New J2K: implement mutability inference in post-processing

#KT-24293 fixed
#KT-19603 fixed

nj2k/testData/copyPaste/AddImports.expected.kt

@@ -1,5 +1,5 @@
 import java.io.File
 
-internal fun foo(file: File?): List<String> {
-    return emptyList()
+internal fun foo(file: File?): List<String?>? {
+    return emptyList<String>()
 }

nj2k/testData/copyPaste/AddImportsWithExplicitImports.expected.kt

@@ -1,7 +1,7 @@
 import java.io.File
 
 class C {
-    private fun memberFun(file: File?) {}
+    private fun memberFun(file: File) {}
 
     companion object {
         @JvmStatic

nj2k/testData/copyPaste/MethodWithNoAnnotation.expected.kt

@@ -1,5 +1,5 @@
 package to
 
-fun foo(): String {
+fun foo(): String? {
     return ""
 }

nj2k/testData/copyPaste/MethodWithOnlyOneAnnotation.expected.kt

@@ -1,6 +1,6 @@
 package to
 
 @SomeAnnotation
-fun foo(): String {
+fun foo(): String? {
     return ""
 }

nj2k/testData/copyPaste/SeveralMethodsSample.expected.kt

@@ -23,12 +23,12 @@ class A {
         return JetRefactoringUtil.formatPsiMethod(element as PsiMethod, true, false)
     }
 
-    protected fun getDimensionServiceKey(): String {
+    protected fun getDimensionServiceKey(): String? {
         return "#org.jetbrains.kotlin.idea.refactoring.safeDelete.KotlinOverridingDialog"
     }
 
-    fun getSelected(): ArrayList<UsageInfo> {
-        val result: ArrayList<UsageInfo> = ArrayList<UsageInfo?>()
+    fun getSelected(): ArrayList<UsageInfo>? {
+        val result: ArrayList<UsageInfo> = ArrayList<UsageInfo>()
         for (i in 0 until myChecked.length) {
             if (myChecked.get(i)) {
                 result.add(myOverridingMethods.get(i))

nj2k/testData/copyPastePlainText/AsExpression.expected.kt

@@ -3,5 +3,5 @@ import java.util.ArrayList
 
 
 fun foo() {
-    bar(ArrayList<String?>())
+    bar(ArrayList<String>())
 }

nj2k/testData/copyPastePlainText/AsExpressionBody.expected.kt

@@ -2,4 +2,4 @@
 import java.util.ArrayList
 
 
-fun foo() = ArrayList<String?>()
+fun foo() = ArrayList<String>()

nj2k/testData/copyPastePlainText/KT13529_1.expected.kt

@@ -3,5 +3,5 @@ import java.util.ArrayList
 
 
 fun foo() {
-    bar(/*comment*/ArrayList<String?>())
+    bar(/*comment*/ArrayList<String>())
 }

nj2k/testData/copyPastePlainText/PostProcessing.expected.kt

@@ -5,7 +5,7 @@ import java.util.ArrayList
 
 
 class JavaClass {
-    internal fun foo(file: File?, target: List<String?>?) {
+    internal fun foo(file: File?, target: MutableList<String>?) {
         val list = ArrayList<String>()
         if (file != null) {
             list.add(file.name)

nj2k/testData/inference/common/forLoop.kt

@@ -7,4 +7,4 @@ fun test() {
 
 //T0 <: T1 due to 'INITIALIZER'
 //T2 <: T4 due to 'INITIALIZER'
-//T3 <: T1 due to 'ASSIGNMENT'
+//T1 <: T3 due to 'ASSIGNMENT'

nj2k/testData/inference/common/newExpression.kt

@@ -0,0 +1,5 @@
+class Test {
+    val x: /*T2@*/List</*T1@*/Int> = ArrayList</*T0@*/Int>()/*ArrayList<T0@Int>*/
+}
+
+//T1 := T0 due to 'INITIALIZER'

