TESTING: helpers/sql-validation.ts is only tested indirectly via CRUD tests.
Location: src/helpers/sql-validation.ts
TDD Steps:
- RED: Write direct unit tests for: isValidColumnName() with valid/invalid patterns, isAllowedColumn() with whitelist, validateColumns() batch validation
- GREEN: All tests should pass
- REFACTOR: Test SQL injection attack patterns
TESTING: helpers/sql-validation.ts is only tested indirectly via CRUD tests.
Location: src/helpers/sql-validation.ts
TDD Steps: