J2K: auto-replacing of if's with safe access

Author: valentinkip

idea/src/org/jetbrains/kotlin/idea/intentions/branchedTransformations/intentions/IfThenToSafeAccessIntention.kt

@@ -58,6 +58,11 @@ public class IfThenToSafeAccessIntention : JetSelfTargetingIntention<JetIfExpres
     }
 
     override fun applyTo(element: JetIfExpression, editor: Editor) {
+        val safeAccessExpr = applyTo(element)
+        safeAccessExpr.inlineReceiverIfApplicableWithPrompt(editor)
+    }
+
+    public fun applyTo(element: JetIfExpression): JetSafeQualifiedExpression {
         val condition = element.getCondition() as JetBinaryExpression
         val receiverExpression = checkNotNull(condition.getNonNullExpression(), "The receiver expression cannot be null")
 
@@ -79,8 +84,7 @@ public class IfThenToSafeAccessIntention : JetSelfTargetingIntention<JetIfExpres
                 }
 
         val resultingExprString = "${receiverExpression.getText()}?.${selectorExpression?.getText()}"
-        val safeAccessExpr = element.replace(resultingExprString) as JetSafeQualifiedExpression
-        safeAccessExpr.inlineReceiverIfApplicableWithPrompt(editor)
+        return element.replace(resultingExprString) as JetSafeQualifiedExpression
     }
 
     fun clauseContainsAppropriateDotQualifiedExpression(clause: JetExpression, receiverExpression: JetExpression): Boolean =

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

@@ -22,11 +22,11 @@ import org.jetbrains.kotlin.diagnostics.Errors
 import org.jetbrains.kotlin.idea.caches.resolve.analyzeFullyAndGetResult
 import org.jetbrains.kotlin.idea.intentions.RemoveExplicitTypeArguments
 import org.jetbrains.kotlin.idea.intentions.SimplifyNegatedBinaryExpressionIntention
+import org.jetbrains.kotlin.idea.intentions.branchedTransformations.intentions.IfThenToSafeAccessIntention
 import org.jetbrains.kotlin.idea.quickfix.RemoveRightPartOfBinaryExpressionFix
 import org.jetbrains.kotlin.j2k.PostProcessor
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.resolve.BindingContext
-import org.jetbrains.kotlin.utils.printAndReturn
 import java.util.ArrayList
 
 public class J2kPostProcessor(override val contextToAnalyzeIn: PsiElement) : PostProcessor {
@@ -65,6 +65,15 @@ public class J2kPostProcessor(override val contextToAnalyzeIn: PsiElement) : Pos
                     intention.applyTo(expression)
                 }
             }
+
+            override fun visitIfExpression(expression: JetIfExpression) {
+                super.visitIfExpression(expression)
+
+                val intention = IfThenToSafeAccessIntention()
+                if (intention.isApplicableTo(expression)) {
+                    intention.applyTo(expression)
+                }
+            }
         })
 
         for (typeArgs in redundantTypeArgs) {

j2k/testData/fileOrElement/codeSimplifications/IfToSafeCall.java

@@ -0,0 +1,9 @@
+import java.io.File;
+
+class C {
+    void foo(File file) {
+        if (file != null) {
+            file.delete();
+        }
+    }
+}

j2k/testData/fileOrElement/codeSimplifications/IfToSafeCall.kt

@@ -0,0 +1,7 @@
+import java.io.File
+
+class C {
+    fun foo(file: File?) {
+        file?.delete()
+    }
+}

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

@@ -982,6 +982,12 @@ public void testAllFilesPresentInCodeSimplifications() throws Exception {
             JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("j2k/testData/fileOrElement/codeSimplifications"), Pattern.compile("^(.+)\\.java$"), true);
         }
 
+        @TestMetadata("IfToSafeCall.java")
+        public void testIfToSafeCall() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("j2k/testData/fileOrElement/codeSimplifications/IfToSafeCall.java");
+            doTest(fileName);
+        }
+
         @TestMetadata("NotIs.java")
         public void testNotIs() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("j2k/testData/fileOrElement/codeSimplifications/NotIs.java");

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

@@ -982,6 +982,12 @@ public void testAllFilesPresentInCodeSimplifications() throws Exception {
             JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("j2k/testData/fileOrElement/codeSimplifications"), Pattern.compile("^(.+)\\.java$"), true);
         }
 
+        @TestMetadata("IfToSafeCall.java")
+        public void testIfToSafeCall() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("j2k/testData/fileOrElement/codeSimplifications/IfToSafeCall.java");
+            doTest(fileName);
+        }
+
         @TestMetadata("NotIs.java")
         public void testNotIs() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("j2k/testData/fileOrElement/codeSimplifications/NotIs.java");