Fix flaky test_maximum_full_file_count by eliminating race condition

[TheLastCicada]

Purpose:

Eliminate a race condition that causes test_maximum_full_file_count to fail intermittently on macOS CI with a misleading 30-second timeout error.

Current Behavior:

The test loop (9 iterations of batch_update → farm_block_with_spend) has a race condition. After farming a block and waiting for wallet sync, the DataLayer wallet's internal singleton state may not have caught up before the next batch_update builds a new spend. The wallet creates a spend against stale singleton state → full node rejects it (INVALID_SPEND_BUNDLE, status 3) → check_mempool_spend_count polls until timeout → test fails after 30 seconds with AssertionError: Timed assertion timed out.

New Behavior:

Three fixes:

1. Fail-fast on spend rejection: New check_mempool_spend_count_or_fail() helper inspects the transaction's sent_to field on each poll iteration. If any entry has MempoolInclusionStatus.FAILED, it raises a RuntimeError immediately with the rejection reason instead of burning 30 seconds on a doomed timeout.

2. Singleton readiness check: Added time_out_assert(10, check_singleton_confirmed, True, data_layer, store_id) after farm_block_with_spend in the test loop. This ensures the DataLayer wallet has processed the previous block's singleton update before the next iteration calls batch_update, closing the race condition. (farm_block_check_singleton already does this; farm_block_with_spend did not.)

3. Relaxed mempool count check: Changed check_mempool_spend_count from == to >= so auto-resends or ancillary transactions adding extra mempool entries don't break the check.

The farm_block_with_spend function signature is unchanged — all ~40 existing callers are unaffected.

Testing Notes:

• All 6 parametrized variants of test_maximum_full_file_count pass locally (611s total)
• ruff lint, ruff format, and mypy all pass

Made with Cursor

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Note

Low Risk
Low risk: changes are isolated to test helpers and assertions, primarily improving synchronization and error reporting for flaky CI behavior.

Overview
Fixes flakiness in test_maximum_full_file_count by ensuring each batch_update spend is fully processed before the next iteration runs.

The test now fails fast when a transaction is rejected (via check_mempool_spend_count_or_fail inspecting sent_to for MempoolInclusionStatus.FAILED), relaxes mempool size checks from == to >=, and adds an explicit check_singleton_confirmed wait after farm_block_with_spend in the update loop to avoid racing on stale singleton state.

^{Written by Cursor Bugbot for commit 0c9b1bb. This will update automatically on new commits. Configure here.}

[coveralls-official]

Pull Request Test Coverage Report for Build 23361347167

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

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• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 11 of 14 (78.57%) changed or added relevant lines in 1 file are covered.
• 7 unchanged lines in 4 files lost coverage.
• Overall coverage increased (+0.01%) to 91.159%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
chia/_tests/core/data_layer/test_data_rpc.py	11	14	78.57%

Files with Coverage Reduction	New Missed Lines	%
chia/timelord/timelord_api.py	1	93.02%
chia/full_node/full_node.py	2	87.57%
chia/timelord/timelord.py	2	74.25%
chia/wallet/wallet_node.py	2	86.25%

Totals
Change from base Build 23360405816:	0.01%
Covered Lines:	105830
Relevant Lines:	115928

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💛 - Coveralls

[github-actions]

File	Coverage	Missing Lines
chia/_tests/core/data_layer/test_data_rpc.py	78.6%	lines 209-211

Total	Missing	Coverage
14 lines	3 lines	78%