Add first pass at integration style tests

In order to better prevent regressions (such as related to concurrency),
Add a integration test framework to simulate running flake8 with
arguments.

1 files changed, 71 insertions, 0 deletions

diff --git a/flake8/tests/test_integration.py b/flake8/tests/test_integration.py
new file mode 100644
index 0000000..55ace48
--- /dev/null
+++ b/flake8/tests/test_integration.py
@@ -0,0 +1,71 @@
+from __future__ import with_statement
+
+import os
+import unittest
+try:
+    from unittest import mock
+except ImportError:
+    import mock  # < PY33
+
+from flake8 import engine
+
+
+class IntegrationTestCase(unittest.TestCase):
+    """Integration style tests to exercise different command line options."""
+
+    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
+
+    def check_files(self, arglist=[], explicit_stdin=False, count=0):
+        """Call check_files."""
+        if explicit_stdin:
+            target_file = "-"
+        else:
+            target_file = self.this_file()
+        argv = ['flake8'] + arglist + [target_file]
+        with mock.patch("sys.argv", argv):
+            style_guide = engine.get_style_guide(parse_argv=True)
+            report = style_guide.check_files()
+        self.assertEqual(report.total_errors, count)
+        return style_guide, report
+
+    def test_no_args(self):
+        # assert there are no reported errors
+        self.check_files()
+
+    def _job_tester(self, jobs):
+        # 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)
+
+    def test_jobs(self):
+        self._job_tester(2)
+        self._job_tester(10)
+
+    def test_stdin(self):
+        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):
+            guide, report = self.check_files(arglist=['--jobs=4'],
+                                             explicit_stdin=True)
+        self.assertEqual(self.count, 1)
+
+    def test_stdin_fail(self):
+        def fake_stdin():
+            return "notathing\n"
+        with mock.patch("pep8.stdin_get_value", fake_stdin):
+            # only assert needed is in check_files
+            guide, report = self.check_files(arglist=['--jobs=4'],
+                                             explicit_stdin=True,
+                                             count=1)