Improve toString generation for enums. Fixes #1916

doc/changelog.markdown

@@ -5,6 +5,7 @@ Lombok Changelog
 * BUGFIX: Since version 1.18.4, the delombok ant task didn't work and errored with a `NoClassDefFoundError`. [Issue #1932](https://github.com/rzwitserloot/lombok/issues/1932)
 * FEATURE: The `@FieldNameConstants` feature now allows you to write the inner type by hand and add whatever you like to it; lombok will add the constants to this class. See the updated [FieldNameConstants feature](https://projectlombok.org/features/experimental/FieldNameConstants) page.
 * FEATURE: There is now a `lombok.config` key to configure `@ToString`'s call super behavior; it's just like `@EqualsAndHashCode` which has had it for a while now. [Issue #1918](https://github.com/rzwitserloot/lombok/issues/1918)
+* ENHANCEMENT: The toString generation of enums now contains the name of the enum constant. [Issue #1916](https://github.com/rzwitserloot/lombok/issues/1916)
 
 ### v1.18.4 (October 30th, 2018)
 * PLATFORM: Support for Eclipse Photon. [Issue #1831](https://github.com/rzwitserloot/lombok/issues/1831)

src/core/lombok/core/LombokNode.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2009-2013 The Project Lombok Authors.
+ * Copyright (C) 2009-2018 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
@@ -279,6 +279,7 @@ public boolean isStructurallySignificant() {
 	public abstract boolean isStatic();
 	public abstract boolean isTransient();
 	public abstract boolean isEnumMember();
+	public abstract boolean isEnumType();
 
 	public abstract int countMethodParameters();
 

src/core/lombok/eclipse/EclipseNode.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2009-2012 The Project Lombok Authors.
+ * Copyright (C) 2009-2018 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
@@ -250,6 +250,11 @@ private Integer getModifiers() {
 		return ((FieldDeclaration) node).getKind() == 3;
 	}
 
+	@Override public boolean isEnumType() {
+		if (getKind() != Kind.TYPE) return false;
+		return (((TypeDeclaration) node).modifiers & ClassFileConstants.AccEnum) != 0;
+	}
+
 	@Override public int countMethodParameters() {
 		if (getKind() != Kind.METHOD) return 0;
 

src/core/lombok/eclipse/handlers/HandleToString.java

@@ -21,7 +21,7 @@
  */
 package lombok.eclipse.handlers;
 
-import static lombok.core.handlers.HandlerUtil.*;
+import static lombok.core.handlers.HandlerUtil.handleFlagUsage;
 import static lombok.eclipse.handlers.EclipseHandlerUtil.*;
 
 import java.util.Arrays;
@@ -31,18 +31,6 @@
 import java.util.List;
 import java.util.Set;
 
-import lombok.AccessLevel;
-import lombok.ConfigurationKeys;
-import lombok.ToString;
-import lombok.core.AST.Kind;
-import lombok.core.AnnotationValues;
-import lombok.core.configuration.CallSuperType;
-import lombok.core.handlers.InclusionExclusionUtils;
-import lombok.core.handlers.InclusionExclusionUtils.Included;
-import lombok.eclipse.Eclipse;
-import lombok.eclipse.EclipseAnnotationHandler;
-import lombok.eclipse.EclipseNode;
-
 import org.eclipse.jdt.internal.compiler.ast.ASTNode;
 import org.eclipse.jdt.internal.compiler.ast.Annotation;
 import org.eclipse.jdt.internal.compiler.ast.BinaryExpression;
@@ -59,12 +47,26 @@
 import org.eclipse.jdt.internal.compiler.ast.Statement;
 import org.eclipse.jdt.internal.compiler.ast.StringLiteral;
 import org.eclipse.jdt.internal.compiler.ast.SuperReference;
+import org.eclipse.jdt.internal.compiler.ast.ThisReference;
 import org.eclipse.jdt.internal.compiler.ast.TypeDeclaration;
 import org.eclipse.jdt.internal.compiler.ast.TypeReference;
 import org.eclipse.jdt.internal.compiler.classfmt.ClassFileConstants;
 import org.eclipse.jdt.internal.compiler.lookup.TypeConstants;
 import org.mangosdk.spi.ProviderFor;
 
+import lombok.AccessLevel;
+import lombok.ConfigurationKeys;
+import lombok.ToString;
+import lombok.core.AST.Kind;
+import lombok.core.AnnotationValues;
+import lombok.core.configuration.CallSuperType;
+import lombok.core.handlers.HandlerUtil.FieldAccess;
+import lombok.core.handlers.InclusionExclusionUtils;
+import lombok.core.handlers.InclusionExclusionUtils.Included;
+import lombok.eclipse.Eclipse;
+import lombok.eclipse.EclipseAnnotationHandler;
+import lombok.eclipse.EclipseNode;
+
 /**
  * Handles the {@code ToString} annotation for eclipse.
  */
@@ -165,38 +167,63 @@ public static MethodDeclaration createToString(EclipseNode type, Collection<Incl
 		boolean includeNames, boolean callSuper, ASTNode source, FieldAccess fieldAccess) {
 
