diff --git a/pom.xml b/pom.xml
index 27ec78e..cbe66e0 100644
--- a/pom.xml
+++ b/pom.xml
@@ -117,6 +117,12 @@
       <version>${mockito.version}</version>
       <scope>test</scope>
     </dependency>
+      <dependency>
+          <groupId>junit</groupId>
+          <artifactId>junit</artifactId>
+          <version>RELEASE</version>
+          <scope>test</scope>
+      </dependency>
   </dependencies>
 
   <build>
diff --git a/src/test/java/fr/iut_fbleau/but3/dev62/mylibrary/subscription/converter/SubscriptionConverterTest.java b/src/test/java/fr/iut_fbleau/but3/dev62/mylibrary/subscription/converter/SubscriptionConverterTest.java
new file mode 100644
index 0000000..dc42b6c
--- /dev/null
+++ b/src/test/java/fr/iut_fbleau/but3/dev62/mylibrary/subscription/converter/SubscriptionConverterTest.java
@@ -0,0 +1,78 @@
+package fr.iut_fbleau.but3.dev62.mylibrary.subscription.converter;
+
+import fr.iut_fbleau.but3.dev62.mylibrary.subscription.*;
+import fr.iut_fbleau.but3.dev62.mylibrary.subscription.entity.Subscription;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+
+import java.util.Calendar;
+import java.util.Date;
+import java.util.UUID;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+@DisplayName("SubscriptionConverter Unit Tests")
+class SubscriptionConverterTest {
+
+    @Nested
+    @DisplayName("toDomain() method tests")
+    class ToDomainTests {
+
+        @Test
+        @DisplayName("Should convert SubscriptionInfo to Subscription domain object")
+        void shouldConvertSubscriptionInfoToDomain() {
+            SubscriptionInfo subscriptionInfo = new SubscriptionInfo(
+                    UUID.randomUUID(),
+                    SubscriptionDuree.M3,
+                    ModePaiement.builder()
+                            .type(TypePaiement.CB)
+                            .details("yes")
+                            .build(),
+                    new Date()
+            );
+
+            Subscription result = SubscriptionConverter.toDomain(subscriptionInfo);
+
+            assertNotNull(result);
+            assertEquals(subscriptionInfo.clientId(), result.getClientId());
+            assertEquals(subscriptionInfo.duree(), result.getDuree());
+            assertEquals(subscriptionInfo.modePaiement().getType(), result.getModePaiement().getType());
+            assertEquals(subscriptionInfo.modePaiement().getDetails(), result.getModePaiement().getDetails());
+            assertEquals(subscriptionInfo.dateDebutSouhaitee(), result.getDateDebutSouhaitee());
+        }
+    }
+
+    @Nested
+    @DisplayName("toDTO() method tests")
+    class ToDTOTests {
+
+        @Test
+        @DisplayName("Should convert Subscription domain object to SubscriptionDTO with all fields mapped correctly")
+        void shouldConvertSubscriptionToDTO() {
+            Subscription subscription = Subscription.builder()
+                    .clientId(UUID.randomUUID())
+                    .duree(SubscriptionDuree.M3)
+                    .modePaiement(ModePaiement.builder()
+                            .type(TypePaiement.CB)
+                            .details("yes")
+                            .build())
+                    .dateDebutSouhaitee(new Date())
+                    .build();
+            subscription.setRandomUUID();
+
+            SubscriptionDTO result = SubscriptionConverter.toDTO(subscription);
+
+            Calendar cal = Calendar.getInstance();
+            cal.setTime(subscription.getDateDebutSouhaitee());
+            cal.add(Calendar.MONTH, subscription.getDuree().getValue());
+
+            assertNotNull(result);
+            assertEquals(subscription.getAbonnementId(), result.getAbonnementId());
+            assertEquals(subscription.getDateDebutSouhaitee(), result.getDateDebut());
+            assertEquals(cal.getTime(), result.getDateFin());
+            assertEquals(subscription.getDuree().getMonthlyPricing(), result.getMontantMensuel());
+        }
+    }
+}
