Eliminate a set of warnings, mostly nullability ones

idea/ide-common/src/org/jetbrains/kotlin/idea/util/CallType.kt

@@ -278,8 +278,6 @@ fun CallTypeAndReceiver<*, *>.receiverTypesWithIndex(
         is CallTypeAndReceiver.ANNOTATION,
         is CallTypeAndReceiver.UNKNOWN ->
             return null
-
-        else -> throw RuntimeException() //TODO: see KT-9394
     }
 
     val resolutionScope = contextElement.getResolutionScope(bindingContext, resolutionFacade)

idea/ide-common/src/org/jetbrains/kotlin/util/descriptorUtils.kt

@@ -73,7 +73,7 @@ fun ClassDescriptor.findCallableMemberBySignature(
                 if (it.containingDeclaration != this) return@firstOrNull false
                 val overridability = OverridingUtil.DEFAULT.isOverridableBy(it as CallableDescriptor, signature, null).result
                 overridability == OVERRIDABLE || (allowOverridabilityConflicts && overridability == CONFLICT)
-            } as? CallableMemberDescriptor
+            }
 }
 
 fun TypeConstructor.supertypesWithAny(): Collection<KotlinType> {

idea/idea-analysis/src/org/jetbrains/kotlin/idea/caches/resolve/JavaResolveExtension.kt

@@ -128,7 +128,7 @@ private fun JavaDescriptorResolver.resolveConstructor(constructor: JavaConstruct
 }
 
 private fun JavaDescriptorResolver.resolveField(field: JavaField): PropertyDescriptor? {
-    return getContainingScope(field)?.getContributedVariables(field.name, NoLookupLocation.FROM_IDE)?.findByJavaElement(field) as? PropertyDescriptor
+    return getContainingScope(field)?.getContributedVariables(field.name, NoLookupLocation.FROM_IDE)?.findByJavaElement(field)
 }
 
 private fun JavaDescriptorResolver.getContainingScope(member: JavaMember): MemberScope? {

idea/idea-analysis/src/org/jetbrains/kotlin/idea/compiler/configuration/BaseKotlinCompilerSettings.kt

@@ -64,7 +64,7 @@ abstract class BaseKotlinCompilerSettings<T : Freezable> protected constructor()
     override fun getState() = XmlSerializer.serialize(_settings, SKIP_DEFAULT_VALUES)
 
     override fun loadState(state: Element) {
-        _settings = XmlSerializer.deserialize(state, _settings.javaClass) ?: createSettings()
+        _settings = XmlSerializer.deserialize(state, _settings.javaClass)
     }
 
     public override fun clone(): Any = super.clone()

idea/idea-analysis/src/org/jetbrains/kotlin/idea/search/usagesSearch/ExpressionsOfTypeProcessor.kt

@@ -139,7 +139,7 @@ class ExpressionsOfTypeProcessor(
         if (runReadAction { searchScope is GlobalSearchScope && !FileTypeIndex.containsFileOfType(KotlinFileType.INSTANCE, searchScope) }) return
 
         // for class from library always use plain search because we cannot search usages in compiled code (we could though)
-        if (classToSearch == null || !runReadAction { classToSearch.isValid && ProjectRootsUtil.isInProjectSource(classToSearch) }) {
+        if (!runReadAction { classToSearch.isValid && ProjectRootsUtil.isInProjectSource(classToSearch) }) {
             possibleMatchesInScopeHandler(searchScope)
             return
         }

