Extract Function: Add backticks to non-identifiers and references originally surrounded in backticks

#KT-8192 Fixed

idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/extractionEngine/ExtractableCodeDescriptor.kt

@@ -23,6 +23,7 @@ import com.intellij.util.containers.MultiMap
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
 import org.jetbrains.kotlin.descriptors.ModuleDescriptor
+import org.jetbrains.kotlin.idea.core.refactoring.JetNameSuggester
 import org.jetbrains.kotlin.idea.core.replaced
 import org.jetbrains.kotlin.idea.refactoring.JetRefactoringBundle
 import org.jetbrains.kotlin.idea.refactoring.introduce.extractionEngine.AnalysisResult.ErrorMessage
@@ -82,13 +83,16 @@ class RenameReplacement(override val parameter: Parameter): ParameterReplacement
 
     override fun invoke(e: JetElement): JetElement {
         var expressionToReplace = (e.getParent() as? JetThisExpression ?: e).getQualifiedExpressionForSelectorOrThis()
+        val parameterName = JetPsiUtil.unquoteIdentifier(parameter.nameForRef)
+        val replacingName =
+                if (e.getText().startsWith('`') || !JetNameSuggester.isIdentifier(parameterName)) "`$parameterName`" else parameterName
         val psiFactory = JetPsiFactory(e)
         val replacement =
                 if (expressionToReplace is JetOperationReferenceExpression) {
-                    psiFactory.createOperationName(parameter.nameForRef)
+                    psiFactory.createOperationName(replacingName)
                 }
                 else {
-                    psiFactory.createSimpleName(parameter.nameForRef)
+                    psiFactory.createSimpleName(replacingName)
                 }
         return expressionToReplace.replaced(replacement)
     }

idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/extractionEngine/ExtractionData.kt

@@ -21,6 +21,7 @@ import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
 import org.jetbrains.kotlin.resolve.calls.model.ResolvedCall
 import com.intellij.openapi.project.Project
 import com.intellij.openapi.util.TextRange
+import com.intellij.psi.PsiNameIdentifierOwner
 import kotlin.properties.Delegates
 import java.util.HashMap
 import org.jetbrains.kotlin.idea.codeInsight.JetFileReferencesResolver
@@ -63,7 +64,7 @@ data class ExtractionOptions(
 
 data class ResolveResult(
         val originalRefExpr: JetSimpleNameExpression,
-        val declaration: PsiNamedElement,
+        val declaration: PsiNameIdentifierOwner,
         val descriptor: DeclarationDescriptor,
         val resolvedCall: ResolvedCall<*>?
 )
@@ -148,7 +149,7 @@ data class ExtractionData(
 
                     val resolvedCall = ref.getResolvedCall(context)
                     val descriptor = context[BindingContext.REFERENCE_TARGET, ref] ?: return
-                    val declaration = DescriptorToSourceUtilsIde.getAnyDeclaration(project, descriptor) as? PsiNamedElement
+                    val declaration = DescriptorToSourceUtilsIde.getAnyDeclaration(project, descriptor) as? PsiNameIdentifierOwner
                                       ?: if (isExtractableIt(descriptor, context)) itFakeDeclaration
                                       else if (isSynthesizedInvoke(descriptor)) synthesizedInvokeDeclaration else return
 

idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/extractionEngine/extractableAnalysisUtil.kt

@@ -709,7 +709,7 @@ private fun ExtractionData.inferParametersInfo(
                 }
 
                 if (!extractThis) {
-                    parameter.currentName = originalDeclaration.getName()
+                    parameter.currentName = originalDeclaration.getNameIdentifier()?.getText()
                 }
 
                 parameter.refCount++

idea/testData/refactoring/extractFunction/parameters/misc/addPrefixToBackticks.kt

@@ -0,0 +1,12 @@
+// PARAM_TYPES: X
+// PARAM_TYPES: Y
+// PARAM_DESCRIPTOR: internal final fun X.test(): kotlin.Unit defined in Y
+// PARAM_DESCRIPTOR: internal final class Y defined in root package
+class X(val x: Int)
+
+// SIBLING:
+class Y(val y: Int) {
+    fun X.test() {
+        <selection>`x`plus y</selection>
+    }
+}

idea/testData/refactoring/extractFunction/parameters/misc/addPrefixToBackticks.kt.after

@@ -0,0 +1,16 @@
+// PARAM_TYPES: X
+// PARAM_TYPES: Y
+// PARAM_DESCRIPTOR: internal final fun X.test(): kotlin.Unit defined in Y
+// PARAM_DESCRIPTOR: internal final class Y defined in root package
+class X(val x: Int)
+
+// SIBLING:
+class Y(val y: Int) {
+    fun X.test() {
+        __dummyTestFun__(this, this@Y)
+    }
+}
+
+private fun __dummyTestFun__(x: X, y1: Y) {
+    x.`x`plus y1.y
+}

idea/testData/refactoring/extractFunction/parameters/misc/idWithBackticks.kt

@@ -0,0 +1,6 @@
+// PARAM_TYPES: kotlin.Int
+// PARAM_DESCRIPTOR: val i: kotlin.Int defined in test
+fun test() {
+    val `i` = 0
+    <selection>`i`plus i</selection>
+}

idea/testData/refactoring/extractFunction/parameters/misc/idWithBackticks.kt.after

@@ -0,0 +1,10 @@
+// PARAM_TYPES: kotlin.Int
+// PARAM_DESCRIPTOR: val i: kotlin.Int defined in test
+fun test() {
+    val `i` = 0
+    __dummyTestFun__(`i`)
+}
+
+private fun __dummyTestFun__(`i`: Int) {
+    `i`plus i
+}

idea/testData/refactoring/extractFunction/parameters/misc/idWithRequiredBackticks.kt

