Java to Kotlin converter: declare private field with no writes as val

j2k/src/org/jetbrains/jet/j2k/Converter.kt

@@ -285,7 +285,7 @@ public class Converter private(val project: Project, val settings: ConverterSett
         else {
             val initializer = field.getInitializer()
             val convertedType = typeConverter.convertVariableType(field)
-            val isVal = field.hasModifierProperty(PsiModifier.FINAL)
+            val isVal = field.isEffectivelyFinal()
             val omitType = !settings.specifyFieldTypeByDefault &&
                     initializer != null &&
                     (modifiers.isPrivate && (isVal || convertedType == typeConverter.convertExpressionType(initializer)) ||

j2k/src/org/jetbrains/jet/j2k/TypeConverter.kt

@@ -263,13 +263,4 @@ class TypeConverter(val settings: ConverterSettings, val conversionScope: Conver
         }
         return false
     }
-
-    private fun PsiVariable.isEffectivelyFinal(): Boolean {
-        if (hasModifierProperty(PsiModifier.FINAL)) return true
-        return when(this) {
-            is PsiLocalVariable -> !hasWriteAccesses(getContainingMethod())
-            is PsiField -> if (hasModifierProperty(PsiModifier.PRIVATE)) !hasWriteAccesses(getContainingClass()) else false
-            else -> false
-        }
-    }
 }

j2k/src/org/jetbrains/jet/j2k/Utils.kt

@@ -93,3 +93,12 @@ fun PsiElement.isInSingleLine(): Boolean {
     }
     return true
 }
+
+fun PsiVariable.isEffectivelyFinal(): Boolean {
+    if (hasModifierProperty(PsiModifier.FINAL)) return true
+    return when(this) {
+        is PsiLocalVariable -> !hasWriteAccesses(getContainingMethod())
+        is PsiField -> if (hasModifierProperty(PsiModifier.PRIVATE)) !hasWriteAccesses(getContainingClass()) else false
+        else -> false
+    }
+}

j2k/tests/test/org/jetbrains/jet/j2k/test/JavaToKotlinConverterTestGenerated.java

@@ -1099,6 +1099,11 @@ public class JavaToKotlinConverterTestGenerated extends AbstractJavaToKotlinConv
             doTest("j2k/tests/testData/ast/field/specifyType.java");
         }
         
+        @TestMetadata("valOrVar.java")
+        public void testValOrVar() throws Exception {
+            doTest("j2k/tests/testData/ast/field/valOrVar.java");
+        }
+        
         @TestMetadata("valWithInit.java")
         public void testValWithInit() throws Exception {
             doTest("j2k/tests/testData/ast/field/valWithInit.java");

j2k/tests/testData/ast/annotations/annotationUsages.kt

@@ -9,10 +9,10 @@ Anon6(array("x", "y"))
 Anon7(javaClass<String>(), javaClass<StringBuilder>())
 Anon8(classes = *array(javaClass<String>(), javaClass<StringBuilder>()))
 class C() {
-    Anon5(1) deprecated("") private var field1 = 0
+    Anon5(1) deprecated("") private val field1 = 0
 
     Anon5(1)
-    private var field2 = 0
+    private val field2 = 0
 
     Anon5(1) var field3 = 0
 

j2k/tests/testData/ast/comments/comments2.kt

@@ -11,7 +11,7 @@ class A() {
         /* body is empty */
     }
 
-    private /*it's private*/ var field = 0
+    private /*it's private*/ val field = 0
 
     public /*it's public*/ fun foo(): Char {
     }

j2k/tests/testData/ast/comments/fieldWithEndOfLineComment.kt

@@ -1,3 +1,3 @@
 class A() {
-    private var isOpen = true // ideally should be atomic boolean
+    private val isOpen = true // ideally should be atomic boolean
 }