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/KeywordCompletion.kt

@@ -254,14 +254,14 @@ object KeywordCompletion {
                 is KtDeclarationWithInitializer -> {
                     val initializer = parent.initializer
                     if (prevParent == initializer) {
-                        return buildFilterWithContext("val v = ", initializer!!, position)
+                        return buildFilterWithContext("val v = ", initializer, position)
                     }
                 }
 
                 is KtParameter -> {
                     val default = parent.defaultValue
                     if (prevParent == default) {
-                        return buildFilterWithContext("val v = ", default!!, position)
+                        return buildFilterWithContext("val v = ", default, position)
                     }
                 }
 

idea/idea-core/src/org/jetbrains/kotlin/idea/core/ExpectedInfos.kt

@@ -568,7 +568,6 @@ class ExpectedInfos(
             }
 
             is PropertyGetterDescriptor -> {
-                if (descriptor !is PropertyGetterDescriptor) return null
                 val property = descriptor.correspondingProperty
                 ExpectedInfo.createForReturnValue(returnTypeToUse(property, hasExplicitReturnType), property)
             }

idea/idea-gradle/src/org/jetbrains/kotlin/idea/inspections/gradle/KotlinGradleInspectionVisitor.kt

@@ -40,7 +40,7 @@ val KOTLIN_PLUGIN_CLASSPATH_MARKER = "${KotlinWithGradleConfigurator.GROUP_ID}:$
 
 abstract class KotlinGradleInspectionVisitor : BaseInspectionVisitor() {
     override fun visitFile(file: GroovyFileBase) {
-        if (file == null || !FileUtilRt.extensionEquals(file.name, GradleConstants.EXTENSION)) return
+        if (!FileUtilRt.extensionEquals(file.name, GradleConstants.EXTENSION)) return
 
         val fileIndex = ProjectRootManager.getInstance(file.project).fileIndex
 

idea/idea-test-framework/src/org/jetbrains/kotlin/idea/test/KotlinStdJSProjectDescriptor.kt

@@ -30,7 +30,7 @@ object KotlinStdJSProjectDescriptor : KotlinLightProjectDescriptor() {
     override fun getSdk(): Sdk? = null
 
     override fun configureModule(module: Module, model: ModifiableRootModel) {
-        val configuration = JSLibraryStdDescription(module.project).createNewLibraryForTests() ?: error("Configuration should exist")
+        val configuration = JSLibraryStdDescription(module.project).createNewLibraryForTests()
 
         val editor = NewLibraryEditor(configuration.libraryType, configuration.properties)
         configuration.addRoots(editor)

idea/idea-test-framework/src/org/jetbrains/kotlin/idea/test/testUtils.kt

@@ -69,7 +69,6 @@ fun Module.configureAs(kind: ModuleKind) {
             this.configureAs(KotlinStdJSProjectDescriptor)
         }
 
-        else -> throw IllegalArgumentException("Unknown kind=$kind")
     }
 }
 

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

@@ -62,7 +62,7 @@ class ConvertFunctionTypeReceiverToParameterIntention : SelfTargetingRangeIntent
 
     class FunctionDefinitionInfo(element: KtFunction) : AbstractProcessableUsageInfo<KtFunction, ConversionData>(element) {
         override fun process(data: ConversionData, elementsToShorten: MutableList<KtElement>) {
-            val function = element as? KtFunction ?: return
+            val function = element ?: return
             val functionParameter = function.valueParameters.getOrNull(data.functionParameterIndex) ?: return
             val functionType = functionParameter.typeReference?.typeElement as? KtFunctionType ?: return
             val functionTypeParameterList = functionType.parameterList ?: return

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

@@ -196,7 +196,7 @@ class DeprecatedCallableAddReplaceWithIntention : SelfTargetingRangeIntention<Kt
         val body = bodyExpression ?: return null
         if (!hasBlockBody()) return body
         val block = body as? KtBlockExpression ?: return null
-        val statement = block.statements.singleOrNull() as? KtExpression ?: return null
+        val statement = block.statements.singleOrNull() ?: return null
         val returnsUnit = (analyze()[BindingContext.DECLARATION_TO_DESCRIPTOR, this] as? FunctionDescriptor)?.returnType?.isUnit() ?: return null
         return when (statement) {
             is KtReturnExpression -> statement.returnedExpression