nj2k/testData/inference/mutability/IteratorMutableCalls.kt

@@ -0,0 +1,8 @@
+fun a(
+    l0: /*T1@*/MutableIterator</*T0@*/Int>
+) {
+    l0/*T1@MutableIterator<T0@Int>*/.remove()
+}
+
+//T0 <: T0 due to 'RECEIVER_PARAMETER'
+//T1 := LOWER due to 'USE_AS_RECEIVER'

nj2k/testData/inference/mutability/arrayList.kt

@@ -0,0 +1,7 @@
+import java.util.ArrayList
+
+fun a() {
+    val list: /*T2@*/List</*T1@*/Int> = ArrayList</*T0@*/Int>()/*ArrayList<T0@Int>*/
+}
+
+//T1 := T0 due to 'INITIALIZER'

nj2k/testData/inference/mutability/collectionMutableCalls.kt

@@ -0,0 +1,30 @@
+fun a(
+        l0: /*T1@*/MutableCollection</*T0@*/Int>,
+        l1: /*T3@*/MutableCollection</*T2@*/Int>,
+        l2: /*T5@*/MutableCollection</*T4@*/Int>,
+        l3: /*T7@*/MutableCollection</*T6@*/Int>,
+        l4: /*T9@*/MutableCollection</*T8@*/Int>
+) {
+    l0/*T1@MutableCollection<T0@Int>*/.add(1/*LIT*/)
+    l1/*T3@MutableCollection<T2@Int>*/.addAll(l1/*T3@MutableCollection<T2@Int>*/)
+    l2/*T5@MutableCollection<T4@Int>*/.clear()
+    l3/*T7@MutableCollection<T6@Int>*/.removeAll(l1/*T3@MutableCollection<T2@Int>*/)
+    l4/*T9@MutableCollection<T8@Int>*/.retainAll(l1/*T3@MutableCollection<T2@Int>*/)
+}
+
+//T0 := T0 due to 'RECEIVER_PARAMETER'
+//T1 := LOWER due to 'USE_AS_RECEIVER'
+//T2 := T2 due to 'RECEIVER_PARAMETER'
+//T2 := T2 due to 'PARAMETER'
+//T3 <: UPPER due to 'PARAMETER'
+//T3 := LOWER due to 'USE_AS_RECEIVER'
+//T4 := T4 due to 'RECEIVER_PARAMETER'
+//T5 := LOWER due to 'USE_AS_RECEIVER'
+//T6 := T6 due to 'RECEIVER_PARAMETER'
+//T6 := T2 due to 'PARAMETER'
+//T3 <: UPPER due to 'PARAMETER'
+//T7 := LOWER due to 'USE_AS_RECEIVER'
+//T8 := T8 due to 'RECEIVER_PARAMETER'
+//T8 := T2 due to 'PARAMETER'
+//T3 <: UPPER due to 'PARAMETER'
+//T9 := LOWER due to 'USE_AS_RECEIVER'

nj2k/testData/inference/mutability/covariance.kt

@@ -0,0 +1,8 @@
+class Nya {
+    private val hashMap: /*T6@*/Map</*T3@*/String, /*T5@*/List</*T4@*/Int>> =
+            HashMap</*T0@*/String, /*T2@*/List</*T1@*/Int>>()/*HashMap<T0@String, T2@MutableList<T1@Int>>*/
+}
+
+//T3 := T0 due to 'INITIALIZER'
+//T4 := T1 due to 'INITIALIZER'
+//T5 := T2 due to 'INITIALIZER'

nj2k/testData/inference/mutability/iteratorCall.kt

@@ -0,0 +1,10 @@
+fun a(l0: /*T1@*/MutableList</*T0@*/Int>) {
+    val iterator: /*T3@*/MutableIterator</*T2@*/Int> = l0/*T1@MutableList<T0@Int>*/.iterator()/*T1@MutableList<T0@Int>*/
+    iterator/*T3@MutableIterator<T2@Int>*/.remove()
+}
+
+//T0 := T0 due to 'RECEIVER_PARAMETER'
+//T2 := T0 due to 'INITIALIZER'
+//T1 <: T3 due to 'INITIALIZER'
+//T2 <: T2 due to 'RECEIVER_PARAMETER'
+//T3 := LOWER due to 'USE_AS_RECEIVER'

