first_stage_test: Make sure the test result is always the same

Make sure the test result does not change, only because the MITOGEN_LOG_LEVEL in
the test environment is different.

Signed-off-by: Marc Hartmayer <[email protected]>

Author: mhartmay

tests/first_stage_test.py

@@ -1,12 +1,36 @@
 import subprocess
 
+try:
+    from io import StringIO
+except ImportError:
+    from StringIO import StringIO
+
 import testlib
 
 import mitogen.core
 import mitogen.parent
 from mitogen.core import b
 
 
+class redirect(object):
+    def __init__(self, name, new):
+        self._name = name
+        self._new = new
+        self._old = None
+
+    def __enter__(self):
+        self._old = getattr(
+            sys,
+            self._name,
+        )
+        setattr(sys, self._name, self._new)
+        return self._new
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        setattr(sys, self._name, self._old)
+        return False
+
+
 class CommandLineTest(testlib.RouterMixin, testlib.TestCase):
     # Ensure this version of Python produces a command line that is sufficient
     # to bootstrap this version of Python.
@@ -17,13 +41,21 @@ class CommandLineTest(testlib.RouterMixin, testlib.TestCase):
     #   * 3.x starting 2.7
 
     def setUp(self):
+        # Make sure we set-up the logger before the Broker is created
+        with redirect('stderr', StringIO()) as f:
+            mitogen.utils.log_to_file(level="DEBUG")
         super(CommandLineTest, self).setUp()
         options = mitogen.parent.Options(max_message_size=123)
         conn = mitogen.parent.Connection(options, self.router)
         conn.context = mitogen.core.Context(None, 123)
         self.args = conn.get_boot_command()
         self.preamble = conn.get_preamble()
         self.conn = conn
+        self.stderr = f
+
+    def tearDown(self):
+        super(CommandLineTest, self).tearDown()
+        mitogen.utils.log_to_file()
 
     def test_valid_syntax(self):
         """Test valid syntax