[fixes #2104] superbuilder + non-list-singulars wouldn’t work due to hardcoded call to emptyList.

16 files changed, 167 insertions, 57 deletions

diff --git a/doc/changelog.markdown b/doc/changelog.markdown
index 89ce9929..acaa74de 100644
--- a/doc/changelog.markdown
+++ b/doc/changelog.markdown
@@ -11,6 +11,7 @@ Lombok Changelog
 * BUGFIX: Fix for java6 regression if a field has javadoc. [Issue #2066](https://github.com/rzwitserloot/lombok/issues/2066)
 * BUGFIX: Delombok now delomboks java10's own `var` as `var` and not as the actual underlying type. [Issue #2049](https://github.com/rzwitserloot/lombok/issues/2049)
 * BUGFIX: If you use `@Builder` and manually write the `build()` method in your builder class, javac would error out instead of deferring to your implementation. [Issue #2050](https://github.com/rzwitserloot/lombok/issues/2050) [Issue #2061](https://github.com/rzwitserloot/lombok/issues/2061)
+* BUGFIX: `@SuperBuilder` together with `@Singular` on non-lists would produce an erroneous `emptyList` call. [Issue #2104](https://github.com/rzwitserloot/lombok/issues/2104).
 * IMPROBABLE BREAKING CHANGE: For fields and parameters marked non-null, if the method body starts with an assert statement to ensure the value isn't null, no code to throw an exception will be generated.
 
 ### v1.18.6 (February 12th, 2019)
diff --git a/src/core/lombok/eclipse/handlers/EclipseSingularsRecipes.java b/src/core/lombok/eclipse/handlers/EclipseSingularsRecipes.java
index 67a9f97d..a8a780d6 100755
--- a/src/core/lombok/eclipse/handlers/EclipseSingularsRecipes.java
+++ b/src/core/lombok/eclipse/handlers/EclipseSingularsRecipes.java
@@ -395,5 +395,8 @@ public class EclipseSingularsRecipes {
 				return new SingleNameReference(builderVariable.toCharArray(), 0);
 			}
 		}
+		
+		protected abstract char[][] getEmptyMakerReceiver(String targetFqn);
+		protected abstract char[] getEmptyMakerSelector(String targetFqn);
 	}
 }
diff --git a/src/core/lombok/eclipse/handlers/HandleSuperBuilder.java b/src/core/lombok/eclipse/handlers/HandleSuperBuilder.java
index 554ab2f0..3a387688 100755
--- a/src/core/lombok/eclipse/handlers/HandleSuperBuilder.java
+++ b/src/core/lombok/eclipse/handlers/HandleSuperBuilder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013-2018 The Project Lombok Authors.
+ * Copyright (C) 2013-2019 The Project Lombok Authors.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -108,7 +108,6 @@ public class HandleSuperBuilder extends EclipseAnnotationHandler<SuperBuilder> {
 	private static final char[] TO_BUILDER_METHOD_NAME = TO_BUILDER_METHOD_NAME_STRING.toCharArray();
 	private static final char[] FILL_VALUES_METHOD_NAME = "$fillValuesFrom".toCharArray();
 	private static final char[] FILL_VALUES_STATIC_METHOD_NAME = "$fillValuesFromInstanceIntoBuilder".toCharArray();
-	private static final char[] EMPTY_LIST = "emptyList".toCharArray();
 	private static final char[] INSTANCE_VARIABLE_NAME = "instance".toCharArray();
 	private static final String BUILDER_VARIABLE_NAME_STRING = "b";
 	private static final char[] BUILDER_VARIABLE_NAME = BUILDER_VARIABLE_NAME_STRING.toCharArray();
@@ -741,10 +740,10 @@ public class HandleSuperBuilder extends EclipseAnnotationHandler<SuperBuilder> {
 			ms.arguments = tgt;
 		} else {
 			Expression ifNull = new EqualExpression(tgt[0], new NullLiteral(0, 0), OperatorIds.EQUAL_EQUAL);
-			MessageSend emptyList = new MessageSend();
-			emptyList.receiver = generateQualifiedNameRef(source, TypeConstants.JAVA, TypeConstants.UTIL, "Collections".toCharArray());
-			emptyList.selector = EMPTY_LIST;
-			ms.arguments = new Expression[] {new ConditionalExpression(ifNull, emptyList, tgt[1])};
+			MessageSend emptyCollection = new MessageSend();
+			emptyCollection.receiver = generateQualifiedNameRef(source, bfd.singularData.getSingularizer().getEmptyMakerReceiver(bfd.singularData.getTargetFqn()));
+			emptyCollection.selector = bfd.singularData.getSingularizer().getEmptyMakerSelector(bfd.singularData.getTargetFqn());
+			ms.arguments = new Expression[] {new ConditionalExpression(ifNull, emptyCollection, tgt[1])};
 		}
 		ms.receiver = new SingleNameReference(BUILDER_VARIABLE_NAME, 0);
 		ms.selector = setterName;
diff --git a/src/core/lombok/eclipse/handlers/singulars/EclipseGuavaSingularizer.java b/src/core/lombok/eclipse/handlers/singulars/EclipseGuavaSingularizer.java
index 54c059b8..642ba9b7 100755
--- a/src/core/lombok/eclipse/handlers/singulars/EclipseGuavaSingularizer.java
+++ b/src/core/lombok/eclipse/handlers/singulars/EclipseGuavaSingularizer.java
@@ -63,6 +63,9 @@ import org.eclipse.jdt.internal.compiler.ast.TypeReference;
 import org.eclipse.jdt.internal.compiler.classfmt.ClassFileConstants;
 
