channel_db: raise specific exception if database is not loaded when we try to find a route

electrum/tests/test_lnpeer.py

@@ -55,6 +55,7 @@ class MockNetwork:
         self.config = simple_config.SimpleConfig(user_config, read_user_dir_function=lambda: user_dir)
         self.asyncio_loop = asyncio.get_event_loop()
         self.channel_db = ChannelDB(self)
+        self.channel_db.data_loaded.set()
         self.path_finder = LNPathFinder(self.channel_db)
         self.tx_queue = tx_queue
 

electrum/tests/test_lnrouter.py

@@ -49,6 +49,7 @@ class Test_LNRouter(TestCaseForTestnet):
             register_callback = lambda *args: None
             interface = None
         fake_network.channel_db = lnrouter.ChannelDB(fake_network())
+        fake_network.channel_db.data_loaded.set()
         cdb = fake_network.channel_db
         path_finder = lnrouter.LNPathFinder(cdb)
         self.assertEqual(cdb.num_channels, 0)