Merge branch 'christianmlong/issue/8'

flake8/engine.py

@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 import re
 import platform
+import warnings
 
 import pep8
 
@@ -8,7 +9,7 @@ from flake8 import __version__
 from flake8 import callbacks
 from flake8.reporter import (multiprocessing, BaseQReport, FileQReport,
                              QueueReport)
-from flake8.util import OrderedSet, is_windows, is_using_stdin
+from flake8 import util
 
 _flake8_noqa = re.compile(r'\s*# flake8[:=]\s*noqa', re.I).search
 
@@ -17,7 +18,7 @@ EXTRA_EXCLUDE = ['.tox', '.eggs', '*.egg']
 
 def _register_extensions():
     """Register all the extensions."""
-    extensions = OrderedSet()
+    extensions = util.OrderedSet()
     extensions.add(('pep8', pep8.__version__))
     parser_hooks = []
     options_hooks = []
@@ -123,10 +124,25 @@ def get_style_guide(**kwargs):
     for options_hook in options_hooks:
         options_hook(options)
 
+    if util.warn_when_using_jobs(options):
+        if not multiprocessing:
+            warnings.warn("The multiprocessing module is not available. "
+                          "Ignoring --jobs arguments.")
+        if util.is_windows():
+            warnings.warn("The --jobs option is not available on Windows. "
+                          "Ignoring --jobs arguments.")
+        if util.is_using_stdin(styleguide.paths):
+            warnings.warn("The --jobs option is not compatible with supplying "
+                          "input using - . Ignoring --jobs arguments.")
+        if options.diff:
+            warnings.warn("The --diff option was specified with --jobs but "
+                          "they are not compatible. Ignoring --jobs arguments."
+                          )
+
     if options.diff:
         options.jobs = None
 
-    force_disable_jobs = is_windows() or is_using_stdin(styleguide.paths)
+    force_disable_jobs = util.force_disable_jobs(styleguide)
 
     if multiprocessing and options.jobs and not force_disable_jobs:
         if options.jobs.isdigit():

flake8/tests/test_engine.py

@@ -39,6 +39,7 @@ class TestEngine(unittest.TestCase):
             with mock.patch('flake8.engine.get_parser') as get_parser:
                 m.ignored_extensions = []
                 StyleGuide.return_value.options.jobs = '42'
+                StyleGuide.return_value.options.diff = False
                 get_parser.return_value = (m, [])
                 engine.get_style_guide(foo='bar')
                 get_parser.assert_called_once_with()
@@ -85,13 +86,13 @@ class TestEngine(unittest.TestCase):
         # ourselves) what system we may be testing on.
 
     def test_windows_disables_jobs(self):
-        with mock.patch('flake8.engine.is_windows') as is_windows:
+        with mock.patch('flake8.util.is_windows') as is_windows:
             is_windows.return_value = True
             guide = engine.get_style_guide()
             assert isinstance(guide, reporter.BaseQReport) is False
 
     def test_stdin_disables_jobs(self):
-        with mock.patch('flake8.engine.is_using_stdin') as is_using_stdin:
+        with mock.patch('flake8.util.is_using_stdin') as is_using_stdin:
             is_using_stdin.return_value = True
             guide = engine.get_style_guide()
             assert isinstance(guide, reporter.BaseQReport) is False

flake8/tests/test_integration.py

@@ -8,6 +8,7 @@ except ImportError:
     import mock  # < PY33
 
 from flake8 import engine
+from flake8.util import is_windows
 
 
 class IntegrationTestCase(unittest.TestCase):
@@ -41,8 +42,15 @@ class IntegrationTestCase(unittest.TestCase):
         # mock stdout.flush so we can count the number of jobs created
         with mock.patch('sys.stdout.flush') as mocked:
             guide, report = self.check_files(arglist=['--jobs=%s' % jobs])
-            self.assertEqual(guide.options.jobs, jobs)
-            self.assertEqual(mocked.call_count, jobs)
+            if is_windows():
+                # The code path where guide.options.jobs gets converted to an
+                # int is not run on windows. So, do the int conversion here.
+                self.assertEqual(int(guide.options.jobs), jobs)
+                # On windows, call count is always zero.
+                self.assertEqual(mocked.call_count, 0)
+            else:
+                self.assertEqual(guide.options.jobs, jobs)
+                self.assertEqual(mocked.call_count, jobs)
 
