KotlinGenerateToStringAction: should generate .contentToString instead java.util.Arrays.toString

#KT-27563 Fixed

idea/src/org/jetbrains/kotlin/idea/actions/generate/KotlinGenerateToStringAction.kt

@@ -43,6 +43,7 @@ import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.descriptorUtil.builtIns
 import org.jetbrains.kotlin.resolve.descriptorUtil.getSuperClassOrAny
 import org.jetbrains.kotlin.resolve.source.getPsi
+import org.jetbrains.kotlin.types.isNullable
 import org.jetbrains.kotlin.utils.addToStdlib.lastIsInstanceOrNull
 
 private fun ClassDescriptor.findDeclaredToString(checkSupers: Boolean): FunctionDescriptor? {
@@ -118,7 +119,10 @@ class KotlinGenerateToStringAction : KotlinGenerateMemberActionBase<KotlinGenera
         protected fun renderVariableValue(variableDescriptor: VariableDescriptor, ref: String): String {
             val type = variableDescriptor.type
             return when {
-                KotlinBuiltIns.isArray(type) || KotlinBuiltIns.isPrimitiveArray(type) -> "\${java.util.Arrays.toString($ref)}"
+                KotlinBuiltIns.isArray(type) || KotlinBuiltIns.isPrimitiveArray(type) -> {
+                    val dot = if (type.isNullable()) "?." else "."
+                    "\${$ref${dot}contentToString()}"
+                }
                 KotlinBuiltIns.isString(type) -> "'$$ref'"
                 else -> "$$ref"
             }

idea/testData/codeInsight/generate/toString/multipeTemplates/arrays.kt.after

@@ -1,5 +1,3 @@
-import java.util.Arrays
-
 // GENERATOR: MULTIPLE_TEMPLATES
 class A(val n: IntArray, val s: Array<String>) {
     val f: Float = 1.0f
@@ -10,8 +8,8 @@ class A(val n: IntArray, val s: Array<String>) {
 
     override fun toString(): String {
         return "A(" +
-                "n=${Arrays.toString(n)}, " +
-                "s=${Arrays.toString(s)}, " +
+                "n=${n.contentToString()}, " +
+                "s=${s.contentToString()}, " +
                 "f=$f" +
                 ")"
     }

idea/testData/codeInsight/generate/toString/singleTemplate/arrays.kt.after

@@ -1,5 +1,3 @@
-import java.util.Arrays
-
 // GENERATOR: SINGLE_TEMPLATE
 class A(val n: IntArray, val s: Array<String>) {
     val f: Float = 1.0f
@@ -9,6 +7,6 @@ class A(val n: IntArray, val s: Array<String>) {
     }
 
     override fun toString(): String {
-        return "A(n=${Arrays.toString(n)}, s=${Arrays.toString(s)}, f=$f)"
+        return "A(n=${n.contentToString()}, s=${s.contentToString()}, f=$f)"
     }
 }

idea/testData/codeInsight/generate/toString/singleTemplate/nullableArrays.kt

@@ -0,0 +1,8 @@
+// GENERATOR: SINGLE_TEMPLATE
+class A(val n: IntArray?, val s: Array<String>) {<caret>
+    val f: Float = 1.0f
+
+    fun foo() {
+
+    }
+}

idea/testData/codeInsight/generate/toString/singleTemplate/nullableArrays.kt.after

@@ -0,0 +1,12 @@
+// GENERATOR: SINGLE_TEMPLATE
+class A(val n: IntArray?, val s: Array<String>) {
+    val f: Float = 1.0f
+
+    fun foo() {
+
+    }
+
+    override fun toString(): String {
+        return "A(n=${n?.contentToString()}, s=${s.contentToString()}, f=$f)"
+    }
+}

idea/tests/org/jetbrains/kotlin/idea/codeInsight/generate/GenerateToStringActionTestGenerated.java

@@ -167,6 +167,11 @@ public class GenerateToStringActionTestGenerated extends AbstractGenerateToStrin
             runTest("idea/testData/codeInsight/generate/toString/singleTemplate/noVars.kt");
         }
 
+        @TestMetadata("nullableArrays.kt")
+        public void testNullableArrays() throws Exception {
+            runTest("idea/testData/codeInsight/generate/toString/singleTemplate/nullableArrays.kt");
+        }
+
         @TestMetadata("singleVar.kt")
         public void testSingleVar() throws Exception {
             runTest("idea/testData/codeInsight/generate/toString/singleTemplate/singleVar.kt");