Fix Neo4j delete: IN TRANSACTIONS is illegal via execute_query

[ShreeBohara]

Docker is available now, so I ran the Cypher merged in #6 against a real Neo4j. It does not work.

Neo.DatabaseError.Transaction.TransactionStartFailed
A query with 'CALL { ... } IN TRANSACTIONS' can only be executed in an implicit
transaction, but tried to execute in an explicit transaction.

driver.execute_query() runs inside an explicit transaction, and IN TRANSACTIONS is only legal in an implicit one. So delete_repository always raised — and sync_repository calls it first, which means the entire Neo4j ingest path failed 100% of the time.

It looked healthy only because the caller swallows sync failures by design and falls back to SQL. That fallback is what kept this invisible.

The fix

delete_repository loops bounded LIMIT batches. That keeps each transaction small without needing implicit-transaction semantics, and it drops the CALL (n) { ... } scoped-variable form, which only exists from Neo4j 5.23. It now returns the number of nodes deleted, so a caller can distinguish "nothing there" from "did not run".

Why the unit tests didn't catch it

They assert "DETACH DELETE" in query against a fake driver. That still passes. A fake driver doesn't enforce transaction semantics, so no amount of mocking would have found this — the bug was invisible to mocks by construction.

Added tests/integration/test_neo4j_live.py: 9 tests against a real server, skipped unless NEO4J_TEST_URI/NEO4J_TEST_PASSWORD are set, so CI and a machine without Docker stay green. Beyond the regression they cover degree via COUNT {}, transitive traversal in both directions, shortest-path directionality, cycle detection, re-sync replacing rather than unioning, cross-repository isolation, and a delete larger than one batch.

Verification

Against neo4j:5-community, kernel 5.26.29:

[PASS] verify_connectivity          [PASS] shortest_path dist=2
[PASS] ensure_schema x2 idempotent  [PASS] shortest_path None when unreachable
[PASS] sync_repository              [PASS] import_cycles
[PASS] degree via COUNT{}           [PASS] re-sync REPLACES not unions
[PASS] edges()                      [PASS] delete_repository returns count
[PASS] transitive reach             [PASS] subgraph gone
[PASS] blast radius (reverse)       [PASS] delete is repo-scoped
=== 14/14 passed ===

Gate	Result
Live Neo4j tests	9/9 pass
Full suite, no server	142 passed, 9 skipped, 0 failed
ruff check src tests	clean

Everything #6 claimed is now actually true, rather than asserted. The remaining honest caveat: this validates the store in isolation, not a full index-then-graph run through the API.

🤖 Generated with Claude Code

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