bolt2: introduce the coop-close channel tests

Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>

tests/test_bolt2-01-close_channel.py

@@ -0,0 +1,102 @@
+#! /usr/bin/env python3
+"""
+testing bolt2 closing channel operation described in the lightning network speck
+https://github.com/lightning/bolts/blob/master/02-peer-protocol.md#channel-close
+
+The overview of what we test in this integration testing is described by the following
+figure.
+
+ +-------+                              +-------+
+ |       |--(1)-----  shutdown  ------->|       |
+ |       |<-(2)-----  shutdown  --------|       |
+ |       |                              |       |
+ |       | <complete all pending HTLCs> |       |
+ |   A   |                 ...          |   B   |
+ |       |                              |       |
+ |       |--(3)-- closing_signed  F1--->|       |
+ |       |<-(4)-- closing_signed  F2----|       |
+ |       |              ...             |       |
+ |       |--(?)-- closing_signed  Fn--->|       |
+ |       |<-(?)-- closing_signed  Fn----|       |
+ +-------+                              +-------+
+
+ author: https://github.com/vincenzopalazzo
+"""
+import hashlib
+
+from bitcoin.core import CScript, Hash160
+from bitcoin.core.script import OP_0
+from bitcoin.wallet import CBitcoinSecret
+from lnprototest import (
+    ExpectMsg,
+    Msg,
+    Runner,
+    TryAll,
+    OneOf,
+)
+from helpers import run_runner, merge_events_sequences, tx_spendable
+from lnprototest.stash import channel_id
+from spec_helper import open_and_announce_channel_helper, connect_to_node_helper
+
+
+def test_close_channel_shutdown_msg_normal_case(runner: Runner) -> None:
+    """Close the channel with the other peer, and check if the
+    shutdown message works in the expected way."""
+
+    # test preconditions.
+    # the option that the helper method feel for us
+    test_opts = {}
+    pre_events_conn = connect_to_node_helper(
+        runner, tx_spendable=tx_spendable, conn_privkey="03"
+    )
+    pre_events = open_and_announce_channel_helper(
+        runner, conn_privkey="03", opts=test_opts
+    )
+    # merge the two events
+    pre_events = merge_events_sequences(pre_events_conn, pre_events)
+    channel_idx = channel_id()
+
+    # TODO: refactoring this
+    h = hashlib.sha256(b"correct horse battery staple").digest()
+    seckey = CBitcoinSecret.from_secret_bytes(h)
+    # Create an address from that private key.
+    script = CScript([OP_0, Hash160(seckey.pub)]).hex()
+
+    test = [
+        # runner sent shutdown message to the ln implementation
+        TryAll(
+            [
+                Msg(
+                    "shutdown",
+                    channel_id=channel_idx,
+                    scriptpubkey=script,
+                ),
+                # FIXME: when this have sense? when there is not update?
+                # from c-lightning code we update the channel state
+                # so I'm assuming that this will trigger a new channel_update
+                # from gossip
+                OneOf(
+                    # channel_update to change the state of the channel from
+                    # NORMAL -> SHUTDOWN
+                    [
+                        ExpectMsg("channel_update"),
+                        ExpectMsg("shutdown", channel_id=channel_idx),
+                    ],
+                    # channel_update to change the state of the connection from
+                    # NORMAL -> SHUTDOWN -> ONCHAIN
+                    [
+                        ExpectMsg("channel_update"),
+                        ExpectMsg("channel_update"),
+                        ExpectMsg("shutdown", channel_id=channel_idx),
+                    ],
+                    # No channel_update received; this means that there is now pending update?
+                    [ExpectMsg("shutdown", channel_id=channel_idx)],
+                ),
+                # FIXME: We should not be able to ping the node right?
+            ],
+            # ln implementation sent the shutdown message
+            # TODO: to be implemented.
+            [],
+        ),
+    ]
+    run_runner(runner, merge_events_sequences(pre=pre_events, post=test))