     def test_jobs(self):
         self._job_tester(2)

flake8/tests/test_warnings.py

@@ -0,0 +1,200 @@
+"""
+    _test_warnings.py
+
+    Tests for the warnings that are emitted by flake8.
+
+    This module is named _test_warnings instead of test_warnings so that a
+    normal nosetests run does not collect it. The tests in this module pass
+    when they are run alone, but they fail when they are run along with other
+    tests (nosetests --with-isolation doesn't help).
+
+    In tox.ini, these tests are run separately.
+"""
+
+from __future__ import with_statement
+
+import os
+import warnings
+import unittest
+try:
+    from unittest import mock
+except ImportError:
+    import mock  # < PY33
+
+from flake8 import engine
+from flake8.util import is_windows
+
+
+class IntegrationTestCaseWarnings(unittest.TestCase):
+    """Integration style tests to check that warnings are issued properly for
+    different command line options."""
+
+    windows_warning_text = ("The --jobs option is not available on Windows."
+                            " Ignoring --jobs arguments.")
+    stdin_warning_text = ("The --jobs option is not compatible with"
+                          " supplying input using - . Ignoring --jobs"
+                          " arguments.")
+
+    def this_file(self):
+        """Return the real path of this file."""
+        this_file = os.path.realpath(__file__)
+        if this_file.endswith("pyc"):
+            this_file = this_file[:-1]
+        return this_file
+
+    @staticmethod
+    def get_style_guide_with_warnings(engine, *args, **kwargs):
+        """
+        Return a style guide object (obtained by calling
+        engine.get_style_guide) and a list of the warnings that were raised in
+        the process.
+
+        Note: not threadsafe
+        """
+
+        # Note
+        # https://docs.python.org/2/library/warnings.html
+        #
+        # The catch_warnings manager works by replacing and then later
+        # restoring the module's showwarning() function and internal list of
+        # filter specifications. This means the context manager is modifying
+        # global state and therefore is not thread-safe
+
+        with warnings.catch_warnings(record=True) as collected_warnings:
+            # Cause all warnings to always be triggered.
+            warnings.simplefilter("always")
+
+            # Get the style guide
+            style_guide = engine.get_style_guide(*args, **kwargs)
+
+        # Now that the warnings have been collected, return the style guide and
+        # the
+        # warnings.
+        return (style_guide, collected_warnings)
+
+    def verify_warnings(self, collected_warnings, expected_warnings):
+        """
+        Verifies that collected_warnings is a sequence that contains user
+        warnings that match the sequence of string values passed in as
+        expected_warnings.
+        """
+        if expected_warnings is None:
+            expected_warnings = []
+
+        collected_user_warnings = [w for w in collected_warnings
+                                   if issubclass(w.category, UserWarning)]
+
+        self.assertEqual(len(collected_user_warnings),
+                         len(expected_warnings))
+
+        collected_warnings_set = set(str(warning.message)
+                                     for warning
+                                     in collected_user_warnings)
+        expected_warnings_set = set(expected_warnings)
+        self.assertEqual(collected_warnings_set, expected_warnings_set)
+
+    def check_files_collect_warnings(self,
+                                     arglist=[],
+                                     explicit_stdin=False,
+                                     count=0,
+                                     verbose=False):
+        """Call check_files and collect any warnings that are issued."""
+        if verbose:
+            arglist.append('--verbose')
+        if explicit_stdin:
+            target_file = "-"
+        else:
+            target_file = self.this_file()
+        argv = ['flake8'] + arglist + [target_file]
+        with mock.patch("sys.argv", argv):
+            (style_guide,
+             collected_warnings,
+             ) = self.get_style_guide_with_warnings(engine,
