Support initialisation of ToMany collections using List.of() etc

- Add Support for List.of() & Collections.emptyList()
- Add Support for Set.of() & Collections.emptySet()
- Add Support for Map.of() & Collections.emptyMap()

Author: rbygrave

ebean-agent/src/main/java/io/ebean/enhance/entity/ConstructorDeferredCode.java

@@ -45,7 +45,7 @@ enum State {
     INVOKE_SPECIAL,
     KT_CHECKCAST,   // optional kotlin state
     KT_LABEL,        // optional kotlin state
-    KT_EMPTYLIST
+    EMPTY
   }
 
   private static final ALoad ALOAD_INSTRUCTION = new ALoad();
@@ -130,11 +130,25 @@ boolean deferVisitMethodInsn(int opcode, String owner, String name, String desc,
       stateInitialiseType = owner;
       return true;
     }
-    if (opcode == INVOKESTATIC && stateAload() && kotlinEmptyList(owner, name, desc)) {
-      codes.add(new NoArgInit(opcode, owner, name, desc, itf));
-      state = State.KT_EMPTYLIST;
-      stateInitialiseType = "java/util/ArrayList";
-      return true;
+    if (opcode == INVOKESTATIC && stateAload()) {
+      if (emptyList(owner, name, desc) || kotlinEmptyList(owner, name, desc)) {
+        codes.add(new NoArgInit(opcode, owner, name, desc, itf));
+        state = State.EMPTY;
+        stateInitialiseType = "java/util/ArrayList";
+        return true;
+      }
+      if (emptySet(owner, name, desc)) {
+        codes.add(new NoArgInit(opcode, owner, name, desc, itf));
+        state = State.EMPTY;
+        stateInitialiseType = "java/util/LinkedHashSet";
+        return true;
+      }
+      if (emptyMap(owner, name, desc)) {
+        codes.add(new NoArgInit(opcode, owner, name, desc, itf));
+        state = State.EMPTY;
+        stateInitialiseType = "java/util/LinkedHashMap";
+        return true;
+      }
     }
     flush();
     return false;
@@ -144,6 +158,24 @@ private boolean isNoArgInit(String name, String desc) {
     return name.equals(INIT) && desc.equals(NOARG_VOID);
   }
 
+  private boolean emptyList(String owner, String name, String desc) {
+    return desc.equals("()Ljava/util/List;")
+      && ((owner.equals("java/util/List") && name.equals("of"))
+      || (owner.equals("java/util/Collections") && name.equals("emptyList")));
+  }
+
+  private boolean emptySet(String owner, String name, String desc) {
+    return desc.equals("()Ljava/util/Set;")
+      && ((owner.equals("java/util/Set") && name.equals("of"))
+      || (owner.equals("java/util/Collections") && name.equals("emptySet")));
+  }
+
+  private boolean emptyMap(String owner, String name, String desc) {
+    return desc.equals("()Ljava/util/Map;")
+      && ((owner.equals("java/util/Map") && name.equals("of"))
+      || (owner.equals("java/util/Collections") && name.equals("emptyMap")));
+  }
+
   private boolean kotlinEmptyList(String owner, String name, String desc) {
     return owner.equals("kotlin/collections/CollectionsKt")
       && name.equals("emptyList")
@@ -232,17 +264,17 @@ private boolean stateInvokeSpecial() {
   }
 
   private boolean stateConsumeDeferred() {
-    return state == State.INVOKE_SPECIAL || state == State.KT_CHECKCAST || state == State.KT_EMPTYLIST;
+    return state == State.INVOKE_SPECIAL || state == State.KT_CHECKCAST || state == State.EMPTY;
   }
 
   /**
    * Return true if the type being initialised is valid for auto initialisation of ToMany or DbArray.
    */
   private boolean isConsumeManyType() {
-    return ("java/util/ArrayList".equals(stateInitialiseType)
+    return "java/util/ArrayList".equals(stateInitialiseType)
       || "java/util/LinkedHashSet".equals(stateInitialiseType)
-      || "java/util/HashSet".equals(stateInitialiseType));
-      //|| "java/util/LinkedHashMap".equals(stateInitialiseType)
+      || "java/util/HashSet".equals(stateInitialiseType)
+      || "java/util/LinkedHashMap".equals(stateInitialiseType);
       //|| "java/util/HashMap".equals(stateInitialiseType));
   }
 

test/pom.xml

@@ -14,6 +14,7 @@
 
   <properties>
     <ebean.version>13.4.0</ebean.version>
+    <java.version>11</java.version>
   </properties>
 
   <dependencies>

test/src/test/java/test/enhancement/WithInitialisedCollections2Test.java

@@ -0,0 +1,40 @@
+package test.enhancement;
+
+import io.ebean.common.BeanList;
+import io.ebean.common.BeanMap;
+import io.ebean.common.BeanSet;
+import org.junit.jupiter.api.Test;
+import test.model.Contact;
+import test.model.WithInitialisedCollections2;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class WithInitialisedCollections2Test extends BaseTest {
+
+  @Test
+  void oneToMany_initialisationCode_expect_removed() {
+    WithInitialisedCollections2 bean = new WithInitialisedCollections2();
+
+    assertThat(bean.listOf()).isInstanceOf(BeanList.class);
+    assertThat(bean.listCollEmpty()).isInstanceOf(BeanList.class);
+    assertThat(bean.setOf()).isInstanceOf(BeanSet.class);
+    assertThat(bean.setCollEmpty()).isInstanceOf(BeanSet.class);
+    assertThat(bean.mapOf()).isInstanceOf(BeanMap.class);
+    assertThat(bean.mapCollEmpty()).isInstanceOf(BeanMap.class);
+
+
+    assertThat(bean.transientList()).isNotInstanceOf(BeanList.class);
+    assertThat(bean.transientList2()).isNotInstanceOf(BeanList.class);
+    assertThat(bean.transientSet()).isNotInstanceOf(BeanSet.class);
+    assertThat(bean.transientSet2()).isNotInstanceOf(BeanSet.class);
+    assertThat(bean.transientMap()).isNotInstanceOf(BeanMap.class);
+    assertThat(bean.transientMap2()).isNotInstanceOf(BeanMap.class);
+
+
+    // these methods work because the underlying collection is a BeanCollection
+    bean.listOf().add(new Contact("junk"));
+    bean.setOf().add(new Contact("junk"));
+    bean.listCollEmpty().add(new Contact("junk"));
+    bean.setCollEmpty().add(new Contact("junk"));
+  }
+}

