Add tests for mapping entities with interface attributes

src/test/java/com/remondis/remap/interfaceMapping/EntityA.java

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+package com.remondis.remap.interfaceMapping;
+
+public class EntityA implements HasId {
+  private String name;
+
+  public EntityA() {
+  }
+
+  public String getName() {
+    return name;
+  }
+
+  public void setName(String name) {
+    this.name = name;
+  }
+}

src/test/java/com/remondis/remap/interfaceMapping/EntityADTO.java

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+package com.remondis.remap.interfaceMapping;
+
+public class EntityADTO {
+  private String name;
+
+  public void setName(String name) {
+    this.name = name;
+  }
+
+  public String getName() {
+    return name;
+  }
+}

src/test/java/com/remondis/remap/interfaceMapping/EntityMappingTest.java

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+package com.remondis.remap.interfaceMapping;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import com.remondis.remap.AssertMapping;
+import com.remondis.remap.Mapper;
+import com.remondis.remap.Mapping;
+
+public class EntityMappingTest {
+
+  private Mapper<EntityA, EntityADTO> entityMapperWithoutId;
+  private Mapper<EntityA, EntityWithIdDTO> entityMapperWithId;
+
+  @Before
+  public void setup() {
+    this.entityMapperWithoutId = Mapping.from(EntityA.class)
+        .to(EntityADTO.class)
+        .omitInSource(HasId::getId)
+        .mapper();
+
+    this.entityMapperWithId = Mapping.from(EntityA.class)
+        .to(EntityWithIdDTO.class)
+        .mapper();
+  }
+
+  @Test
+  public void shouldMapEntityWithoutInterfaceAttribute() {
+    EntityA entity = new EntityA();
+    entity.setName("Test Entity");
+    EntityADTO dto = entityMapperWithoutId.map(entity);
+
+    assertEquals("Test Entity", dto.getName());
+  }
+
+  @Test
+  public void shouldMapEntityWithInterfaceAttribute() {
+    EntityA entity = new EntityA();
+    entity.setName("Test Entity");
+    EntityWithIdDTO dto = entityMapperWithId.map(entity);
+
+    assertEquals("Test Entity", dto.getName());
+    assertEquals(Long.valueOf(1), dto.getId());
+  }
+
+  @Test
+  public void shouldComplainAboutImplicitMapping() {
+    Mapper<EntityA, EntityADTO> implicitMapper = Mapping.from(EntityA.class)
+        .to(EntityADTO.class)
+        .omitInSource(EntityA::getId)
+        .mapper();
+
+    assertThatThrownBy(() -> AssertMapping.of(implicitMapper)
+        .expectNoImplicitMappings()
+        .ensure()).isInstanceOf(AssertionError.class)
+            .hasMessageContaining("The mapper was expected to create no implicit mappings");
+  }
+}

src/test/java/com/remondis/remap/interfaceMapping/EntityWithIdDTO.java

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+package com.remondis.remap.interfaceMapping;
+
+public class EntityWithIdDTO {
+  private Long id;
+  private String name;
+
+  public void setId(Long id) {
+    this.id = id;
+  }
+
+  public void setName(String name) {
+    this.name = name;
+  }
+
+  public Long getId() {
+    return id;
+  }
+
+  public String getName() {
+    return name;
+  }
+}

src/test/java/com/remondis/remap/interfaceMapping/HasId.java

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+package com.remondis.remap.interfaceMapping;
+
+public interface HasId {
+  default Long getId() {
+    return 1L;
+  }
+}