 		String typeName = getTypeName(type);
+		boolean isEnum = type.isEnumType();
+
 		char[] suffix = ")".toCharArray();
 		String infixS = ", ";
 		char[] infix = infixS.toCharArray();
 		int pS = source.sourceStart, pE = source.sourceEnd;
 		long p = (long)pS << 32 | pE;
 		final int PLUS = OperatorIds.PLUS;
 
-		char[] prefix;
+		String prefix;
 
 		if (callSuper) {
-			prefix = (typeName + "(super=").toCharArray();
+			prefix = "(super=";
 		} else if (members.isEmpty()) {
-			prefix = (typeName + "()").toCharArray();
+			prefix = isEnum ? "" : "()";
 		} else if (includeNames) {
 			Included<EclipseNode, ToString.Include> firstMember = members.iterator().next();
 			String name = firstMember.getInc() == null ? "" : firstMember.getInc().name();
 			if (name.isEmpty()) name = firstMember.getNode().getName();
-			prefix = (typeName + "(" + name + "=").toCharArray();
+			prefix = "(" + name + "=";
 		} else {
-			prefix = (typeName + "(").toCharArray();
+			prefix = "(";
 		}
 
 		boolean first = true;
-		Expression current = new StringLiteral(prefix, pS, pE, 0);
-		setGeneratedBy(current, source);
+		Expression current;
+		if (!isEnum) {
+			current = new StringLiteral((typeName + prefix).toCharArray(), pS, pE, 0);
+			setGeneratedBy(current, source);
+		} else {
+			current = new StringLiteral((typeName + ".").toCharArray(), pS, pE, 0);
+			setGeneratedBy(current, source);
+
+			MessageSend thisName = new MessageSend();
+			thisName.sourceStart = pS; thisName.sourceEnd = pE;
+			setGeneratedBy(thisName, source);
+			thisName.receiver = new ThisReference(pS, pE);
+			setGeneratedBy(thisName.receiver, source);
+			thisName.selector = "name".toCharArray();
+			current = new BinaryExpression(current, thisName, PLUS);
+			setGeneratedBy(current, source);
+
+			if (!prefix.isEmpty()) {
+				StringLiteral px = new StringLiteral(prefix.toCharArray(), pS, pE, 0);
+				setGeneratedBy(px, source);				
+				current = new BinaryExpression(current, px, PLUS);
+				current.sourceStart = pS; current.sourceEnd = pE;
+				setGeneratedBy(current, source);
+			}
+		}
 
 		if (callSuper) {
 			MessageSend callToSuper = new MessageSend();
 			callToSuper.sourceStart = pS; callToSuper.sourceEnd = pE;
 			setGeneratedBy(callToSuper, source);
 			callToSuper.receiver = new SuperReference(pS, pE);
-			setGeneratedBy(callToSuper, source);
+			setGeneratedBy(callToSuper.receiver, source);
 			callToSuper.selector = "toString".toCharArray();
 			current = new BinaryExpression(current, callToSuper, PLUS);
 			setGeneratedBy(current, source);

src/core/lombok/javac/JavacNode.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2009-2017 The Project Lombok Authors.
+ * Copyright (C) 2009-2018 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
@@ -317,6 +317,12 @@ private JCModifiers getModifiers() {
 		return mods != null && (Flags.ENUM & mods.flags) != 0;
 	}
 
+	@Override public boolean isEnumType() {
+		if (getKind() != Kind.TYPE) return false;
+		JCModifiers mods = getModifiers();
+		return mods != null && (Flags.ENUM & mods.flags) != 0;
+	}
+
 	@Override public boolean isTransient() {
 		if (getKind() != Kind.FIELD) return false;
 		JCModifiers mods = getModifiers();

src/core/lombok/javac/handlers/HandleToString.java

@@ -166,23 +166,34 @@ static JCMethodDecl createToString(JavacNode typeNode, Collection<Included<Javac
 		boolean first = true;
 