@@ -0,0 +1,6 @@
+// PARAM_TYPES: kotlin.Int
+// PARAM_DESCRIPTOR: val 0: kotlin.Int defined in test
+fun test() {
+    val `0` = 0
+    <selection>`0`plus 1</selection>
+}

idea/testData/refactoring/extractFunction/parameters/misc/idWithRequiredBackticks.kt.after

@@ -0,0 +1,10 @@
+// PARAM_TYPES: kotlin.Int
+// PARAM_DESCRIPTOR: val 0: kotlin.Int defined in test
+fun test() {
+    val `0` = 0
+    __dummyTestFun__(`0`)
+}
+
+private fun __dummyTestFun__(`0`: Int) {
+    `0`plus 1
+}

idea/testData/refactoring/extractFunction/parameters/misc/replaceWithBackticks.kt

@@ -0,0 +1,6 @@
+// PARAM_TYPES: kotlin.Int
+// PARAM_DESCRIPTOR: val i: kotlin.Int defined in test
+fun test() {
+    val i = 0
+    <selection>`i`plus i</selection>
+}

idea/testData/refactoring/extractFunction/parameters/misc/replaceWithBackticks.kt.after

@@ -0,0 +1,10 @@
+// PARAM_TYPES: kotlin.Int
+// PARAM_DESCRIPTOR: val i: kotlin.Int defined in test
+fun test() {
+    val i = 0
+    __dummyTestFun__(`i`)
+}
+
+private fun __dummyTestFun__(i: Int) {
+    `i`plus i
+}

idea/testData/refactoring/extractFunction/parameters/misc/replaceWithBackticks2.kt

@@ -0,0 +1,6 @@
+// PARAM_TYPES: kotlin.Int
+// PARAM_DESCRIPTOR: val i: kotlin.Int defined in test
+fun test() {
+    val i = 0
+    <selection>i plus `i`</selection>
+}

idea/testData/refactoring/extractFunction/parameters/misc/replaceWithBackticks2.kt.after

@@ -0,0 +1,10 @@
+// PARAM_TYPES: kotlin.Int
+// PARAM_DESCRIPTOR: val i: kotlin.Int defined in test
+fun test() {
+    val i = 0
+    __dummyTestFun__(i)
+}
+
+private fun __dummyTestFun__(i: Int) {
+    i plus `i`
+}

idea/tests/org/jetbrains/kotlin/idea/refactoring/introduce/JetExtractionTestGenerated.java

@@ -1873,6 +1873,12 @@ public class JetExtractionTestGenerated extends AbstractJetExtractionTest {
             @TestDataPath("$PROJECT_ROOT")
             @RunWith(JUnit3RunnerWithInners.class)
             public static class Misc extends AbstractJetExtractionTest {
+                @TestMetadata("addPrefixToBackticks.kt")
+                public void testAddPrefixToBackticks() throws Exception {
+                    String fileName = JetTestUtils.navigationMetadata("idea/testData/refactoring/extractFunction/parameters/misc/addPrefixToBackticks.kt");
+                    doExtractFunctionTest(fileName);
+                }
+
                 public void testAllFilesPresentInMisc() throws Exception {
                     JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/refactoring/extractFunction/parameters/misc"), Pattern.compile("^(.+)\\.kt$"), true);
                 }
@@ -1895,6 +1901,18 @@ public class JetExtractionTestGenerated extends AbstractJetExtractionTest {
                     doExtractFunctionTest(fileName);
                 }
 
+                @TestMetadata("idWithBackticks.kt")
+                public void testIdWithBackticks() throws Exception {
+                    String fileName = JetTestUtils.navigationMetadata("idea/testData/refactoring/extractFunction/parameters/misc/idWithBackticks.kt");
+                    doExtractFunctionTest(fileName);
+                }
+
+                @TestMetadata("idWithRequiredBackticks.kt")
+                public void testIdWithRequiredBackticks() throws Exception {
+                    String fileName = JetTestUtils.navigationMetadata("idea/testData/refactoring/extractFunction/parameters/misc/idWithRequiredBackticks.kt");
+                    doExtractFunctionTest(fileName);
+                }
+
                 @TestMetadata("innerClassObject.kt")
                 public void testInnerClassObject() throws Exception {
                     String fileName = JetTestUtils.navigationMetadata("idea/testData/refactoring/extractFunction/parameters/misc/innerClassObject.kt");
@@ -1979,6 +1997,18 @@ public class JetExtractionTestGenerated extends AbstractJetExtractionTest {
                     doExtractFunctionTest(fileName);
                 }
 
+                @TestMetadata("replaceWithBackticks.kt")
+                public void testReplaceWithBackticks() throws Exception {
+                    String fileName = JetTestUtils.navigationMetadata("idea/testData/refactoring/extractFunction/parameters/misc/replaceWithBackticks.kt");
+                    doExtractFunctionTest(fileName);
+                }
+
+                @TestMetadata("replaceWithBackticks2.kt")
+                public void testReplaceWithBackticks2() throws Exception {
+                    String fileName = JetTestUtils.navigationMetadata("idea/testData/refactoring/extractFunction/parameters/misc/replaceWithBackticks2.kt");
+                    doExtractFunctionTest(fileName);
+                }
+
                 @TestMetadata("thisInObject.kt")
                 public void testThisInObject() throws Exception {
                     String fileName = JetTestUtils.navigationMetadata("idea/testData/refactoring/extractFunction/parameters/misc/thisInObject.kt");