change CaseConcurrencyException message and add unit test (#2446)

src/main/java/uk/gov/hmcts/ccd/data/casedetails/DefaultCaseDetailsRepository.java

@@ -77,7 +77,10 @@ public CaseDetails set(final CaseDetails caseDetails) {
             em.flush();
         } catch (StaleObjectStateException | OptimisticLockException e) {
             LOG.info("Optimistic Lock Exception: Case data has been altered, UUID={}", caseDetails.getReference(), e);
-            throw new CaseConcurrencyException("The case data has been altered outside of this transaction.");
+            throw new CaseConcurrencyException("""
+                Unfortunately we were unable to save your work to the case as \
+                another action happened at the same time.
+                Please review the case and try again.""");
         } catch (PersistenceException e) {
             if (e.getCause() instanceof ConstraintViolationException && isDuplicateReference(e)) {
                 LOG.warn("ConstraintViolationException happen for UUID={}. ConstraintName: {}",

src/test/java/uk/gov/hmcts/ccd/data/casedetails/DefaultCaseDetailsRepositoryTest.java

@@ -27,13 +27,17 @@
 import uk.gov.hmcts.ccd.domain.service.common.AccessControlService;
 import uk.gov.hmcts.ccd.domain.service.security.AuthorisedCaseDefinitionDataService;
 import uk.gov.hmcts.ccd.endpoint.exceptions.BadRequestException;
+import uk.gov.hmcts.ccd.endpoint.exceptions.CaseConcurrencyException;
 import uk.gov.hmcts.ccd.infrastructure.user.UserAuthorisation;
 import uk.gov.hmcts.ccd.infrastructure.user.UserAuthorisation.AccessLevel;
 
 import javax.inject.Inject;
+import javax.persistence.EntityManager;
+import javax.persistence.OptimisticLockException;
 import javax.servlet.ServletContext;
 import javax.servlet.ServletRequestEvent;
 import java.io.IOException;
+import java.lang.reflect.Field;
 import java.time.LocalDate;
 import java.time.LocalDateTime;
 import java.time.ZoneOffset;
@@ -57,9 +61,13 @@
 import static org.hamcrest.Matchers.notNullValue;
 import static org.junit.Assert.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertAll;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyList;
 import static org.mockito.ArgumentMatchers.anySet;
+import static org.mockito.Mockito.doThrow;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 import static uk.gov.hmcts.ccd.TestFixtures.loadCaseTypeDefinition;
 import static uk.gov.hmcts.ccd.domain.service.common.AccessControlService.CAN_READ;
@@ -125,6 +133,41 @@ public void clearDown() {
         listener.requestDestroyed(new ServletRequestEvent(context, request));
     }
 
+    @Test
+    public void setShouldThrowCaseConcurrencyException() throws NoSuchFieldException, IllegalAccessException {
+        EntityManager emMock = mock(EntityManager.class);
+        CaseDetailsMapper caseDetailsMapper = mock(CaseDetailsMapper.class);
+
+        DefaultCaseDetailsRepository defaultCaseDetailsRepository =
+            new DefaultCaseDetailsRepository(caseDetailsMapper, null, null,
+                applicationParams);
+
+        Field emField = DefaultCaseDetailsRepository.class.getDeclaredField("em");
+        emField.setAccessible(true);
+        emField.set(defaultCaseDetailsRepository, emMock);
+
+        CaseDetails caseDetails = new CaseDetails();
+        caseDetails.setReference(1L);
+
+        CaseDetailsEntity caseDetailsEntity = new CaseDetailsEntity();
+        caseDetailsEntity.setReference(1L);
+        caseDetailsEntity.setLastModified(LocalDateTime.now(ZoneOffset.UTC));
+        caseDetailsEntity.setVersion(1);
+
+        when(caseDetailsMapper.modelToEntity(caseDetails)).thenReturn(caseDetailsEntity);
+        when(emMock.merge(caseDetailsEntity)).thenReturn(caseDetailsEntity);
+        doThrow(new OptimisticLockException()).when(emMock).flush();
+
+        CaseConcurrencyException exception = assertThrows(CaseConcurrencyException.class,
+            () -> defaultCaseDetailsRepository.set(caseDetails));
+
+        assertThat(exception.getMessage(), is("Unfortunately we were unable to save your work to the case as "
+            + "another action happened at the same time.\nPlease review the case and try again."));
+
+        verify(emMock).merge(caseDetailsEntity);
+        verify(emMock).flush();
+    }
+
     @Test
     public void setShouldPersistCaseDetails() {
         CaseDetails caseDetails = new CaseDetails();