fix(gcs): paginate object prefixes with maxResults

[electrum]

Summary

Applies maxResults to the combined object and prefix listing, with one page token covering both result types.

Type of change

• Bug fix (fix:)
• New feature (feat:)
• Breaking change (feat!: or fix!:)
• Docs / chore

GCP Compatibility

The behavior was reproduced in real GCS with objects under a/ and b/:

$ gcloud storage cp /dev/null gs://$BUCKET/a/file
Copying file:///dev/null to gs://$BUCKET/a/file
$ gcloud storage cp /dev/null gs://$BUCKET/b/file
Copying file:///dev/null to gs://$BUCKET/b/file

$ curl --include --get \
    --header "Authorization: Bearer $(gcloud auth print-access-token)" \
    --data-urlencode 'delimiter=/' \
    --data-urlencode 'maxResults=1' \
    "https://storage.googleapis.com/storage/v1/b/$BUCKET/o"
HTTP/2 200
content-type: application/json; charset=UTF-8

{
  "kind": "storage#objects",
  "nextPageToken": "CgJhLw==",
  "prefixes": [
    "a/"
  ]
}

Floci previously returned every prefix and no page token because only items[] participated in pagination. Real GCS was also checked with includeTrailingDelimiter=true: a same-named prefix and object are both returned when maxResults=1, and together consume one result slot. With versioning enabled, each generation remains a separate, generation-ordered result slot while the same-named prefix is returned once, keeping continuation pages stable.

Checklist

• ./mvnw test passes locally
• New or updated integration test added
• Commit messages follow Conventional Commits

[greptile-apps]

Greptile Summary

This PR fixes GCS delimiter-based listings so maxResults and page tokens operate over the combined sequence of objects and prefixes.

• Groups same-name object generations while pairing a trailing-delimiter prefix with only the first generation.
• Sorts generations deterministically to keep offset-based continuation pages stable.
• Adds REST integration coverage for combined pagination and versioned trailing-delimiter objects.
• Adds Java SDK compatibility coverage for paginated directory prefixes.

Confidence Score: 5/5

The PR appears safe to merge, with the previously reported generation-loss and unstable-pagination findings fully addressed.

Same-name generations are preserved as separate results and sorted deterministically before offset pagination, while prefixes and objects share the intended page budget. Both previous review threads are resolved, and no new actionable defect remains.

Important Files Changed

Filename	Overview
src/main/java/io/floci/gcp/services/gcs/GcsObjectController.java	Combines objects and prefixes into one deterministic result sequence before applying pagination.
src/test/java/io/floci/gcp/services/gcs/GcsListFilterRestIntegrationTest.java	Covers combined object-prefix pages, shared result slots, and stable version-generation continuation pages.
compatibility-tests/sdk-test-java/src/test/java/io/floci/gcp/test/GcsListFiltersTest.java	Verifies through the Java GCS SDK that directory prefixes honor page size and expose a continuation token.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[List matching objects] --> B{Delimiter supplied?}
    B -- No --> C[Convert each object to a listed result]
    B -- Yes --> D[Group objects by name]
    D --> E[Sort same-name generations numerically]
    E --> F[Merge ordered object names and prefixes]
    F --> G[Pair a same-name prefix with first object generation]
    G --> H[Emit remaining generations separately]
    C --> I[Paginate combined listed results]
    H --> I
    I --> J[Split current page into items and prefixes]
    J --> K[Return one shared nextPageToken]

Loading

_{Reviews (3): Last reviewed commit: "fix(gcs): paginate object prefixes with ..." | Re-trigger Greptile}