Add a separate logging test case with a test for proofofwork.LogOutput()

src/tests/test_log.py

@@ -0,0 +1,21 @@
+"""Tests for logging"""
+
+import subprocess
+import sys
+import unittest
+
+from pybitmessage import proofofwork
+
+
+class TestLog(unittest.TestCase):
+    """A test case for logging"""
+
+    @unittest.skipIf(
+        sys.hexversion < 0x3000000, 'assertLogs is new in version 3.4')
+    def test_LogOutput(self):
+        """Use proofofwork.LogOutput to log output of a shell command"""
+        def echo():
+            """Call the echo shell command"""
+            with proofofwork.LogOutput():
+                subprocess.call(['echo', 'HELLO'])
+        self.assertLogs(echo(), 'HELLO')  # pylint: disable=no-member