Add deep copy instead of shallow copy in mappers

Closes #166

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## [Unreleased]
 - Close public access to TarantoolResult*Impl ([#326](https://github.com/tarantool/cartridge-java/issues/326))
+- Add deep copy instead of shallow copy in default message pack mapper
+
 ## [0.10.1] - 2023-01-13
 
 ### Internal and API changes

src/main/java/io/tarantool/driver/mappers/DefaultMessagePackMapper.java

@@ -22,6 +22,7 @@
 import java.util.Map;
 import java.util.Optional;
 import java.util.function.Function;
+import java.util.stream.Collectors;
 
 import static io.tarantool.driver.mappers.MapperReflectionUtils.getInterfaceParameterClass;
 
@@ -55,8 +56,10 @@ public DefaultMessagePackMapper() {
      */
     public DefaultMessagePackMapper(DefaultMessagePackMapper mapper) {
         this();
-        this.valueConverters.putAll(mapper.valueConverters);
-        this.objectConverters.putAll(mapper.objectConverters);
+        this.valueConverters.putAll(mapper.valueConverters.entrySet().stream()
+            .collect(Collectors.toMap(Map.Entry::getKey, e -> new ArrayList<>(e.getValue()))));
+        this.objectConverters.putAll(mapper.objectConverters.entrySet().stream()
+            .collect(Collectors.toMap(Map.Entry::getKey, e -> new ArrayList<>(e.getValue()))));
     }
 
     @SuppressWarnings("unchecked")

src/test/java/io/tarantool/driver/mappers/DefaultMessagePackMapperTest.java

@@ -16,6 +16,7 @@
 import org.msgpack.value.impl.ImmutableLongValueImpl;
 import org.msgpack.value.impl.ImmutableStringValueImpl;
 
+import java.lang.reflect.Field;
 import java.math.BigDecimal;
 import java.util.Arrays;
 import java.util.HashMap;
@@ -186,6 +187,31 @@ void registerObjectConverter() throws MessagePackObjectMapperException {
         assertEquals(testValue, mapper.toValue(testTuple).asMapValue().map());
     }
 
+    @Test
+    void test_defaultMessagePackMapperCopy_shouldWorkFine() throws MessagePackValueMapperException,
+        NoSuchFieldException, IllegalAccessException {
+        DefaultMessagePackMapper mapper = DefaultMessagePackMapperFactory.getInstance().defaultComplexTypesMapper();
+        MessagePackMapper copiedMapper = mapper.copy();
+        MessagePackMapper copiedOfMapper = DefaultMessagePackMapperFactory.getInstance().copyOf(mapper);
+
+        Field privateField
+            = DefaultMessagePackMapper.class.getDeclaredField("valueConverters");
+        // Set the accessibility as true
+        privateField.setAccessible(true);
+
+        assertEquals(1, ((List) ((Map) privateField.get(mapper)).get(ValueType.MAP)).size());
+        assertEquals(1, ((List) ((Map) privateField.get(copiedMapper)).get(ValueType.MAP)).size());
+
+        mapper.registerValueConverter(ValueType.MAP, CustomTuple.class,
+            (ValueConverter<MapValue, CustomTuple>) v -> null);
+
+        assertEquals(2, ((List) ((Map) privateField.get(mapper)).get(ValueType.MAP)).size());
+        assertEquals(1, ((List) ((Map) privateField.get(copiedMapper)).get(ValueType.MAP)).size());
+        assertEquals(1, ((List) ((Map) privateField.get(copiedOfMapper)).get(ValueType.MAP)).size());
+
+        mapper.copy();
+    }
+
     //TODO: add this test when will it be resolved https://github.com/tarantool/cartridge-java/issues/118
 //    @Test
 //    void should_getObject_returnShort_ifParameterObjectClassIsShort() {