j2k/tests/testData/ast/constructors/withManyDefaultParams.java

@@ -1,13 +1,13 @@
 //file
 public class Test {
   private final String myName;
-  private boolean a;
+  boolean a;
-  private double b;
+  double b;
-  private float c;
+  float c;
-  private long d;
+  long d;
-  private int e;
+  int e;
-  private short f;
+  protected short f;
-  private char g;
+  protected char g;
 
   public Test() {}
 

j2k/tests/testData/ast/constructors/withManyDefaultParams.kt

@@ -1,4 +1,4 @@
-public class Test private(private val myName: String, private var a: Boolean, private var b: Double, private var c: Float, private var d: Long, private var e: Int, private var f: Short, private var g: Char) {
+public class Test private(private val myName: String, var a: Boolean, var b: Double, var c: Float, var d: Long, var e: Int, protected var f: Short, protected var g: Char) {
     class object {
 
         public fun create(): Test {

j2k/tests/testData/ast/enum/enumWithNameField.kt

@@ -1,4 +1,4 @@
 enum class E {
     I
-    private var name: String = 0
+    private val name: String = 0
 }

j2k/tests/testData/ast/field/classChildExtendsBase.kt

@@ -1,7 +1,7 @@
 class Base() {
-    private var myFirst: String = 0
+    private val myFirst: String = 0
 }
 
 class Child() : Base() {
-    private var mySecond: String = 0
+    private val mySecond: String = 0
 }

j2k/tests/testData/ast/field/privateField.kt

@@ -1,3 +1,3 @@
 class C() {
-    private var f: Foo = 0
+    private val f: Foo = 0
 }

j2k/tests/testData/ast/field/specifyType.java

@@ -20,6 +20,7 @@ class A {
     String foo() { return "x"; }
 
     void bar() {
+        field5 = new ArrayList<String>();
         field7++;
         field8++;
         field9 = null;

j2k/tests/testData/ast/field/specifyType.kt

@@ -21,6 +21,7 @@ class A() {
     }
 
     fun bar() {
+        field5 = ArrayList<String>()
         field7++
         field8++
         field9 = null

j2k/tests/testData/ast/field/valOrVar.java

@@ -0,0 +1,12 @@
+//file
+class A {
+    private final int field1 = 0;
+    private int field2 = 0;
+    private int field3 = 0;
+    final int field4 = 0;
+    int field5 = 0;
+
+    void foo() {
+        field3 = field2;
+    }
+}

j2k/tests/testData/ast/field/valOrVar.kt

@@ -0,0 +1,11 @@
+class A() {
+    private val field1 = 0
+    private val field2 = 0
+    private var field3 = 0
+    val field4 = 0
+    var field5 = 0
+
+    fun foo() {
+        field3 = field2
+    }
+}

j2k/tests/testData/ast/issues/comments.kt

@@ -15,7 +15,7 @@ class C() {
     /**
      * This is a field doc comment.
      */
-    private var i: Int = 0
+    private val i: Int = 0
 
     /**
      * This is a function doc comment.

j2k/tests/testData/ast/nullability/FieldComparedWithNull.kt

@@ -1,5 +1,5 @@
 class C() {
-    private var s: String? = x()
+    private val s = x()
 
     fun foo() {
         if (s == null) {

j2k/tests/testData/ast/settings/specifyFieldTypeByDefault.java

@@ -8,10 +8,4 @@ class A {
     final List<String> field2 = new ArrayList<String>();
     public final int field3 = 0;
     protected final int field4 = 0;
-
-    private List<String> field5 = new ArrayList<String>();
-    List<String> field6 = new ArrayList<String>();
-
-    private int field7 = 0;
-    int field8 = 0;
 }

j2k/tests/testData/ast/settings/specifyFieldTypeByDefault.kt

@@ -7,10 +7,4 @@ class A() {
     val field2: List<String> = ArrayList<String>()
     public val field3: Int = 0
     protected val field4: Int = 0
-
-    private var field5: List<String> = ArrayList<String>()
-    var field6: List<String> = ArrayList<String>()
-
-    private var field7: Int = 0
-    var field8: Int = 0
 }