CLDSRV-898: handle checksums in CompleteMultipartUpload

[leif-scality]

• Calculate and compare the final object checksum with the one sent by the headers
• Check that all parts have the correct checksum and checksum type
• stores the final checksum when FULL_OBJECT (COMPOSITE are going to be stored by https://scality.atlassian.net/browse/S3C-10399)
• lint tests/unit/api/multipartUpload.js

[claude]

LGTM

Review by Claude Code

[codecov]

❌ 1 Tests Failed:

Tests completed	Failed	Passed	Skipped
9218	1	9217	0

View the full list of 2 ❄️ flaky test(s)

"before each" hook for "should retrieve a part put after part copied from MPU"::GET object With default signature With PartNumber field uploadPartCopy "before each" hook for "should retrieve a part put after part copied from MPU"

Flake rate in main: 100.00% (Passed 0 times, Failed 9 times)

Stack Traces | 6.26s run time

Connection timed out after 5000 ms

should create a bunch of objects and their versions::put and head object with versioning With v4 signature on versioning suspended then enabled bucket w/ null version should create a bunch of objects and their versions

Flake rate in main: 13.81% (Passed 668 times, Failed 107 times)

Stack Traces | 600s run time

Timeout of 600000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves. (.../test/versioning/objectHead.js)

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[bert-e]

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[bert-e]

Incorrect fix version

The Fix Version/s in issue CLDSRV-898 contains:

• None

Considering where you are trying to merge, I ignored possible hotfix versions and I expected to find:

• 9.4.0

Please check the Fix Version/s of CLDSRV-898, or the target
branch of this pull request.

[claude]

LGTM

Well-designed separation of CompleteMPU's final-object checksum semantics from body-digest validation. The callNext double-callback guard in processParts is a good defensive pattern for the mixed callback/promise flow. Test coverage is thorough across all algorithm/type combinations, including edge cases for default MPUs, legacy MPUs, and soft-null vs InternalError distinction.

Review by Claude Code

[jonathan-gramain]

Shouldn't this be in constants too?

[leif-scality]

The algorithms object contains the TAG of each algo already, this object is just for testing that the tag was not changed in the algorithms object

[jonathan-gramain]

Could you construct it from algorithms? If algorithm is supposed to be a constant and we are concerned that it may be accidentally changed, what about using Object.freeze on it?

[leif-scality]

The goal of the test if to raise an error if we change the xmlTag for some reason in algorithms. If we construct it from algorithms then we will never detect the change. algorithms is already Object.freeze

[jonathan-gramain]

Then, why not using Object.freeze for each subcomponent of algorithms if the goal is to ensure that it's never modified, that would be probably a better answer than a test checking this. Just my two cents, no big deal otherwise.

[claude]

LGTM

The checksum handling for CompleteMultipartUpload is well-implemented: the split between md5-only body validation and final-object checksum assertion correctly matches AWS behavior. The callNext guard in processParts properly prevents double-callbacks in the mixed callback/promise flow. Per-part validation, final-object computation, and header assertion are thorough. Tests cover the full (algorithm, type) matrix including edge cases (default MPU, legacy MPU, missing parts).

Review by Claude Code

[claude]

• completeMultipartUpload.js:352 — When storedMetadata.checksumType is undefined (legacy MPU created before the checksum feature), the error message interpolates undefined into user-facing text: "The upload was created using the undefined checksum mode." Split the !mpuType guard into a separate branch with an appropriate message.
  
  Review by Claude Code

[claude]

LGTM — solid implementation with thorough test coverage.

One minor nit:
- Orphaned JSDoc in validateChecksums.js:332-337: the validateChecksumsNoChunking JSDoc now sits above the new validateContentMd5 function instead of its intended target.

Review by Claude Code

[claude]

• require('../../../lib/services') inside an it() callback at tests/unit/api/multipartUpload.js:4119. The project testing conventions require require()/import at the top of the file, never inside describe or function bodies. Move it alongside the other top-level imports.
  - Add const services = require('../../../lib/services'); at the top of the file and reference it from the test.
  
  Review by Claude Code

[claude]

LGTM

The checksum validation logic is well-structured: moving CompleteMPU out of checksumedMethods into md5OnlyMethods correctly distinguishes body-digest headers from final-object-checksum headers. The callNext double-callback guard in the Promise-to-callback bridge is appropriate defensive coding. Test coverage is thorough across all algorithm/type combinations, edge cases (default vs explicit MPU, legacy MPU, missing parts), and the new x-amz-checksum-type header validation.

Review by Claude Code

[claude]

• lib/api/completeMultipartUpload.js:623: callNext is not defined — will throw ReferenceError at runtime when computeFinalChecksum returns an error on an explicit (non-default) MPU. Should be next.
  - Replace callNext(error, destBucket) with next(error, destBucket)
  
  Review by Claude Code

[claude]

LGTM

Review by Claude Code

[claude]

LGTM

Review by Claude Code

[claude]

• validateContentMd5 has a dead MissingChecksum branch unreachable from its only caller (md5OnlyValidationFunc pre-checks)
  • Consider making the function self-contained by removing the caller's pre-check, or documenting the precondition
• computeCompositeMPUChecksum was made async but contains no await — the composite algorithms all use synchronous digest
  • If intentional for consistency with computeFullObjectMPUChecksum, add a comment explaining the choice

Review by Claude Code

[claude]

LGTM

Solid implementation of checksum handling in CompleteMultipartUpload. The separation of completeMultipartUpload from checksumedMethods into the md5OnlyMethods path is clean and correct — the x-amz-checksum-* header carries final-object semantics for CompleteMPU, not body-digest semantics. The validatePerPartChecksums, computeFinalChecksum, and validateCompleteMultipartUploadChecksum functions are well-structured with proper error paths. The async/await migration of computeCompositeMPUChecksum is necessary for the async crc64nvme.digest and is handled correctly. Test coverage is thorough across the algorithm/type matrix.

Review by Claude Code

[claude]

LGTM

Solid implementation of checksum validation and computation for CompleteMultipartUpload. The separation of CompleteMPU's x-amz-checksum-* header semantics (final-object checksum) from the body-digest validators used by other methods is clean and well-tested. The FULL_OBJECT vs COMPOSITE shape validation, the dual-form algorithm handling, and the default-vs-explicit MPU error strategy are all correct. Test coverage is comprehensive across the matrix of algorithm/type combinations, edge cases, and backward compatibility with legacy MPUs.

Review by Claude Code

[claude]

LGTM

Well-structured implementation with good separation of concerns: body-digest validation (md5-only path), per-part checksum validation, final-object checksum computation, and header-level final checksum assertion. Good test coverage across the AWS (algorithm, type) matrix, default MPU edge cases, and legacy backward compatibility. The defensive failOrSkip pattern (soft-null for default MPUs vs InternalError for explicit) is a clean way to handle upgrade-boundary robustness.

Review by Claude Code

[leif-scality]

/approve

[bert-e]

Incorrect fix version

The Fix Version/s in issue CLDSRV-898 contains:

• None

Considering where you are trying to merge, I ignored possible hotfix versions and I expected to find:

• 9.4.0

Please check the Fix Version/s of CLDSRV-898, or the target
branch of this pull request.

The following options are set: approve

[leif-scality]

ping

[bert-e]

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