Validate indexer values

Make sure that indexer values are one of the supported indexers.
Invalid values would have raised an invalid indexer exception on
access.

Author: rouilj

roundup/configuration.py

@@ -408,6 +408,18 @@ def str2value(self, value):
             return _val
         raise OptionValueError(self, value, self.class_description)
 
+class IndexerOption(Option):
+    """Valid options for indexer"""
+
+    allowed = ['', 'xapian', 'whoosh', 'native']
+    class_description = "Allowed values: %s" % ', '.join("'%s'" % a
+                                                         for a in allowed)
+
+    def str2value(self, value):
+        _val = value.lower()
+        if _val in self.allowed:
+            return _val
+        raise OptionValueError(self, value, self.class_description)
 
 class MailAddressOption(Option):
 
@@ -742,7 +754,7 @@ def str2value(self, value):
             "email?"),
         (BooleanOption, "email_registration_confirmation", "yes",
             "Offer registration confirmation by email or only through the web?"),
-        (Option, "indexer", "",
+        (IndexerOption, "indexer", "",
             "Force Roundup to use a particular text indexer.\n"
             "If no indexer is supplied, the first available indexer\n"
             "will be used in the following order:\n"

test/test_config.py

@@ -381,7 +381,7 @@ def testInvalidIndexerLanguage_w_native(self):
         self.assertEqual(config['INDEXER_LANGUAGE'], 'NO_LANG')
 
     def testInvalidIndexerLanguage_w_xapian(self):
-        """ Use explicit xapian indexer. VAerify exception is
+        """ Use explicit xapian indexer. Verify exception is
             generated.
         """
 
@@ -418,3 +418,23 @@ def testLoadConfig(self):
         # uppercase name passes as does tuple index for setting in web
         self.assertEqual(config['WEB_COOKIE_TAKES_PRECEDENCE'], 0)
         self.assertEqual(config[('web','cookie_takes_precedence')], 0)
+
+
+    def testInvalidIndexerValue(self):
+        """ Mistype native indexer. Verify exception is
+            generated.
+        """
+
+        print("Testing indexer nati")
+
+        self.munge_configini(mods=[ ("indexer = ", "nati") ])
+
+        with self.assertRaises(configuration.OptionValueError) as cm:
+            config.load(self.dirname)
+
+        self.assertIn("OptionValueError", repr(cm.exception))
+        # look for failing value
+        self.assertEqual("nati", cm.exception.args[1])
+        # look for supported values
+        self.assertIn("whoosh", cm.exception.args[2])
+