scaffolding for testing version checking

dev-requirements.txt

@@ -2,6 +2,7 @@
 mock
 codecov
 cryptography
+pytest-catchlog
 pytest-cov
 pytest-tornado
 pytest>=2.8

jupyterhub/tests/test_version.py

@@ -0,0 +1,20 @@
+"""Test version checking"""
+import logging
+
+import pytest
+
+from .._version import _check_version
+
+
+@pytest.mark.parametrize('hub_version, singleuser_version, log_level, msg', [
+    ('0.8.0', '0.8.0', logging.DEBUG, 'both on version'),
+])
+def test_check_version(hub_version, singleuser_version, log_level, msg, caplog):
+    log = logging.getLogger()
+    caplog.set_level(logging.DEBUG)
+    _check_version(hub_version, singleuser_version, log)
+    assert len(caplog.records) == 1
+    record = caplog.records[0]
+    assert record.levelno == log_level
+    assert msg in record.getMessage()
+