Extract Function: Forbid inappropriate declarations inside extractable fragment

#KT-20467 Fixed
 #KT-20469 Fixed

idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/extractFunction/ExtractKotlinFunctionHandler.kt

@@ -28,9 +28,9 @@ import org.jetbrains.kotlin.idea.refactoring.getExtractionContainers
 import org.jetbrains.kotlin.idea.refactoring.introduce.extractFunction.ui.KotlinExtractFunctionDialog
 import org.jetbrains.kotlin.idea.refactoring.introduce.extractionEngine.*
 import org.jetbrains.kotlin.idea.refactoring.introduce.selectElementsWithTargetSibling
+import org.jetbrains.kotlin.idea.refactoring.introduce.validateExpressionElements
 import org.jetbrains.kotlin.idea.util.psi.patternMatching.toRange
-import org.jetbrains.kotlin.psi.KtBlockExpression
-import org.jetbrains.kotlin.psi.KtFile
+import org.jetbrains.kotlin.psi.*
 
 class ExtractKotlinFunctionHandler(
         private val allContainersEnabled: Boolean = false,
@@ -69,6 +69,7 @@ class ExtractKotlinFunctionHandler(
                 file,
                 "Select target code block",
                 listOf(CodeInsightUtils.ElementKind.EXPRESSION),
+                ::validateExpressionElements,
                 { elements, parent -> parent.getExtractionContainers(elements.size == 1, allContainersEnabled) },
                 continuation
         )

idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/introduceParameter/KotlinIntroduceParameterHandler.kt

@@ -187,6 +187,7 @@ fun selectNewParameterContext(
             file = file,
             title = "Introduce parameter to declaration",
             elementKinds = listOf(CodeInsightUtils.ElementKind.EXPRESSION),
+            elementValidator = ::validateExpressionElements,
             getContainers = { _, parent ->
                 val parents = parent.parents
                 val stopAt = (parent.parents.zip(parent.parents.drop(1)))

idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/introduceProperty/KotlinIntroducePropertyHandler.kt

@@ -31,6 +31,7 @@ import org.jetbrains.kotlin.idea.refactoring.introduce.extractionEngine.*
 import org.jetbrains.kotlin.idea.refactoring.introduce.selectElementsWithTargetSibling
 import org.jetbrains.kotlin.idea.refactoring.introduce.showErrorHint
 import org.jetbrains.kotlin.idea.refactoring.introduce.showErrorHintByKey
+import org.jetbrains.kotlin.idea.refactoring.introduce.validateExpressionElements
 import org.jetbrains.kotlin.idea.util.psi.patternMatching.toRange
 import org.jetbrains.kotlin.psi.KtBlockExpression
 import org.jetbrains.kotlin.psi.KtClassBody
@@ -73,6 +74,7 @@ class KotlinIntroducePropertyHandler(
                 file,
                 "Select target code block",
                 listOf(CodeInsightUtils.ElementKind.EXPRESSION),
+                ::validateExpressionElements,
                 { _, parent ->
                     parent.getExtractionContainers(strict = true, includeAll = true).filter { it is KtClassBody || (it is KtFile && !it.isScript()) }
                 },

idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/introduceTypeAlias/IntroduceTypeAliasHandler.kt

@@ -55,6 +55,7 @@ open class KotlinIntroduceTypeAliasHandler : RefactoringActionHandler {
                 file,
                 "Select target code block",
                 listOf(TYPE_ELEMENT, TYPE_CONSTRUCTOR),
+                { null },
                 { _, parent -> listOf(parent.containingFile) },
                 continuation
         )

idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/introduceTypeParameter/KotlinIntroduceTypeParameterHandler.kt

@@ -74,6 +74,7 @@ object KotlinIntroduceTypeParameterHandler : RefactoringActionHandler {
                 file,
                 "Introduce type parameter to declaration",
                 listOf(CodeInsightUtils.ElementKind.TYPE_ELEMENT),
+                { null },
                 { _, parent -> getPossibleTypeParameterContainers(parent) },
                 continuation
         )

idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/introduceUtil.kt

@@ -47,6 +47,7 @@ fun selectElementsWithTargetSibling(
         file: KtFile,
         title: String,
         elementKinds: Collection<CodeInsightUtils.ElementKind>,
+        elementValidator: (List<PsiElement>) -> String?,
         getContainers: (elements: List<PsiElement>, commonParent: PsiElement) -> List<PsiElement>,
         continuation: (elements: List<PsiElement>, targetSibling: PsiElement) -> Unit
 ) {
@@ -69,7 +70,7 @@ fun selectElementsWithTargetSibling(
         continuation(elements, outermostParent)
     }
 
