From ef1e54eda975b7c5b6992fadb4e042b6bc1b9fea Mon Sep 17 00:00:00 2001
From: Toshiaki Kameyama <kmymtsak@gmail.com>
Date: Tue, 18 Feb 2020 01:20:24 +0900
Subject: [PATCH] ReplaceToStringWithStringTemplateInspection: insert curly
 braces if needed

#KT-36735 Fixed
---
 .../ReplaceToStringWithStringTemplateInspection.kt    | 11 ++++++-----
 .../callExpression.kt                                 |  3 +++
 .../callExpression.kt.after                           |  3 +++
 .../inspections/LocalInspectionTestGenerated.java     |  5 +++++
 4 files changed, 17 insertions(+), 5 deletions(-)
 create mode 100644 idea/testData/inspectionsLocal/replaceToStringWithStringTemplate/callExpression.kt
 create mode 100644 idea/testData/inspectionsLocal/replaceToStringWithStringTemplate/callExpression.kt.after

diff --git a/idea/src/org/jetbrains/kotlin/idea/inspections/ReplaceToStringWithStringTemplateInspection.kt b/idea/src/org/jetbrains/kotlin/idea/inspections/ReplaceToStringWithStringTemplateInspection.kt
index 837a6b44246..0d13b241487 100644
--- a/idea/src/org/jetbrains/kotlin/idea/inspections/ReplaceToStringWithStringTemplateInspection.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/inspections/ReplaceToStringWithStringTemplateInspection.kt
@@ -7,11 +7,10 @@ package org.jetbrains.kotlin.idea.inspections
 
 import com.intellij.openapi.editor.Editor
 import com.intellij.openapi.project.Project
+import org.jetbrains.kotlin.idea.core.canDropBraces
+import org.jetbrains.kotlin.idea.core.dropBraces
 import org.jetbrains.kotlin.idea.intentions.isToString
-import org.jetbrains.kotlin.psi.KtBlockStringTemplateEntry
-import org.jetbrains.kotlin.psi.KtDotQualifiedExpression
-import org.jetbrains.kotlin.psi.KtPsiFactory
-import org.jetbrains.kotlin.psi.KtReferenceExpression
+import org.jetbrains.kotlin.psi.*
 
 class ReplaceToStringWithStringTemplateInspection : AbstractApplicabilityBasedInspection<KtDotQualifiedExpression>(
     KtDotQualifiedExpression::class.java
@@ -24,7 +23,9 @@ class ReplaceToStringWithStringTemplateInspection : AbstractApplicabilityBasedIn
 
     override fun applyTo(element: KtDotQualifiedExpression, project: Project, editor: Editor?) {
         val variable = element.receiverExpression.text
-        element.replace(KtPsiFactory(element).createExpression("\"$$variable\""))
+        val replaced = element.replace(KtPsiFactory(element).createExpression("\"\${$variable}\""))
+        val blockStringTemplateEntry = (replaced as? KtStringTemplateExpression)?.entries?.firstOrNull() as? KtBlockStringTemplateEntry
+        if (blockStringTemplateEntry?.canDropBraces() == true) blockStringTemplateEntry.dropBraces()
     }
 
     override fun inspectionText(element: KtDotQualifiedExpression) = "Call of 'toString' could be replaced with string template"
diff --git a/idea/testData/inspectionsLocal/replaceToStringWithStringTemplate/callExpression.kt b/idea/testData/inspectionsLocal/replaceToStringWithStringTemplate/callExpression.kt
new file mode 100644
index 00000000000..92e827842c8
--- /dev/null
+++ b/idea/testData/inspectionsLocal/replaceToStringWithStringTemplate/callExpression.kt
@@ -0,0 +1,3 @@
+data class Num(val x: Int)
+
+fun demo(x: Int) = Num(x).toString()<caret>
\ No newline at end of file
diff --git a/idea/testData/inspectionsLocal/replaceToStringWithStringTemplate/callExpression.kt.after b/idea/testData/inspectionsLocal/replaceToStringWithStringTemplate/callExpression.kt.after
new file mode 100644
index 00000000000..1487d4cdaa6
--- /dev/null
+++ b/idea/testData/inspectionsLocal/replaceToStringWithStringTemplate/callExpression.kt.after
@@ -0,0 +1,3 @@
+data class Num(val x: Int)
+
+fun demo(x: Int) = "${Num(x)}"
\ No newline at end of file
diff --git a/idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java b/idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java
index 73e800c2ac1..51084291353 100644
--- a/idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java
+++ b/idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java
@@ -11001,6 +11001,11 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
             KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("idea/testData/inspectionsLocal/replaceToStringWithStringTemplate"), Pattern.compile("^([\\w\\-_]+)\\.(kt|kts)$"), null, true);
         }
 
+        @TestMetadata("callExpression.kt")
+        public void testCallExpression() throws Exception {
+            runTest("idea/testData/inspectionsLocal/replaceToStringWithStringTemplate/callExpression.kt");
+        }
+
         @TestMetadata("nonReference.kt")
         public void testNonReference() throws Exception {
             runTest("idea/testData/inspectionsLocal/replaceToStringWithStringTemplate/nonReference.kt");