 abstract class EclipseGuavaSingularizer extends EclipseSingularizer {
+	protected static final char[] OF = {'o', 'f'};
+	protected static final char[][] CGCC = {{'c', 'o', 'm'}, {'g', 'o', 'o', 'g', 'l', 'e'}, {'c', 'o', 'm', 'm', 'o', 'n'}, {'c', 'o', 'l', 'l', 'e', 'c', 't'}};
+	
 	protected String getSimpleTargetTypeName(SingularData data) {
 		return GuavaTypeMap.getGuavaTypeName(data.getTargetFqn());
 	}
@@ -75,15 +78,23 @@ abstract class EclipseGuavaSingularizer extends EclipseSingularizer {
 	
 	protected char[][] makeGuavaTypeName(String simpleName, boolean addBuilder) {
 		char[][] tokenizedName = new char[addBuilder ? 6 : 5][];
-		tokenizedName[0] = new char[] {'c', 'o', 'm'};
-		tokenizedName[1] = new char[] {'g', 'o', 'o', 'g', 'l', 'e'};
-		tokenizedName[2] = new char[] {'c', 'o', 'm', 'm', 'o', 'n'};
-		tokenizedName[3] = new char[] {'c', 'o', 'l', 'l', 'e', 'c', 't'};
+		tokenizedName[0] = CGCC[0];
+		tokenizedName[1] = CGCC[1];
+		tokenizedName[2] = CGCC[2];
+		tokenizedName[3] = CGCC[3];
 		tokenizedName[4] = simpleName.toCharArray();
 		if (addBuilder) tokenizedName[5] = new char[] { 'B', 'u', 'i', 'l', 'd', 'e', 'r'};
 		return tokenizedName;
 	}
 	
+	@Override protected char[] getEmptyMakerSelector(String targetFqn) {
+		return OF;
+	}
+	
+	@Override protected char[][] getEmptyMakerReceiver(String targetFqn) {
+		return CGCC;
+	}
+	
 	@Override public List<EclipseNode> generateFields(SingularData data, EclipseNode builderType) {
 		String simpleTypeName = getSimpleTargetTypeName(data);
 		char[][] tokenizedName = makeGuavaTypeName(simpleTypeName, true);
diff --git a/src/core/lombok/eclipse/handlers/singulars/EclipseJavaUtilListSingularizer.java b/src/core/lombok/eclipse/handlers/singulars/EclipseJavaUtilListSingularizer.java
index 80d49fe7..7ea04821 100755
--- a/src/core/lombok/eclipse/handlers/singulars/EclipseJavaUtilListSingularizer.java
+++ b/src/core/lombok/eclipse/handlers/singulars/EclipseJavaUtilListSingularizer.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015 The Project Lombok Authors.
+ * Copyright (C) 2015-2019 The Project Lombok Authors.
  * 
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -55,6 +55,16 @@ public class EclipseJavaUtilListSingularizer extends EclipseJavaUtilListSetSingu
 		return LombokImmutableList.of("java.util.List", "java.util.Collection", "java.lang.Iterable");
 	}
 	
