Repository: bitcoin/bitcoin
File: test/functional/wallet_assumeutxo.py (Python)

Code before:

        assert_equal(n1.getblockchaininfo()["blocks"], SNAPSHOT_BASE_HEIGHT)

        self.log.info("Backup from the snapshot height can be loaded during background sync")
        n1.restorewallet("w", "backup_w.dat")
        # Balance of w wallet is still still 0 because n1 has not synced yet
        assert_equal(n1.getbalance(), 0)

        self.log.info("Backup from before the snapshot height can't be loaded during background sync")
        assert_raises_rpc_error(-4, "Wallet loading failed. Error loading wallet. Wallet requires blocks to be downloaded, and software does not currently support loading wallets while blocks are being downloaded out of order when using assumeutxo snapshots. Wallet should be able to load successfully after node sync reaches height 299", n1.restorewallet, "w2", "backup_w2.dat")

        self.log.info("Test loading descriptors during background sync")
        wallet_name = "w1"
        n1.createwallet(wallet_name, disable_private_keys=True)
        key = get_generate_key()
        time = n1.getblockchaininfo()['time']
        timestamp = 0
        expected_error_message = f"Rescan failed for descriptor with timestamp {timestamp}. There was an error reading a block from time {time}, which is after or within 7200 seconds of key creation, and could contain transactions pertaining to the desc. As a result, transactions and coins using this desc may not appear in the wallet. This error is likely caused by an in-progress assumeutxo background sync. Check logs or getchainstates RPC for assumeutxo background sync progress and try again later."
        result = self.import_descriptor(n1, wallet_name, key, timestamp)
        assert_equal(result[0]['error']['code'], -1)
        assert_equal(result[0]['error']['message'], expected_error_message)

        self.log.info("Test that rescanning blocks from before the snapshot fails when blocks are not available from the background sync yet")
        w1 = n1.get_wallet_rpc(wallet_name)
        assert_raises_rpc_error(-1, "Failed to rescan unavailable blocks likely due to an in-progress assumeutxo background sync. Check logs or getchainstates RPC for assumeutxo background sync progress and try again later.", w1.rescanblockchain, 100)

        PAUSE_HEIGHT = FINAL_HEIGHT - 40

        self.log.info("Restarting node to stop at height %d", PAUSE_HEIGHT)
        self.restart_node(1, extra_args=[
            f"-stopatheight={PAUSE_HEIGHT}", *self.extra_args[1]])

        # Finally connect the nodes and let them sync.
        #
        # Set `wait_for_connect=False` to avoid a race between performing connection
        # assertions and the -stopatheight tripping.
        self.connect_nodes(0, 1, wait_for_connect=False)

        n1.wait_until_stopped(timeout=5)

        self.log.info(
            "Restarted node before snapshot validation completed, reloading...")
        self.restart_node(1, extra_args=self.extra_args[1])

        # TODO: inspect state of e.g. the wallet before reconnecting
        self.connect_nodes(0, 1)

        self.log.info(
            f"Ensuring snapshot chain syncs to tip. ({FINAL_HEIGHT})")
        self.wait_until(lambda: n1.getchainstates()[
                        'chainstates'][-1]['blocks'] == FINAL_HEIGHT)

Review comment (suggestion):
nit: similar to below

``` suggestion
        assert_greater_than(n3.pruneblockchain(START_HEIGHT), 0)
```

Code after:
        for n in self.nodes:
            assert_equal(n.getblockchaininfo()[
                         "headers"], SNAPSHOT_BASE_HEIGHT)

        # This backup is created at the snapshot height, so it's
        # not part of the background sync anymore
        w.backupwallet("backup_w.dat")

        self.log.info("-- Testing assumeutxo")

        assert_equal(n0.getblockcount(), SNAPSHOT_BASE_HEIGHT)
        assert_equal(n1.getblockcount(), START_HEIGHT)

        self.log.info(
            f"Creating a UTXO snapshot at height {SNAPSHOT_BASE_HEIGHT}")
        dump_output = n0.dumptxoutset('utxos.dat', "latest")

        assert_equal(
            dump_output['txoutset_hash'],
            "d2b051ff5e8eef46520350776f4100dd710a63447a8e01d917e92e79751a63e2")
        assert_equal(dump_output["nchaintx"], 334)
        assert_equal(n0.getblockchaininfo()["blocks"], SNAPSHOT_BASE_HEIGHT)

        # Mine more blocks on top of the snapshot that n1 hasn't yet seen. This
        # will allow us to test n1's sync-to-tip on top of a snapshot.
        w_skp = address_to_scriptpubkey(w_address)
        w2_skp = address_to_scriptpubkey(w2_address)
        for i in range(100):
            if i % 3 == 0:
                self.mini_wallet.send_to(from_node=n0, scriptPubKey=w_skp, amount=1 * COIN)
                self.mini_wallet.send_to(from_node=n0, scriptPubKey=w2_skp, amount=10 * COIN)
            self.generate(n0, nblocks=1, sync_fun=self.no_op)

        assert_equal(n0.getblockcount(), FINAL_HEIGHT)
        assert_equal(n1.getblockcount(), START_HEIGHT)
        assert_equal(n2.getblockcount(), START_HEIGHT)

        assert_equal(n0.getblockchaininfo()["blocks"], FINAL_HEIGHT)

        self.log.info(
            f"Loading snapshot into second node from {dump_output['path']}")
        loaded = n1.loadtxoutset(dump_output['path'])
        self.validate_snapshot_import(n1, loaded, dump_output['base_hash'])

        self.log.info("Backup from the snapshot height can be loaded during background sync")
        n1.restorewallet("w", "backup_w.dat")
        # Balance of w wallet is still 0 because n1 has not synced yet
        assert_equal(n1.getbalance(), 0)

        self.log.info("Backup from before the snapshot height can't be loaded during background sync")
        expected_error_message = "Wallet loading failed. Error loading wallet. Wallet requires blocks to be downloaded, and software does not currently support loading wallets while blocks are being downloaded out of order when using assumeutxo snapshots. Wallet should be able to load successfully after node sync reaches height 299"