J2K converter applies IfNullToElvisIntention automatically

idea/src/org/jetbrains/kotlin/idea/intentions/IfNullToElvisIntention.kt

@@ -41,6 +41,11 @@ public class IfNullToElvisIntention : JetSelfTargetingOffsetIndependentIntention
     }
 
     override fun applyTo(element: JetIfExpression, editor: Editor) {
+        val newElvis = applyTo(element)
+        editor.getCaretModel().moveToOffset(newElvis.getRight()!!.getTextOffset())
+    }
+
+    public fun applyTo(element: JetIfExpression): JetBinaryExpression {
         val (initializer, declaration, ifNullExpr) = calcData(element)!!
         val factory = JetPsiFactory(element)
 
@@ -67,7 +72,7 @@ public class IfNullToElvisIntention : JetSelfTargetingOffsetIndependentIntention
             declaration.setType(explicitTypeToAdd)
         }
 
-        editor.getCaretModel().moveToOffset(newElvis.getRight()!!.getTextOffset())
+        return newElvis
     }
 
     private data class Data(

idea/src/org/jetbrains/kotlin/idea/j2k/J2kPostProcessor.kt

@@ -18,16 +18,14 @@ package org.jetbrains.kotlin.idea.j2k
 
 import com.intellij.openapi.editor.RangeMarker
 import com.intellij.openapi.util.TextRange
-import com.intellij.psi.PsiComment
 import com.intellij.psi.PsiElement
-import com.intellij.psi.PsiWhiteSpace
 import com.intellij.psi.codeStyle.CodeStyleManager
 import com.intellij.psi.search.LocalSearchScope
 import com.intellij.psi.search.searches.ReferencesSearch
-import com.intellij.psi.util.PsiTreeUtil
 import org.jetbrains.kotlin.diagnostics.Diagnostic
 import org.jetbrains.kotlin.diagnostics.Errors
 import org.jetbrains.kotlin.idea.caches.resolve.getResolutionFacade
+import org.jetbrains.kotlin.idea.intentions.IfNullToElvisIntention
 import org.jetbrains.kotlin.idea.intentions.RemoveExplicitTypeArguments
 import org.jetbrains.kotlin.idea.intentions.SimplifyNegatedBinaryExpressionIntention
 import org.jetbrains.kotlin.idea.intentions.branchedTransformations.intentions.IfThenToElvisIntention
@@ -141,6 +139,15 @@ public class J2kPostProcessor(private val formatCode: Boolean) : PostProcessor {
                             return
                         }
                     }
+
+                    run {
+                        val intention = IfNullToElvisIntention()
+                        if (intention.isApplicableTo(expression)) {
+                            intention.applyTo(expression)
+                            return
+                        }
+                    }
+
                 }
             }
         })

j2k/testData/fileOrElement/codeSimplifications/IfNullReturnToElvis.java

@@ -0,0 +1,9 @@
+import java.io.File;
+
+class C {
+    String foo(File file) {
+        File parent = file.getParentFile();
+        if (parent == null) return "";
+        return parent.getName();
+    }
+}

j2k/testData/fileOrElement/codeSimplifications/IfNullReturnToElvis.kt

@@ -0,0 +1,8 @@
+import java.io.File
+
+class C {
+    fun foo(file: File): String {
+        val parent = file.getParentFile() ?: return ""
+        return parent.getName()
+    }
+}

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

@@ -937,6 +937,12 @@ public class JavaToKotlinConverterForWebDemoTestGenerated extends AbstractJavaTo
             JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("j2k/testData/fileOrElement/codeSimplifications"), Pattern.compile("^(.+)\\.java$"), true);
         }
 
+        @TestMetadata("IfNullReturnToElvis.java")
+        public void testIfNullReturnToElvis() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("j2k/testData/fileOrElement/codeSimplifications/IfNullReturnToElvis.java");
+            doTest(fileName);
+        }
+
         @TestMetadata("IfToElvis.java")
         public void testIfToElvis() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("j2k/testData/fileOrElement/codeSimplifications/IfToElvis.java");

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

@@ -937,6 +937,12 @@ public class JavaToKotlinConverterSingleFileTestGenerated extends AbstractJavaTo
             JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("j2k/testData/fileOrElement/codeSimplifications"), Pattern.compile("^(.+)\\.java$"), true);
         }
 
+        @TestMetadata("IfNullReturnToElvis.java")
+        public void testIfNullReturnToElvis() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("j2k/testData/fileOrElement/codeSimplifications/IfNullReturnToElvis.java");
+            doTest(fileName);
+        }
+
         @TestMetadata("IfToElvis.java")
         public void testIfToElvis() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("j2k/testData/fileOrElement/codeSimplifications/IfToElvis.java");