diff --git a/src/test/java/fr/iut_fbleau/but3/dev62/mylibrary/subscription/entity/SubscriptionTest.java b/src/test/java/fr/iut_fbleau/but3/dev62/mylibrary/subscription/entity/SubscriptionTest.java
new file mode 100644
index 0000000..eb50063
--- /dev/null
+++ b/src/test/java/fr/iut_fbleau/but3/dev62/mylibrary/subscription/entity/SubscriptionTest.java
@@ -0,0 +1,67 @@
+package fr.iut_fbleau.but3.dev62.mylibrary.subscription.entity;
+
+import fr.iut_fbleau.but3.dev62.mylibrary.subscription.ModePaiement;
+import fr.iut_fbleau.but3.dev62.mylibrary.subscription.SubscriptionDuree;
+import fr.iut_fbleau.but3.dev62.mylibrary.subscription.TypePaiement;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import java.util.Date;
+import java.util.UUID;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class SubscriptionTest {
+
+    @Test
+    @DisplayName("Builder should create a valid Subscription instance")
+    void testSubscriptionBuilder() {
+        UUID id = UUID.randomUUID();
+        UUID id2 = UUID.randomUUID();
+        Date adj = new Date();
+
+        Subscription subscription = Subscription.builder()
+                .abonnementId(id)
+                .clientId(id2)
+                .duree(SubscriptionDuree.M3)
+                .modePaiement(ModePaiement.builder()
+                        .type(TypePaiement.CB)
+                        .details("yes")
+                        .build())
+                .dateDebutSouhaitee(adj)
+                .build();
+
+
+        assertEquals(id, subscription.getAbonnementId());
+        assertEquals(id2, subscription.getClientId());
+        assertEquals(SubscriptionDuree.M3, subscription.getDuree());
+        assertEquals(TypePaiement.CB, subscription.getModePaiement().getType());
+        assertEquals("yes", subscription.getModePaiement().getDetails());
+        assertEquals(adj, subscription.getDateDebutSouhaitee());
+    }
+
+    @Test
+    @DisplayName("setRandomUUID should set a new non-null UUID")
+    void testSetRandomUUID() {
+        Subscription subscription = Subscription.builder().build();
+        UUID originalId = subscription.getAbonnementId();
+
+        subscription.setRandomUUID();
+
+        assertNotNull(subscription.getAbonnementId());
+        assertNotEquals(originalId, subscription.getAbonnementId());
+    }
+
+    @Test
+    @DisplayName("Two setRandomUUID calls should produce different UUIDs")
+    void testSetRandomUUIDTwice() {
+        Subscription subscription = Subscription.builder().build();
+        subscription.setRandomUUID();
+        UUID firstId = subscription.getAbonnementId();
+
+        subscription.setRandomUUID();
+        UUID secondId = subscription.getAbonnementId();
+
+        assertNotEquals(firstId, secondId);
+    }
+}
diff --git a/src/test/java/fr/iut_fbleau/but3/dev62/mylibrary/subscription/exception/SubscriptionNotFoundExceptionTest.java b/src/test/java/fr/iut_fbleau/but3/dev62/mylibrary/subscription/exception/SubscriptionNotFoundExceptionTest.java
new file mode 100644
index 0000000..e857fbc
--- /dev/null
+++ b/src/test/java/fr/iut_fbleau/but3/dev62/mylibrary/subscription/exception/SubscriptionNotFoundExceptionTest.java
@@ -0,0 +1,48 @@
+package fr.iut_fbleau.but3.dev62.mylibrary.subscription.exception;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import java.util.UUID;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class SubscriptionNotFoundExceptionTest {
+
+    @Test
+    @DisplayName("Exception message should contain the UUID provided")
+    void testExceptionMessageContainsUUID() {
+        UUID uuid = UUID.randomUUID();
+
+        SubscriptionNotFoundException exception = new SubscriptionNotFoundException(uuid);
+
+        String expectedMessage = String.format("The Subscription with id %s does not exist", uuid);
+        assertEquals(expectedMessage, exception.getMessage());
+    }
+
+    @Test
+    @DisplayName("Exception should use the correct constant message format")
+    void testExceptionUsesConstantMessageFormat() {
+        UUID uuid = UUID.randomUUID();
