Modified IfThenToElvis to not apply when using '!!' would be better

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

@@ -29,6 +29,8 @@ import org.jetbrains.jet.plugin.intentions.branchedTransformations.isNotNullExpr
 import org.jetbrains.jet.plugin.intentions.branchedTransformations.replace
 import org.jetbrains.jet.plugin.intentions.branchedTransformations.inlineLeftSideIfApplicableWithPrompt
 import org.jetbrains.jet.plugin.intentions.branchedTransformations.isStableVariable
+import org.jetbrains.jet.plugin.intentions.branchedTransformations.throwsNullPointerExceptionWithNoArguments
+import org.jetbrains.jet.lang.psi.JetThrowExpression
 
 public class IfThenToElvisIntention : JetSelfTargetingIntention<JetIfExpression>("if.then.to.elvis", javaClass()) {
 
@@ -42,8 +44,15 @@ public class IfThenToElvisIntention : JetSelfTargetingIntention<JetIfExpression>
         if (expression == null || !expression.isStableVariable()) return false
 
         return when (condition.getOperationToken()) {
-            JetTokens.EQEQ -> thenClause.isNotNullExpression() && elseClause.evaluatesTo(expression)
-            JetTokens.EXCLEQ -> elseClause.isNotNullExpression() && thenClause.evaluatesTo(expression)
+            JetTokens.EQEQ ->
+                thenClause.isNotNullExpression() && elseClause.evaluatesTo(expression) &&
+                !(thenClause is JetThrowExpression && thenClause.throwsNullPointerExceptionWithNoArguments())
+
+
+            JetTokens.EXCLEQ ->
+                elseClause.isNotNullExpression() && thenClause.evaluatesTo(expression) &&
+                !(elseClause is JetThrowExpression && elseClause.throwsNullPointerExceptionWithNoArguments())
+
             else -> false
         }
     }

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

@@ -79,4 +79,12 @@
     <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>throwsNPEwithArgument.kt</file>
+    <line>4</line>
+    <module>light_idea_test_case</module>
+    <entry_point TYPE="file" FQNAME="temp:///src/src/throwsNPEwithArgument.kt" />
+    <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">If-Then foldable to '?:'</problem_class>
+    <description>Replace 'if' expression with elvis expression</description>
+  </problem>
 </problems>

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

@@ -0,0 +1,6 @@
+// IS_APPLICABLE: false
+// WITH_RUNTIME
+fun main(args: Array<String>) {
+    val t: String? = "abc"
+    if (t != null<caret>) t else throw KotlinNullPointerException()
+}

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

@@ -0,0 +1,6 @@
+// IS_APPLICABLE: false
+// WITH_RUNTIME
+fun main(args: Array<String>) {
+    val t: String? = "abc"
+    if (t == null<caret>) throw NullPointerException() else t
+}

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

@@ -0,0 +1,5 @@
+// WITH_RUNTIME
+fun main(args: Array<String>) {
+    val t: String? = "abc"
+    if (t != null<caret>) t else throw NullPointerException("'t' must not be null")
+}

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

@@ -0,0 +1,4 @@
+// WITH_RUNTIME
+fun main(args: Array<String>) {
+    "abc" ?: throw NullPointerException("'t' must not be null")
+}