mybatis#101: Add test which violates equals contract

- Use identity hashmap to check relations for creations

Author: epochcoder

src/main/java/org/apache/ibatis/executor/resultset/DefaultResultSetHandler.java

@@ -27,6 +27,7 @@
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.IdentityHashMap;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
@@ -92,7 +93,7 @@ public class DefaultResultSetHandler implements ResultSetHandler {
   private final ReflectorFactory reflectorFactory;
 
   // pending creations property tracker
-  private final Map<Object, PendingRelation> pendingPccRelations = new HashMap<>();
+  private final Map<Object, PendingRelation> pendingPccRelations = new IdentityHashMap<>();
 
   // nested resultmaps
   private final Map<CacheKey, Object> nestedResultObjects = new HashMap<>();

src/test/java/org/apache/ibatis/submitted/collection_in_constructor/CollectionInConstructorTest.java

@@ -181,4 +181,40 @@ void testImmutableNestedObjects() {
               container.getStores());
     }
   }
+
+  @Test
+  void testImmutableNestedObjectsWithBadEquals() {
+    try (SqlSession sqlSession = sqlSessionFactory.openSession()) {
+      Mapper mapper = sqlSession.getMapper(Mapper.class);
+      List<Container1> containers = mapper.getContainers();
+
+      Container1 expectedContainer1 = new Container1();
+      expectedContainer1.setNum(1);
+      expectedContainer1.setType("storesWithClerks");
+      expectedContainer1.setStores(Arrays.asList(
+          new Store9(1, "Store 1",
+              Arrays.asList(new Clerk(1001, "Clerk 1001"), new Clerk(1003, "Clerk 1003"),
+                  new Clerk(1004, "Clerk 1004"))),
+          new Store9(2, "Store 2", Arrays.asList()), new Store9(3, "Store 3", Arrays.asList())));
+
+      Container1 expectedContainer2 = new Container1();
+      expectedContainer2.setNum(1);
+      expectedContainer2.setType("storesWithManagers");
+      expectedContainer2.setStores(Arrays.asList(
+          new Store9(1, "Store 1", Arrays.asList(new Clerk(1002, "Clerk 1002"), new Clerk(1005, "Clerk 1005")))));
+
+      // cannot use direct equals as we overwrote it with a bad impl on purpose
+      org.assertj.core.api.Assertions.assertThat(containers).isNotNull().hasSize(2);
+      assertContainer1(containers.get(0), expectedContainer1);
+      assertContainer1(containers.get(1), expectedContainer2);
+    }
+  }
+
+  private static void assertContainer1(Container1 container1, Container1 expectedContainer1) {
+    org.assertj.core.api.Assertions.assertThat(container1).isNotNull().satisfies(c -> {
+      org.assertj.core.api.Assertions.assertThat(c.getNum()).isEqualTo(expectedContainer1.getNum());
+      org.assertj.core.api.Assertions.assertThat(c.getType()).isEqualTo(expectedContainer1.getType());
+      org.assertj.core.api.Assertions.assertThat(c.getStores()).isEqualTo(expectedContainer1.getStores());
+    });
+  }
 }

src/test/java/org/apache/ibatis/submitted/collection_in_constructor/Container1.java

@@ -0,0 +1,67 @@
+/*
+ *    Copyright 2009-2024 the original author or authors.
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *       https://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+
+package org.apache.ibatis.submitted.collection_in_constructor;
+
+import java.util.List;
+import java.util.Objects;
+
+public class Container1 {
+
+  private Integer num;
+  private String type;
+  private List<Store9> stores;
+
+  public Integer getNum() {
+    return num;
+  }
+
+  public void setNum(Integer num) {
+    this.num = num;
+  }
+
+  public List<Store9> getStores() {
+    return stores;
+  }
+
+  public void setStores(List<Store9> stores) {
+    this.stores = stores;
+  }
+
+  public String getType() {
+    return type;
+  }
+
+  public void setType(String type) {
+    this.type = type;
+  }
+
+  @Override
+  // simulate a misbehaving object with a bad equals override
+  public boolean equals(Object o) {
+    if (this == o)
+      return true;
+    if (o == null || getClass() != o.getClass())
+      return false;
+    Container1 that = (Container1) o;
+    return Objects.equals(num, that.num);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(num);
+  }
+}

src/test/java/org/apache/ibatis/submitted/collection_in_constructor/Mapper.java

@@ -39,4 +39,6 @@ public interface Mapper {
 
   Container getAContainer();
 
+  List<Container1> getContainers();
+
 }

src/test/java/org/apache/ibatis/submitted/collection_in_constructor/Store9.java

@@ -0,0 +1,66 @@
+/*
+ *    Copyright 2009-2024 the original author or authors.
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *       https://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+package org.apache.ibatis.submitted.collection_in_constructor;
+
+import java.util.List;
+import java.util.Objects;
+
+public class Store9 {
+
+  private final Integer id;
+  private final String name;
+  private final List<Clerk> clerks;
+
+  public Store9(Integer id, String name, List<Clerk> clerks) {
+    this.id = id;
+    this.name = name;
+    this.clerks = clerks;
+  }
+
+  public Integer getId() {
+    return id;
+  }
+
+  public String getName() {
+    return name;
+  }
+
+  public List<Clerk> getClerks() {
+    return clerks;
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(id);
+  }
+
+  @Override
+  public boolean equals(Object obj) {
+    if (this == obj) {
+      return true;
+    }
+    if (!(obj instanceof Store9)) {
+      return false;
+    }
+    Store9 other = (Store9) obj;
+    return Objects.equals(id, other.id);
+  }
+
+  @Override
+  public String toString() {
+    return "Store9 [id=" + id + ", name=" + name + ", clerks=" + clerks + "]";
+  }
+}

src/test/resources/org/apache/ibatis/submitted/collection_in_constructor/Mapper.xml

@@ -236,4 +236,45 @@
     order by s.id, i.id
   ]]></select>
 
-</mapper>
+  <resultMap
+      type="org.apache.ibatis.submitted.collection_in_constructor.Clerk"
+      id="immutableClerkRM">
+    <constructor>
+      <idArg column="id" javaType="int" />
+      <arg column="name" javaType="string" />
+    </constructor>
+  </resultMap>
+
+  <resultMap
+      type="org.apache.ibatis.submitted.collection_in_constructor.Store9"
+      id="store9RM">
+    <constructor>
+      <idArg column="id" javaType="int" />
+      <arg column="name" javaType="string" />
+      <arg javaType="list" resultMap="immutableClerkRM" columnPrefix="clerk_" />
+    </constructor>
+  </resultMap>
+
+  <resultMap
+      type="org.apache.ibatis.submitted.collection_in_constructor.Container1"
+      id="container1RM">
+    <id column="type" property="type"/>
+    <result column="num" property="num" />
+    <collection property="stores" resultMap="store9RM"/>
+  </resultMap>
+
+  <select id="getContainers" resultMap="container1RM"
+      resultOrdered="true"><![CDATA[
+    select
+      1 num
+      , casewhen(c.is_manager, rtrim('storesWithManagers'), rtrim('storesWithClerks')) as type
+      , s.id
+      , s.name
+      , c.id clerk_id
+      , c.name clerk_name
+    from store s
+      left join clerk c on c.store_id = s.id
+    order by type, s.id, c.id
+  ]]></select>
+
+</mapper>