+
+        SubscriptionNotFoundException exception = new SubscriptionNotFoundException(uuid);
+
+        assertEquals("The Subscription with id {0} does not exist",
+                SubscriptionNotFoundException.THE_SUBSCRIPTION_WITH_ID_DOES_NOT_EXIST_MESSAGE);
+        assertTrue(exception.getMessage().contains(uuid.toString()));
+    }
+
+    @Test
+    @DisplayName("Exception should be properly thrown and caught")
+    void testExceptionCanBeThrownAndCaught() {
+        UUID uuid = UUID.randomUUID();
+
+        try {
+            throw new SubscriptionNotFoundException(uuid);
+        } catch (SubscriptionNotFoundException e) {
+            String expectedMessage = String.format("The Subscription with id %s does not exist", uuid);
+            assertEquals(expectedMessage, e.getMessage());
+        }
+    }
+}
diff --git a/src/test/java/fr/iut_fbleau/but3/dev62/mylibrary/subscription/repository/SubscriptionRepositoryTest.java b/src/test/java/fr/iut_fbleau/but3/dev62/mylibrary/subscription/repository/SubscriptionRepositoryTest.java
new file mode 100644
index 0000000..07be69f
--- /dev/null
+++ b/src/test/java/fr/iut_fbleau/but3/dev62/mylibrary/subscription/repository/SubscriptionRepositoryTest.java
@@ -0,0 +1,194 @@
+package fr.iut_fbleau.but3.dev62.mylibrary.subscription.repository;
+
+import fr.iut_fbleau.but3.dev62.mylibrary.subscription.ModePaiement;
+import fr.iut_fbleau.but3.dev62.mylibrary.subscription.SubscriptionDuree;
+import fr.iut_fbleau.but3.dev62.mylibrary.subscription.TypePaiement;
+import fr.iut_fbleau.but3.dev62.mylibrary.subscription.entity.Subscription;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+
+import java.util.Date;
+import java.util.Optional;
+import java.util.UUID;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class SubscriptionRepositoryTest {
+
+    private SubscriptionRepository repository;
+    private Subscription subscription1;
+    private Subscription subscription2;
+
+    @BeforeEach
+    void setUp() {
+        repository = new SubscriptionRepository();
+
+        subscription1 = Subscription.builder()
+                .clientId(UUID.randomUUID())
+                .duree(SubscriptionDuree.M3)
+                .modePaiement(ModePaiement.builder()
+                        .type(TypePaiement.CB)
+                        .details("yes")
+                        .build())
+                .dateDebutSouhaitee(new Date())
+                .build();
+        subscription1.setRandomUUID();
+
+        subscription2 = Subscription.builder()
+                .clientId(UUID.randomUUID())
+                .duree(SubscriptionDuree.M6)
+                .modePaiement(ModePaiement.builder()
+                        .type(TypePaiement.Paypal)
+                        .details("No")
+                        .build())
+                .dateDebutSouhaitee(new Date(0))
+                .build();
+        subscription2.setRandomUUID();
+    }
+
+    @Test
+    @DisplayName("New repository should be empty")
+    void testNewRepositoryIsEmpty() {
+        assertTrue(repository.findAll().isEmpty());
+        assertEquals(0, repository.findAll().size());
+    }
+
+    @Nested
+    @DisplayName("Save operations")
+    class SaveOperations {
+
+        @Test
+        @DisplayName("Save should add a new subscription")
+        void testSaveNewSubscription() {
+            Subscription saved = repository.save(subscription1);
+
+            assertEquals(1, repository.findAll().size());
+            assertEquals(subscription1.getAbonnementId(), saved.getAbonnementId());
+            assertEquals(subscription1.getClientId(), saved.getClientId());
+        }
+
+        @Test
+        @DisplayName("Save should update existing subscription with same ID")
+        void testSaveUpdatesExistingSubscription() {
+            repository.save(subscription1);
+            UUID uuid = subscription1.getAbonnementId();
+
+            Subscription updatedSubscription = Subscription.builder()
