db: allow requesting a default if key not found

sopel/db.py

@@ -276,7 +276,7 @@ def delete_nick_value(self, nick, key):
         finally:
             session.close()
 
-    def get_nick_value(self, nick, key):
+    def get_nick_value(self, nick, key, default=None):
         """Retrieves the value for a given key associated with a nick."""
         nick = Identifier(nick)
         session = self.ssession()
@@ -288,6 +288,8 @@ def get_nick_value(self, nick, key):
                 .one_or_none()
             if result is not None:
                 result = result.value
+            elif default is not None:
+                result = default
             return _deserialize(result)
         except SQLAlchemyError:
             session.rollback()
@@ -415,7 +417,7 @@ def delete_channel_value(self, channel, key):
         finally:
             session.close()
 
-    def get_channel_value(self, channel, key):
+    def get_channel_value(self, channel, key, default=None):
         """Retrieves the value for a given key associated with a channel."""
         channel = Identifier(channel).lower()
         session = self.ssession()
@@ -426,6 +428,8 @@ def get_channel_value(self, channel, key):
                 .one_or_none()
             if result is not None:
                 result = result.value
+            elif default is not None:
+                result = default
             return _deserialize(result)
         except SQLAlchemyError:
             session.rollback()
@@ -435,13 +439,13 @@ def get_channel_value(self, channel, key):
 
     # NICK AND CHANNEL FUNCTIONS
 
-    def get_nick_or_channel_value(self, name, key):
+    def get_nick_or_channel_value(self, name, key, default=None):
         """Gets the value `key` associated to the nick or channel  `name`."""
         name = Identifier(name)
         if name.is_nick():
-            return self.get_nick_value(name, key)
+            return self.get_nick_value(name, key, default)
         else:
-            return self.get_channel_value(name, key)
+            return self.get_channel_value(name, key, default)
 
     def get_preferred_value(self, names, key):
         """Gets the value for the first name which has it set.

test/test_db.py

@@ -151,6 +151,11 @@ def test_get_nick_value(db):
         assert found_value == value
 
 
+def test_get_nick_value_default(db):
+    assert db.get_nick_value("TestUser", "DoesntExist") == None
+    assert db.get_nick_value("TestUser", "DoesntExist", "MyDefault") == "MyDefault"
+
+
 def test_delete_nick_value(db):
     nick = 'Embolalia'
     db.set_nick_value(nick, 'wasd', 'uldr')
@@ -255,13 +260,23 @@ def test_get_channel_value(db):
     assert result == 'zxcv'
 
 
+def test_get_channel_value_default(db):
+    assert db.get_channel_value("TestChan", "DoesntExist") == None
+    assert db.get_channel_value("TestChan", "DoesntExist", "MyDefault") == "MyDefault"
+
+
 def test_get_nick_or_channel_value(db):
     db.set_nick_value('asdf', 'qwer', 'poiu')
     db.set_channel_value('#asdf', 'qwer', '/.,m')
     assert db.get_nick_or_channel_value('asdf', 'qwer') == 'poiu'
     assert db.get_nick_or_channel_value('#asdf', 'qwer') == '/.,m'
 
 
+def test_get_nick_or_channel_value_default(db):
+    assert db.get_nick_or_channel_value("Test", "DoesntExist") == None
+    assert db.get_nick_or_channel_value("Test", "DoesntExist", "MyDefault") == "MyDefault"
+
+
 def test_get_preferred_value(db):
     db.set_nick_value('asdf', 'qwer', 'poiu')
     db.set_channel_value('#asdf', 'qwer', '/.,m')