch.object(multiprocessing, "get_start_method", return_value="fork")
-def test_oserrors_are_reraised(_):
+def test_oserrors_are_reraised():
     """Verify that unexpected OSErrors will cause the Manager to reraise."""
     err = OSError(errno.EAGAIN, "Ominous message")
     with mock.patch("_multiprocessing.SemLock", side_effect=err):
@@ -48,14 +47,6 @@ def test_oserrors_are_reraised(_):
     assert serial.call_count == 0
 
 
-@mock.patch.object(multiprocessing, "get_start_method", return_value="spawn")
-def test_multiprocessing_is_disabled(_):
-    """Verify not being able to import multiprocessing forces jobs to 0."""
-    style_guide = style_guide_mock()
-    manager = checker.Manager(style_guide, finder.Checkers([], [], []))
-    assert manager.jobs == 0
-
-
 def test_multiprocessing_cpu_count_not_implemented():
     """Verify that jobs is 0 if cpu_count is unavailable."""
     style_guide = style_guide_mock()
@@ -66,22 +57,18 @@ def test_multiprocessing_cpu_count_not_implemented():
         "cpu_count",
         side_effect=NotImplementedError,
     ):
-        manager = checker.Manager(style_guide, finder.Checkers([], [], []))
+        manager = checker.Manager(style_guide, finder.Checkers([], [], []), [])
     assert manager.jobs == 0
 
 
-@mock.patch.object(multiprocessing, "get_start_method", return_value="spawn")
-def test_make_checkers(_):
+def test_make_checkers():
     """Verify that we create a list of FileChecker instances."""
     style_guide = style_guide_mock()
     style_guide.options.filenames = ["file1", "file2"]
-    manager = checker.Manager(style_guide, finder.Checkers([], [], []))
+    manager = checker.Manager(style_guide, finder.Checkers([], [], []), [])
 
     with mock.patch("flake8.utils.fnmatch", return_value=True):
         with mock.patch("flake8.processor.FileProcessor"):
-            manager.make_checkers(["file1", "file2"])
+            manager.start()
 
-    assert manager._all_checkers
-    for file_checker in manager._all_checkers:
-        assert file_checker.filename in style_guide.options.filenames
-    assert not manager.checkers  # the files don't exist
+    assert manager.filenames == ("file1", "file2")

tests/unit/test_legacy_api.py

@@ -1,57 +1,12 @@
 """Tests for Flake8's legacy API."""
 from __future__ import annotations
 
-import argparse
-import configparser
-import os.path
 from unittest import mock
 
 import pytest
 
 from flake8.api import legacy as api
 from flake8.formatting import base as formatter
-from flake8.options import config
-
-
-def test_get_style_guide():
-    """Verify the methods called on our internal Application."""
-    prelim_opts = argparse.Namespace(
-        append_config=[],
-        config=None,
-        isolated=False,
-        output_file=None,
-        verbose=0,
-        enable_extensions=None,
-        require_plugins=None,
-    )
-    mockedapp = mock.Mock()
-    mockedapp.parse_preliminary_options.return_value = (prelim_opts, [])
-    mockedapp.program = "flake8"
-
-    cfg = configparser.RawConfigParser()
-    cfg_dir = os.getcwd()
-
-    with mock.patch.object(config, "load_config", return_value=(cfg, cfg_dir)):
-        with mock.patch("flake8.main.application.Application") as application:
-            application.return_value = mockedapp
-            style_guide = api.get_style_guide()
-
-    application.assert_called_once_with()
-    mockedapp.parse_preliminary_options.assert_called_once_with([])
-    mockedapp.find_plugins.assert_called_once_with(
-        cfg,
-        cfg_dir,
-        enable_extensions=None,
-        require_plugins=None,
-    )
-    mockedapp.register_plugin_options.assert_called_once_with()
-    mockedapp.parse_configuration_and_cli.assert_called_once_with(
-        cfg, cfg_dir, []
-    )
-    mockedapp.make_formatter.assert_called_once_with()
-    mockedapp.make_guide.assert_called_once_with()
-    mockedapp.make_file_checker_manager.assert_called_once_with()
-    assert isinstance(style_guide, api.StyleGuide)
 
 
 def test_styleguide_options():