+                    .abonnementId(uuid)
+                    .clientId(UUID.randomUUID())
+                    .duree(SubscriptionDuree.M12)
+                    .modePaiement(ModePaiement.builder()
+                            .type(TypePaiement.CB)
+                            .details("maybe")
+                            .build())
+                    .dateDebutSouhaitee(new Date(500000))
+                    .build();
+
+            Subscription saved = repository.save(updatedSubscription);
+
+            assertEquals(1, repository.findAll().size());
+            assertEquals(uuid, saved.getAbonnementId());
+            assertEquals(SubscriptionDuree.M12, saved.getDuree());
+            assertEquals("maybe", saved.getModePaiement().getDetails());
+        }
+
+        @Test
+        @DisplayName("Save multiple subscriptions should add all of them")
+        void testSaveMultipleSubscriptions() {
+            repository.save(subscription1);
+            repository.save(subscription2);
+
+            assertEquals(2, repository.findAll().size());
+            assertTrue(repository.findAll().contains(subscription1));
+            assertTrue(repository.findAll().contains(subscription2));
+        }
+    }
+
+    @Nested
+    @DisplayName("Find operations")
+    class FindOperations {
+
+        @BeforeEach
+        void setUpSubscriptions() {
+            repository.save(subscription1);
+            repository.save(subscription2);
+        }
+
+        @Test
+        @DisplayName("FindAll should return all subscriptions")
+        void testFindAll() {
+            assertEquals(2, repository.findAll().size());
+        }
+
+        @Test
+        @DisplayName("findByUuid should return subscription with matching ID")
+        void testfindByUuid() {
+            Optional<Subscription> found = repository.findByClientUuid(subscription1.getClientId());
+
+            assertTrue(found.isPresent());
+            assertEquals(subscription1.getAbonnementId(), found.get().getAbonnementId());
+            assertEquals(subscription1.getDuree(), found.get().getDuree());
+        }
+
+        @Test
+        @DisplayName("FindById should return empty Optional when ID doesn't exist")
+        void testFindByIdNotFound() {
+            Optional<Subscription> found = repository.findByUuid(UUID.randomUUID());
+
+            assertTrue(found.isEmpty());
+        }
+
+        @Test
+        @DisplayName("ExistsById should return true when ID exists")
+        void testExistsByIdExists() {
+            assertTrue(repository.existsById(subscription1.getAbonnementId()));
+        }
+
+        @Test
+        @DisplayName("ExistsById should return false when ID doesn't exist")
+        void testExistsByIdNotExists() {
+            assertFalse(repository.existsById(UUID.randomUUID()));
+        }
+    }
+
+    @Nested
+    @DisplayName("Delete operations")
+    class DeleteOperations {
+
+        @BeforeEach
+        void setUpSubscriptions() {
+            repository.save(subscription1);
+            repository.save(subscription2);
+        }
+
+        @Test
+        @DisplayName("Delete should remove the specified subscription")
+        void testDelete() {
+            repository.delete(subscription1);
+
+            assertEquals(1, repository.findAll().size());
+            assertFalse(repository.findAll().contains(subscription1));
+            assertTrue(repository.findAll().contains(subscription2));
+        }
+
+        @Test
+        @DisplayName("DeleteAll should remove all subscriptions")
+        void testDeleteAll() {
+            repository.deleteAll();
+
+            assertTrue(repository.findAll().isEmpty());
+        }
+
+        @Test
+        @DisplayName("Delete should not throw exception when subscription doesn't exist")
+        void testDeleteNonExistentSubscription() {
+            Subscription nonExistent = Subscription.builder().clientId(UUID.randomUUID()).build();
+            nonExistent.setRandomUUID();
+
