pytest: Add test for `dev-forget-channel`

Signed-off-by: Christian Decker <decker.christian@gmail.com>

tests/test_lightningd.py

@@ -3405,6 +3405,28 @@ class LightningDTests(BaseLightningDTests):
         except:
             pass
 
+    @unittest.skipIf(not DEVELOPER, "needs DEVELOPER=1")
+    def test_forget_channel(self):
+        l1 = self.node_factory.get_node()
+        l2 = self.node_factory.get_node()
+        self.give_funds(l1, 10**6)
+        l1.rpc.connect(l2.info['id'], 'localhost', l2.info['port'])
+        l1.rpc.fundchannel(l2.info['id'], 10**5)
+
+        assert len(l1.rpc.listpeers()['peers']) == 1
+
+        # This should fail, the funding tx is in the mempool and may confirm
+        self.assertRaises(ValueError, l1.rpc.dev_forget_channel, l2.info['id'])
+        assert len(l1.rpc.listpeers()['peers']) == 1
+
+        # Forcing should work
+        l1.rpc.dev_forget_channel(l2.info['id'], True)
+        assert len(l1.rpc.listpeers()['peers']) == 0
+
+        # And restarting should keep that peer forgotten
+        l1.restart()
+        assert len(l1.rpc.listpeers()['peers']) == 0
+
 
 if __name__ == '__main__':
     unittest.main(verbosity=2)