J2K: not initialized field of non-primitive type should have null initializer

#KT-11544 Fixed

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

@@ -255,6 +255,9 @@ class TypeConverter(val converter: Converter) {
                     }
                 }
             }
+            else if (variable is PsiField && !variable.hasWriteAccesses(converter.referenceSearcher, variable.containingClass)) {
+                return Nullability.Nullable
+            }
 
             if (variable.isMainMethodParameter() ) {
                 return Nullability.NotNull

j2k/testData/fileOrElement/callChainExpression/libraryFieldCall.kt

@@ -1,10 +1,9 @@
-// ERROR: Property must be initialized or be abstract
 internal object Library {
-    val ourOut: java.io.PrintStream
+    val ourOut: java.io.PrintStream? = null
 }
 
 internal class User {
     fun main() {
-        Library.ourOut.print(1)
+        Library.ourOut!!.print(1)
     }
 }

j2k/testData/fileOrElement/callChainExpression/libraryStringFieldCall.kt

@@ -1,10 +1,9 @@
-// ERROR: Property must be initialized or be abstract
 internal class Library {
-    val myString: String
+    val myString: String? = null
 }
 
 internal class User {
     fun main() {
-        Library().myString.isEmpty()
+        Library().myString!!.isEmpty()
     }
 }

j2k/testData/fileOrElement/class/classWithMultiplyFields.kt

@@ -1,5 +1,5 @@
 internal class T {
-    var a: String
-    var b: String
+    var a: String? = null
+    var b: String? = null
     var c = "abc"
 }

j2k/testData/fileOrElement/constructors/nestedClassNameInParameterDefaults2.kt

@@ -1,4 +1,3 @@
-// ERROR: Property must be initialized or be abstract
 import A.Nested
 
 internal class A @JvmOverloads constructor(nested: Nested = Nested(Nested.FIELD)) {
@@ -12,5 +11,5 @@ internal class A @JvmOverloads constructor(nested: Nested = Nested(Nested.FIELD)
 }
 
 internal class B {
-    var nested: Nested
+    var nested: Nested? = null
 }

j2k/testData/fileOrElement/constructors/nestedClassNameInParameterDefaults3.kt

@@ -1,4 +1,3 @@
-// ERROR: Property must be initialized or be abstract
 package pack
 
 import pack.A.Nested
@@ -14,5 +13,5 @@ internal class A @JvmOverloads constructor(nested: Nested = Nested(Nested.FIELD)
 }
 
 internal class B {
-    var nested: Nested
+    var nested: Nested? = null
 }

j2k/testData/fileOrElement/constructors/nestedClassNameInParameterDefaults4.kt

@@ -1,4 +1,3 @@
-// ERROR: Property must be initialized or be abstract
 package pack
 
 import pack.A.*
@@ -14,5 +13,5 @@ internal class A @JvmOverloads constructor(nested: Nested = Nested(Nested.FIELD)
 }
 
 internal class B {
-    var nested: Nested
+    var nested: Nested? = null
 }

j2k/testData/fileOrElement/field/internalField.kt

@@ -1,5 +1,4 @@
 // ERROR: Unresolved reference: Foo
-// ERROR: Property must be initialized or be abstract
 internal class C {
-    var f: Foo
+    var f: Foo? = null
 }

j2k/testData/fileOrElement/field/needInitializer.java

@@ -0,0 +1,22 @@
+public class Init {
+    public String field1;
+    public String field2;
+
+    public int field3;
+    public int field4;
+
+    public Init() {
+        field1 = "str";
+        field3 = 1;
+
+        String prop1;
+        prop1 = "aaa";
+
+        String prop2;
+
+        int prop3;
+        prop3 = 1;
+
+        int prop4;
+    }
+}

j2k/testData/fileOrElement/field/needInitializer.kt

@@ -0,0 +1,22 @@
+class Init {
+    var field1: String
+    var field2: String? = null
+
+    var field3: Int = 0
+    var field4: Int = 0
+
+    init {
+        field1 = "str"
+        field3 = 1
+
+        val prop1: String
+        prop1 = "aaa"
+
+        val prop2: String
+
+        val prop3: Int
+        prop3 = 1
+
+        val prop4: Int
+    }
+}

j2k/testData/fileOrElement/field/protectedField.kt

@@ -1,5 +1,4 @@
 // ERROR: Unresolved reference: Foo
-// ERROR: Property must be initialized or be abstract
 internal class C {
-    protected var f: Foo
+    protected var f: Foo? = null
 }

j2k/testData/fileOrElement/field/publicField.kt

@@ -1,5 +1,4 @@
 // ERROR: Unresolved reference: Foo
-// ERROR: Property must be initialized or be abstract
 internal class C {
-    var f: Foo
+    var f: Foo? = null
 }

j2k/testData/fileOrElement/field/varWithoutInit.kt

@@ -1,5 +1,4 @@
 // ERROR: Unresolved reference: Foo
-// ERROR: Property must be initialized or be abstract
 internal class C {
-    var f: Foo
+    var f: Foo? = null
 }

j2k/testData/fileOrElement/issues/kt-5400.kt

@@ -1,8 +1,7 @@
-// ERROR: Property must be initialized or be abstract
 internal open class Base {
     internal inner class Nested
 }
 
 internal class Derived : Base() {
-    var field: Base.Nested
+    var field: Base.Nested? = null
 }

j2k/tests/org/jetbrains/kotlin/j2k/JavaToKotlinConverterForWebDemoTestGenerated.java

@@ -1825,6 +1825,12 @@ public class JavaToKotlinConverterForWebDemoTestGenerated extends AbstractJavaTo
             doTest(fileName);
         }
 
+        @TestMetadata("needInitializer.java")
+        public void testNeedInitializer() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("j2k/testData/fileOrElement/field/needInitializer.java");
+            doTest(fileName);
+        }
+
         @TestMetadata("privateField.java")
         public void testPrivateField() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("j2k/testData/fileOrElement/field/privateField.java");

j2k/tests/org/jetbrains/kotlin/j2k/JavaToKotlinConverterSingleFileTestGenerated.java

@@ -1825,6 +1825,12 @@ public class JavaToKotlinConverterSingleFileTestGenerated extends AbstractJavaTo
             doTest(fileName);
         }
 
+        @TestMetadata("needInitializer.java")
+        public void testNeedInitializer() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("j2k/testData/fileOrElement/field/needInitializer.java");
+            doTest(fileName);
+        }
+
         @TestMetadata("privateField.java")
         public void testPrivateField() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("j2k/testData/fileOrElement/field/privateField.java");