fix(storage): percent-encode object key in multipart fallback URL

[waleedlatif1]

Summary

• buildObjectFallbackUrl constructed the object location from a raw key. A key containing spaces or reserved characters (+, ?, #) — or the pre-existing AWS branch — would yield a structurally invalid URL
• Encode the key per path segment (preserving / separators) across all branches: AWS virtual-hosted, custom path-style, and custom virtual-hosted (R2)

Context

Addresses a Greptile review comment on the v0.6.102 release PR (#4871). Not currently triggerable — keys are generated as kb/<uuid>-<sanitizeFileName(name)> and sanitizeFileName strips everything except [a-zA-Z0-9.-], so only / can appear today. This is a robustness fix that future-proofs the location value and corrects the long-standing AWS branch.

Type of Change

• Bug fix

Testing

• bun run scripts/check-api-validation-contracts.ts passes; biome clean
• location is informational (serving uses the encoded path + /api/files/serve), so no behavior change for existing valid keys

Checklist

• Code follows project style guidelines
• Self-reviewed my changes
• No new warnings introduced
• I confirm that I have read and agree to the terms outlined in the Contributor License Agreement (CLA)

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Project	Deployment	Actions	Updated (UTC)
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[cursor]

PR Summary

Low Risk
Narrow change to informational fallback URLs when the SDK omits Location; serving still uses the encoded API path, and current KB keys are already sanitized.

Overview
When S3 multipart completion omits Location, buildObjectFallbackUrl now builds the fallback object URL using a percent-encoded key (each path segment encoded, / kept), instead of inserting the raw key. That applies to AWS virtual-hosted URLs and custom endpoint path-style / virtual-hosted branches, so keys with spaces or reserved characters produce valid URLs.

New unit tests cover completeS3MultipartUpload fallback behavior: SDK Location when present, AWS and MinIO/R2-style fallbacks, trailing-slash endpoints, and encoding of special characters in the key.

^{Reviewed by Cursor Bugbot for commit 3383635. Configure here.}

[greptile-apps]

Greptile Summary

This PR fixes buildObjectFallbackUrl to percent-encode each segment of the object key (using encodeURIComponent per segment, preserving / separators) before embedding it into the fallback URL. The fix applies consistently to all three URL shapes: AWS virtual-hosted, custom path-style (MinIO/Ceph), and custom virtual-hosted (R2).

• client.ts: Adds a 3-line encodedKey derivation at the top of buildObjectFallbackUrl and substitutes it for the raw key in all three return branches.
• client.test.ts: Adds completeS3MultipartUpload to the import/mock surface and six new test cases covering every code path — including SDK-provided Location, each fallback branch, trailing-slash stripping, and percent-encoding of a key containing a space.

Confidence Score: 5/5

Safe to merge — the change is narrowly scoped to the fallback URL builder and does not touch the actual S3 upload path or the /api/files/serve serving path.

The fix is a 3-line addition inside a single private helper. All three return branches are covered by new tests, mock state is reset in beforeEach so tests are order-independent, and the location field is explicitly documented as informational — serving continues to use the separately-encoded path field unchanged.

No files require special attention.

Important Files Changed

Filename	Overview
apps/sim/lib/uploads/providers/s3/client.ts	Adds per-segment percent-encoding of the object key in buildObjectFallbackUrl, consistently applied across all three URL construction branches.
apps/sim/lib/uploads/providers/s3/client.test.ts	Adds mock for CompleteMultipartUploadCommand and six focused tests covering all buildObjectFallbackUrl branches plus the encoding behavior; beforeEach correctly resets shared mock state.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A["completeS3MultipartUpload(key, uploadId, parts)"] --> B["s3Client.send(CompleteMultipartUploadCommand)"]
    B --> C{response.Location present?}
    C -- Yes --> D["use response.Location directly"]
    C -- No --> E["buildObjectFallbackUrl(bucket, region, key)"]
    E --> F["encodedKey = key.split('/').map(encodeURIComponent).join('/')"]
    F --> G{S3_CONFIG.endpoint set?}
    G -- No --> H["https://bucket.s3.region.amazonaws.com/encodedKey"]
    G -- Yes --> I{forcePathStyle?}
    I -- Yes --> J["base/bucket/encodedKey (path-style)"]
    I -- No --> K["bucket.hostname/encodedKey (virtual-hosted)"]
    D & H & J & K --> L["return { location, path, key }"]

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[waleedlatif1]

@greptile

[waleedlatif1]

@cursor review

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✅ Bugbot reviewed your changes and found no new issues!

Comment @cursor review or bugbot run to trigger another review on this PR

^{Reviewed by Cursor Bugbot for commit 16fc733. Configure here.}

[waleedlatif1]

@greptile

[waleedlatif1]

@cursor review

[cursor]

✅ Bugbot reviewed your changes and found no new issues!

Comment @cursor review or bugbot run to trigger another review on this PR

^{Reviewed by Cursor Bugbot for commit 3383635. Configure here.}