From a9ddc4da1ab4b09809f62d7ba8af71c8b6924d1c Mon Sep 17 00:00:00 2001
From: Alexey Sedunov <alexey.sedunov@jetbrains.com>
Date: Fri, 5 Feb 2016 15:18:57 +0300
Subject: [PATCH] Change Signature: Warn about safe call receiver being
 transformed to value argument  #KT-8744 Fixed

---
 .../KotlinChangeSignatureUsageProcessor.kt    | 23 +++++++++++++++++++
 .../ReceiverInSafeCallBefore.kt               |  5 ++++
 .../ReceiverInSafeCallMessages.txt            |  1 +
 .../KotlinChangeSignatureTest.kt              |  2 ++
 4 files changed, 31 insertions(+)
 create mode 100644 idea/testData/refactoring/changeSignature/ReceiverInSafeCallBefore.kt
 create mode 100644 idea/testData/refactoring/changeSignature/ReceiverInSafeCallMessages.txt

diff --git a/idea/src/org/jetbrains/kotlin/idea/refactoring/changeSignature/KotlinChangeSignatureUsageProcessor.kt b/idea/src/org/jetbrains/kotlin/idea/refactoring/changeSignature/KotlinChangeSignatureUsageProcessor.kt
index 2dccc1c82f6..d3d29f54e0c 100644
--- a/idea/src/org/jetbrains/kotlin/idea/refactoring/changeSignature/KotlinChangeSignatureUsageProcessor.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/refactoring/changeSignature/KotlinChangeSignatureUsageProcessor.kt
@@ -584,6 +584,7 @@ class KotlinChangeSignatureUsageProcessor : ChangeSignatureUsageProcessor {
         if (function is KtCallableDeclaration && newReceiverInfo != originalReceiverInfo) {
             findReceiverIntroducingConflicts(result, function, newReceiverInfo)
             findInternalExplicitReceiverConflicts(refUsages.get(), result, originalReceiverInfo)
+            findReceiverToParameterInSafeCallsConflicts(refUsages.get(), result, info)
             findThisLabelConflicts(refUsages, result, info, function)
         }
 
@@ -674,6 +675,28 @@ class KotlinChangeSignatureUsageProcessor : ChangeSignatureUsageProcessor {
         }
     }
 
+    private fun findReceiverToParameterInSafeCallsConflicts(
+            usages: Array<UsageInfo>,
+            result: MultiMap<PsiElement, String>,
+            changeInfo: KotlinChangeInfo
+    ) {
+        val originalReceiverInfo = changeInfo.methodDescriptor.receiver
+        if (originalReceiverInfo == null || originalReceiverInfo !in changeInfo.getNonReceiverParameters()) return
+
+        for (usageInfo in usages) {
+            if (!(usageInfo is KotlinFunctionCallUsage || usageInfo is KotlinPropertyCallUsage)) continue
+
+            val callElement = usageInfo.element as? KtElement ?: continue
+            val qualifiedExpression = callElement.getQualifiedExpressionForSelector()
+            if (qualifiedExpression is KtSafeQualifiedExpression) {
+                result.putValue(
+                        callElement,
+                        "Receiver can't be safely transformed to value argument: ${CommonRefactoringUtil.htmlEmphasize(qualifiedExpression.text)}"
+                )
+            }
+        }
+    }
+
     private fun findReceiverIntroducingConflicts(
             result: MultiMap<PsiElement, String>,
             callable: PsiElement,
diff --git a/idea/testData/refactoring/changeSignature/ReceiverInSafeCallBefore.kt b/idea/testData/refactoring/changeSignature/ReceiverInSafeCallBefore.kt
new file mode 100644
index 00000000000..e5e061416fd
--- /dev/null
+++ b/idea/testData/refactoring/changeSignature/ReceiverInSafeCallBefore.kt
@@ -0,0 +1,5 @@
+interface A {
+    val parent: A?
+}
+
+fun A.<caret>ext(): Int = 1 + (parent?.ext() ?: 0)
\ No newline at end of file
diff --git a/idea/testData/refactoring/changeSignature/ReceiverInSafeCallMessages.txt b/idea/testData/refactoring/changeSignature/ReceiverInSafeCallMessages.txt
new file mode 100644
index 00000000000..36c74e9df60
--- /dev/null
+++ b/idea/testData/refactoring/changeSignature/ReceiverInSafeCallMessages.txt
@@ -0,0 +1 @@
+Receiver can't be safely transformed to value argument: parent?.ext()
\ No newline at end of file
diff --git a/idea/tests/org/jetbrains/kotlin/idea/refactoring/changeSignature/KotlinChangeSignatureTest.kt b/idea/tests/org/jetbrains/kotlin/idea/refactoring/changeSignature/KotlinChangeSignatureTest.kt
index 2ae21081ed6..a5a085e49b1 100644
--- a/idea/tests/org/jetbrains/kotlin/idea/refactoring/changeSignature/KotlinChangeSignatureTest.kt
+++ b/idea/tests/org/jetbrains/kotlin/idea/refactoring/changeSignature/KotlinChangeSignatureTest.kt
@@ -949,4 +949,6 @@ class KotlinChangeSignatureTest : KotlinCodeInsightTestCase() {
         receiverParameterInfo = null
         newParameters[0].name = "a"
     }
+
+    fun testReceiverInSafeCall() = doTestConflict { receiverParameterInfo = null }
 }
\ No newline at end of file