Replace with string templates: add curly braces if needed

#KT-37173 Fixed

idea/src/org/jetbrains/kotlin/idea/inspections/ReplaceStringFormatWithLiteralInspection.kt

@@ -13,6 +13,9 @@ import com.intellij.openapi.project.Project
 import com.intellij.psi.PsiElementVisitor
 import org.jetbrains.kotlin.idea.KotlinBundle
 import org.jetbrains.kotlin.idea.caches.resolve.analyze
+import org.jetbrains.kotlin.idea.core.canDropBraces
+import org.jetbrains.kotlin.idea.core.dropBraces
+import org.jetbrains.kotlin.idea.core.replaced
 import org.jetbrains.kotlin.idea.imports.importableFqName
 import org.jetbrains.kotlin.idea.intentions.ConvertToStringTemplateIntention
 import org.jetbrains.kotlin.idea.intentions.callExpression
@@ -76,10 +79,15 @@ class ReplaceStringFormatWithLiteralInspection : AbstractKotlinInspection() {
 
             val args = callExpression.valueArguments.mapNotNull { it.getArgumentExpression() }
             val format = args[0].text.removePrefix("\"").removeSuffix("\"")
-            val replaceArgs = args.asSequence().drop(1).mapTo(LinkedList()) { ConvertToStringTemplateIntention.buildText(it, false) }
+            val replaceArgs = args.asSequence().drop(1).mapTo(LinkedList()) { ConvertToStringTemplateIntention.buildText(it, true) }
             val stringLiteral = stringPlaceHolder.replace(format) { replaceArgs.pop() }
-
-            (qualifiedExpression ?: callExpression).also { it.replace(KtPsiFactory(it).createStringTemplate(stringLiteral)) }
+            (qualifiedExpression ?: callExpression)
+                .let { it.replaced(KtPsiFactory(it).createStringTemplate(stringLiteral)) }
+                .entries
+                .forEach {
+                    val blockEntry = (it as? KtBlockStringTemplateEntry)
+                    if (blockEntry?.canDropBraces() == true) blockEntry.dropBraces()
+                }
         }
     }
 }

idea/testData/inspectionsLocal/replaceStringFormatWithLiteral/curlyBraces.kt

@@ -0,0 +1,6 @@
+// WITH_RUNTIME
+fun main() {
+    val id = "abc"
+    val date = "123"
+    val s = String.format(<caret>"%s_%s_%s", id, date, id)
+}

idea/testData/inspectionsLocal/replaceStringFormatWithLiteral/curlyBraces.kt.after

@@ -0,0 +1,6 @@
+// WITH_RUNTIME
+fun main() {
+    val id = "abc"
+    val date = "123"
+    val s = "${id}_${date}_$id"
+}

idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java

@@ -11162,6 +11162,11 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
             KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("idea/testData/inspectionsLocal/replaceStringFormatWithLiteral"), Pattern.compile("^([\\w\\-_]+)\\.(kt|kts)$"), null, true);
         }
 
+        @TestMetadata("curlyBraces.kt")
+        public void testCurlyBraces() throws Exception {
+            runTest("idea/testData/inspectionsLocal/replaceStringFormatWithLiteral/curlyBraces.kt");
+        }
+
         @TestMetadata("formattableArgs.kt")
         public void testFormattableArgs() throws Exception {
             runTest("idea/testData/inspectionsLocal/replaceStringFormatWithLiteral/formattableArgs.kt");