From 7c2f6ecba77f99702e057a7c1aa2ed0c8b160f14 Mon Sep 17 00:00:00 2001
From: Toshiaki Kameyama <kmymtsak@gmail.com>
Date: Fri, 26 Jul 2019 22:23:50 +0900
Subject: [PATCH] Redundant curly braces in string template: remove braces for
 'this'

#KT-32972 Fixed
---
 .../jetbrains/kotlin/idea/core/psiModificationUtils.kt |  8 ++++++--
 .../necessaryBrackets7.kt                              |  2 ++
 .../unnecessaryBrackets9.kt                            |  3 +++
 .../unnecessaryBrackets9.kt.after                      |  3 +++
 .../idea/inspections/LocalInspectionTestGenerated.java | 10 ++++++++++
 5 files changed, 24 insertions(+), 2 deletions(-)
 create mode 100644 idea/testData/inspectionsLocal/removeCurlyBracesFromTemplate/necessaryBrackets7.kt
 create mode 100644 idea/testData/inspectionsLocal/removeCurlyBracesFromTemplate/unnecessaryBrackets9.kt
 create mode 100644 idea/testData/inspectionsLocal/removeCurlyBracesFromTemplate/unnecessaryBrackets9.kt.after

diff --git a/idea/idea-core/src/org/jetbrains/kotlin/idea/core/psiModificationUtils.kt b/idea/idea-core/src/org/jetbrains/kotlin/idea/core/psiModificationUtils.kt
index 551f64dbca7..b4c73797ea6 100644
--- a/idea/idea-core/src/org/jetbrains/kotlin/idea/core/psiModificationUtils.kt
+++ b/idea/idea-core/src/org/jetbrains/kotlin/idea/core/psiModificationUtils.kt
@@ -558,10 +558,14 @@ fun KtModifierList.normalize(): KtModifierList {
 }
 
 fun KtBlockStringTemplateEntry.canDropBraces() =
-    expression is KtNameReferenceExpression && canPlaceAfterSimpleNameEntry(nextSibling)
+    (expression is KtNameReferenceExpression || expression is KtThisExpression) && canPlaceAfterSimpleNameEntry(nextSibling)
 
 fun KtBlockStringTemplateEntry.dropBraces(): KtSimpleNameStringTemplateEntry {
-    val name = (expression as KtNameReferenceExpression).getReferencedNameElement().text
+    val name = if (expression is KtThisExpression) {
+        KtTokens.THIS_KEYWORD.value
+    } else {
+        (expression as KtNameReferenceExpression).getReferencedNameElement().text
+    }
     val newEntry = KtPsiFactory(this).createSimpleNameStringTemplateEntry(name)
     return replaced(newEntry)
 }
\ No newline at end of file
diff --git a/idea/testData/inspectionsLocal/removeCurlyBracesFromTemplate/necessaryBrackets7.kt b/idea/testData/inspectionsLocal/removeCurlyBracesFromTemplate/necessaryBrackets7.kt
new file mode 100644
index 00000000000..4c8b27bf84a
--- /dev/null
+++ b/idea/testData/inspectionsLocal/removeCurlyBracesFromTemplate/necessaryBrackets7.kt
@@ -0,0 +1,2 @@
+// PROBLEM: none
+fun String.bar() = "x <caret>${this.length}"
\ No newline at end of file
diff --git a/idea/testData/inspectionsLocal/removeCurlyBracesFromTemplate/unnecessaryBrackets9.kt b/idea/testData/inspectionsLocal/removeCurlyBracesFromTemplate/unnecessaryBrackets9.kt
new file mode 100644
index 00000000000..56ea42bb742
--- /dev/null
+++ b/idea/testData/inspectionsLocal/removeCurlyBracesFromTemplate/unnecessaryBrackets9.kt
@@ -0,0 +1,3 @@
+// HIGHLIGHT: GENERIC_ERROR_OR_WARNING
+
+fun String.bar() = "x <caret>${this}"
\ No newline at end of file
diff --git a/idea/testData/inspectionsLocal/removeCurlyBracesFromTemplate/unnecessaryBrackets9.kt.after b/idea/testData/inspectionsLocal/removeCurlyBracesFromTemplate/unnecessaryBrackets9.kt.after
new file mode 100644
index 00000000000..8ec2dbddbcd
--- /dev/null
+++ b/idea/testData/inspectionsLocal/removeCurlyBracesFromTemplate/unnecessaryBrackets9.kt.after
@@ -0,0 +1,3 @@
+// HIGHLIGHT: GENERIC_ERROR_OR_WARNING
+
+fun String.bar() = "x $this"
\ 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 83b4d10d5be..4b2de55a465 100644
--- a/idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java
+++ b/idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java
@@ -7890,6 +7890,11 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
             runTest("idea/testData/inspectionsLocal/removeCurlyBracesFromTemplate/necessaryBrackets6.kt");
         }
 
+        @TestMetadata("necessaryBrackets7.kt")
+        public void testNecessaryBrackets7() throws Exception {
+            runTest("idea/testData/inspectionsLocal/removeCurlyBracesFromTemplate/necessaryBrackets7.kt");
+        }
+
         @TestMetadata("unnecessaryBrackets1.kt")
         public void testUnnecessaryBrackets1() throws Exception {
             runTest("idea/testData/inspectionsLocal/removeCurlyBracesFromTemplate/unnecessaryBrackets1.kt");
@@ -7929,6 +7934,11 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
         public void testUnnecessaryBrackets8() throws Exception {
             runTest("idea/testData/inspectionsLocal/removeCurlyBracesFromTemplate/unnecessaryBrackets8.kt");
         }
+
+        @TestMetadata("unnecessaryBrackets9.kt")
+        public void testUnnecessaryBrackets9() throws Exception {
+            runTest("idea/testData/inspectionsLocal/removeCurlyBracesFromTemplate/unnecessaryBrackets9.kt");
+        }
     }
 
     @TestMetadata("idea/testData/inspectionsLocal/removeEmptyParenthesesFromAnnotationEntry")