+	private static final char[] EMPTY_LIST = {'e', 'm', 'p', 't', 'y', 'L', 'i', 's', 't'};
+	
+	@Override protected char[][] getEmptyMakerReceiver(String targetFqn) {
+		return JAVA_UTIL_COLLECTIONS;
+	}
+	
+	@Override protected char[] getEmptyMakerSelector(String targetFqn) {
+		return EMPTY_LIST;
+	}
+	
 	@Override public void appendBuildCode(SingularData data, EclipseNode builderType, List<Statement> statements, char[] targetVariableName, String builderVariable) {
 		if (useGuavaInstead(builderType)) {
 			guavaListSetSingularizer.appendBuildCode(data, builderType, statements, targetVariableName, builderVariable);
diff --git a/src/core/lombok/eclipse/handlers/singulars/EclipseJavaUtilMapSingularizer.java b/src/core/lombok/eclipse/handlers/singulars/EclipseJavaUtilMapSingularizer.java
index 9ad1b6fe..b642522f 100755
--- a/src/core/lombok/eclipse/handlers/singulars/EclipseJavaUtilMapSingularizer.java
+++ b/src/core/lombok/eclipse/handlers/singulars/EclipseJavaUtilMapSingularizer.java
@@ -68,6 +68,20 @@ public class EclipseJavaUtilMapSingularizer extends EclipseJavaUtilSingularizer
 		return LombokImmutableList.of("java.util.Map", "java.util.SortedMap", "java.util.NavigableMap");
 	}
 	
+	private static final char[] EMPTY_SORTED_MAP = {'e', 'm', 'p', 't', 'y', 'S', 'o', 'r', 't', 'e', 'd', 'M', 'a', 'p'};
+	private static final char[] EMPTY_NAVIGABLE_MAP = {'e', 'm', 'p', 't', 'y', 'N', 'a', 'v', 'i', 'g', 'a', 'b', 'l', 'e', 'M', 'a', 'p'};
+	private static final char[] EMPTY_MAP = {'e', 'm', 'p', 't', 'y', 'M', 'a', 'p'};
+	
+	@Override protected char[][] getEmptyMakerReceiver(String targetFqn) {
+		return JAVA_UTIL_COLLECTIONS;
+	}
+	
+	@Override protected char[] getEmptyMakerSelector(String targetFqn) {
+		if (targetFqn.endsWith("SortedMap")) return EMPTY_SORTED_MAP;
+		if (targetFqn.endsWith("NavigableMap")) return EMPTY_NAVIGABLE_MAP;
+		return EMPTY_MAP;
+	}
+	
 	@Override public List<char[]> listFieldsToBeGenerated(SingularData data, EclipseNode builderType) {
 		if (useGuavaInstead(builderType)) {
 			return guavaMapSingularizer.listFieldsToBeGenerated(data, builderType);
diff --git a/src/core/lombok/eclipse/handlers/singulars/EclipseJavaUtilSetSingularizer.java b/src/core/lombok/eclipse/handlers/singulars/EclipseJavaUtilSetSingularizer.java
index 200e615e..2076ec7d 100644
--- a/src/core/lombok/eclipse/handlers/singulars/EclipseJavaUtilSetSingularizer.java
+++ b/src/core/lombok/eclipse/handlers/singulars/EclipseJavaUtilSetSingularizer.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015 The Project Lombok Authors.
+ * Copyright (C) 2015-2019 The Project Lombok Authors.
  * 
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -37,6 +37,20 @@ public class EclipseJavaUtilSetSingularizer extends EclipseJavaUtilListSetSingul
 		return LombokImmutableList.of("java.util.Set", "java.util.SortedSet", "java.util.NavigableSet");
 	}
 	
