IDEA plugin: fixed crashing ifExpressionToElvis intention when applying to if expression which is part of another expression.

#EA-57307 fixed

idea/src/org/jetbrains/jet/plugin/intentions/branchedTransformations/intentions/IfThenToElvisIntention.kt

@@ -31,6 +31,8 @@ import org.jetbrains.jet.plugin.intentions.branchedTransformations.inlineLeftSid
 import org.jetbrains.jet.plugin.intentions.branchedTransformations.isStableVariable
 import org.jetbrains.jet.plugin.intentions.branchedTransformations.throwsNullPointerExceptionWithNoArguments
 import org.jetbrains.jet.lang.psi.JetThrowExpression
+import org.jetbrains.jet.lang.psi.JetPsiUtil
+import org.jetbrains.jet.lang.psi.JetExpression
 
 public class IfThenToElvisIntention : JetSelfTargetingIntention<JetIfExpression>("if.then.to.elvis", javaClass()) {
 
@@ -73,7 +75,12 @@ public class IfThenToElvisIntention : JetSelfTargetingIntention<JetIfExpression>
                 }
 
         val resultingExprString = "${left.getText()} ?: ${right.getText()}"
-        val elvis = element.replace(resultingExprString) as JetBinaryExpression
+        val resultingExpression = JetPsiUtil.deparenthesize(element.replace(resultingExprString) as? JetExpression)
+
+        assert(resultingExpression is JetBinaryExpression,
+               "Unexpected expression type: ${resultingExpression?.javaClass}, expected JetBinaryExpression, element = '${element.getText()}'")
+
+        val elvis= resultingExpression as JetBinaryExpression
         elvis.inlineLeftSideIfApplicableWithPrompt(editor)
     }
 }

idea/testData/intentions/branched/ifThenToElvis/ifAsPartOfExpression.kt

@@ -0,0 +1,9 @@
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+fun main(args: Array<String>) {
+    val foo = maybeFoo()
+    val bar = "bar"
+    val x = "baz" + if (foo == null<caret>) bar else foo
+}

idea/testData/intentions/branched/ifThenToElvis/ifAsPartOfExpression.kt.after

@@ -0,0 +1,8 @@
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+fun main(args: Array<String>) {
+    val bar = "bar"
+    val x = "baz" + (maybeFoo() ?: bar)
+}

idea/testData/intentions/branched/ifThenToElvis/inspectionData/expected.xml

@@ -47,6 +47,14 @@
     <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">If-Then foldable to '?:'.</problem_class>
     <description>Replace 'if' expression with elvis expression</description>
   </problem>
+  <problem>
+    <file>ifAsPartOfExpression.kt</file>
+    <line>8</line>
+    <module>light_idea_test_case</module>
+    <entry_point TYPE="file" FQNAME="temp:///src/src/ifAsPartOfExpression.kt" />
+    <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">If-Then foldable to '?:'.</problem_class>
+    <description>Replace 'if' expression with elvis expression</description>
+  </problem>
   <problem>
     <file>ifAndElseNotInBlocks.kt</file>
     <line>8</line>

idea/tests/org/jetbrains/jet/plugin/intentions/CodeTransformationTestGenerated.java

@@ -413,6 +413,11 @@ public class CodeTransformationTestGenerated extends AbstractCodeTransformationT
             doTestIfThenToElvis("idea/testData/intentions/branched/ifThenToElvis/ifAsExpression.kt");
         }
         
+        @TestMetadata("ifAsPartOfExpression.kt")
+        public void testIfAsPartOfExpression() throws Exception {
+            doTestIfThenToElvis("idea/testData/intentions/branched/ifThenToElvis/ifAsPartOfExpression.kt");
+        }
+        
         @TestMetadata("lhsEqualsNull.kt")
         public void testLhsEqualsNull() throws Exception {
             doTestIfThenToElvis("idea/testData/intentions/branched/ifThenToElvis/lhsEqualsNull.kt");