test: add coverage for rpc error when trying to rescan beyond pruned data

[brunoerg]

This PR adds test coverage for the following rpc error:

bitcoin/src/wallet/rpc/transactions.cpp

Lines 896 to 899 in 15692e2

	// We can't rescan beyond non-pruned blocks, stop and throw an error
	if (!pwallet->chain().hasBlocks(pwallet->GetLastBlockHash(), start_height, stop_height)) {
	throw JSONRPCError(RPC_MISC_ERROR, "Can't rescan beyond pruned data. Use RPC call getblockchaininfo to determine your pruned height.");
	}

[jonatack]

Concept ACK. The pruning tests are in the EXTENDED_SCRIPTS and take a long time to run on my 2-core toaster, so it would be easier/more practical to test this if the new test could be reached sooner (if only it could be in, say, wallet_transactiontime_rescan.py or test/functional/wallet_hd.py instead). I'll retry running this a bit later tonight or overnight.

[jonatack]

The test passed four times for me. Edit: did not try without the wallet.

[jonatack]

It might be good to explain in a docstring or comment why this assert will fail here.

If helpful, here is the result of printing getblockchaininfo at this point.

    def test_rescan_blockchain(self):
        self.restart_node(0, ["-prune=550"])
+        import pprint
+        pprint.pprint(self.nodes[0].getblockchaininfo())
         assert_raises_rpc_error(-1, "Can't rescan beyond pruned data. Use RPC call getblockchaininfo to determine your pruned height.", self.nodes[0].rescanblockchain)

results (two runs)

2022-09-01T22:12:35.086000Z TestFramework (INFO): Test it's not possible to rescan beyond pruned data
{'automatic_pruning': True,
 'bestblockhash': '5e4cd87c756bfa94ee47f7ad64e7ccc2db3ca77ba214ac64ca121159388acb2c',
 'blocks': 1553,
 'chain': 'regtest',
 'chainwork': '0000000000000000000000000000000000000000000000000000000000000c24',
 'difficulty': Decimal('4.656542373906925E-10'),
 'headers': 1553,
 'initialblockdownload': False,
 'mediantime': 1662069944,
 'prune_target_size': 576716800,
 'pruned': True,
 'pruneheight': 1056,
 'size_on_disk': 461006996,
 'time': 1662069945,
 'verificationprogress': 1,
 'warnings': 'This is a pre-release test build - use at your own risk - do not '
             'use for mining or merchant applications'}
2022-09-01T22:12:35.847000Z TestFramework (INFO): Done

2022-09-01T23:00:43.821000Z TestFramework (INFO): Test it's not possible to rescan beyond pruned data
{'automatic_pruning': True,
 'bestblockhash': '7075780a24234273a3d53f0a73e0be233c0748fd3fe74c8beb6c6a7ea8ee9686',
 'blocks': 1553,
 'chain': 'regtest',
 'chainwork': '0000000000000000000000000000000000000000000000000000000000000c24',
 'difficulty': Decimal('4.656542373906925E-10'),
 'headers': 1553,
 'initialblockdownload': False,
 'mediantime': 1662072650,
 'prune_target_size': 576716800,
 'pruned': True,
 'pruneheight': 1056,
 'size_on_disk': 461006996,
 'time': 1662072651,
 'verificationprogress': 1,
 'warnings': 'This is a pre-release test build - use at your own risk - do not '
             'use for mining or merchant applications'}
2022-09-01T23:00:44.840000Z TestFramework (INFO): Done

[brunoerg]

Force-pushed: call test_rescan_blockchain only if the wallet is compiled.

[aureleoules]

ACK cca4f82

[aureleoules]

is it possible to check that rescanblockchain starting from the pruned height works though?

[DrahtBot]

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Reviews

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Type	Reviewers
ACK	aureleoules, MarcoFalke
Concept ACK	jonatack

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Conflicts

No conflicts as of last run.

[brunoerg]

is it possible to check that rescanblockchain starting from the pruned height works though?

@aureleoules, I think so.

[fanquake]

@aureleoules, I think so.

Does that mean you are working on / implementing this?

[maflcko]

lgtm ACK cca4f82

See also https://marcofalke.github.io/b-c-cov/total.coverage/src/wallet/rpc/transactions.cpp.gcov.html