+	private static final char[] EMPTY_SORTED_SET = {'e', 'm', 'p', 't', 'y', 'S', 'o', 'r', 't', 'e', 'd', 'S', 'e', 't'};
+	private static final char[] EMPTY_NAVIGABLE_SET = {'e', 'm', 'p', 't', 'y', 'N', 'a', 'v', 'i', 'g', 'a', 'b', 'l', 'e', 'S', 'e', 't'};
+	private static final char[] EMPTY_SET = {'e', 'm', 'p', 't', 'y', 'S', 'e', 't'};
+	
+	@Override protected char[][] getEmptyMakerReceiver(String targetFqn) {
+		return JAVA_UTIL_COLLECTIONS;
+	}
+	
+	@Override protected char[] getEmptyMakerSelector(String targetFqn) {
+		if (targetFqn.endsWith("SortedSet")) return EMPTY_SORTED_SET;
+		if (targetFqn.endsWith("NavigableSet")) return EMPTY_NAVIGABLE_SET;
+		return EMPTY_SET;
+	}
+	
 	@Override public void appendBuildCode(SingularData data, EclipseNode builderType, List<Statement> statements, char[] targetVariableName, String builderVariable) {
 		if (useGuavaInstead(builderType)) {
 			guavaListSetSingularizer.appendBuildCode(data, builderType, statements, targetVariableName, builderVariable);
diff --git a/src/core/lombok/javac/handlers/HandleSuperBuilder.java b/src/core/lombok/javac/handlers/HandleSuperBuilder.java
index 798ff7b4..290ef89f 100644
--- a/src/core/lombok/javac/handlers/HandleSuperBuilder.java
+++ b/src/core/lombok/javac/handlers/HandleSuperBuilder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013-2018 The Project Lombok Authors.
+ * Copyright (C) 2013-2019 The Project Lombok Authors.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -725,8 +725,9 @@ public class HandleSuperBuilder extends JavacAnnotationHandler<SuperBuilder> {
 			arg = tgt[0];
 		} else {
 			JCExpression eqNull = maker.Binary(CTC_EQUAL, tgt[0], maker.Literal(CTC_BOT, null));
-			JCExpression emptyList = maker.Apply(List.<JCExpression>nil(), chainDots(type, "java", "util", "Collections", "emptyList"), List.<JCExpression>nil());
-			arg = maker.Conditional(eqNull, emptyList, tgt[1]);
+			String emptyMaker = bfd.singularData.getSingularizer().getEmptyMaker(bfd.singularData.getTargetFqn());
+			JCExpression emptyCollection = maker.Apply(List.<JCExpression>nil(), chainDots(type, emptyMaker.split("\\.")), List.<JCExpression>nil());
+			arg = maker.Conditional(eqNull, emptyCollection, tgt[1]);
 		}
 		JCMethodInvocation apply = maker.Apply(List.<JCExpression>nil(), maker.Select(maker.Ident(type.toName(BUILDER_VARIABLE_NAME)), bfd.name), List.of(arg));
 		JCExpressionStatement exec = maker.Exec(apply);
diff --git a/src/core/lombok/javac/handlers/JavacSingularsRecipes.java b/src/core/lombok/javac/handlers/JavacSingularsRecipes.java
index a51079a8..a5895951 100644
--- a/src/core/lombok/javac/handlers/JavacSingularsRecipes.java
+++ b/src/core/lombok/javac/handlers/JavacSingularsRecipes.java
@@ -437,5 +437,7 @@ public class JavacSingularsRecipes {
 		protected abstract String getAddMethodName();
 		
 		protected abstract int getTypeArgumentsCount();
+		
+		protected abstract String getEmptyMaker(String target);
 	}
 }
diff --git a/src/core/lombok/javac/handlers/singulars/JavacGuavaSingularizer.java b/src/core/lombok/javac/handlers/singulars/JavacGuavaSingularizer.java
index c0dd7a42..5b022206 100644
--- a/src/core/lombok/javac/handlers/singulars/JavacGuavaSingularizer.java
+++ b/src/core/lombok/javac/handlers/singulars/JavacGuavaSingularizer.java
@@ -51,6 +51,10 @@ abstract class JavacGuavaSingularizer extends JavacSingularizer {
 		return GuavaTypeMap.getGuavaTypeName(data.getTargetFqn());
 	}
 	
