fix: add missing whatsapp service tests to fix CI build

- Add basic test coverage for whatsapp service stub implementation
- Fixes CI failure where whatsapp service had no test files
- All tests pass and linting is clean

Author: Oghenesuvwe-dev

service/whatsapp/whatsapp_test.go

@@ -0,0 +1,47 @@
+package whatsapp
+
+import (
+	"context"
+	"testing"
+)
+
+func TestNew(t *testing.T) {
+	service, err := New()
+	if err != nil {
+		t.Errorf("New() error = %v, want nil", err)
+		return
+	}
+	if service == nil {
+		t.Error("New() returned nil service")
+	}
+}
+
+func TestService_LoginWithSessionCredentials(t *testing.T) {
+	service := &Service{}
+	err := service.LoginWithSessionCredentials("", "", "", "", nil, nil)
+	if err != nil {
+		t.Errorf("LoginWithSessionCredentials() error = %v, want nil", err)
+	}
+}
+
+func TestService_LoginWithQRCode(t *testing.T) {
+	service := &Service{}
+	err := service.LoginWithQRCode()
+	if err != nil {
+		t.Errorf("LoginWithQRCode() error = %v, want nil", err)
+	}
+}
+
+func TestService_AddReceivers(_ *testing.T) {
+	service := &Service{}
+	// Should not panic
+	service.AddReceivers("test1", "test2")
+}
+
+func TestService_Send(t *testing.T) {
+	service := &Service{}
+	err := service.Send(context.Background(), "subject", "message")
+	if err != nil {
+		t.Errorf("Send() error = %v, want nil", err)
+	}
+}