[ravindra-RKB]

Description

Add unit test coverage for TxUpdate methods in crates/core/tests/test_tx_update.rs.

TxUpdate is the primary interchange data structure used across BDK chain sources to communicate discovered transaction data, but its test target previously only checked default emptiness (test_empty).

This adds test coverage for:

• test_is_empty_false_when_any_field_populated: verifies that is_empty() returns false when any individual field (txs, txouts, anchors, seen_ats, evicted_ats) is populated.
• test_extend: verifies extending with an empty update is idempotent, extending an empty update populates all fields, and extending with a populated update properly combines txs, overwrites conflicting txouts with the new output, and unions set fields (anchors, seen_ats, evicted_ats).
• test_map_anchors: verifies that map_anchors transforms anchor types while preserving all transactions, txouts, seen_ats, and evicted_ats.

Notes to the reviewers

• All tests pass locally via cargo test -p bdk_core --test test_tx_update.
• Formatting verified with cargo fmt --all --check and lints verified with cargo clippy -p bdk_core --all-targets -- -D warnings.

Changelog notice

• Add unit tests for TxUpdate methods in bdk_core.

Checklists

All Submissions:

• I followed the contribution guidelines

New Features:

• I've added tests for the new feature

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 80.24%. Comparing base (0ff6ade) to head (a223eca).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2410      +/-   ##
==========================================
+ Coverage   80.00%   80.24%   +0.24%     
==========================================
  Files          31       31              
  Lines        6187     6187              
  Branches      292      292              
==========================================
+ Hits         4950     4965      +15     
+ Misses       1167     1156      -11     
+ Partials       70       66       -4     

Flag	Coverage Δ
rust	80.24% <ø> (+0.24%)	⬆️

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[evanlinjin]

Thanks for putting this together, @ravindra-RKB. The tests are clear and CI is green.

I'm going to close it, though, for the same reason as #2113 and #2116 (see #2111 (comment)). is_empty, extend and map_anchors just pass each field through, so these tests can't catch the kind of bugs we worry about, and they'd need updating every time TxUpdate gains a field. The lib.rs reformat is already handled by #2405.

If you'd like to keep working on test coverage, these would help a lot more:

• merge_chains correctness: are the prev-blockhash cases in merge_chains_with_prev_blockhash (crates/chain/tests/test_local_chain.rs) complete?
• How bdk_electrum, bdk_esplora and bdk_bitcoind_rpc build their updates (fix(bitcoind_rpc): emit invalidated heights when start_height is above agreement point #2167 fixed a bug of that kind).
• Gaps you find by running coverage locally.