+	@Override protected String getEmptyMaker(String target) {
+		return target + ".of";
+	}
+	
 	protected String getBuilderMethodName(SingularData data) {
 		String simpleTypeName = getSimpleTargetTypeName(data);
 		if ("ImmutableSortedSet".equals(simpleTypeName) || "ImmutableSortedMap".equals(simpleTypeName)) return "naturalOrder";
diff --git a/src/core/lombok/javac/handlers/singulars/JavacJavaUtilListSingularizer.java b/src/core/lombok/javac/handlers/singulars/JavacJavaUtilListSingularizer.java
index e5c5a170..b4ad3428 100644
--- a/src/core/lombok/javac/handlers/singulars/JavacJavaUtilListSingularizer.java
+++ b/src/core/lombok/javac/handlers/singulars/JavacJavaUtilListSingularizer.java
@@ -46,6 +46,10 @@ public class JavacJavaUtilListSingularizer extends JavacJavaUtilListSetSingulari
 		return LombokImmutableList.of("java.util.List", "java.util.Collection", "java.lang.Iterable");
 	}
 	
+	@Override protected String getEmptyMaker(String target) {
+		return "java.util.Collections.emptyList";
+	}
+	
 	@Override public void appendBuildCode(SingularData data, JavacNode builderType, JCTree source, ListBuffer<JCStatement> statements, Name targetVariableName, String builderVariable) {
 		JavacTreeMaker maker = builderType.getTreeMaker();
 		List<JCExpression> jceBlank = List.nil();
diff --git a/src/core/lombok/javac/handlers/singulars/JavacJavaUtilMapSingularizer.java b/src/core/lombok/javac/handlers/singulars/JavacJavaUtilMapSingularizer.java
index 7b9ee653..3e498cac 100644
--- a/src/core/lombok/javac/handlers/singulars/JavacJavaUtilMapSingularizer.java
+++ b/src/core/lombok/javac/handlers/singulars/JavacJavaUtilMapSingularizer.java
@@ -54,6 +54,12 @@ public class JavacJavaUtilMapSingularizer extends JavacJavaUtilSingularizer {
 		return LombokImmutableList.of("java.util.Map", "java.util.SortedMap", "java.util.NavigableMap");
 	}
 	
+	@Override protected String getEmptyMaker(String target) {
+		if (target.endsWith("NavigableMap")) return "java.util.Collections.emptyNavigableMap";
+		if (target.endsWith("SortedMap")) return "java.util.Collections.emptySortedMap";
+		return "java.util.Collections.emptyMap";
+	}
+	
 	@Override protected JavacSingularizer getGuavaInstead(JavacNode node) {
 		return new JavacGuavaMapSingularizer();
 	}
diff --git a/src/core/lombok/javac/handlers/singulars/JavacJavaUtilSetSingularizer.java b/src/core/lombok/javac/handlers/singulars/JavacJavaUtilSetSingularizer.java
index 22d74896..7c870c0a 100644
--- a/src/core/lombok/javac/handlers/singulars/JavacJavaUtilSetSingularizer.java
+++ b/src/core/lombok/javac/handlers/singulars/JavacJavaUtilSetSingularizer.java
@@ -40,6 +40,12 @@ public class JavacJavaUtilSetSingularizer extends JavacJavaUtilListSetSingulariz
 		return LombokImmutableList.of("java.util.Set", "java.util.SortedSet", "java.util.NavigableSet");
 	}
 	
+	@Override protected String getEmptyMaker(String target) {
+		if (target.endsWith("SortedSet")) return "java.util.Collections.emptySortedSet";
+		if (target.endsWith("NavigableSet")) return "java.util.Collections.emptyNavigableSet";
+		return "java.util.Collections.emptySet";
+	}
+	
 	@Override public void appendBuildCode(SingularData data, JavacNode builderType, JCTree source, ListBuffer<JCStatement> statements, Name targetVariableName, String builderVariable) {
 		JavacTreeMaker maker = builderType.getTreeMaker();
 		
diff --git a/test/transform/resource/after-delombok/SuperBuilderWithGenericsAndToBuilder.java b/test/transform/resource/after-delombok/SuperBuilderWithGenericsAndToBuilder.java
index deb5a223..af67e900 100644
--- a/test/transform/resource/after-delombok/SuperBuilderWithGenericsAndToBuilder.java
+++ b/test/transform/resource/after-delombok/SuperBuilderWithGenericsAndToBuilder.java
@@ -1,14 +1,16 @@
-import java.util.List;

+import java.util.Map;

 public class SuperBuilderWithGenericsAndToBuilder {

 	public static class Parent<A> {

 		A field1;

