veza/veza-backend-api/API_STABILITY_REPORT.md

2.1 KiB

API Stabilization Report

Executive Summary

Phase 4 focused on stabilizing the core API handlers by replacing brittle error handling logic with robust sentinel errors, ensuring consistency across services, and verifying cross-layer interactions with micro-E2E tests.

Key Accomplishments

1. Handler Audits & Repairs

  • PlaylistHandler: Replaced string literal checks ("playlist not found") with sentinel errors (services.ErrPlaylistNotFound).
  • BitrateHandler: Standardized error responses to use services.ErrInvalidTrackID, ErrInvalidBitrate, etc.
  • CommentHandler: Implemented specific error codes (404, 403) for ErrCommentNotFound, ErrParentCommentNotFound, ErrForbidden.
  • RoomHandler: Fixed "Blind 404" issue where internal errors were masked. Now distinguishes ErrRoomNotFound from other errors.

2. Service Layer Refactoring

  • Centralized Errors: Created internal/services/errors.go to consolidate common errors and prevent duplication.
  • Updated Services: PlaylistService, BitrateAdaptationService, CommentService, RoomService now return consistent, exported sentinel errors wrapping low-level DB errors.

3. Verification & Testing

  • Unit/Integration Tests: Updated all affected service and handler tests to assert new error types.
  • Micro-E2E Test Suite: Created internal/handlers/api_flow_test.go (TestAPIFlow_UserJourney) simulating a complete user session:
    1. Artist uploads Track.
    2. Listener streams (Bitrate Adaptation).
    3. Listener comments on Track.
    4. Artist replies.
    5. Listener attempts unauthorized delete (Fail).
    6. Listener creates Playlist and adds Track.

Status Checklist

  • All defined handlers audit for HTTP semantics.
  • Brittle string matching replaced with errors.Is.
  • Cross-layer error consistency verified.
  • Regression testing via E2E flow.

Recommendations for Phase 5 (Frontend Integration)

  • The API is now stable and returns predictable error codes (400, 401, 403, 404).
  • Frontend clients should handle 403 for permission issues specifically.
  • 404 reliably indicates resource missing, not internal error.