test/src/test/java/test/enhancement/WithInitialisedCollectionsTest.java

@@ -7,18 +7,18 @@
 import java.util.ArrayList;
 import java.util.List;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.*;
 
 public class WithInitialisedCollectionsTest extends BaseTest {
 
-
   @Test
   public void test() {
 
     WithInitialisedCollections bean = new WithInitialisedCollections();
     assertNotNull(bean);
 
-    assertTrue(bean instanceof EntityBean);
+    assertInstanceOf(EntityBean.class, bean);
 
     EntityBean eb = (EntityBean)bean;
     String[] props = eb._ebean_getPropertyNames();
@@ -43,7 +43,6 @@ public void test() {
 
     assertNotNull(bean.getMyset());
     assertNotNull(bean.getMyLinkedSet());
-
   }
 
 
@@ -53,7 +52,7 @@ public void test_withTransient() {
     WithInitialisedCollectionAndTransient bean = new WithInitialisedCollectionAndTransient();
     assertNotNull(bean);
 
-    assertTrue(bean instanceof EntityBean);
+    assertInstanceOf(EntityBean.class, bean);
 
     assertNotNull(bean.getBuffer());
 
@@ -69,7 +68,7 @@ public void test_withAtTransient() {
     WithInitialisedCollectionAndAtTransient bean = new WithInitialisedCollectionAndAtTransient();
     assertNotNull(bean);
 
-    assertTrue(bean instanceof EntityBean);
+    assertInstanceOf(EntityBean.class, bean);
 
     assertNotNull(bean.getBuffer());
 
@@ -87,6 +86,6 @@ public void test_withConstructor() {
 
     WithInitialisedCollectionsAndConstructor bean = new WithInitialisedCollectionsAndConstructor(contacts);
 
-    assertTrue(bean.getContacts().size() == 1);
+    assertThat(bean.getContacts()).hasSize(1);
   }
 }

test/src/test/java/test/model/WithInitialisedCollections2.java

@@ -0,0 +1,98 @@
+package test.model;
+
+
+import javax.persistence.CascadeType;
+import javax.persistence.Entity;
+import javax.persistence.OneToMany;
+import javax.persistence.Transient;
+import java.util.*;
+
+@Entity
+public class WithInitialisedCollections2 extends BaseEntity {
+
+  String name;
+
+  @OneToMany(cascade = CascadeType.PERSIST)
+  final List<Contact> listOf = List.of();
+  @OneToMany(cascade = CascadeType.PERSIST)
+  final Set<Contact> setOf = Set.of();
+  @OneToMany(cascade = CascadeType.PERSIST)
+  Map<Long,Contact> mapOf = Map.of();
+
+  @OneToMany(cascade = CascadeType.PERSIST)
+  final List<Contact> listCollEmpty = Collections.emptyList();
+  @OneToMany(cascade = CascadeType.PERSIST)
+  final Set<Contact> setCollEmpty = Collections.emptySet();
+  @OneToMany(cascade = CascadeType.PERSIST)
+  Map<Long,Contact> mapCollEmpty = Collections.emptyMap();
+
+  @Transient
+  List<String> transientList = List.of();
+  @Transient
+  Set<String> transientSet = Set.of();
+  @Transient
+  Map<String,Contact> transientMap = Map.of();
+  @Transient
+  List<String> transientList2 = Collections.emptyList();
+  @Transient
+  Set<String> transientSet2 = Collections.emptySet();
+  @Transient
+  Map<String,Contact> transientMap2 = Collections.emptyMap();
+
+  public String name() {
+    return name;
+  }
+
+  public WithInitialisedCollections2 setName(String name) {
+    this.name = name;
+    return this;
+  }
+
+  public List<Contact> listOf() {
+    return listOf;
+  }
+
+  public Set<Contact> setOf() {
+    return setOf;
+  }
+
+  public Map<Long, Contact> mapOf() {
+    return mapOf;
+  }
+
+  public List<Contact> listCollEmpty() {
+    return listCollEmpty;
+  }
+
+  public Set<Contact> setCollEmpty() {
+    return setCollEmpty;
+  }
+
+  public Map<Long, Contact> mapCollEmpty() {
+    return mapCollEmpty;
+  }
+
+  public List<String> transientList() {
+    return transientList;
+  }
+
+  public Set<String> transientSet() {
+    return transientSet;
+  }
+
+  public List<String> transientList2() {
+    return transientList2;
+  }
+
+  public Set<String> transientSet2() {
+    return transientSet2;
+  }
+
+  public Map<String, Contact> transientMap() {
+    return transientMap;
+  }
+
+  public Map<String, Contact> transientMap2() {
+    return transientMap2;
+  }
+}