-		List<String> items;

+		Map<Integer, String> items;

 		@java.lang.SuppressWarnings("all")

 		public static abstract class ParentBuilder<A, C extends Parent<A>, B extends ParentBuilder<A, C, B>> {

 			@java.lang.SuppressWarnings("all")

 			private A field1;

 			@java.lang.SuppressWarnings("all")

-			private java.util.ArrayList<String> items;

+			private java.util.ArrayList<Integer> items$key;

+			@java.lang.SuppressWarnings("all")

+			private java.util.ArrayList<String> items$value;

 			@java.lang.SuppressWarnings("all")

 			protected B $fillValuesFrom(final C instance) {

 				ParentBuilder.$fillValuesFromInstanceIntoBuilder(instance, this);

@@ -17,7 +19,7 @@ public class SuperBuilderWithGenericsAndToBuilder {
 			@java.lang.SuppressWarnings("all")

 			private static <A> void $fillValuesFromInstanceIntoBuilder(final Parent<A> instance, final ParentBuilder<A, ?, ?> b) {

 				b.field1(instance.field1);

-				b.items(instance.items == null ? java.util.Collections.emptyList() : instance.items);

+				b.items(instance.items == null ? java.util.Collections.emptyMap() : instance.items);

 			}

 			@java.lang.SuppressWarnings("all")

 			protected abstract B self();

@@ -29,26 +31,39 @@ public class SuperBuilderWithGenericsAndToBuilder {
 				return self();

 			}

 			@java.lang.SuppressWarnings("all")

-			public B item(final String item) {

-				if (this.items == null) this.items = new java.util.ArrayList<String>();

-				this.items.add(item);

+			public B item(final Integer itemKey, final String itemValue) {

+				if (this.items$key == null) {

+					this.items$key = new java.util.ArrayList<Integer>();

+					this.items$value = new java.util.ArrayList<String>();

+				}

+				this.items$key.add(itemKey);

+				this.items$value.add(itemValue);

 				return self();

 			}

 			@java.lang.SuppressWarnings("all")

-			public B items(final java.util.Collection<? extends String> items) {

-				if (this.items == null) this.items = new java.util.ArrayList<String>();

-				this.items.addAll(items);

+			public B items(final java.util.Map<? extends Integer, ? extends String> items) {

+				if (this.items$key == null) {

+					this.items$key = new java.util.ArrayList<Integer>();

+					this.items$value = new java.util.ArrayList<String>();

+				}

+				for (final java.util.Map.Entry<? extends Integer, ? extends String> $lombokEntry : items.entrySet()) {

+					this.items$key.add($lombokEntry.getKey());

+					this.items$value.add($lombokEntry.getValue());

+				}

 				return self();

 			}

 			@java.lang.SuppressWarnings("all")

 			public B clearItems() {

-				if (this.items != null) this.items.clear();

+				if (this.items$key != null) {

+					this.items$key.clear();

+					this.items$value.clear();

+				}

 				return self();

 			}

 			@java.lang.Override

 			@java.lang.SuppressWarnings("all")

 			public java.lang.String toString() {

-				return "SuperBuilderWithGenericsAndToBuilder.Parent.ParentBuilder(field1=" + this.field1 + ", items=" + this.items + ")";

+				return "SuperBuilderWithGenericsAndToBuilder.Parent.ParentBuilder(field1=" + this.field1 + ", items$key=" + this.items$key + ", items$value=" + this.items$value + ")";

 			}

 		}

 		@java.lang.SuppressWarnings("all")

@@ -70,16 +85,18 @@ public class SuperBuilderWithGenericsAndToBuilder {
 		@java.lang.SuppressWarnings("all")

 		protected Parent(final ParentBuilder<A, ?, ?> b) {

 			this.field1 = b.field1;

-			java.util.List<String> items;

-			switch (b.items == null ? 0 : b.items.size()) {

+			java.util.Map<Integer, String> items;

+			switch (b.items$key == null ? 0 : b.items$key.size()) {

 			case 0: 

-				items = java.util.Collections.emptyList();

+				items = java.util.Collections.emptyMap();

 				break;

 			case 1: 

-				items = java.util.Collections.singletonList(b.items.get(0));

+				items = java.util.Collections.singletonMap(b.items$key.get(0), b.items$value.get(0));

 				break;

 			default: 

