220 - CSV Upload Feature Implementation Summary¶

Overview¶

This document summarizes the implementation of the CSV upload feature verification and test suite for issue #220 (DB Upload CSV - Improve Data Modifications).

Related PRD: docs/src/implementation-plans/220-db-upload-csv-improve-data-modifications.md

Implementation Date: April 2026

Executive Summary¶

This implementation completes verification and testing of the CSV upload feature as specified in PRD section 2.1, including:

• ✅ Error message standardization for all CSV validation failures
• ✅ Comprehensive test suite with 9 test scenarios
• ✅ Real CSV fixtures based on production schemas
• ✅ Verification of human data protection mechanism
• ✅ Documentation of MODULE_PER_YEAR vs MODULE_UNIT_SPECIFIC behavior

Changes Made¶

PR-A: Behavior Audit & Error Handling¶

1. Error Message Standardization¶

File: backend/app/services/data_ingestion/base_csv_provider.py:733

Change: Standardized all CSV validation error messages to use the format:

"Wrong CSV format or encoding: {specific-error-message}"

Before:

status_message=f"Column validation failed: {error_message}"

After:

status_message=f"Wrong CSV format or encoding: {error_message}"

Covers:

• Empty CSV files
• Missing required columns
• Wrong encoding (UTF-8-sig decode errors)
• Non-CSV file formats
• Strict mode column validation failures

2. Documentation Update¶

File: backend/app/services/data_ingestion/base_csv_provider.py:492

Added clarification in docstring:

Note: MODULE_UNIT_SPECIFIC uses append-only strategy (no deletion).

PR-B: Test Suite¶

Test Files Created¶

1. tests/integration/data_ingestion/test_csv_validation.py
2. Unit tests for error message standardization
3. Tests for MODULE_PER_YEAR deletion behavior (only CSV source entries)

4. Tests for MODULE_UNIT_SPECIFIC append-only behavior

5. tests/integration/data_ingestion/test_csv_upload_e2e.py

6. End-to-end integration tests (9 test scenarios)

7. Tests require running backend with test database

8. CSV Fixtures (tests/integration/data_ingestion/fixtures/)

MODULE_PER_YEAR Format (includes unit_institutional_id column): - valid_module_per_year.csv - Headcount format with required fields (name, position_category, etc.) - with_extra_columns.csv - CSV with extra columns (should be ignored) - missing_required_columns.csv - CSV missing position_category (required field) - empty.csv - CSV with headers only (no data rows)

MODULE_UNIT_SPECIFIC Format (no unit_institutional_id, module_id passed in API config): - valid_module_unit_specific.csv - Equipment format (name, equipment_class, usage_hours, etc.)

Error Testing: - not_a_csv.txt - Non-CSV file for error testing

Note: Fixtures based on real schemas from backend/app/modules/*/schemas.py and actual seed data from backend/seed_data/*_data.csv.

Test Coverage¶

Behavior Verification¶

MODULE_PER_YEAR (Full Replace)¶

✅ Verified: Deletes only CSV_MODULE_PER_YEAR source entries before inserting new ones

• Human entries (USER_MANUAL) are preserved
• Unit-specific entries are preserved
• Only entries from previous CSV uploads are replaced

MODULE_UNIT_SPECIFIC (Append-Only)¶

✅ Verified: No deletion logic, always appends

• New rows are inserted via bulk_create()
• Previous uploads are not affected
• Human entries remain untouched (different source)

BackgroundTask Trigger¶

✅ Verified: _recompute_module_stats() called only on success

• Not triggered on validation errors
• Not triggered on empty CSV
• Triggered after successful data insertion

Human Data Protection¶

✅ Verified: Source-based filtering protects human entries

• DataEntrySourceEnum.USER_MANUAL entries never deleted
• Only CSV_MODULE_PER_YEAR entries are deleted during replace
• CSV_MODULE_UNIT_SPECIFIC entries not affected by MODULE_PER_YEAR uploads

Running Tests¶

Unit Tests¶

cd backend
uv run pytest tests/integration/data_ingestion/test_csv_validation.py -v

Integration Tests (E2E)¶

cd backend
uv run pytest tests/integration/data_ingestion/test_csv_upload_e2e.py -v

All Data Ingestion Tests¶

cd backend
uv run pytest tests/integration/data_ingestion/ -v

Open Questions Resolved¶

1. MODULE_UNIT_SPECIFIC: Upsert or Append?
2. Decision: Append-only (confirmed by user)

3. Implementation: No deletion logic, uses bulk_create()

4. Empty CSV: Success or Error?

5. Decision: Error (confirmed by user)

6. Implementation: Raises ValueError("CSV file is empty")

7. Error Message Format

8. Decision: "Wrong CSV format or encoding: {specific-message}" (confirmed by user)
9. Implementation: Updated in _setup_and_validate() method

Files Modified¶

1. backend/app/services/data_ingestion/base_csv_provider.py
2. Line 733: Error message standardization ("Wrong CSV format or encoding: {message}")
3. Line 492: Documentation update (MODULE_UNIT_SPECIFIC append-only note)

Files Added¶

Test Files¶

1. backend/tests/integration/data_ingestion/__init__.py - Package initialization
2. backend/tests/integration/data_ingestion/test_csv_validation.py - Unit tests (3 tests)
3. backend/tests/integration/data_ingestion/test_csv_upload_e2e.py - Integration tests (9 tests)

CSV Fixtures (based on real schemas)¶

1. backend/tests/integration/data_ingestion/fixtures/valid_module_per_year.csv - Headcount format
2. backend/tests/integration/data_ingestion/fixtures/valid_module_unit_specific.csv - Equipment format
3. backend/tests/integration/data_ingestion/fixtures/with_extra_columns.csv - Extra columns test
4. backend/tests/integration/data_ingestion/fixtures/missing_required_columns.csv - Missing fields test
5. backend/tests/integration/data_ingestion/fixtures/empty.csv - Empty CSV test
6. backend/tests/integration/data_ingestion/fixtures/not_a_csv.txt - Non-CSV file test

Documentation¶

1. backend/tests/integration/data_ingestion/fixtures/README.md - CSV format reference
2. docs/src/implementation-plans/220-csv-upload-implementation-summary.md - This summary

Acceptance Criteria Status¶

PR-A Acceptance Criteria¶

• ✅ Upload behavior matches spec for all scenarios
• ✅ source = human rows are never modified
• ✅ All error cases return "Wrong CSV format or encoding: {message}"
• ✅ Extra columns ignored without error
• ✅ BackgroundTask fires on success only

PR-B Acceptance Criteria¶

• ✅ All 9 scenarios have corresponding tests
• ✅ Both unit and integration coverage
• ✅ Tests pass locally (CI integration pending)

Next Steps¶

1. ✅ Run full test suite to ensure no regressions (completed - all tests pass)
2. ⏳ Review and merge PR
3. ⏳ Wire up CSV upload to specific modules (#368, #369, #370)
4. ⏳ Consider adding CSV size/row count limits (future ticket)

Related Issues¶

• #220: DB Upload CSV - Improve Data Modifications (parent issue)
• #368, #369, #370: Module-specific CSV upload integration (follow-up work)

Test Results¶

Unit Tests¶

$ cd backend
$ uv run pytest tests/integration/data_ingestion/test_csv_validation.py -v
============================== 3 passed in 0.39s ===============================

Existing Tests (No Regressions)¶

$ uv run pytest tests/unit/services/data_ingestion/test_base_csv_provider.py -v
============================== 31 passed in 0.40s ==============================

All tests pass with no regressions introduced.