+            assertDoesNotThrow(() -> repository.delete(nonExistent));
+            assertEquals(2, repository.findAll().size());
+        }
+    }
+}
diff --git a/src/test/java/fr/iut_fbleau/but3/dev62/mylibrary/subscription/usecase/SubscriptionUseCaseTest.java b/src/test/java/fr/iut_fbleau/but3/dev62/mylibrary/subscription/usecase/SubscriptionUseCaseTest.java
new file mode 100644
index 0000000..d775ce7
--- /dev/null
+++ b/src/test/java/fr/iut_fbleau/but3/dev62/mylibrary/subscription/usecase/SubscriptionUseCaseTest.java
@@ -0,0 +1,218 @@
+package fr.iut_fbleau.but3.dev62.mylibrary.subscription.usecase;
+
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+
+import java.util.UUID;
+
+class SubscriptionUseCaseTest {
+
+    @Mock
+    private SubscriptionRepository subscriptionRepository;
+
+    @InjectMocks
+    private SubscriptionUseCase subscriptionUseCase;
+
+    private UUID subscriptionId;
+    private UUID subscriptionClientId;
+    private Subscription testSubscription;
+    private SubscriptionInfo validSubscriptionInfo;
+
+    @BeforeEach
+    void setUp() {
+        subscriptionId = UUID.randomUUID();
+        subscriptionClientId = UUID.randomUUID();
+
+        Date adj = new Date();
+
+        testSubscription = Subscription.builder()
+                .abonnementId(subscriptionId)
+                .clientId(subscriptionClientId)
+                .duree(SubscriptionDuree.M3)
+                .modePaiement(ModePaiement.builder()
+                        .type(TypePaiement.CB)
+                        .details("yes")
+                        .build())
+                .dateDebutSouhaitee(new Date())
+                .build();
+
+        validSubscriptionInfo = new SubscriptionInfo(
+                subscriptionClientId,
+                SubscriptionDuree.M3,
+                ModePaiement.builder()
+                        .type(TypePaiement.CB)
+                        .details("yes")
+                        .build(),
+                adj
+        );
+    }
+
+    @Nested
+    @DisplayName("Register subscription tests")
+    class RegisterSubscriptionTests {
+
+        @Test
+        @DisplayName("Should register subscription when valid data is provided")
+
+        void testRegisterSubscriptionWithValidData() throws NotValidSubscriptionException {
+            when(subscriptionRepository.save(any(Subscription.class))).thenReturn(testSubscription);
+
+            SubscriptionDTO returnedSubscriptionDTO = subscriptionUseCase.registerSubscription(validSubscriptionInfo);
+
+            assertNotNull(returnedSubscriptionDTO);
+            assertEquals(subscriptionId, returnedSubscriptionDTO.getAbonnementId());
+            verify(subscriptionRepository, times(1)).save(any(Subscription.class));
+        }
+
+        @Test
+        @DisplayName("Should throw exception when subscription data is not valid")
+        void testRegisterSubscriptionWithInvalidData() {
+            SubscriptionInfo invalidSubscriptionInfo = new SubscriptionInfo(
+                    null,
+                    null,
+                    null,
+                    null
+            );
+
+            assertThrows(NotValidSubscriptionException.class,
+                    () -> subscriptionUseCase.registerSubscription(invalidSubscriptionInfo));
+
+            verify(subscriptionRepository, never()).save(any(Subscription.class));
+        }
+    }
+
+    @Nested
+    @DisplayName("Find subscription tests")
+    class FindSubscriptionTests {
+
+        @Test
+        @DisplayName("Should return subscription when client UUID exists")
+        void testFindSubscriptionByUuid() {
+            when(subscriptionRepository.findByClientUuid(subscriptionClientId)).thenReturn(Optional.of(testSubscription));
+
+            Optional<SubscriptionDTO> foundSubscription = subscriptionUseCase.findSubscriptionByUuid(subscriptionClientId);
+
+            assertTrue(foundSubscription.isPresent());
+            assertEquals(testSubscription.getAbonnementId(), foundSubscription.get().getAbonnementId());