-				items = java.util.Collections.unmodifiableList(new java.util.ArrayList<String>(b.items));

+				items = new java.util.LinkedHashMap<Integer, String>(b.items$key.size() < 1073741824 ? 1 + b.items$key.size() + (b.items$key.size() - 3) / 3 : java.lang.Integer.MAX_VALUE);

+				for (int $i = 0; $i < b.items$key.size(); $i++) items.put(b.items$key.get($i), (String) b.items$value.get($i));

+				items = java.util.Collections.unmodifiableMap(items);

 			}

 			this.items = items;

 		}

@@ -157,6 +174,6 @@ public class SuperBuilderWithGenericsAndToBuilder {
 		}

 	}

 	public static void test() {

-		Child<Integer> x = Child.<Integer>builder().field3(0.0).field1(5).item("").build().toBuilder().build();

+		Child<Integer> x = Child.<Integer>builder().field3(0.0).field1(5).item(5, "").build().toBuilder().build();

 	}

 }

diff --git a/test/transform/resource/after-ecj/SuperBuilderWithGenericsAndToBuilder.java b/test/transform/resource/after-ecj/SuperBuilderWithGenericsAndToBuilder.java
index 107ee362..ce960d61 100644
--- a/test/transform/resource/after-ecj/SuperBuilderWithGenericsAndToBuilder.java
+++ b/test/transform/resource/after-ecj/SuperBuilderWithGenericsAndToBuilder.java
@@ -1,9 +1,10 @@
-import java.util.List;

+import java.util.Map;

 public class SuperBuilderWithGenericsAndToBuilder {

   public static @lombok.experimental.SuperBuilder(toBuilder = true) class Parent<A> {

     public static abstract @java.lang.SuppressWarnings("all") class ParentBuilder<A, C extends Parent<A>, B extends ParentBuilder<A, C, B>> {

       private @java.lang.SuppressWarnings("all") A field1;

-      private @java.lang.SuppressWarnings("all") java.util.ArrayList<String> items;

+      private @java.lang.SuppressWarnings("all") java.util.ArrayList<Integer> items$key;

+      private @java.lang.SuppressWarnings("all") java.util.ArrayList<String> items$value;

       public ParentBuilder() {

         super();

       }

@@ -13,7 +14,7 @@ public class SuperBuilderWithGenericsAndToBuilder {
       }

       private static @java.lang.SuppressWarnings("all") <A>void $fillValuesFromInstanceIntoBuilder(final Parent<A> instance, final ParentBuilder<A, ?, ?> b) {

         b.field1(instance.field1);

-        b.items(((instance.items == null) ? java.util.Collections.emptyList() : instance.items));

+        b.items(((instance.items == null) ? java.util.Collections.emptyMap() : instance.items));

       }

       protected abstract @java.lang.SuppressWarnings("all") B self();

       public abstract @java.lang.SuppressWarnings("all") C build();

@@ -21,25 +22,39 @@ public class SuperBuilderWithGenericsAndToBuilder {
         this.field1 = field1;

         return self();

       }

-      public @java.lang.SuppressWarnings("all") B item(final String item) {

-        if ((this.items == null))

-            this.items = new java.util.ArrayList<String>();

-        this.items.add(item);

+      public @java.lang.SuppressWarnings("all") B item(final Integer itemKey, final String itemValue) {

+        if ((this.items$key == null))

+            {

+              this.items$key = new java.util.ArrayList<Integer>();

+              this.items$value = new java.util.ArrayList<String>();

+            }

+        this.items$key.add(itemKey);

+        this.items$value.add(itemValue);

         return self();

       }

-      public @java.lang.SuppressWarnings("all") B items(final java.util.Collection<? extends String> items) {

-        if ((this.items == null))

-            this.items = new java.util.ArrayList<String>();

-        this.items.addAll(items);

+      public @java.lang.SuppressWarnings("all") B items(final java.util.Map<? extends Integer, ? extends String> items) {

+        if ((this.items$key == null))

+            {

+              this.items$key = new java.util.ArrayList<Integer>();

+              this.items$value = new java.util.ArrayList<String>();

+            }

+        for (java.util.Map.Entry<? extends Integer, ? extends String> $lombokEntry : items.entrySet()) 

