transcription/docs/mvp/mvp-step7-results.md

Step 7 Results: Error Handling Standardization and Operational Visibility

Summary

Step 7 was implemented across the MVP runtime boundaries with a shared error taxonomy, actionable UI error surfacing, worker failure normalization, and API error envelope handling.

All required validation gates in docs/step7.md were executed and passed.

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Scope Delivered

Implemented

• Shared application error contract and taxonomy
• Service-layer error normalization (upload + transcription)
• UI error presentation helpers with suggested actions and error references
• Worker failure persistence format with category/suggestion/error_id markers
• API exception handlers for structured error responses
• Targeted tests for new error contract behavior

Not implemented in this step

• External lane execution (-m external) was not required for Step 7 completion and was not run in this pass.

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Files Added

• src/transcription/errors.py
• src/transcription/api/errors.py
• src/transcription/ui/error_presenter.py
• tests/test_errors.py
• tests/api/test_error_responses.py
• docs/step7.md

Files Updated

• src/transcription/app.py
• src/transcription/services/upload.py
• src/transcription/services/transcription.py
• src/transcription/ui/upload_page.py
• src/transcription/ui/jobs_page.py
• src/transcription/worker.py
• tests/services/test_upload.py
• tests/services/test_transcription.py
• tests/services/test_worker.py
• tests/integration/test_pipeline_flow.py
• uv.lock

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Implementation Notes by Phase

Phase A/B (Foundation)

• Added ErrorCategory enum and AppError base type in src/transcription/errors.py.
• Added helper utilities:
  • new_error_id()
  • build_error_envelope(...)
  • classify_unexpected_error(...)
  • format_error_detail(...)

Phase C (Service/Provider normalization)

• UploadError now extends AppError and includes category/suggestion/retriable metadata.
• PromptLoadError and TranscriptionError now extend AppError.
• Provider failures are mapped with deterministic category semantics (auth/payload/provider-failure cases).

Phase D (UI visibility)

• Added src/transcription/ui/error_presenter.py.
• Upload and jobs pages now use centralized UI error rendering and summary helpers.
• UI error paths now include more visible/actionable guidance and reference IDs.

Phase E (Worker failure handling)

• Worker now normalizes exception handling into structured persisted error_detail strings with:
  • category marker
  • suggestion marker
  • error_id marker
• Logging now includes category/error_id context in failure paths.

Phase F (API envelope)

• Added src/transcription/api/errors.py and registered handlers in app factory.
• AppError and unexpected exceptions now serialize to stable API envelopes with mapped status codes.

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Validation Commands and Outcomes

All commands were executed with uv run python -m pytest ... and completed successfully.

1. uv run python -m pytest tests/test_errors.py -q ✅
2. uv run python -m pytest tests/services/test_upload.py -q ✅
3. uv run python -m pytest tests/services/test_transcription.py -q ✅
4. uv run python -m pytest tests/providers/test_openrouter.py -q ✅
5. uv run python -m pytest tests/services/test_worker.py -q ✅
6. uv run python -m pytest tests/integration/test_pipeline_flow.py -q ✅
7. uv run python -m pytest tests/api/test_error_responses.py -q ✅
8. uv run python -m pytest tests/ui/test_upload_page.py -q ✅
9. uv run python -m pytest tests/ui/test_jobs_page.py -q ✅
10. uv run python -m pytest -m "not external" -q ✅
11. uv run python -m pytest --collect-only -q ✅
12. uv run python -m pytest -m unit -q ✅
13. uv run python -m pytest -m integration -q ✅
14. uv run python -m pytest tests/integration/test_pipeline_flow.py -q ✅
15. uv run python -m pytest tests/ui/test_upload_page.py -q ✅
16. uv run python -m pytest tests/ui/test_jobs_page.py -q ✅
17. uv run python -m pytest -q ✅

Observed warning (non-blocking): Starlette/FastAPI TestClient deprecation warning related to httpx package naming.

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Policy Alignment Check (docs/error_handling.md)

Aligned items:

• Stable taxonomy categories are implemented.
• Unexpected errors are normalized.
• User-facing UI paths include actionable guidance and references.
• Worker persistence includes trace-friendly failure detail.
• API error responses are structured and category-aware.

Follow-up candidates:

• Add richer UI tests that validate rendered suggested-action content end-to-end (current tests focus helper/service contracts).
• Consider typed storage fields for error metadata instead of packed error_detail strings in a future schema revision.

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Step 7 Definition of Done Status

• Shared error taxonomy implemented across MVP layers
• GUI error paths upgraded for visibility/actionability
• Worker failure persistence and log context standardized
• API error envelope handling added and tested
• Phase-level and full-suite validation gates passed
• Results documented in this report

Step 7 is complete.