+            verify(subscriptionRepository, times(1)).findByClientUuid(subscriptionClientId);
+        }
+
+        @Test
+        @DisplayName("Should return empty Optional when UUID doesn't exist")
+        void testFindSubscriptionByUuidNotFound() {
+            UUID uuid = UUID.randomUUID();
+
+            Optional<SubscriptionDTO> foundSubscription = subscriptionUseCase.findSubscriptionByUuid(uuid);
+
+            assertTrue(foundSubscription.isEmpty());
+        }
+    }
+
+
+    @Nested
+    @DisplayName("Update subscription tests")
+    class UpdateSubscriptionTests {
+
+        @Test
+        @DisplayName("Should update subscription when valid data is provided")
+        void testUpdateSubscriptionWithValidData() throws SubscriptionNotFoundException, NotValidSubscriptionException {
+            when(subscriptionRepository.findByUuid(subscriptionId)).thenReturn(Optional.of(testSubscription));
+
+            Subscription updatedSubscription = Subscription.builder()
+                    .abonnementId(subscriptionId)
+                    .clientId(subscriptionClientId)
+                    .duree(SubscriptionDuree.M6)
+                    .modePaiement(ModePaiement.builder()
+                            .type(TypePaiement.Paypal)
+                            .details("no")
+                            .build())
+                    .dateDebutSouhaitee(new Date(0))
+                    .build();
+
+            when(subscriptionRepository.save(any(Subscription.class))).thenReturn(updatedSubscription);
+
+            SubscriptionInfo updateInfo = new SubscriptionInfo(
+                    subscriptionClientId,
+                    SubscriptionDuree.M6,
+                    ModePaiement.builder()
+                            .type(TypePaiement.Paypal)
+                            .details("no")
+                            .build(),
+                    new Date(0)
+            );
+
+            SubscriptionDTO result = subscriptionUseCase.updateSubscription(subscriptionId, updateInfo);
+
+            assertNotNull(result);
+            assertEquals(subscriptionId, result.getAbonnementId());
+            assertEquals(new Date(0), result.getDateDebut());
+            verify(subscriptionRepository, times(1)).findByUuid(subscriptionId);
+            verify(subscriptionRepository, times(1)).save(any(Subscription.class));
+        }
+
+        @Test
+        @DisplayName("Should throw exception when subscription ID doesn't exist")
+        void testUpdateSubscriptionNotFound() {
+            UUID nonExistentId = UUID.randomUUID();
+            when(subscriptionRepository.findByUuid(nonExistentId)).thenReturn(Optional.empty());
+
+            assertThrows(SubscriptionNotFoundException.class,
+                    () -> subscriptionUseCase.updateSubscription(nonExistentId, validSubscriptionInfo));
+
+            verify(subscriptionRepository, times(1)).findByUuid(nonExistentId);
+            verify(subscriptionRepository, never()).save(any(Subscription.class));
+        }
+    }
+
+    @Nested
+    @DisplayName("Delete subscription tests")
+    class DeleteSubscriptionTests {
+
+        @Test
+        @DisplayName("Should delete subscription when ID exists")
+        void testDeleteSubscription() throws SubscriptionNotFoundException {
+            when(subscriptionRepository.findByUuid(subscriptionId)).thenReturn(Optional.of(testSubscription));
+
+            assertDoesNotThrow(() -> subscriptionUseCase.deleteSubscription(subscriptionId));
+
+            verify(subscriptionRepository, times(1)).findByUuid(subscriptionId);
+            verify(subscriptionRepository, times(1)).delete(testSubscription);
+        }
+
+        @Test
+        @DisplayName("Should throw exception when deleting unknown subscription")
+        void testDeleteSubscriptionNotFound() {
+            UUID nonExistentId = UUID.randomUUID();
+            when(subscriptionRepository.findByUuid(nonExistentId)).thenReturn(Optional.empty());
+
