Add missing unit tests for the operator

[hossain-rayhan]

Summary of New Unit Tests Created

1. internal/cnpg/cnpg_cluster_test.go (NEW FILE)
   Tests for the CNPG cluster specification builder:

TestGetCnpgClusterSpec - Tests cluster creation with various configurations (basic, custom sidecar, TLS ready, custom gateway image)
TestGetInheritedMetadataLabels - Tests label generation for standard names, special characters, and empty names
TestGetBootstrapConfiguration - Tests bootstrap with InitDB vs Recovery scenarios
TestGetMaxStopDelayOrDefault - Tests default and custom stop delay values
2. internal/utils/replication_context_test.go (NEW FILE)
Comprehensive tests for the ReplicationContext struct:

TestReplicationContext_IsPrimary - NoReplication, Primary, Replica states
TestReplicationContext_IsReplicating - All replication states
TestReplicationContext_GetReplicationSource - Source determination logic
TestReplicationContext_EndpointEnabled - Endpoint enablement scenarios
TestReplicationContext_IsAzureFleetNetworking - Azure Fleet detection
TestReplicationContext_IsIstioNetworking - Istio detection
TestReplicationContext_String - String representation
TestReplicationContext_CreateStandbyNamesList - Standby list generation
TestReplicationContext_GenerateExternalClusterServices - External service generation
TestReplicationContext_GenerateIncomingServiceNames - Incoming service names
TestReplicationContext_GenerateOutgoingServiceNames - Outgoing service names
TestGenerateCNPGClusterName - Cluster name generation with length constraints
3. internal/utils/util_test.go (EXPANDED)
Added missing tests:

TestGetPortFor - Port resolution for postgres, sidecar, gateway, and unknown ports
TestGetGatewayImageForDocumentDB - Gateway image selection logic
TestGetDocumentDBImageForInstance - DocumentDB image selection logic
TestGetEnvironmentSpecificAnnotations - Cloud-specific annotations (EKS, AKS, GKE)
TestGenerateServiceName_PublicFunction - Service name generation with truncation
TestEnsureServiceIP - Service IP validation for various service types
TestGetDocumentDBServiceDefinition_LoadBalancerAnnotations - LoadBalancer annotation logic
TestGetDocumentDBServiceDefinition_ServiceNameLength - Service name length constraints
Test Results
All tests pass successfully:

[Copilot]

Pull request overview

This pull request adds comprehensive unit tests for the DocumentDB Kubernetes Operator, significantly improving test coverage across three key internal packages.

Changes:

• Added 3 new test files with extensive test coverage for CNPG cluster specification building, replication context handling, and utility functions
• Refactored existing tests to use standard library strings.Contains instead of custom helper functions
• Added tests for previously untested utility functions including port resolution, image selection, environment-specific annotations, and service name generation

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
operator/src/internal/utils/util_test.go	Removed custom contains helper functions in favor of strings.Contains; added 8 new test functions covering port resolution, image selection, annotations, service name generation, and service IP validation
operator/src/internal/utils/replication_context_test.go	New test file with 13 test functions covering all ReplicationContext methods including state checks, networking strategies, service name generation, and cluster name generation
operator/src/internal/cnpg/cnpg_cluster_test.go	New test file with 4 test functions covering CNPG cluster specification generation, inherited metadata labels, bootstrap configuration, and stop delay settings