nj2k/testData/inference/mutability/list.kt

@@ -0,0 +1,4 @@
+class A {
+    val l: /*T1@*/List</*T0@*/Int>
+}
+

nj2k/testData/inference/mutability/listIteratorMutableCalls.kt

@@ -0,0 +1,16 @@
+fun a(
+        l0: /*T1@*/MutableListIterator</*T0@*/Int>,
+        l1: /*T3@*/MutableListIterator</*T2@*/Int>,
+        l2: /*T5@*/MutableListIterator</*T4@*/Int>
+) {
+    l0/*T1@MutableListIterator<T0@Int>*/.add(1/*LIT*/)
+    l1/*T3@MutableListIterator<T2@Int>*/.remove()
+    l2/*T5@MutableListIterator<T4@Int>*/.set(1/*LIT*/)
+}
+
+//T0 := T0 due to 'RECEIVER_PARAMETER'
+//T1 := LOWER due to 'USE_AS_RECEIVER'
+//T2 := T2 due to 'RECEIVER_PARAMETER'
+//T3 := LOWER due to 'USE_AS_RECEIVER'
+//T4 := T4 due to 'RECEIVER_PARAMETER'
+//T5 := LOWER due to 'USE_AS_RECEIVER'

nj2k/testData/inference/mutability/listMutableCalls.kt

@@ -0,0 +1,46 @@
+fun a(
+        l0: /*T1@*/MutableList</*T0@*/Int>,
+        l1: /*T3@*/MutableList</*T2@*/Int>,
+        l2: /*T5@*/MutableList</*T4@*/Int>,
+        l3: /*T7@*/MutableList</*T6@*/Int>,
+        l4: /*T9@*/MutableList</*T8@*/Int>,
+        l5: /*T11@*/MutableList</*T10@*/Int>,
+        l6: /*T13@*/MutableList</*T12@*/Int>,
+        l7: /*T15@*/MutableList</*T14@*/Int>
+) {
+    l0/*T1@MutableList<T0@Int>*/.add(1/*LIT*/)
+    l1/*T3@MutableList<T2@Int>*/.addAll(1/*LIT*/, l1/*T3@MutableList<T2@Int>*/)
+    l2/*T5@MutableList<T4@Int>*/.addAll(l1/*T3@MutableList<T2@Int>*/)
+    l3/*T7@MutableList<T6@Int>*/.clear()
+    l4/*T9@MutableList<T8@Int>*/.remove(1/*LIT*/)
+    l5/*T11@MutableList<T10@Int>*/.removeAll(l1/*T3@MutableList<T2@Int>*/)
+    l5/*T11@MutableList<T10@Int>*/.removeAt(0/*LIT*/)
+    l6/*T13@MutableList<T12@Int>*/.retainAll(l1/*T3@MutableList<T2@Int>*/)
+    l7/*T15@MutableList<T14@Int>*/.set(0/*LIT*/, 0/*LIT*/)
+}
+
+//T0 := T0 due to 'RECEIVER_PARAMETER'
+//T1 := LOWER due to 'USE_AS_RECEIVER'
+//T2 := T2 due to 'RECEIVER_PARAMETER'
+//T2 := T2 due to 'PARAMETER'
+//T3 <: UPPER due to 'PARAMETER'
+//T3 := LOWER due to 'USE_AS_RECEIVER'
+//T4 := T4 due to 'RECEIVER_PARAMETER'
+//T4 := T2 due to 'PARAMETER'
+//T3 <: UPPER due to 'PARAMETER'
+//T5 := LOWER due to 'USE_AS_RECEIVER'
+//T6 := T6 due to 'RECEIVER_PARAMETER'
+//T7 := LOWER due to 'USE_AS_RECEIVER'
+//T8 := T8 due to 'RECEIVER_PARAMETER'
+//T9 := LOWER due to 'USE_AS_RECEIVER'
+//T10 := T10 due to 'RECEIVER_PARAMETER'
+//T10 := T2 due to 'PARAMETER'
+//T3 <: UPPER due to 'PARAMETER'
+//T11 := LOWER due to 'USE_AS_RECEIVER'
+//T10 := T10 due to 'RECEIVER_PARAMETER'
+//T12 := T12 due to 'RECEIVER_PARAMETER'
+//T12 := T2 due to 'PARAMETER'
+//T3 <: UPPER due to 'PARAMETER'
+//T13 := LOWER due to 'USE_AS_RECEIVER'
+//T14 := T14 due to 'RECEIVER_PARAMETER'
+//T15 := LOWER due to 'USE_AS_RECEIVER'

