refactor: rename and delete some patterns (#2970)

data-access-object/src/test/java/com/iluwatar/dao/InMemoryCustomerDaoTest.java

@@ -0,0 +1,161 @@
+/*
+ * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt).
+ *
+ * The MIT License
+ * Copyright © 2014-2022 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.iluwatar.dao;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assumptions.assumeTrue;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Tests {@link InMemoryCustomerDao}.
+ */
+class InMemoryCustomerDaoTest {
+
+  private InMemoryCustomerDao dao;
+  private static final Customer CUSTOMER = new Customer(1, "Freddy", "Krueger");
+
+  @BeforeEach
+  void setUp() {
+    dao = new InMemoryCustomerDao();
+    assertTrue(dao.add(CUSTOMER));
+  }
+
+  /**
+   * Represents the scenario when the DAO operations are being performed on a non-existent
+   * customer.
+   */
+  @Nested
+  class NonExistingCustomer {
+
+    @Test
+    void addingShouldResultInSuccess() throws Exception {
+      try (var allCustomers = dao.getAll()) {
+        assumeTrue(allCustomers.count() == 1);
+      }
+
+      final var nonExistingCustomer = new Customer(2, "Robert", "Englund");
+      var result = dao.add(nonExistingCustomer);
+      assertTrue(result);
+
+      assertCustomerCountIs(2);
+      assertEquals(nonExistingCustomer, dao.getById(nonExistingCustomer.getId()).get());
+    }
+
+    @Test
+    void deletionShouldBeFailureAndNotAffectExistingCustomers() throws Exception {
+      final var nonExistingCustomer = new Customer(2, "Robert", "Englund");
+      var result = dao.delete(nonExistingCustomer);
+
+      assertFalse(result);
+      assertCustomerCountIs(1);
+    }
+
+    @Test
+    void updateShouldBeFailureAndNotAffectExistingCustomers() {
+      final var nonExistingId = getNonExistingCustomerId();
+      final var newFirstname = "Douglas";
+      final var newLastname = "MacArthur";
+      final var customer = new Customer(nonExistingId, newFirstname, newLastname);
+      var result = dao.update(customer);
+
+      assertFalse(result);
+      assertFalse(dao.getById(nonExistingId).isPresent());
+    }
+
+    @Test
+    void retrieveShouldReturnNoCustomer() throws Exception {
+      assertFalse(dao.getById(getNonExistingCustomerId()).isPresent());
+    }
+  }
+
+  /**
+   * Represents the scenario when the DAO operations are being performed on an already existing
+   * customer.
+   */
+  @Nested
+  class ExistingCustomer {
+
+    @Test
+    void addingShouldResultInFailureAndNotAffectExistingCustomers() throws Exception {
+      var result = dao.add(CUSTOMER);
+
+      assertFalse(result);
+      assertCustomerCountIs(1);
+      assertEquals(CUSTOMER, dao.getById(CUSTOMER.getId()).get());
+    }
+
+    @Test
+    void deletionShouldBeSuccessAndCustomerShouldBeNonAccessible() throws Exception {
+      var result = dao.delete(CUSTOMER);
+
+      assertTrue(result);
+      assertCustomerCountIs(0);
+      assertFalse(dao.getById(CUSTOMER.getId()).isPresent());
+    }
+
+    @Test
+    void updationShouldBeSuccessAndAccessingTheSameCustomerShouldReturnUpdatedInformation() throws
+        Exception {
+      final var newFirstname = "Bernard";
+      final var newLastname = "Montgomery";
+      final var customer = new Customer(CUSTOMER.getId(), newFirstname, newLastname);
+      var result = dao.update(customer);
+
+      assertTrue(result);
+
+      final var cust = dao.getById(CUSTOMER.getId()).get();
+      assertEquals(newFirstname, cust.getFirstName());
+      assertEquals(newLastname, cust.getLastName());
+    }
+
+    @Test
+    void retriveShouldReturnTheCustomer() {
+      var optionalCustomer = dao.getById(CUSTOMER.getId());
+
+      assertTrue(optionalCustomer.isPresent());
+      assertEquals(CUSTOMER, optionalCustomer.get());
+    }
+  }
+
+  /**
+   * An arbitrary number which does not correspond to an active Customer id.
+   *
+   * @return an int of a customer id which doesn't exist
+   */
+  private int getNonExistingCustomerId() {
+    return 999;
+  }
+
+  private void assertCustomerCountIs(int count) throws Exception {
+    try (var allCustomers = dao.getAll()) {
+      assertEquals(count, allCustomers.count());
+    }
+  }
+}