Add get_service_options API to merge together global & local network options

First part of #642.

classes.py

@@ -544,6 +544,22 @@ class PyLinkNetworkCore(structures.CamelCaseToSnakeCase):
 
         return default
 
+    def get_service_options(self, servicename: str, option: str, itertype: type, global_option=None):
+        """
+        Returns a merged copy of the requested service bot option. This includes:
+
+        1) If present, the value of the config option servers::<NETNAME>::<SERVICENAME>_<OPTION> (netopt)
+        2) If present, the value of the config option <SERVICENAME>::<GLOBAL_OPTION>, where
+           <GLOBAL_OPTION> is either the 'global_option' keyword value or <OPTION> (globalopt)
+
+        For itertype, the following types are allowed:
+            - list: items are combined as globalopt + netopt
+            - dict: items are combined as {**globalopt, **netopt}
+        """
+        netopt = self.serverdata.get('%s_%s' % (servicename, option)) or itertype()
+        globalopt = conf.conf.get(servicename, {}).get(global_option or option) or itertype()
+        return utils.merge_iterables(globalopt, netopt)
+
     def has_cap(self, capab):
         """
         Returns whether this protocol module instance has the requested capability.

test/protocol_test_fixture.py

@@ -258,6 +258,49 @@ class BaseProtocolTest(unittest.TestCase):
             self.assertEqual(f('myserv', 'myopt'), 998877)  # Read local option
             self.assertEqual(f('myserv', 'myopt', default='unused'), 998877)
 
+    def test_get_service_options_list(self):
+        f = self.p.get_service_options
+        self.assertEqual(f('myserv', 'items', list), [])  # No value anywhere
+
+        # Define global option
+        with patch.dict(conf.conf, {'myserv': {'items': [1, 10, 100], 'empty': []}}):
+            self.assertEqual(f('myserv', 'items', list), [1, 10, 100])  # Global value only
+            self.assertEqual(f('myserv', 'empty', list), [])
+
+            # Both global and local options exist
+            with patch.dict(self.p.serverdata, {'myserv_items': [2, 4, 6, 8], 'empty': []}):
+                self.assertEqual(f('myserv', 'items', list), [1, 10, 100, 2, 4, 6, 8])
+                # Custom global_option setting
+                self.assertEqual(f('myserv', 'items', list, global_option='nonexistent'), [2, 4, 6, 8])
+                self.assertEqual(f('myserv', 'empty', list), [])
+
+        # Define local option
+        with patch.dict(self.p.serverdata, {'myserv_items': [1, 0, 0, 3]}):
+            self.assertEqual(f('myserv', 'items', list), [1, 0, 0, 3])  # Read local option
+
+    def test_get_service_options_dict(self):
+        f = self.p.get_service_options
+        self.assertEqual(f('chanman', 'items', dict), {})  # No value anywhere
+
+        # This is just mildly relevant test data, it's not actually used anywhere.
+        globalopt = {'o': '@', 'v': '+', 'a': '!', 'h': '%'}
+        localopt  = {'a': '&', 'q': '~'}
+        # Define global option
+        with patch.dict(conf.conf, {'chanman': {'prefixes': globalopt, 'empty': {}}}):
+            self.assertEqual(f('chanman', 'prefixes', dict), globalopt)  # Global value only
+            self.assertEqual(f('chanman', 'empty', dict), {})
+
+            # Both global and local options exist
+            with patch.dict(self.p.serverdata, {'chanman_prefixes': localopt, 'empty': {}}):
+                self.assertEqual(f('chanman', 'prefixes', dict), {**globalopt, **localopt})
+
+                self.assertEqual(f('chanman', 'items', dict), {})  # No value anywhere
+                self.assertEqual(f('chanman', 'empty', dict), {})
+
+        # Define local option
+        with patch.dict(self.p.serverdata, {'chanman_prefixes': localopt}):
+            self.assertEqual(f('chanman', 'prefixes', dict), localopt)  # Read local option
+
     ### MODE HANDLING
     def test_parse_modes_channel_rfc(self):
         # These are basic tests that only use RFC 1459 defined modes.
@@ -436,7 +479,7 @@ class BaseProtocolTest(unittest.TestCase):
             "Cycling a ban +b-b should remove it (different case)"
         )
 
-    def test_parse_mode_channel_prefixmode_has_nick(self):
+    def test_parse_modes_channel_prefixmode_has_nick(self):
         c = self.p.channels['#'] = Channel(self.p, name='#')
         u = self._make_user('mynick', uid='myuid')
         c.users.add(u)

test/test_utils.py

@@ -254,5 +254,22 @@ class UtilsTestCase(unittest.TestCase):
         self.assertFalse(f('*9*', '14', lambda s: s.zfill(13)))
         self.assertTrue(f('*chin*', 'machine', str.upper))
 
+    def test_merge_iterables(self):
+        f = utils.merge_iterables
+        self.assertEqual(f([], []), [])
+        self.assertEqual(f({}, {}), {})
+        self.assertEqual(f(set(), set()), set())
+
+        self.assertEqual(f([1,2], [4,5,6]), [1,2,4,5,6])
+        self.assertEqual(f({'a': 'b'}, {'c': 'd', 'e': 'f'}),
+                         {'a': 'b', 'c': 'd', 'e': 'f'})
+        self.assertEqual(f({0,1,2}, {1,3,5}),
+                         {0,1,2,3,5})
+
+        with self.assertRaises(ValueError):
+            f([1,2,3], {'a': 'b'})  # mismatched type
+        with self.assertRaises(ValueError):
+            f([], set())  # mismatched type
+
 if __name__ == '__main__':
     unittest.main()

utils.py

@@ -851,3 +851,21 @@ def match_text(glob, text, filterfunc=str.lower):
         text = filterfunc(text)
 
     return re.match(_glob2re(glob), text)
+
+def merge_iterables(A, B):
+    """
+    Merges the values in two iterables. A and B must be of the same type, and one of the following:
+
+    - list: items are combined as A + B
+    - set:  items are combined as A | B
+    - dict: items are combined as {**A, **B}
+    """
+    if type(A) != type(B):
+        raise ValueError("inputs must be the same type")
+
+    if isinstance(A, list):
+        return A + B
+    elif isinstance(A, set):
+        return A | B
+    elif isinstance(A, dict):
+        return {**A, **B}