test_lightningd.py: make tests more robust by suppressing reconnects.

Got some intermittant failures, mainly caused by the tests being slow
enough that the peer reconnected.  We should always suppress
reconnection if we can, and not stress too much in the !DEVELOPER case
where we can't.

We should turn off dev-no-reconnect *always* unless told we will
reconnect, and since we can't if !DEVELOPER, don't do the connection
check there.

Instead of adding an option to line_graph, we remove it in favor
of connect (since we only use it with n=2 anyway).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

tests/test_lightningd.py

@@ -130,6 +130,8 @@ class NodeFactory(object):
             daemon.env["LIGHTNINGD_DEV_MEMLEAK"] = "1"
             if VALGRIND:
                 daemon.env["LIGHTNINGD_DEV_NO_BACKTRACE"] = "1"
+            if not may_reconnect:
+                daemon.opts["dev-no-reconnect"] = None
 
         if fake_bitcoin_cli:
             cli = os.path.join(lightning_dir, "fake-bitcoin-cli")
@@ -243,7 +245,8 @@ class BaseLightningDTests(unittest.TestCase):
         return 1 if errors else 0
 
     def checkReconnect(self, node):
-        if node.may_reconnect:
+        # Without DEVELOPER, we can't suppress reconnection.
+        if node.may_reconnect or not DEVELOPER:
             return 0
         if node.daemon.is_in_log('Peer has reconnected'):
             return 1
@@ -277,16 +280,9 @@ class BaseLightningDTests(unittest.TestCase):
 
 
 class LightningDTests(BaseLightningDTests):
-    def connect(self):
-        # Better to have clear failure because they didn't reconnect, than
-        # catch it at the end that we had an unexpected reconnect.
-        if DEVELOPER:
-            opts = {'dev-no-reconnect': None}
-        else:
-            opts = None
-
-        l1 = self.node_factory.get_node(options=opts)
-        l2 = self.node_factory.get_node(options=opts)
+    def connect(self, may_reconnect=False):
+        l1 = self.node_factory.get_node(may_reconnect=may_reconnect)
+        l2 = self.node_factory.get_node(may_reconnect=may_reconnect)
         ret = l1.rpc.connect(l2.info['id'], 'localhost', l2.info['port'])
 
         assert ret['id'] == l2.info['id']
@@ -332,21 +328,6 @@ class LightningDTests(BaseLightningDTests):
         decoded2 = bitcoind.rpc.decoderawtransaction(tx)
         raise ValueError("Can't find {} payment in {} (1={} 2={})".format(amount, tx, decoded, decoded2))
 
-    def line_graph(self, n=2):
-        """Build a line graph of the specified length and fund it.
-        """
-        nodes = [self.node_factory.get_node() for _ in range(n)]
-
-        for i in range(len(nodes) - 1):
-            nodes[i].rpc.connect(
-                nodes[i + 1].info['id'],
-                'localhost',
-                nodes[i + 1].info['port']
-            )
-            self.fund_channel(nodes[i], nodes[i + 1], 10**6)
-
-        return nodes
-
     def pay(self, lsrc, ldst, amt, label=None, async=False):
         if not label:
             label = ''.join(random.choice(string.ascii_letters + string.digits) for _ in range(20))
@@ -1268,9 +1249,7 @@ class LightningDTests(BaseLightningDTests):
         wait_forget_channels(l2)
 
     def test_closing_while_disconnected(self):
-        l1 = self.node_factory.get_node(may_reconnect=True)
-        l2 = self.node_factory.get_node(may_reconnect=True)
-        l1.rpc.connect(l2.info['id'], 'localhost', l2.info['port'])
+        l1, l2 = self.connect(may_reconnect=True)
 
         self.fund_channel(l1, l2, 10**6)
         self.pay(l1, l2, 200000000)
@@ -2260,7 +2239,8 @@ class LightningDTests(BaseLightningDTests):
         wait_forget_channels(l2)
 
     def test_gossip_jsonrpc(self):
-        l1, l2 = self.line_graph(n=2)
+        l1, l2 = self.connect()
+        self.fund_channel(l1, l2, 10**6)
 
         # Shouldn't send announce signatures until 6 deep.
         assert not l1.daemon.is_in_log('peer_out WIRE_ANNOUNCEMENT_SIGNATURES')
@@ -3968,8 +3948,8 @@ class LightningDTests(BaseLightningDTests):
 
     @unittest.skipIf(not DEVELOPER, "needs DEVELOPER=1 for --dev-broadcast-interval")
     def test_channel_reenable(self):
-        l1, l2 = self.line_graph(n=2)
-        l1.may_reconnect = l2.may_reconnect = True
+        l1, l2 = self.connect(may_reconnect=True)
+        self.fund_channel(l1, l2, 10**6)
 
         l1.bitcoin.generate_block(6)
         l1.daemon.wait_for_log('Received node_announcement for node {}'.format(l2.info['id']))