idea/src/org/jetbrains/kotlin/idea/quickfix/ChangeSuspendInHierarchyFix.kt

@@ -150,7 +150,7 @@ class ChangeSuspendInHierarchyFix(
 
             return DFS.dfs(
                     listOf(this),
-                    { (it as? FunctionDescriptor)?.getOverridables() ?: emptyList() },
+                    { it?.getOverridables() ?: emptyList() },
                     object : DFS.CollectingNodeHandler<FunctionDescriptor, FunctionDescriptor, ArrayList<FunctionDescriptor>>(ArrayList()) {
                         override fun afterChildren(current: FunctionDescriptor) {
                             if (current.getOverridables().isEmpty()) {
@@ -173,7 +173,7 @@ class ChangeSuspendInHierarchyFix(
                         containingClassDescriptor.defaultType,
                         currentClassDescriptor.defaultType
                 ) ?: return@filter false
-                val signatureInCurrentClass = it.substitute(substitutor) as? FunctionDescriptor ?: return@filter false
+                val signatureInCurrentClass = it.substitute(substitutor) ?: return@filter false
                 OverridingUtil.DEFAULT.isOverridableBy(signatureInCurrentClass, currentDescriptor, null).result ==
                         OverridingUtil.OverrideCompatibilityInfo.Result.CONFLICT
             }

idea/src/org/jetbrains/kotlin/idea/quickfix/createFromUsage/callableBuilder/CallableBuilder.kt

@@ -586,7 +586,6 @@ class CallableBuilder(val config: CallableBuilderConfiguration) {
             if (returnTypeRefs.isNotEmpty()) {
                 val returnType = typeCandidates[callableInfo.returnTypeInfo]!!.getTypeByRenderedType(
                         returnTypeRefs.map { it.text }
-                        ?: throw AssertionError("Expression for return type shouldn't be empty: declaration = ${declaration.text}")
                 )
                 if (returnType != null) {
                     // user selected a given type
@@ -603,7 +602,6 @@ class CallableBuilder(val config: CallableBuilderConfiguration) {
                 if (parameterTypeRef != null) {
                     val parameterType = parameterTypeExpressions[i].typeCandidates.getTypeByRenderedType(
                             listOf(parameterTypeRef.text)
-                            ?: throw AssertionError("Expression for parameter type shouldn't be empty: declaration = ${declaration.text}")
                     )
                     if (parameterType != null) {
                         replaceWithLongerName(listOf(parameterTypeRef), parameterType)

idea/src/org/jetbrains/kotlin/idea/quickfix/createFromUsage/callableBuilder/CallableInfo.kt

@@ -102,7 +102,6 @@ abstract class TypeInfo(val variance: Variance) {
                 val classDeclaration = receiverClassDescriptor?.let { DescriptorToSourceUtils.getSourceFromDescriptor(it) }
                 if (!config.isExtension && classDeclaration != null) classDeclaration else config.currentFile
             }
-            else -> throw IllegalArgumentException("Unexpected placement: $placement")
         }
         return when (containingElement) {
             is KtClassOrObject -> (containingElement.resolveToDescriptor() as? ClassDescriptorWithResolutionScopes)?.scopeForMemberDeclarationResolution

idea/src/org/jetbrains/kotlin/idea/refactoring/changeSignature/usages/KotlinFunctionCallUsage.kt

@@ -334,7 +334,7 @@ class KotlinFunctionCallUsage(
             if (receiverValue is ExpressionReceiver && !receiverValue.expression.isValid) {
                 receiverValue = receiverValue.wrapInvalidated(element)
             }
-            ArgumentInfo(param, index, resolvedArgument, receiverValue as? ReceiverValue)
+            ArgumentInfo(param, index, resolvedArgument, receiverValue)
         }
 
         val lastParameterIndex = newParameters.lastIndex

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

@@ -182,7 +182,7 @@ data class ExtractionData(
     fun getPossibleTypes(expression: KtExpression, resolvedCall: ResolvedCall<*>?, context: BindingContext): Set<KotlinType> {
         val dataFlowInfo = context.getDataFlowInfoAfter(expression)
 
-        (resolvedCall?.getImplicitReceiverValue() as? ImplicitReceiver)?.let {
+        resolvedCall?.getImplicitReceiverValue()?.let {
             return dataFlowInfo.getCollectedTypes(DataFlowValueFactory.createDataFlowValueForStableReceiver(it))
         }
 