+            assertThrows(SubscriptionNotFoundException.class,
+                    () -> subscriptionUseCase.deleteSubscription(nonExistentId));
+
+            verify(subscriptionRepository, times(1)).findByUuid(nonExistentId);
+            verify(subscriptionRepository, never()).delete(any(Subscription.class));
+        }
+    }
+}
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
diff --git a/src/test/java/fr/iut_fbleau/but3/dev62/mylibrary/subscription/validator/SubscriptionValidatorTest.java b/src/test/java/fr/iut_fbleau/but3/dev62/mylibrary/subscription/validator/SubscriptionValidatorTest.java
new file mode 100644
index 0000000..da0d041
--- /dev/null
+++ b/src/test/java/fr/iut_fbleau/but3/dev62/mylibrary/subscription/validator/SubscriptionValidatorTest.java
@@ -0,0 +1,200 @@
+package fr.iut_fbleau.but3.dev62.mylibrary.subscription.validator;
+
+import fr.iut_fbleau.but3.dev62.mylibrary.subscription.ModePaiement;
+import fr.iut_fbleau.but3.dev62.mylibrary.subscription.SubscriptionDuree;
+import fr.iut_fbleau.but3.dev62.mylibrary.subscription.SubscriptionInfo;
+import fr.iut_fbleau.but3.dev62.mylibrary.subscription.TypePaiement;
+import fr.iut_fbleau.but3.dev62.mylibrary.subscription.exception.NotValidSubscriptionException;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+
+import java.util.Date;
+import java.util.UUID;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class SubscriptionValidatorTest {
+
+    private SubscriptionInfo validSubscription() {
+
+        UUID uuid = UUID.randomUUID();
+        Date adj = new Date();
+
+        return new SubscriptionInfo(
+                uuid,
+                SubscriptionDuree.M3,
+                ModePaiement.builder()
+                        .type(TypePaiement.CB)
+                        .details("yes")
+                        .build(),
+                adj
+        );
+    }
+
+    @Test
+    @DisplayName("Should validate subscription with valid data")
+    void testValidateValidSubscription() {
+        assertDoesNotThrow(() -> SubscriptionValidator.validate(validSubscription()));
+    }
+
+    @Nested
+    @DisplayName("UUID validation tests")
+    class UuidValidationTests {
+
+        @Test
+        @DisplayName("Should Be valid")
+        void testValidatenormalUUID() {
+            SubscriptionInfo subscription = new SubscriptionInfo(
+                    UUID.randomUUID(),
+                    SubscriptionDuree.M3,
+                    ModePaiement.builder()
+                            .type(TypePaiement.CB)
+                            .details("yes")
+                            .build(),
+                    new Date(0)
+            );
+
+            assertDoesNotThrow(() -> SubscriptionValidator.validate(subscription));
+        }
+
+        @Test
+        @DisplayName("Should throw exception when UUID is blank")
+        void testValidateBlankUuid() {
+            SubscriptionInfo subscription = new SubscriptionInfo(
+                    null,
+                    SubscriptionDuree.M3,
+                    ModePaiement.builder()
+                            .type(TypePaiement.CB)
+                            .details("yes")
+                            .build(),
+                    new Date(0)
+            );
+
+            NotValidSubscriptionException exception = assertThrows(NotValidSubscriptionException.class,
+                    () -> SubscriptionValidator.validate(subscription));
+
+            assertEquals(SubscriptionValidator.Client_ID_NOT_VALID, exception.getMessage());
+        }
+    }
+
+    @Nested
+    @DisplayName("Date validation tests")
+    class DateValidationTests {
+
+        @Test
+        @DisplayName("Should be good")
+        void testValidateTodayDate() {
+            SubscriptionInfo subscription = new SubscriptionInfo(
+                    UUID.randomUUID(),
+                    SubscriptionDuree.M3,
+                    ModePaiement.builder()
+                            .type(TypePaiement.CB)
+                            .details("yes")
