Single-expression string template is inspection for strings and intention otherwise #KT-13113 Fixed

(cherry picked from commit 266f9d0)

idea/src/org/jetbrains/kotlin/idea/intentions/RemoveSingleExpressionStringTemplateIntention.kt

@@ -30,9 +30,15 @@ private fun KtStringTemplateExpression.singleExpressionOrNull() =
         children.singleOrNull()?.children?.firstOrNull() as? KtExpression
 
 class RemoveSingleExpressionStringTemplateInspection : IntentionBasedInspection<KtStringTemplateExpression>(
-        RemoveSingleExpressionStringTemplateIntention()
+        RemoveSingleExpressionStringTemplateIntention(),
+        additionalChecker = {
+            templateExpression ->
+            templateExpression.singleExpressionOrNull()?.let {
+                KotlinBuiltIns.isString(it.getType(it.analyze()))
+            } ?: false
+        }
 ) {
-    override val problemText = "Single-expression string template"
+    override val problemText = "Redundant string template"
 }
 
 class RemoveSingleExpressionStringTemplateIntention : SelfTargetingOffsetIndependentIntention<KtStringTemplateExpression>(

idea/testData/inspections/removeSingleExpressionStringTemplate/inspectionData/expected.xml

@@ -0,0 +1,10 @@
+<problems>
+    <problem>
+        <file>test.kt</file>
+        <line>4</line>
+        <module>light_idea_test_case</module>
+        <entry_point TYPE="file" FQNAME="temp:///src/test.kt" />
+        <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">Remove redundant string template</problem_class>
+        <description>Redundant string template</description>
+    </problem>
+</problems>

idea/testData/inspections/removeSingleExpressionStringTemplate/inspectionData/inspections.test

@@ -0,0 +1 @@
+// INSPECTION_CLASS: org.jetbrains.kotlin.idea.intentions.RemoveSingleExpressionStringTemplateInspection

idea/testData/inspections/removeSingleExpressionStringTemplate/test.kt

@@ -0,0 +1,6 @@
+// NO
+val x = "Hello"
+// YES
+val y = "$x"
+// NO
+val z = "${y.hashCode()}"

idea/tests/org/jetbrains/kotlin/idea/codeInsight/InspectionTestGenerated.java

@@ -226,6 +226,12 @@ public class InspectionTestGenerated extends AbstractInspectionTest {
             doTest(fileName);
         }
 
+        @TestMetadata("removeSingleExpressionStringTemplate/inspectionData/inspections.test")
+        public void testRemoveSingleExpressionStringTemplate_inspectionData_Inspections_test() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspections/removeSingleExpressionStringTemplate/inspectionData/inspections.test");
+            doTest(fileName);
+        }
+
         @TestMetadata("replaceCallWithComparison/inspectionData/inspections.test")
         public void testReplaceCallWithComparison_inspectionData_Inspections_test() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/inspections/replaceCallWithComparison/inspectionData/inspections.test");