Whitelist allowed test names

unittests/errors_test.py

 #!/usr/bin/env python
 # Copyright 2014 The LUCI Authors. All rights reserved.
 # Use of this source code is governed under the Apache License, Version 2.0
 # that can be found in the LICENSE file.
 
 import json
 import os
 import shutil
 import subprocess
 import tempfile
@@ skipping 321 matching lines @@
 """)
       subp = subprocess.Popen(
                     repo.recipes_cmd + ['run', 'do_nothing'],
                               stdout=subprocess.PIPE)
       stdout, _ = subp.communicate()
       self.assertRegexpMatches(
           stdout, r'from the root of a \'testproj\' checkout')
       self.assertRegexpMatches(
           stdout, r'\./foo/bar/recipes\.py run .* do_nothing')
 
+  def test_invalid_test_names(self):
+    # Full tests in recipe_engine/unittests/recipe_test_api_test.py
+    with RecipeRepo() as repo:
+      repo.make_recipe('test_recipe', """
+DEPS = []
+def RunSteps(api):
+  pass
 
-
+def GenTests(api):
+  yield api.test('best test')
+""")
+      subp = subprocess.Popen(
+                    repo.recipes_cmd + ['simulation_test', 'test_recipe'],
+                    stdout=subprocess.PIPE)
+      stdout, _ = subp.communicate()
+      self.assertIn('Traceback', stdout)
+      self.assertIn('Invalid test name', stdout)
 
 
 if __name__ == '__main__':
   unittest.main()