--- a/tests/test_checker.py	Fri Jul 08 00:16:33 2016 +0800
+++ b/tests/test_checker.py	Fri Jul 08 00:31:50 2016 +0800
@@ -1,4 +1,4 @@
-from checker import run, read_linter_config
+from checker import run, read_linter_config, prevalidate
 
 
 def test_run():
@@ -30,3 +30,13 @@
 
     config = read_linter_config('perfectlinter')
     assert config is None
+
+
+def test_prevalidate():
+    assert not prevalidate({})
+
+    config = {'scm': 'fossil', 'url': 'http://www.fossil-scm.org/'}
+    assert not prevalidate(config)
+
+    config = {'scm': 'hg', 'url': 'https://selenic.com/hg'}
+    assert prevalidate(config)