fix: drop head after complete in multipart uploads

[ferhatelmas]

What kind of change does this PR introduce?

Bug fix

What is the current behavior?

We do headObject after multipart upload to get object metadata. It adds latency to uploads.

What is the new behavior?

Count bytes locally, get etag from multipart complete, set last modified similar to single upload, then drop head object call.

Additional context

Upload abort handler is cleaned up in success as well.
This will improve tail latency in uploads.

[Copilot]

Pull request overview

This PR removes the post-multipart HeadObject request in the S3 backend upload flow by deriving upload metadata locally (ETag from multipart completion, lastModified set at completion time, and content length tracked via multipart progress). This targets reduced latency (especially tail latency) for multipart uploads.

Changes:

• Drop HeadObject call after multipart upload completion and construct ObjectMetadata from multipart completion + local progress tracking.
• Track uploaded byte count during multipart uploads via httpUploadProgress.loaded and return it as contentLength/size.
• Update and extend S3 backend tests to assert the new metadata behavior and absence of HeadObject requests.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
src/storage/backend/s3/adapter.ts	Removes HeadObject after multipart completion; returns metadata using multipart completion output and locally tracked uploaded bytes.
src/storage/backend/s3/adapter.test.ts	Updates multipart upload tests to stop expecting HeadObject, and adds coverage for unknown-size multipart uploads with/without progress events.

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[coveralls]

Coverage Report for CI Build 25805067938

Coverage increased (+0.2%) to 75.048%

Details

• Coverage increased (+0.2%) from the base build.
• Patch coverage: 7 uncovered changes across 1 file (20 of 27 lines covered, 74.07%).
• 2 coverage regressions across 1 file.

Uncovered Changes

File	Changed	Covered	%
src/storage/backend/s3/adapter.ts	27	20	74.07%

Coverage Regressions

2 previously-covered lines in 1 file lost coverage.

File	Lines Losing Coverage	Coverage
src/storage/backend/s3/adapter.ts	2	62.68%

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Coverage Stats

Relevant Lines:	10312
Covered Lines:	8165
Line Coverage:	79.18%
Relevant Branches:	5955
Covered Branches:	4043
Branch Coverage:	67.89%
Branches in Coverage %:	Yes
Coverage Strength:	413.41 hits per line

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💛 - Coveralls

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated no new comments.

[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated no new comments.