[Integration Test] EmploymentService

[adnanvaldes]

Overview

Add comprehensive integration tests for EmploymentService to verify database behavior, constraints, and data persistence beyond what unit tests cover.

Context

EmploymentService has specific SQLite constraints that need testing:

• CHECK(end IS NULL OR end >= start) (to mark boolean values)
• UNIQUE(company, start)

Test Scenarios to Implement

1. Database Constraints Enforcement

• Test UNIQUE constraint prevents duplicate (company, start) at DB level
• Test CHECK constraint enforces end is null or >= startvalues
• Test constraint violations even when bypassing service validation

2. Data Type Conversion & Serialization

• Test date serialization roundtrip (Python date → SQLite TEXT → Python date)
• Test accepting ISO date strings ("2025-07-21")
• Test accepting date objects
• Test empty notes field (NULL vs "")

3. Transaction Behavior

• Test rollback when duplicate travel added
• Test successful commit for valid travel
• Test multiple operations in single transaction

4. Query Behavior

• Test find() with start filter
• Test find() with end filter
• Test find() with compant filter
• Test find() with multiple filters combined
• Test case handling (service uppercases input)

5. Schema & ID Management

• Verify employment table created with all constraints
• Test AUTOINCREMENT assigns sequential IDs
• Test ID doesn't reuse after deletion

6. Edge Cases

• Test notes field with special characters and Unicode

Files to Create/Modify

• tests/integration/test_work_service_integration.py

Acceptance Criteria

• All 20+ test scenarios implemented
• Tests use fake_db fixture
• All tests pass consistently

Notes

Existing integration tests in tests/integration/test_employment_service_integration.py cover basic scenarios. This issue tracks expansion to comprehensive database behavior testing.