-    selectElementsWithTargetParent(operationName, editor, file, title, elementKinds, getContainers, ::onSelectionComplete)
+    selectElementsWithTargetParent(operationName, editor, file, title, elementKinds, elementValidator, getContainers, ::onSelectionComplete)
 }
 
 fun selectElementsWithTargetParent(
@@ -78,6 +79,7 @@ fun selectElementsWithTargetParent(
         file: KtFile,
         title: String,
         elementKinds: Collection<CodeInsightUtils.ElementKind>,
+        elementValidator: (List<PsiElement>) -> String?,
         getContainers: (elements: List<PsiElement>, commonParent: PsiElement) -> List<PsiElement>,
         continuation: (elements: List<PsiElement>, targetParent: PsiElement) -> Unit
 ) {
@@ -86,6 +88,11 @@ fun selectElementsWithTargetParent(
     }
 
     fun selectTargetContainer(elements: List<PsiElement>) {
+        elementValidator(elements)?.let {
+            showErrorHint(file.project, editor, it, operationName)
+            return
+        }
+
         val physicalElements = elements.map { it.substringContextOrThis }
         val parent = PsiTreeUtil.findCommonParent(physicalElements)
                      ?: throw AssertionError("Should have at least one parent: ${physicalElements.joinToString("\n")}")
@@ -236,4 +243,11 @@ fun <T : KtDeclaration> insertDeclaration(declaration: T, targetSibling: PsiElem
     return (targetContainer.addBefore(declaration, anchor) as T).apply {
         targetContainer.addBefore(KtPsiFactory(declaration).createWhiteSpace("\n\n"), anchor)
     }
+}
+
+internal fun validateExpressionElements(elements: List<PsiElement>): String? {
+    if (elements.any { it is KtConstructor<*> || it is KtParameter || it is KtTypeAlias || it is KtPropertyAccessor }) {
+        return "Refactoring is not applicable to this code fragment"
+    }
+    return null
 }

idea/testData/refactoring/extractFunction/basic/selectedConstructor.kt

@@ -0,0 +1,4 @@
+// SIBLING:
+class Foo {
+    <selection>constructor(bar: Int)</selection>
+}

idea/testData/refactoring/extractFunction/basic/selectedConstructor.kt.conflicts

@@ -0,0 +1 @@
+Refactoring is not applicable to this code fragment

idea/testData/refactoring/extractFunction/basic/selectedParameter.kt

@@ -0,0 +1,2 @@
+// SIBLING:
+class Foo(<selection>bar: String = "baz"</selection>)

idea/testData/refactoring/extractFunction/basic/selectedParameter.kt.conflicts

@@ -0,0 +1 @@
+Refactoring is not applicable to this code fragment

idea/testData/refactoring/extractFunction/script/NotExpression.kts.conflicts

@@ -1 +1 @@
-Cannot refactor in this place
+Cannot refactor in this place

idea/testData/refactoring/introduceParameter/script/TopLevelExpression.kts.conflicts

@@ -1 +1 @@
-Cannot refactor in this place
+Cannot refactor in this place

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

@@ -986,6 +986,16 @@ public class ExtractionTestGenerated extends AbstractExtractionTest {
                 runTest("idea/testData/refactoring/extractFunction/basic/refInReturn.kt");
             }
 
+            @TestMetadata("selectedConstructor.kt")
+            public void testSelectedConstructor() throws Exception {
+                runTest("idea/testData/refactoring/extractFunction/basic/selectedConstructor.kt");
+            }
+
+            @TestMetadata("selectedParameter.kt")
+            public void testSelectedParameter() throws Exception {
+                runTest("idea/testData/refactoring/extractFunction/basic/selectedParameter.kt");
+            }
+
             @TestMetadata("suspendCall.kt")
             public void testSuspendCall() throws Exception {
                 runTest("idea/testData/refactoring/extractFunction/basic/suspendCall.kt");