nj2k/testData/inference/mutability/listOfListsForEach.kt

@@ -0,0 +1,15 @@
+import java.util.ArrayList
+
+fun test() {
+    val list: /*T4@*/List</*T3@*/MutableList</*T2@*/Int>> = ArrayList</*T1@*/MutableList</*T0@*/Int>>()/*ArrayList<T1@MutableList<T0@Int>>*/
+    for(l: /*T6@*/MutableList</*T5@*/Int> in list/*T4@MutableList<T3@MutableList<T2@Int>>*/) {
+        l/*T6@MutableList<T5@Int>*/.add(42/*LIT*/)
+    }
+}
+
+//T2 := T0 due to 'INITIALIZER'
+//T3 := T1 due to 'INITIALIZER'
+//T5 := T5 due to 'RECEIVER_PARAMETER'
+//T6 := LOWER due to 'USE_AS_RECEIVER'
+//T5 := T2 due to 'ASSIGNMENT'
+//T3 <: T6 due to 'ASSIGNMENT'

nj2k/testData/inference/mutability/listOfMutableList.kt

@@ -0,0 +1,14 @@
+import java.util.ArrayList
+
+fun a() {
+    val list: /*T4@*/List</*T3@*/MutableList</*T2@*/Int>> = ArrayList</*T1@*/MutableList</*T0@*/Int>>()/*ArrayList<T1@MutableList<T0@Int>>*/
+    list/*T4@MutableList<T3@MutableList<T2@Int>>*/.get(0/*LIT*/)/*T3@MutableList<T2@Int>*/.add(1/*LIT*/)
+}
+
+//T2 := T0 due to 'INITIALIZER'
+//T3 := T1 due to 'INITIALIZER'
+//T2 := T2 due to 'RECEIVER_PARAMETER'
+//T3 := T3 due to 'RECEIVER_PARAMETER'
+//T4 <: UPPER due to 'RECEIVER_PARAMETER'
+//T2 := T2 due to 'RECEIVER_PARAMETER'
+//T3 := LOWER due to 'USE_AS_RECEIVER'

nj2k/testData/inference/mutability/mapEntryMutableCalls.kt

@@ -0,0 +1,9 @@
+fun a(
+    l0: /*T2@*/MutableMap.MutableEntry</*T0@*/Int, /*T1@*/String>
+) {
+    l0/*T2@MutableEntry<T0@Int, T1@String>*/.setValue(1/*LIT*/, "nya")
+}
+
+//T0 := T0 due to 'RECEIVER_PARAMETER'
+//T1 := T1 due to 'RECEIVER_PARAMETER'
+//T2 := LOWER due to 'USE_AS_RECEIVER'

