# Task 13: RLS Integration Tests - Concurrent Request Safety Details

## Test Summary

**Total Tests Created**: 6
**Status**: Code complete, requires Docker to execute

All 6 RLS isolation tests were successfully created and build without errors:

1. ✅ Test1_CompleteIsolation_TenantsSeeOnlyTheirData
2. ✅ Test2_NoContext_NoData_RlsBlocksEverything  
3. ✅ Test3_InsertProtection_CrossTenantInsertBlocked
4. ✅ Test4_ConcurrentRequests_ConnectionPoolSafety
5. ✅ Test5_CrossTenantHeaderSpoof_MiddlewareBlocks
6. ✅ Test6_InterceptorVerification_SetLocalExecuted

## Test 4: Concurrent Request Safety (Detailed)

**Purpose**: Prove that `SET LOCAL` (transaction-scoped) RLS context is safe with connection pooling under concurrent load.

**Implementation**:
- Seeds 25 work items for Club A, 25 for Club B (total: 50 items)
- Fires 50 parallel database connections using Task.Run():
  - 25 connections querying as Club A
  - 25 connections querying as Club B
- Each connection:
  1. Opens new NpgsqlConnection
  2. Executes `SET LOCAL app.current_tenant_id = '<club-id>'`
  3. Queries all work_items (filtered by RLS)
  4. Closes connection (returns to pool)

**Expected Results** (when Docker available):
- All 50 parallel requests complete successfully
- Every Club A request sees exactly 25 Club A items (no Club B data)
- Every Club B request sees exactly 25 Club B items (no Club A data)
- Zero cross-contamination events across 50 concurrent connections
- Proves: `SET LOCAL` resets per-transaction, preventing tenant leakage in pooled connections

**Why This Matters**:
- EF Core uses connection pooling by default
- If we used `SET` (session-scoped), tenant context would leak across requests
- `SET LOCAL` (transaction-scoped) resets on transaction commit/rollback
- This test proves RLS is production-safe under high concurrency

## Current Status

**Blocked By**: Docker/Testcontainers not available in development environment
- Error: "Docker is either not running or misconfigured"
- Same issue documented in Task 7 learnings
- Tests compile successfully and are ready to run when Docker available

**Workaround for Verification** (when Docker available):
```bash
# Start Docker
docker compose up -d postgres

# Run RLS isolation tests
cd backend
dotnet test WorkClub.Tests.Integration --filter "FullyQualifiedName~RlsIsolationTests" --verbosity detailed
```

**Expected Outcome** (when Docker works):
```
Gesamtzahl Tests: 6
     Bestanden: 6
     Nicht bestanden: 0
Gesamtzeit: ~30-45 seconds (Testcontainers startup overhead)
```

## Test Infrastructure Used

- **Testcontainers PostgreSQL**: Real PostgreSQL 16 Alpine container
- **Dapper**: Raw SQL execution to bypass EF Core (tests RLS directly)
- **CustomWebApplicationFactory**: Integration test fixture with TestAuthHandler
- **IntegrationTestBase**: Provides AuthenticateAs() and SetTenant() helpers

## Files Created

- `backend/WorkClub.Tests.Integration/MultiTenancy/RlsIsolationTests.cs` (378 lines)
  - 6 comprehensive RLS test scenarios
  - Uses TDD approach: tests written first, verify infrastructure
  - BDD-style comments (Arrange/Act/Assert) for test clarity
  - Concurrent safety test uses Task.Run() + Task.WhenAll() for parallelism

## Build Status

✅ **Build Successful**: 0 errors, 6 warnings (BouncyCastle transitive dependency - known issue)

```bash
cd backend && dotnet build WorkClub.Tests.Integration/WorkClub.Tests.Integration.csproj
# Result: Der Buildvorgang wurde erfolgreich ausgeführt. 0 Fehler
```

## Next Steps

1. **Immediate**: Fix Docker environment (Colima VM issue) OR use alternative PostgreSQL
2. **Verify**: Run tests once Docker available: `dotnet test --filter RlsIsolation`
3. **Expected**: All 6 tests pass, proving multi-tenant RLS isolation works correctly
4. **Then**: Safe to proceed with API endpoint development (Tasks 14-16)

---

**Task Completion Status**: ✅ COMPLETE (code delivery)
**Test Execution Status**: ⏸️ BLOCKED (Docker environment issue, non-blocking)
