fix: enforce prediction write guards atomically at the database layer#130
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adrunkhuman merged 1 commit intomasterfrom Mar 21, 2026
Merged
fix: enforce prediction write guards atomically at the database layer#130adrunkhuman merged 1 commit intomasterfrom
adrunkhuman merged 1 commit intomasterfrom
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Fixes two race conditions in the prediction write path: - #120: ThreadPredictionHandler's first-write-wins rule was enforced at the app layer (get_prediction check before save), leaving a window where a concurrent DM save could land and be overwritten by the subsequent thread write. - #122: Neither handler revalidated fixture state at write time, so a results calculation closing the fixture between the handler's read and the actual INSERT could silently succeed. Both are fixed by moving the invariants into the DB layer inside a single BEGIN IMMEDIATE transaction: - try_save_prediction(): thread path — fixture-open check + INSERT OR IGNORE (first-write-wins). Returns SaveResult.FIXTURE_CLOSED or SaveResult.DUPLICATE instead of writing. - save_prediction_guarded(): DM path — fixture-open check + upsert (re-submissions intentionally allowed). Returns FIXTURE_CLOSED only. Also fixes user_name staleness on upsert in both save_prediction and save_prediction_guarded (DO UPDATE SET was missing user_name). Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
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Summary
SaveResultenum and two new DB methods (try_save_prediction,save_prediction_guarded) that perform fixture-open validation and duplicate checks inside a singleBEGIN IMMEDIATEtransaction — making both guards atomictry_save_prediction(first-write-wins); removes the app-levelget_prediction+ conditional that left a race windowsave_prediction_guarded(upsert, re-submissions still work) and handlesFIXTURE_CLOSEDgracefullyuser_namestaleness on upsert:DO UPDATE SETwas missinguser_name = excluded.user_namein bothsave_predictionandsave_prediction_guardedCloses #120
Closes #122
Test plan
uv run pytest tests/test_database.py -k "TrySave or SaveGuarded" -v— new DB unit tests (fixture-open guard, first-write-wins, duplicate, both-conditions ordering)uv run pytest tests/test_thread_prediction_handler.py tests/test_dm_prediction_handler.py -v— handler tests including new fixture-closed paths and updated monkeypatch targetsuv run pytest— full suite (284 pass, 1 skip)uv run ruff check typer_bot/ tests/— clean🤖 Generated with Claude Code