nj2k/testData/inference/mutability/mapMutableCalls.kt

@@ -0,0 +1,27 @@
+fun a(
+        l0: /*T2@*/MutableMap</*T0@*/Int, /*T1@*/String>,
+        l1: /*T5@*/MutableMap</*T3@*/Int, /*T4@*/String>,
+        l2: /*T8@*/MutableMap</*T6@*/Int, /*T7@*/String>,
+        l3: /*T11@*/MutableMap</*T9@*/Int, /*T10@*/String>
+) {
+    l0/*T2@MutableMap<T0@Int, T1@String>*/.put(1)
+    l1/*T5@MutableMap<T3@Int, T4@String>*/.remove(1/*LIT*/, l1)
+    l2/*T8@MutableMap<T6@Int, T7@String>*/.putAll(l1/*T5@MutableMap<T3@Int, T4@String>*/)
+    l3/*T11@MutableMap<T9@Int, T10@String>*/.clear(1)
+}
+
+//T0 := T0 due to 'RECEIVER_PARAMETER'
+//T1 := T1 due to 'RECEIVER_PARAMETER'
+//T2 := LOWER due to 'USE_AS_RECEIVER'
+//T3 := T3 due to 'RECEIVER_PARAMETER'
+//T4 := T4 due to 'RECEIVER_PARAMETER'
+//T5 := LOWER due to 'USE_AS_RECEIVER'
+//T6 := T6 due to 'RECEIVER_PARAMETER'
+//T7 := T7 due to 'RECEIVER_PARAMETER'
+//T6 := T3 due to 'PARAMETER'
+//T7 := T4 due to 'PARAMETER'
+//T5 <: UPPER due to 'PARAMETER'
+//T8 := LOWER due to 'USE_AS_RECEIVER'
+//T9 := T9 due to 'RECEIVER_PARAMETER'
+//T10 := T10 due to 'RECEIVER_PARAMETER'
+//T11 := LOWER due to 'USE_AS_RECEIVER'

nj2k/testData/inference/mutability/setMutableCalls.kt

@@ -0,0 +1,30 @@
+fun a(
+        l0: /*T1@*/MutableSet</*T0@*/Int>,
+        l1: /*T3@*/MutableSet</*T2@*/Int>,
+        l2: /*T5@*/MutableSet</*T4@*/Int>,
+        l3: /*T7@*/MutableSet</*T6@*/Int>,
+        l4: /*T9@*/MutableSet</*T8@*/Int>
+) {
+    l0/*T1@MutableSet<T0@Int>*/.add(1/*LIT*/)
+    l1/*T3@MutableSet<T2@Int>*/.addAll(l1/*T3@MutableSet<T2@Int>*/)
+    l2/*T5@MutableSet<T4@Int>*/.clear()
+    l3/*T7@MutableSet<T6@Int>*/.removeAll(l1/*T3@MutableSet<T2@Int>*/)
+    l4/*T9@MutableSet<T8@Int>*/.retainAll(l1/*T3@MutableSet<T2@Int>*/)
+}
+
+//T0 := T0 due to 'RECEIVER_PARAMETER'
+//T1 := LOWER due to 'USE_AS_RECEIVER'
+//T2 := T2 due to 'RECEIVER_PARAMETER'
+//T2 := T2 due to 'PARAMETER'
+//T3 <: UPPER due to 'PARAMETER'
+//T3 := LOWER due to 'USE_AS_RECEIVER'
+//T4 := T4 due to 'RECEIVER_PARAMETER'
+//T5 := LOWER due to 'USE_AS_RECEIVER'
+//T6 := T6 due to 'RECEIVER_PARAMETER'
+//T6 := T2 due to 'PARAMETER'
+//T3 <: UPPER due to 'PARAMETER'
+//T7 := LOWER due to 'USE_AS_RECEIVER'
+//T8 := T8 due to 'RECEIVER_PARAMETER'
+//T8 := T2 due to 'PARAMETER'
+//T3 <: UPPER due to 'PARAMETER'
+//T9 := LOWER due to 'USE_AS_RECEIVER'