+          {

+            this.items$key.add($lombokEntry.getKey());

+            this.items$value.add($lombokEntry.getValue());

+          }

         return self();

       }

       public @java.lang.SuppressWarnings("all") B clearItems() {

-        if ((this.items != null))

-            this.items.clear();

+        if ((this.items$key != null))

+            {

+              this.items$key.clear();

+              this.items$value.clear();

+            }

         return self();

       }

       public @java.lang.Override @java.lang.SuppressWarnings("all") java.lang.String toString() {

-        return (((("SuperBuilderWithGenericsAndToBuilder.Parent.ParentBuilder(field1=" + this.field1) + ", items=") + this.items) + ")");

+        return (((((("SuperBuilderWithGenericsAndToBuilder.Parent.ParentBuilder(field1=" + this.field1) + ", items$key=") + this.items$key) + ", items$value=") + this.items$value) + ")");

       }

     }

     private static final @java.lang.SuppressWarnings("all") class ParentBuilderImpl<A> extends ParentBuilder<A, Parent<A>, ParentBuilderImpl<A>> {

@@ -54,20 +69,23 @@ public class SuperBuilderWithGenericsAndToBuilder {
       }

     }

     A field1;

-    @lombok.Singular List<String> items;

+    @lombok.Singular Map<Integer, String> items;

     protected @java.lang.SuppressWarnings("all") Parent(final ParentBuilder<A, ?, ?> b) {

       super();

       this.field1 = b.field1;

-      java.util.List<String> items;

-      switch (((b.items == null) ? 0 : b.items.size())) {

+      java.util.Map<Integer, String> items;

+      switch (((b.items$key == null) ? 0 : b.items$key.size())) {

       case 0 : 

-          items = java.util.Collections.emptyList();

+          items = java.util.Collections.emptyMap();

           break;

       case 1 : 

-          items = java.util.Collections.singletonList(b.items.get(0));

+          items = java.util.Collections.singletonMap(b.items$key.get(0), b.items$value.get(0));

           break;

       default : 

-          items = java.util.Collections.unmodifiableList(new java.util.ArrayList<String>(b.items));

+          items = new java.util.LinkedHashMap<Integer, String>(((b.items$key.size() < 0x40000000) ? ((1 + b.items$key.size()) + ((b.items$key.size() - 3) / 3)) : java.lang.Integer.MAX_VALUE));

+          for (int $i = 0;; ($i < b.items$key.size()); $i ++) 

+            items.put(b.items$key.get($i), b.items$value.get($i));

+          items = java.util.Collections.unmodifiableMap(items);

       }

       this.items = items;

     }

@@ -129,6 +147,6 @@ public class SuperBuilderWithGenericsAndToBuilder {
     super();

   }

   public static void test() {

-    Child<Integer> x = Child.<Integer>builder().field3(0.0).field1(5).item("").build().toBuilder().build();

+    Child<Integer> x = Child.<Integer>builder().field3(0.0).field1(5).item(5, "").build().toBuilder().build();

   }

 }

diff --git a/test/transform/resource/before/SuperBuilderWithGenericsAndToBuilder.java b/test/transform/resource/before/SuperBuilderWithGenericsAndToBuilder.java
index dae68034..1f2caf6d 100644
--- a/test/transform/resource/before/SuperBuilderWithGenericsAndToBuilder.java
+++ b/test/transform/resource/before/SuperBuilderWithGenericsAndToBuilder.java
@@ -1,10 +1,10 @@
-import java.util.List;
+import java.util.Map;
 
 public class SuperBuilderWithGenericsAndToBuilder {
 	@lombok.experimental.SuperBuilder(toBuilder = true)
 	public static class Parent<A> {
 		A field1;
-		@lombok.Singular List<String> items;
+		@lombok.Singular Map<Integer, String> items;
 	}
 	
 	@lombok.experimental.SuperBuilder(toBuilder = true)
@@ -13,6 +13,6 @@ public class SuperBuilderWithGenericsAndToBuilder {
 	}
 	
 	public static void test() {
-		Child<Integer> x = Child.<Integer>builder().field3(0.0).field1(5).item("").build().toBuilder().build();
+		Child<Integer> x = Child.<Integer>builder().field3(0.0).field1(5).item(5, "").build().toBuilder().build();
 	}
 }