Added blik PaymentMethodType

src/main/java/com/checkout/common/PaymentMethodType.java

@@ -30,6 +30,8 @@ public enum PaymentMethodType {
     BENEFIT,
     @SerializedName("bizum")
     BIZUM,
+    @SerializedName("blik")
+    BLIK,
     @SerializedName("boost")
     BOOST,
     @SerializedName("bpi")
@@ -134,7 +136,7 @@ public enum PaymentMethodType {
     VISA,
     @SerializedName("wechatpay")
     WECHATPAY,
-    
+
     // Payment method categories
     @SerializedName("card_scheme")
     CARD_SCHEME,

src/test/java/com/checkout/GsonSerializerTest.java

@@ -1,5 +1,6 @@
 package com.checkout;
 
+import com.checkout.common.PaymentMethodType;
 import com.checkout.common.PaymentSourceType;
 import com.checkout.financial.FinancialActionsQueryResponse;
 import com.checkout.issuing.cardholders.CardholderCardsResponse;
@@ -202,6 +203,21 @@ void shouldDeserializeProductWithUnknownEnumValue() {
         assertNull(productResponse.getTypeAsEnum());
     }
 
+    @Test
+    void shouldSerializePaymentMethodTypeBlikCorrectly() {
+        // Test that BLIK payment method type serializes to "blik"
+        String json = serializer.toJson(PaymentMethodType.BLIK);
+        assertEquals("\"blik\"", json);
+    }
+
+    @Test
+    void shouldDeserializePaymentMethodTypeBlikCorrectly() {
+        // Test that "blik" string deserializes to PaymentMethodType.BLIK
+        String json = "\"blik\"";
+        PaymentMethodType paymentMethodType = serializer.fromJson(json, PaymentMethodType.class);
+        assertEquals(PaymentMethodType.BLIK, paymentMethodType);
+    }
+
     @Test
     void shouldDeserializeProductWithNullType() {
         String json = "{ \"Type\": null, \"name\": \"Product Name\" }";

src/test/java/com/checkout/handlepaymentsandpayouts/flow/FlowTestIT.java

@@ -174,6 +174,40 @@ private PaymentSessionCreateRequest createPaymentSessionCreateRequest() {
                 .build();
     }
 
+    @Test
+    void shouldCreatePaymentSessionWithBlikInDisabledMethods() {
+        // Test BLIK in disabled payment methods list
+        final PaymentSessionCreateRequest request = PaymentSessionCreateRequest.builder()
+                .amount(1000L)
+                .currency(Currency.EUR)
+                .paymentType(PaymentType.REGULAR)
+                .reference("ORD-NO-BLIK-456")
+                .description("Payment without BLIK")
+                .displayName("No BLIK Test")
+                .processingChannelId(System.getenv("CHECKOUT_PROCESSING_CHANNEL_ID"))
+                .successUrl("https://example.com/payments/success")
+                .failureUrl("https://example.com/payments/failure")
+                .billing(createBillingInformation())
+                .billingDescriptor(createBillingDescriptor())
+                .risk(createRiskRequest())
+                .threeDS(createThreeDSRequest())
+                .capture(true)
+                .locale(LocaleType.EN_GB)
+                .enabledPaymentMethods(Collections.singletonList(PaymentMethodType.CARD))
+                .disabledPaymentMethods(Collections.singletonList(PaymentMethodType.BLIK))
+                .paymentMethodConfiguration(createPaymentMethodConfiguration())
+                .build();
+
+        final CompletableFuture<PaymentSessionResponse> future =
+                checkoutApi.flowClient().requestPaymentSession(request);
+        final PaymentSessionResponse response = future.join();
+
+        assertNotNull(response);
+        assertNotNull(response.getId());
+        assertNotNull(response.getPaymentSessionToken());
+        assertNotNull(response.getPaymentSessionSecret());
+    }
+
     private PaymentSessionSubmitRequest createPaymentSessionSubmitRequest() {
         return PaymentSessionSubmitRequest.builder()
                 .sessionData("encrypted_session_data")

src/test/java/com/checkout/handlepaymentsandpayouts/flow/PaymentSessionSerializationTest.java

@@ -109,6 +109,64 @@ void shouldDeserializePaymentSessionCreateRequestWithCustomerSummary() {
         }, "Should deserialize PaymentSessionCreateRequest with Customer.CustomerSummary without GSON reflection errors");
     }
 
+    @Test
+    void shouldSerializePaymentSessionCreateRequestWithBlikPaymentMethod() {
+        Customer customer = Customer.builder()
+                .email("blik@example.com")
+                .name("BLIK Customer")
+                .id("cust_blik_123")
+                .build();
+
+        PaymentSessionCreateRequest request = PaymentSessionCreateRequest.builder()
+                .amount(2000L)
+                .currency(Currency.EUR)
+                .reference("blik-ref-456")
+                .paymentType(PaymentType.REGULAR)
+                .description("Test BLIK payment")
+                .customer(customer)
+                .locale(LocaleType.EN_GB)
+                .enabledPaymentMethods(Collections.singletonList(PaymentMethodType.BLIK))
+                .capture(true)
+                .build();
+
+        assertDoesNotThrow(() -> {
+            String json = serializer.toJson(request);
+            assertNotNull(json);
+            assertTrue(json.contains("\"blik\""), "Should contain serialized BLIK payment method");
+            assertTrue(json.contains("blik@example.com"), "Should contain customer email");
+            assertTrue(json.contains("BLIK Customer"), "Should contain customer name");
+        }, "Should serialize PaymentSessionCreateRequest with BLIK payment method without errors");
+    }
+
+    @Test
+    void shouldDeserializePaymentSessionCreateRequestWithBlikPaymentMethod() {
+        String json = "{"
+                + "\"amount\":2000,"
+                + "\"currency\":\"EUR\","
+                + "\"reference\":\"blik-ref-456\","
+                + "\"payment_type\":\"Regular\","
+                + "\"description\":\"Test BLIK payment\","
+                + "\"customer\":{"
+                + "  \"email\":\"blik@example.com\","
+                + "  \"name\":\"BLIK Customer\","
+                + "  \"id\":\"cust_blik_123\""
+                + "},"
+                + "\"locale\":\"en-GB\","
+                + "\"enabled_payment_methods\":[\"blik\"],"
+                + "\"capture\":true"
+                + "}";
+
+        assertDoesNotThrow(() -> {
+            PaymentSessionCreateRequest request = serializer.fromJson(json, PaymentSessionCreateRequest.class);
+            assertNotNull(request);
+            assertNotNull(request.getEnabledPaymentMethods());
+            assertEquals(1, request.getEnabledPaymentMethods().size());
+            assertEquals(PaymentMethodType.BLIK, request.getEnabledPaymentMethods().get(0));
+            assertEquals("blik@example.com", request.getCustomer().getEmail());
+            assertEquals("BLIK Customer", request.getCustomer().getName());
+        }, "Should deserialize PaymentSessionCreateRequest with BLIK payment method without errors");
+    }
+
     @Test
     void shouldRoundTripSerializePaymentSessionCreateRequestWithCustomer() {
         Customer.CustomerSummary summary = Customer.CustomerSummary.builder()