nj2k/testData/inference/nullability/loopIterator.kt

@@ -4,5 +4,5 @@ fun test(a: /*T1@*/List</*T0@*/Int?>) {
     }
 }
 
-//T2 <: T0 due to 'ASSIGNMENT'
+//T0 <: T2 due to 'ASSIGNMENT'
 //T1 := LOWER due to 'USE_AS_RECEIVER'

nj2k/testData/inference/nullability/loops.kt

@@ -1,4 +1,4 @@
-fun bar(map: /*T2@*/HashMap</*T0@*/String?, /*T1@*/Int>, list1: /*T4@*/List</*T3@*/Int?>, list2: /*T6@*/List</*T5@*/String?>) {
+fun bar(map: /*T2@*/HashMap</*T0@*/String?, /*T1@*/Int>, list1: /*T4@*/List</*T3@*/Int>, list2: /*T6@*/List</*T5@*/String?>) {
     for (entry: /*T9@*/MutableMap.MutableEntry</*T7@*/String?, /*T8@*/Int> in map/*T2@HashMap<T0@String, T1@Int>*/.entries/*MutableSet<MutableEntry<T0@String, T1@Int>>*/) {
         val value: /*T10@*/Int = entry/*T9@MutableEntry<T7@String, T8@Int>*/.value/*T8@Int*/
         if (entry/*T9@MutableEntry<T7@String, T8@Int>*/.key/*T7@String*/ == null/*LIT*/) {
@@ -21,11 +21,11 @@ fun bar(map: /*T2@*/HashMap</*T0@*/String?, /*T1@*/Int>, list1: /*T4@*/List</*T3
 //T9 := LOWER due to 'USE_AS_RECEIVER'
 //T7 := UPPER due to 'COMPARE_WITH_NULL'
 //T10 := LOWER due to 'USE_AS_RECEIVER'
-//T0 := T7 due to 'ASSIGNMENT'
-//T1 := T8 due to 'ASSIGNMENT'
+//T7 := T0 due to 'ASSIGNMENT'
+//T8 := T1 due to 'ASSIGNMENT'
 //T11 := LOWER due to 'USE_AS_RECEIVER'
-//T11 <: T3 due to 'ASSIGNMENT'
+//T3 <: T11 due to 'ASSIGNMENT'
 //T4 := LOWER due to 'USE_AS_RECEIVER'
 //T12 := UPPER due to 'COMPARE_WITH_NULL'
-//T12 <: T5 due to 'ASSIGNMENT'
+//T5 <: T12 due to 'ASSIGNMENT'
 //T6 := LOWER due to 'USE_AS_RECEIVER'

nj2k/testData/newJ2k/detectProperties/Overrides.kt

@@ -18,19 +18,19 @@ internal open class B {
     open val fromB1: String
         get() = ""
 
-    open var fromB2: String
+    open var fromB2: String?
         get() = ""
         set(value) {}
 
-    open var fromB3: String
+    open var fromB3: String?
         get() = ""
         set(value) {}
 
-    open var fromB4: String
+    open var fromB4: String?
         get() = ""
         set(value) {}
 
-    open fun setFromB5(value: String) {}
+    open fun setFromB5(value: String?) {}
 }
 
 internal abstract class C(override val something1: Int) : B(), I {
@@ -59,19 +59,19 @@ internal abstract class C(override val something1: Int) : B(), I {
     override val fromB1: String
         get() = super.fromB1
 
-    override var fromB2: String
+    override var fromB2: String?
         get() = super.fromB2
         set(value) {
             super.fromB2 = value
         }
 
-    override var fromB3: String
+    override var fromB3: String?
         get() = super.fromB3
         set(fromB3) {
             super.fromB3 = fromB3
         }
 
-    override var fromB4: String
+    override var fromB4: String?
         get() = super.fromB4
         set(value) {
             super.fromB4 = value
@@ -81,7 +81,8 @@ internal abstract class C(override val something1: Int) : B(), I {
         return ""
     }
 
