P1: Increase test coverage to 80%

[BadgerOps]

Test Coverage Below Target

Priority: P1 - High
Estimate: 6 hours
Review Reference: REVIEW.md (P1-6)

Current State

• Overall: 52.5%
• internal/http: 51.6%
• internal/storage: 72.2%
• Target: 80%

Missing Test Scenarios

1. Error paths in HTTP handlers - Many error branches untested
2. Pagination edge cases - Offset/limit boundary conditions
3. CIDR computation edge cases - /31, /32 prefixes
4. Export functionality - CSV generation, field filtering
5. Migration rollback scenarios
6. Concurrent access patterns

Solution

Add comprehensive test files:

• internal/http/handlers_error_test.go - Error scenarios
• Pagination boundary tests
• CIDR edge case tests (/31, /32 handling)
• CSV export with various field combinations
• Concurrent pool operation tests

Example Missing Tests:

func TestPoolsHandlers_StorageErrors(t *testing.T) {
    // Use mock store that returns errors
    // Test each handler's error path
}

func TestBlocks_EdgeCases(t *testing.T) {
    // Test /31 and /32 prefix handling
    // Test huge pagination requests
    // Test negative offsets
}

func TestExport_AllFormats(t *testing.T) {
    // Test CSV field selection
    // Test empty datasets
    // Test large datasets (memory usage)
}

Acceptance Criteria

• Overall coverage >= 80%
• All error paths in handlers tested
• Pagination edge cases covered
• CIDR /31 and /32 tests added
• CSV export comprehensively tested
• Concurrent access tests added
• Coverage report generated and checked in CI

Validation

make cover
# Check coverage.html - should show 80%+ overall
make test-race
# Verify no race conditions in new tests