add tests

src/main/java/it/gov/pagopa/rtp/activator/repository/ActivationMapper.java

@@ -19,7 +19,7 @@ public Payer toDomain(ActivationEntity activationEntity) {
     }
 
     public ActivationEntity toDbEntity(Payer payer) {
-        return ActivationEntity.builder().id(payer.payerID().toString())
+        return ActivationEntity.builder().id(payer.payerID().getId().toString())
                 .fiscalCode(payer.fiscalCode())
                 .rtpSpId(payer.rtpSpId())
                 .effectiveActivationDate(payer.effectiveActivationDate())

src/main/java/it/gov/pagopa/rtp/activator/service/ActivationPayerServiceImpl.java

@@ -26,7 +26,8 @@ public Mono<Payer> activatePayer(String rtpSpId, String fiscalCode) {
         Payer payer = new Payer(payerID, rtpSpId, fiscalCode, Instant.now());
 
         return activationDBRepository.findByFiscalCode(fiscalCode)
-                .flatMap(existingEntity -> Mono.<Payer>error(new PayerAlreadyExists()))
-                .switchIfEmpty(activationDBRepository.save(payer));
+
+            .flatMap(existingEntity -> Mono.<Payer>error(new PayerAlreadyExists())) 
+            .switchIfEmpty(Mono.defer(() -> activationDBRepository.save(payer)));
     }
 }

src/test/java/it/gov/pagopa/rtp/activator/domain/PayerIDTest.java

@@ -0,0 +1,22 @@
+package it.gov.pagopa.rtp.activator.domain;
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.*;
+import java.util.UUID;
+
+public class PayerIDTest {
+
+    @Test
+    public void testCreateNew() {
+        PayerID payerID = PayerID.createNew();
+        assertNotNull(payerID);
+        assertNotNull(payerID.getId());
+    }
+
+    @Test
+    public void testConstructor() {
+        UUID uuid = UUID.randomUUID();
+        PayerID payerID = new PayerID(uuid);
+        assertNotNull(payerID);
+        assertEquals(uuid, payerID.getId());
+    }
+}

src/test/java/it/gov/pagopa/rtp/activator/repository/ActivationMapperTest.java

@@ -0,0 +1,47 @@
+package it.gov.pagopa.rtp.activator.repository;
+
+import org.junit.jupiter.api.Test;
+
+import it.gov.pagopa.rtp.activator.domain.Payer;
+import it.gov.pagopa.rtp.activator.domain.PayerID;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import java.time.Instant;
+import java.util.UUID;
+
+public class ActivationMapperTest {
+
+    private ActivationMapper mapper = new ActivationMapper();
+
+    @Test
+    public void testToDomain() {
+        ActivationEntity activationEntity = new ActivationEntity();
+        activationEntity.setId(UUID.randomUUID().toString());
+        activationEntity.setRtpSpId("RTP_SP_ID");
+        activationEntity.setFiscalCode("FISCAL_CODE");
+        activationEntity.setEffectiveActivationDate(Instant.ofEpochSecond(1732517304));
+
+        Payer payer = mapper.toDomain(activationEntity);
+
+        assertNotNull(payer);
+        assertEquals(activationEntity.getId(), payer.payerID().getId().toString());
+        assertEquals(activationEntity.getRtpSpId(), payer.rtpSpId());
+        assertEquals(activationEntity.getFiscalCode(), payer.fiscalCode());
+        assertEquals(activationEntity.getEffectiveActivationDate(), payer.effectiveActivationDate());
+    }
+
+    @Test
+    public void testToDbEntity() {
+        PayerID payerID = new PayerID(UUID.randomUUID());
+        Payer payer = new Payer(payerID, "RTP_SP_ID", "FISCAL_CODE", Instant.ofEpochSecond(1732517304));
+
+        ActivationEntity activationEntity = mapper.toDbEntity(payer);
+
+        assertNotNull(activationEntity);
+        assertEquals(payer.payerID().getId().toString(), activationEntity.getId());
+        assertEquals(payer.rtpSpId(), activationEntity.getRtpSpId());
+        assertEquals(payer.fiscalCode(), activationEntity.getFiscalCode());
+        assertEquals(payer.effectiveActivationDate(), activationEntity.getEffectiveActivationDate());
+    }
+}

src/test/java/it/gov/pagopa/rtp/activator/service/ActivationPayerServiceImplTest.java

@@ -0,0 +1,63 @@
+package it.gov.pagopa.rtp.activator.service;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import it.gov.pagopa.rtp.activator.domain.Payer;
+import it.gov.pagopa.rtp.activator.domain.PayerID;
+import it.gov.pagopa.rtp.activator.domain.errors.PayerAlreadyExists;
+import it.gov.pagopa.rtp.activator.repository.ActivationDBRepository;
+
+import reactor.core.publisher.Mono;
+import reactor.test.StepVerifier;
+
+import java.time.Instant;
+
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.when;
+
+@ExtendWith(MockitoExtension.class)
+public class ActivationPayerServiceImplTest {
+
+    @Mock
+    private ActivationDBRepository activationDBRepository;
+
+    @InjectMocks
+    private ActivationPayerServiceImpl activationPayerService;
+
+    private Payer payer;
+
+    @BeforeEach
+    public void setUp() {
+        payer = new Payer(PayerID.createNew(), "RTP_SP_ID", "FISCAL_CODE", Instant.now());
+
+    }
+
+    @Test
+    public void testActivatePayerSuccessful() {
+        when(activationDBRepository.findByFiscalCode("FISCAL_CODE")).thenReturn(Mono.empty());
+        when(activationDBRepository.save(any())).thenReturn(Mono.just(payer));
+
+        Mono<Payer> result = activationPayerService.activatePayer("RTP_SP_ID", "FISCAL_CODE");
+
+        StepVerifier.create(result)
+            .expectNext(payer)
+            .verifyComplete();
+    }
+
+    @Test
+    public void testActivatePayerAlreadyExists() {
+        when(activationDBRepository.findByFiscalCode("FISCAL_CODE")).thenReturn(Mono.just(payer));
+
+        Mono<Payer> result = activationPayerService.activatePayer("RTP_SP_ID", "FISCAL_CODE");
+
+        StepVerifier.create(result)
+            .expectError(PayerAlreadyExists.class)
+            .verify();
+    }
+}