#383 Add EnumSetProperty (#441)

* 383 -> add EnumSetProperty.java

* 383 -> code climate edits

* 383 -> edit by review comments

* 383 -> edit by review comments

* 383 -> Fix constructor call

Author: lengeligor

src/main/java/ch/jalu/configme/properties/EnumSetProperty.java

@@ -0,0 +1,31 @@
+package ch.jalu.configme.properties;
+
+import ch.jalu.configme.properties.types.EnumSetPropertyType;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Arrays;
+import java.util.EnumSet;
+import java.util.Set;
+
+/**
+ * EnumSet property.
+ *
+ * @param <E> the enum type
+ */
+public class EnumSetProperty<E extends Enum<E>> extends SetProperty<E> {
+
+    public EnumSetProperty(@NotNull String path, @NotNull Class<E> enumClass, @NotNull EnumSet<E> defaultValue) {
+        super(new EnumSetPropertyType(enumClass), path, defaultValue);
+    }
+
+    public EnumSetProperty(@NotNull String path, @NotNull Class<E> enumClass, @NotNull E @NotNull... defaultValue) {
+        super(new EnumSetPropertyType(enumClass), path, newEnumSet(enumClass, defaultValue));
+    }
+
+    private static <E extends Enum<E>> @NotNull Set<E> newEnumSet(@NotNull Class<E> enumClass,
+                                                                  E @NotNull [] defaultValue) {
+        EnumSet<E> enumSet = EnumSet.noneOf(enumClass);
+        enumSet.addAll(Arrays.asList(defaultValue));
+        return enumSet;
+    }
+}

src/test/java/ch/jalu/configme/properties/EnumSetPropertyTest.java

@@ -0,0 +1,66 @@
+package ch.jalu.configme.properties;
+
+import ch.jalu.configme.properties.convertresult.PropertyValue;
+import ch.jalu.configme.resource.PropertyReader;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import java.util.EnumSet;
+import java.util.Set;
+
+import static ch.jalu.configme.TestUtils.isErrorValueOf;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.mockito.BDDMockito.given;
+
+/**
+ * Test for {@link EnumSetProperty}.
+ */
+@ExtendWith(MockitoExtension.class)
+class EnumSetPropertyTest {
+
+    @Mock
+    private PropertyReader reader;
+
+    @Test
+    void shouldReturnEnumSetDefaultValue() {
+        // given
+        EnumSet<TestEnum> set = EnumSet.of(TestEnum.ENTRY_A);
+        EnumSetProperty<TestEnum> property =
+            new EnumSetProperty<>("enum.path", TestEnum.class, set);
+        given(reader.getObject(property.getPath()))
+            .willReturn(null);
+
+        // when
+        PropertyValue<Set<TestEnum>> result = property.determineValue(reader);
+
+        // then
+        assertThat(result, isErrorValueOf(EnumSet.of(TestEnum.ENTRY_A)));
+    }
+
+    @Test
+    void shouldReturnEnumSetDefaultValueFromArray() {
+        // given
+        EnumSetProperty<TestEnum> property =
+            new EnumSetProperty<>("enum.path", TestEnum.class, new TestEnum[]{TestEnum.ENTRY_B, TestEnum.ENTRY_C});
+        given(reader.getObject(property.getPath()))
+            .willReturn(null);
+
+        // when
+        PropertyValue<Set<TestEnum>> result = property.determineValue(reader);
+
+        // then
+        assertThat(result, isErrorValueOf(EnumSet.of(TestEnum.ENTRY_B, TestEnum.ENTRY_C)));
+    }
+
+    private enum TestEnum {
+
+        ENTRY_A,
+
+        ENTRY_B,
+
+        ENTRY_C
+
+    }
+}