Handle potentially null payment method when canceling subscription

service/src/test/java/org/whispersystems/textsecuregcm/subscriptions/BraintreeManagerTest.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2023 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.whispersystems.textsecuregcm.subscriptions;
+
+import static org.junit.jupiter.api.Assertions.assertTimeoutPreemptively;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import com.braintreegateway.BraintreeGateway;
+import com.braintreegateway.Customer;
+import com.braintreegateway.CustomerGateway;
+import java.time.Duration;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.Executors;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+class BraintreeManagerTest {
+
+  private BraintreeGateway braintreeGateway;
+  private BraintreeManager braintreeManager;
+
+  @BeforeEach
+  void setup() {
+    braintreeGateway = mock(BraintreeGateway.class);
+    braintreeManager = new BraintreeManager(braintreeGateway,
+        Set.of("usd"),
+        Map.of("usd", "usdMerchant"),
+        mock(BraintreeGraphqlClient.class),
+        Executors.newSingleThreadExecutor());
+  }
+
+  @Test
+  void cancelAllActiveSubscriptions_nullDefaultPaymentMethod() {
+
+    final Customer customer = mock(Customer.class);
+    when(customer.getDefaultPaymentMethod()).thenReturn(null);
+
+    final CustomerGateway customerGateway = mock(CustomerGateway.class);
+    when(customerGateway.find(anyString())).thenReturn(customer);
+
+    when(braintreeGateway.customer()).thenReturn(customerGateway);
+
+    assertTimeoutPreemptively(Duration.ofSeconds(5), () ->
+        braintreeManager.cancelAllActiveSubscriptions("customerId")).join();
+  }
+}