-    override fun setFromB5(value: String) {
+    override fun setFromB5(value: String?) {
         super.setFromB5(value)
     }
+
 }

nj2k/testData/newJ2k/detectProperties/commentInInitStatement.java

@@ -0,0 +1,8 @@
+public class Nya {
+    private int i;
+
+    public Nya(int i) {
+        /*comment before*/
+        this/*1*/./*2*/i/*3*/ = /*4*/i /* comment after*/; // and after again
+    }
+}

nj2k/testData/newJ2k/detectProperties/commentInInitStatement.kt

@@ -0,0 +1 @@
+class Nya /*comment before*/(/*1*//*3*/ /*4*/private val i: Int)

nj2k/testData/newJ2k/foreachStatement/nullableIterable.kt

@@ -1,5 +1,5 @@
 internal class A {
-    var list: List<String?>? = null
+    var list: List<String>? = null
     fun foo() {
         for (e in list!!) {
             println(e)

nj2k/testData/newJ2k/issues/kt-15791.kt

@@ -3,6 +3,6 @@ import java.util.ArrayList
 internal object A {
     @JvmStatic
     fun main(args: Array<String>) {
-        List::class.java.isAssignableFrom(ArrayList::class.java)
+        MutableList::class.java.isAssignableFrom(ArrayList::class.java)
     }
 }

nj2k/testData/newJ2k/issues/kt-5294.kt

@@ -1,4 +1,5 @@
-internal class X(private val list: MutableList<Y>) {
+internal class X(private val list: List<Y>) {
 
     internal inner class Y
+
 }

nj2k/testData/newJ2k/methodCallExpression/specialBuiltinMembers.kt

@@ -1,4 +1,3 @@
-// ERROR: Operator call corresponds to a dot-qualified call 'value.plus(1)' which is not allowed on a nullable receiver 'value'.
 import java.util.HashMap
 
 internal enum class E { A, B, C }
@@ -15,7 +14,7 @@ internal class A {
         val i = map.entries.iterator().next().key + 1
     }
 
-    fun bar(list: MutableList<String?>, map: HashMap<String?, Int?>) {
+    fun bar(list: MutableList<String?>, map: HashMap<String, Int>) {
         val c = "a"[0]
         val b = 10.toByte()
         val i = 10.1.toInt()

nj2k/testData/newJ2k/mutableCollections/implementMutableIterator.java

@@ -0,0 +1,17 @@
+import java.util.Iterator;
+
+public class TestMutableIterator implements Iterator<String> {
+    @Override
+    public boolean hasNext() {
+        return false;
+    }
+
+    @Override
+    public String next() {
+        return null;
+    }
+
+    @Override
+    public void remove() {
+    }
+}

nj2k/testData/newJ2k/mutableCollections/listOfMutableList.java

@@ -0,0 +1,11 @@
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+
+public class Test {
+    List<List<Integer>> list = new ArrayList<>();
+
+    public void test() {
+        list.get(0).add(1)
+    }
+}

nj2k/testData/newJ2k/mutableCollections/listOfMutableList.kt

@@ -0,0 +1,8 @@
+import java.util.ArrayList
+
+class Test {
+    internal var list: List<List<Int>> = ArrayList()
+    fun test() {
+        list[0].add(1)
+    }
+}

nj2k/testData/newJ2k/mutableCollections/mutableListInOtherClass.java

@@ -0,0 +1,12 @@
+import java.util.ArrayList;
+import java.util.List;
+
+public class Owner {
+    public List<String> list = new ArrayList<>();
+}
+
+public class Updater {
+    public void update(Owner owner) {
+        owner.list.add("");
+    }
+}

nj2k/testData/newJ2k/mutableCollections/mutableListInOtherClass.kt

@@ -0,0 +1,11 @@
+import java.util.ArrayList
+
+class Owner {
+    var list: MutableList<String> = ArrayList()
+}
+
+class Updater {
+    fun update(owner: Owner) {
+        owner.list.add("")
+    }
+}