[thebadalov]

Issue number: closes #8655

Summary

Changes

CachePersistenceLayer._update_record now writes validation_key_attr when payload validation is enabled, the same way _put_in_progress_record and DynamoDBPersistenceLayer._update_record already do. Before this, the COMPLETED record replaced the in-progress one without the payload hash.

Added test_idempotent_function_and_lambda_handler_redis_validation_same_payload, which checks that the completed record keeps the hash and that a retry with the same payload returns the stored response without running the handler again. It fails on the current develop and passes with the fix.

User experience

With payload_validation_jmespath set on the Redis/Valkey layer:

• Before: a retry with the same payload raised IdempotencyValidationError: Payload does not match stored record for this event key.
• After: the same-payload retry returns the stored response, and a retry with a different payload still raises IdempotencyValidationError.

Records written without payload validation are unchanged.

Testing

• tests/functional/idempotency and tests/unit/idempotency: 203 passed
• make format-check lint-check and mypy on the idempotency package: clean
• Checked against a local Redis server: same payload returns the stored response, different payload raises, TTL is kept, no validation field is written when validation is off

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[boring-cyborg]

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[blacksoxx]

Read the diff against develop; I did not run the suite here, so these are reading notes.

The asymmetry is exactly as described: _put_in_progress_record writes validation_key_attr when payload_validation_enabled, and the DynamoDB layer's _update_record appends #validation_key = :validation_key under the same condition, so the Redis _update_record was the one place that dropped the hash when the record moved to COMPLETED. With the four lines the completed record carries the hash again, which is what _get_record reads back into payload_hash for the next validation. Records written without payload validation stay as they are.

The functional test pins both halves, the stored hash and the second call not re-running the handler. Nothing blocking from my side.

[leandrodamascena]

Thanks @thebadalov, confirmed against a real Valkey server: on develop the completed record loses the hash and a same-payload retry raises, with your change the retry returns the stored response and a different payload still raises. Records without validation are unchanged, and old records written before the fix keep behaving as they did until they expire, so nothing breaks on upgrade.

I'm approving now. This goes out in 3.40.0, so it will sit here for a while before I merge it. No rebase needed in the meantime, and you'll be credited in the release notes.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.01%. Comparing base (1ba1118) to head (054efac).
⚠️ Report is 1 commits behind head on develop.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #8656   +/-   ##
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  Coverage    97.00%   97.01%           
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  Files          321      321           
  Lines        16421    16423    +2     
  Branches      1483     1484    +1     
========================================
+ Hits         15930    15932    +2     
  Misses         350      350           
  Partials       141      141           

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[powertools-for-aws-oss-automation]

Awesome work, congrats on your first merged pull request and thank you for helping improve everyone's experience!