+                            .build(),
+                    new Date()
+            );
+
+            assertDoesNotThrow(() -> SubscriptionValidator.validate(subscription));
+        }
+
+        @Test
+        @DisplayName("Should throw exception when Date is null")
+        void testValidateNullDate() {
+            SubscriptionInfo subscription = new SubscriptionInfo(
+                    UUID.randomUUID(),
+                    SubscriptionDuree.M3,
+                    ModePaiement.builder()
+                            .type(TypePaiement.CB)
+                            .details("yes")
+                            .build(),
+                    null
+            );
+
+            NotValidSubscriptionException exception = assertThrows(NotValidSubscriptionException.class,
+                    () -> SubscriptionValidator.validate(subscription));
+
+            assertEquals(SubscriptionValidator.LA_DATE_DE_DEBUT_N_A_PAS_ETE_RENSEIGNEE, exception.getMessage());
+        }
+    }
+
+    @Nested
+    @DisplayName("ModePaiement validation tests")
+    class ModePaiementValidationTests {
+
+        @Test
+        @DisplayName("Should be good")
+        void testValidateGoodModePaiement() {
+            SubscriptionInfo subscription = new SubscriptionInfo(
+                    UUID.randomUUID(),
+                    SubscriptionDuree.M3,
+                    ModePaiement.builder()
+                            .type(TypePaiement.CB)
+                            .details("yes")
+                            .build(),
+                    new Date()
+            );
+
+            assertDoesNotThrow(() -> SubscriptionValidator.validate(subscription));
+        }
+
+        @Test
+        @DisplayName("Should throw exception when Date is null")
+        void testValidateNullModePaiement() {
+            SubscriptionInfo subscription = new SubscriptionInfo(
+                    UUID.randomUUID(),
+                    SubscriptionDuree.M3,
+                    ModePaiement.builder()
+                            .type(null)
+                            .details("yes")
+                            .build(),
+                    new Date()
+            );
+
+            NotValidSubscriptionException exception = assertThrows(NotValidSubscriptionException.class,
+                    () -> SubscriptionValidator.validate(subscription));
+
+            assertEquals(SubscriptionValidator.LE_TYPE_DE_PAYEMENT_N_EST_PAS_PRIS_EN_CHARGE, exception.getMessage());
+        }
+    }
+
+    @Nested
+    @DisplayName("Durée validation tests")
+    class DureeValidationTests {
+
+        @Test
+        @DisplayName("Should be good")
+        void testValidateGoodDuree() {
+            SubscriptionInfo subscription = new SubscriptionInfo(
+                    UUID.randomUUID(),
+                    SubscriptionDuree.M3,
+                    ModePaiement.builder()
+                            .type(TypePaiement.CB)
+                            .details("yes")
+                            .build(),
+                    new Date()
+            );
+
+            assertDoesNotThrow(() -> SubscriptionValidator.validate(subscription));
+        }
+
+        @Test
+        @DisplayName("Should throw exception when Date is null")
+        void testValidateNullDuree() {
+            SubscriptionInfo subscription = new SubscriptionInfo(
+                    UUID.randomUUID(),
+                    null,
+                    ModePaiement.builder()
+                            .type(TypePaiement.CB)
+                            .details("yes")
+                            .build(),
+                    new Date()
+            );
+
+            NotValidSubscriptionException exception = assertThrows(NotValidSubscriptionException.class,
+                    () -> SubscriptionValidator.validate(subscription));
+
+            assertEquals(SubscriptionValidator.LA_DUREE_RENSEIGNEE_N_EST_PAS_CORRECTE, exception.getMessage());
+        }
+    }
+}
\ No newline at end of file