From 7fbb304c8fab7ab4de1a1d6017add78445f0c9cf Mon Sep 17 00:00:00 2001
From: Andreas Dangel <adangel@users.sourceforge.net>
Date: Sat, 28 Jan 2017 10:43:17 +0100
Subject: [PATCH] java: ImmutableFieldRule - use enum

---
 .../java/rule/design/ImmutableFieldRule.java  | 25 +++++++++++--------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/design/ImmutableFieldRule.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/design/ImmutableFieldRule.java
index 74d01f4a1c..c2d9ce2983 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/design/ImmutableFieldRule.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/design/ImmutableFieldRule.java
@@ -33,9 +33,14 @@ import net.sourceforge.pmd.lang.symboltable.NameOccurrence;
  */
 public class ImmutableFieldRule extends AbstractJavaRule {
 
-    private static final int MUTABLE = 0;
-    private static final int IMMUTABLE = 1;
-    private static final int CHECKDECL = 2;
+    private enum FieldImmutabilityType {
+        /** Variable is changed in methods and/or in lambdas */
+        MUTABLE,
+        /** Variable is not changed outside the constructor. */
+        IMMUTABLE,
+        /** Variable is only written during declaration, if at all. */
+        CHECKDECL;
+    }
 
     @Override
     public Object visit(ASTClassOrInterfaceDeclaration node, Object data) {
@@ -48,11 +53,11 @@ public class ImmutableFieldRule extends AbstractJavaRule {
                 continue;
             }
 
-            int result = initializedInConstructor(entry.getValue(), new HashSet<>(constructors));
-            if (result == MUTABLE) {
+            FieldImmutabilityType result = initializedInConstructor(entry.getValue(), new HashSet<>(constructors));
+            if (result == FieldImmutabilityType.MUTABLE) {
                 continue;
             }
-            if (result == IMMUTABLE || result == CHECKDECL && initializedWhenDeclared(field)) {
+            if (result == FieldImmutabilityType.IMMUTABLE || result == FieldImmutabilityType.CHECKDECL && initializedWhenDeclared(field)) {
                 addViolation(data, field.getNode(), field.getImage());
             }
         }
@@ -63,8 +68,8 @@ public class ImmutableFieldRule extends AbstractJavaRule {
         return ((Node)field.getAccessNodeParent()).hasDescendantOfType(ASTVariableInitializer.class);
     }
 
-    private int initializedInConstructor(List<NameOccurrence> usages, Set<ASTConstructorDeclaration> allConstructors) {
-        int result = MUTABLE;
+    private FieldImmutabilityType initializedInConstructor(List<NameOccurrence> usages, Set<ASTConstructorDeclaration> allConstructors) {
+        FieldImmutabilityType result = FieldImmutabilityType.MUTABLE;
         int methodInitCount = 0;
         int lambdaUsage = 0;
         Set<Node> consSet = new HashSet<>();
@@ -98,11 +103,11 @@ public class ImmutableFieldRule extends AbstractJavaRule {
             }
         }
         if (usages.isEmpty() || methodInitCount == 0 && lambdaUsage == 0 && consSet.isEmpty()) {
-            result = CHECKDECL;
+            result = FieldImmutabilityType.CHECKDECL;
         } else {
             allConstructors.removeAll(consSet);
             if (allConstructors.isEmpty() && methodInitCount == 0 && lambdaUsage == 0) {
-                result = IMMUTABLE;
+                result = FieldImmutabilityType.IMMUTABLE;
             }
         }
         return result;