 		String typeName = getTypeName(typeNode);
+		boolean isEnum = typeNode.isEnumType();
+
 		String infix = ", ";
 		String suffix = ")";
 		String prefix;
 		if (callSuper) {
-			prefix = typeName + "(super=";
+			prefix = "(super=";
 		} else if (members.isEmpty()) {
-			prefix = typeName + "()";
+			prefix = isEnum ? "" : "()";
 		} else if (includeNames) {
 			Included<JavacNode, ToString.Include> firstMember = members.iterator().next();
 			String name = firstMember.getInc() == null ? "" : firstMember.getInc().name();
 			if (name.isEmpty()) name = firstMember.getNode().getName();
-			prefix = typeName + "(" + name + "=";
+			prefix = "(" + name + "=";
+		} else {
+			prefix = "(";
+		}
+
+		JCExpression current;
+		if (!isEnum) { 
+			current = maker.Literal(typeName + prefix);
 		} else {
-			prefix = typeName + "(";
+			current = maker.Binary(CTC_PLUS, maker.Literal(typeName + "."), maker.Apply(List.<JCExpression>nil(),
+					maker.Select(maker.Ident(typeNode.toName("this")), typeNode.toName("name")),
+					List.<JCExpression>nil()));
+			if (!prefix.isEmpty()) current = maker.Binary(CTC_PLUS, current, maker.Literal(prefix));
 		}
 
-		JCExpression current = maker.Literal(prefix);
 
 		if (callSuper) {
 			JCMethodInvocation callToSuper = maker.Apply(List.<JCExpression>nil(),

test/transform/resource/after-delombok/DataOnEnum.java

@@ -8,7 +8,7 @@ public String getSomeField() {
 	@java.lang.Override
 	@java.lang.SuppressWarnings("all")
 	public java.lang.String toString() {
-		return "DataOnEnum(someField=" + this.getSomeField() + ")";
+		return "DataOnEnum." + this.name() + "(someField=" + this.getSomeField() + ")";
 	}
 	@java.lang.SuppressWarnings("all")
 	private DataOnEnum(final String someField) {

test/transform/resource/after-delombok/ToStringEnum.java

@@ -0,0 +1,28 @@
+enum ToStringEnum1 {
+	CONSTANT;
+	@java.lang.Override
+	@java.lang.SuppressWarnings("all")
+	public java.lang.String toString() {
+		return "ToStringEnum1." + this.name();
+	}
+}
+enum ToStringEnum2 {
+	CONSTANT;
+	int x;
+	String name;
+	@java.lang.Override
+	@java.lang.SuppressWarnings("all")
+	public java.lang.String toString() {
+		return "ToStringEnum2." + this.name() + "(x=" + this.x + ", name=" + this.name + ")";
+	}
+}
+class ToStringEnum3 {
+	enum MemberEnum {
+		CONSTANT;
+		@java.lang.Override
+		@java.lang.SuppressWarnings("all")
+		public java.lang.String toString() {
+			return "ToStringEnum3.MemberEnum." + this.name();
+		}
+	}
+}

test/transform/resource/after-ecj/DataOnEnum.java

@@ -7,7 +7,7 @@
     return this.someField;
   }
   public @java.lang.Override @java.lang.SuppressWarnings("all") java.lang.String toString() {
-    return (("DataOnEnum(someField=" + this.getSomeField()) + ")");
+    return (((("DataOnEnum." + this.name()) + "(someField=") + this.getSomeField()) + ")");
   }
   private @java.lang.SuppressWarnings("all") DataOnEnum(final String someField) {
     super();

test/transform/resource/after-ecj/ToStringEnum.java

@@ -0,0 +1,41 @@
+import lombok.ToString;
+@ToString enum ToStringEnum1 {
+  CONSTANT(),
+  <clinit>() {
+  }
+  ToStringEnum1() {
+    super();
+  }
+  public @java.lang.Override @java.lang.SuppressWarnings("all") java.lang.String toString() {
+    return ("ToStringEnum1." + this.name());
+  }
+}
+@ToString enum ToStringEnum2 {
+  CONSTANT(),
+  int x;
+  String name;
+  <clinit>() {
+  }
+  ToStringEnum2() {
+    super();
+  }
+  public @java.lang.Override @java.lang.SuppressWarnings("all") java.lang.String toString() {
+    return (((((("ToStringEnum2." + this.name()) + "(x=") + this.x) + ", name=") + this.name) + ")");
+  }
+}
+class ToStringEnum3 {
+  @ToString enum MemberEnum {
+    CONSTANT(),
+    <clinit>() {
+    }
+    MemberEnum() {
+      super();
+    }
+    public @java.lang.Override @java.lang.SuppressWarnings("all") java.lang.String toString() {
+      return ("ToStringEnum3.MemberEnum." + this.name());
+    }
+  }
+  ToStringEnum3() {
+    super();
+  }
+}

test/transform/resource/before/ToStringEnum.java

@@ -0,0 +1,17 @@
+import lombok.ToString;
+@ToString
+enum ToStringEnum1 {
+	CONSTANT;
+}
+@ToString
+enum ToStringEnum2 {
+	CONSTANT();
+	int x;
+	String name;
+}
+class ToStringEnum3 {
+	@ToString 
+	enum MemberEnum {
+		CONSTANT;
+	}
+}