doc(crud-cluster): add test for method

Add tests for `ConfigurationUtils#addUsers(...)` method

Needed for #30

Author: nickkkccc

testcontainers/src/test/java/org/testcontainers/containers/tarantool/config/ConfigurationUtilsTest.java

@@ -0,0 +1,143 @@
+/*
+ * Copyright (c) 2025 VK DIGITAL TECHNOLOGIES LIMITED LIABILITY COMPANY
+ * All Rights Reserved.
+ */
+
+package org.testcontainers.containers.tarantool.config;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.stream.Stream;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
+import io.tarantool.autogen.Tarantool3Configuration;
+import io.tarantool.autogen.credentials.Credentials;
+import io.tarantool.autogen.credentials.users.Users;
+import io.tarantool.autogen.credentials.users.usersProperty.UsersProperty;
+
+class ConfigurationUtilsTest {
+
+  public static Stream<Arguments> dataForTestAddUsersMethod() {
+
+    /*
+    /**********************************************************
+    /* Additional user properties
+    /**********************************************************
+    */
+    final String userPwd = "user-pwd";
+    final String userName = "user-name";
+    final UsersProperty usersProperty = UsersProperty.builder().withPassword(userPwd).build();
+    Map<String, UsersProperty> users =
+        new HashMap<>() {
+          {
+            put(userName, usersProperty);
+          }
+        };
+
+    /*
+    /**********************************************************
+    /* Without credentials section
+    /**********************************************************
+    */
+    final Tarantool3Configuration oldConfigWithoutCredSection = new Tarantool3Configuration();
+    final Tarantool3Configuration expectedConfigWithoutCredSection =
+        Tarantool3Configuration.builder()
+            .withCredentials(
+                Credentials.builder()
+                    .withUsers(
+                        Users.builder().withAdditionalProperty(userName, usersProperty).build())
+                    .build())
+            .build();
+
+    /*
+    /**********************************************************
+    /* With credentials section without users
+    /**********************************************************
+    */
+    final Tarantool3Configuration oldConfigWithCredWithoutUsersSection =
+        Tarantool3Configuration.builder().withCredentials(new Credentials()).build();
+    final Tarantool3Configuration expectedConfigWithCredWithoutUsersSection =
+        Tarantool3Configuration.builder()
+            .withCredentials(
+                Credentials.builder()
+                    .withUsers(
+                        Users.builder().withAdditionalProperty(userName, usersProperty).build())
+                    .build())
+            .build();
+
+    /*
+    /**********************************************************
+    /* With credentials and users sections
+    /**********************************************************
+    */
+    final Tarantool3Configuration oldConfigWithCredWithUsersSection =
+        Tarantool3Configuration.builder()
+            .withCredentials(Credentials.builder().withUsers(new Users()).build())
+            .build();
+    final Tarantool3Configuration expectedConfigWithCredWithUsersSection =
+        Tarantool3Configuration.builder()
+            .withCredentials(
+                Credentials.builder()
+                    .withUsers(
+                        Users.builder().withAdditionalProperty(userName, usersProperty).build())
+                    .build())
+            .build();
+
+    /*
+    /**********************************************************
+    /* Override users with same name
+    /**********************************************************
+    */
+    final Tarantool3Configuration oldConfigWithUser =
+        Tarantool3Configuration.builder()
+            .withCredentials(
+                Credentials.builder()
+                    .withUsers(
+                        Users.builder()
+                            .withAdditionalProperty(userName, new UsersProperty())
+                            .build())
+                    .build())
+            .build();
+    final Tarantool3Configuration expectedConfigWithUser =
+        Tarantool3Configuration.builder()
+            .withCredentials(
+                Credentials.builder()
+                    .withUsers(
+                        Users.builder().withAdditionalProperty(userName, usersProperty).build())
+                    .build())
+            .build();
+    Assertions.assertNotEquals(oldConfigWithUser, expectedConfigWithUser);
+
+    return Stream.of(
+        // old config null
+        Arguments.of(null, Collections.emptyMap(), null),
+
+        // without credentials
+        Arguments.of(oldConfigWithoutCredSection, users, expectedConfigWithoutCredSection),
+
+        // with credentials and without users
+        Arguments.of(
+            oldConfigWithCredWithoutUsersSection, users, expectedConfigWithCredWithoutUsersSection),
+
+        // with credentials and with users
+        Arguments.of(
+            oldConfigWithCredWithUsersSection, users, expectedConfigWithCredWithUsersSection),
+
+        // override user with same name
+        Arguments.of(oldConfigWithUser, users, expectedConfigWithUser));
+  }
+
+  @ParameterizedTest
+  @MethodSource("dataForTestAddUsersMethod")
+  void testAddUsersMethod(
+      Tarantool3Configuration oldConfig,
+      Map<String, UsersProperty> additionalUsers,
+      Tarantool3Configuration expected) {
+    Assertions.assertEquals(expected, ConfigurationUtils.addUsers(oldConfig, additionalUsers));
+  }
+}