# Test Strategy: ID Synchronization and Cross-Filter Recovery

## Overview
This document outlines the testing strategy for the ID synchronization and cross-filter recovery feature. The strategy focuses on ensuring that object identity remains stable across environments and that complex dashboard configurations (like cross-filters) are preserved during migration.

## Testing Tiers
- **CRITICAL**: `IdMappingService` — Tested for sync accuracy, upsert logic, and resilience to API failures.
- **STANDARD**: `MigrationEngine` — Tested for YAML transformation, ZIP orchestration, and regex-based metadata patching.
- **STANDARD**: Migration API Routes — Tested for configuration management and data retrieval.

## Methodology
- **Unit Testing**: Isolated logic tests for remapping and synchronization.
- **E2E Orchestration**: Verification of the full ZIP transformation pipeline via `test_transform_zip_end_to_end`.
- **Contract Testing**: Alignment with `@PRE` conditions and `@TEST_DATA` fixtures as defined in the semantic protocol.

## Test Files
- `backend/tests/core/test_mapping_service.py`
- `backend/tests/core/test_migration_engine.py`
- `backend/src/api/routes/__tests__/test_migration_routes.py`