+                                                    parse_argv=True)
+            report = style_guide.check_files()
+        self.assertEqual(report.total_errors, count)
+        return style_guide, report, collected_warnings
+
+    def check_files_no_warnings_allowed(self,
+                                        arglist=[],
+                                        explicit_stdin=False,
+                                        count=0,
+                                        verbose=False):
+        """Call check_files, and assert that there were no warnings issued."""
+        (style_guide,
+         report,
+         collected_warnings,
+         ) = self.check_files_collect_warnings(arglist=arglist,
+                                               explicit_stdin=explicit_stdin,
+                                               count=count,
+                                               verbose=verbose)
+        self.verify_warnings(collected_warnings, expected_warnings=None)
+        return style_guide, report
+
+    def _job_tester(self, jobs, verbose=False):
+        # mock stdout.flush so we can count the number of jobs created
+        with mock.patch('sys.stdout.flush') as mocked:
+            (guide,
+             report,
+             collected_warnings,
+             ) = self.check_files_collect_warnings(
+                arglist=['--jobs=%s' % jobs],
+                verbose=verbose)
+
+            if is_windows():
+                # The code path where guide.options.jobs gets converted to an
+                # int is not run on windows. So, do the int conversion here.
+                self.assertEqual(int(guide.options.jobs), jobs)
+                # On windows, call count is always zero.
+                self.assertEqual(mocked.call_count, 0)
+            else:
+                self.assertEqual(guide.options.jobs, jobs)
+                self.assertEqual(mocked.call_count, jobs)
+
+            expected_warings = []
+            if verbose and is_windows():
+                expected_warings.append(self.windows_warning_text)
+            self.verify_warnings(collected_warnings, expected_warings)
+
+    def test_jobs(self, verbose=False):
+        self._job_tester(2, verbose=verbose)
+        self._job_tester(10, verbose=verbose)
+
+    def test_no_args_no_warnings(self, verbose=False):
+        self.check_files_no_warnings_allowed(verbose=verbose)
+
+    def test_stdin_jobs_warning(self, verbose=False):
+        self.count = 0
+
+        def fake_stdin():
+            self.count += 1
+            with open(self.this_file(), "r") as f:
+                return f.read()
+
+        with mock.patch("pep8.stdin_get_value", fake_stdin):
+            (style_guide,
+             report,
+             collected_warnings,
+             ) = self.check_files_collect_warnings(arglist=['--jobs=4'],
+                                                   explicit_stdin=True,
+                                                   verbose=verbose)
+            expected_warings = []
+            if verbose:
+                expected_warings.append(self.stdin_warning_text)
+                if is_windows():
+                    expected_warings.append(self.windows_warning_text)
+            self.verify_warnings(collected_warnings, expected_warings)
+        self.assertEqual(self.count, 1)
+
+    def test_jobs_verbose(self):
+        self.test_jobs(verbose=True)
+
+    def test_no_args_no_warnings_verbose(self):
+        self.test_no_args_no_warnings(verbose=True)
+
+    def test_stdin_jobs_warning_verbose(self):
+        self.test_stdin_jobs_warning(verbose=True)
+
+
+if __name__ == '__main__':
+    unittest.main()

flake8/util.py

@@ -54,6 +54,15 @@ def is_using_stdin(paths):
     return '-' in paths
 
 
+def warn_when_using_jobs(options):
+    return (options.verbose and options.jobs and options.jobs.isdigit() and
+            int(options.jobs) > 1)
+
+
+def force_disable_jobs(styleguide):
+    return is_windows() or is_using_stdin(styleguide.paths)
+
+
 def flag_on(val):
     """Return true if flag is on"""
     return str(val).upper() in ('1', 'T', 'TRUE', 'ON')

tox.ini

@@ -6,6 +6,7 @@ envlist =
 [testenv]
 usedevelop = True
 deps =
+    mock
 commands =
     python setup.py test -q
     python setup.py flake8