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

@@ -282,7 +282,7 @@ open class KotlinIntroduceParameterHandler(
                             is KtExpression -> matchedElement
                             is KtStringTemplateEntryWithExpression -> matchedElement.expression
                             else -> null
-                        } as? KtExpression
+                        }
                         matchedExpr?.toRange()
                     }
         }

idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/introduceVariable/KotlinIntroduceVariableHandler.kt

@@ -211,7 +211,7 @@ object KotlinIntroduceVariableHandler : RefactoringActionHandler {
                     actualExpression = reference!!
                     diff = actualExpression.textRange.startOffset - emptyBody.textRange.startOffset
                     actualExpressionText = actualExpression.text
-                    emptyBody = anchor!!.replace(emptyBody) as KtBlockExpression
+                    emptyBody = anchor.replace(emptyBody) as KtBlockExpression
                     elem = findElementByOffsetAndText(diff, actualExpressionText, emptyBody)
                     if (elem != null) {
                         reference = elem as KtExpression
@@ -335,7 +335,7 @@ object KotlinIntroduceVariableHandler : RefactoringActionHandler {
                         is KtExpression -> candidate
                         is KtStringTemplateEntryWithExpression -> candidate.expression
                         else -> throw AssertionError("Unexpected candidate element: " + candidate.text)
-                    } as? KtExpression
+                    }
                 }
     }
 

idea/src/org/jetbrains/kotlin/idea/refactoring/kotlinRefactoringUtil.kt

@@ -953,7 +953,7 @@ fun checkSuperMethodsWithPopup(
             .setResizable(false)
             .setRequestFocus(true)
             .setItemChoosenCallback {
-                val value = list.selectedValue as? String ?: return@setItemChoosenCallback
+                val value = list.selectedValue ?: return@setItemChoosenCallback
                 val chosenElements = if (value == renameBase) deepestSuperMethods + declaration else listOf(declaration)
                 action(chosenElements)
             }

idea/src/org/jetbrains/kotlin/idea/refactoring/memberInfo/KotlinMemberInfoStorage.kt

@@ -100,8 +100,6 @@ fun extractClassMembers(
                 .mapTo(result) { KotlinMemberInfo(it as KtNamedDeclaration, isCompanionMember = isCompanion) }
     }
 
-    if (aClass !is KtClassOrObject) return emptyList()
-
     val result = ArrayList<KotlinMemberInfo>()
 
     if (collectSuperTypeEntries) {

idea/src/org/jetbrains/kotlin/idea/refactoring/move/moveFilesUtil.kt

@@ -50,7 +50,7 @@ fun invokeMoveFilesOrDirectoriesRefactoring(
 
     project.executeCommand(MoveHandler.REFACTORING_NAME) {
         val selectedDir = (if (moveDialog != null) moveDialog.targetDirectory else initialTargetDirectory) ?: return@executeCommand
-        val updatePackageDirective = (moveDialog as? KotlinAwareMoveFilesOrDirectoriesDialog)?.updatePackageDirective
+        val updatePackageDirective = moveDialog?.updatePackageDirective
 
         try {
             val choice = if (elements.size > 1 || elements[0] is PsiDirectory) intArrayOf(-1) else null

idea/src/org/jetbrains/kotlin/idea/refactoring/pullUp/markingUtils.kt

@@ -76,7 +76,6 @@ fun markElements(
                                    ?: resolvedCall.extensionReceiver
                                    ?: resolvedCall.dispatchReceiver
                                    ?: return
-                    if (receiver !is ReceiverValue) return
 
                     val implicitThis = receiver.type.constructor.declarationDescriptor as? ClassDescriptor ?: return
                     if (implicitThis.isCompanionObject

idea/src/org/jetbrains/kotlin/idea/refactoring/rename/RenameImportAliasByReferenceHandler.kt

@@ -24,7 +24,7 @@ import org.jetbrains.kotlin.psi.KtSimpleNameExpression
 
 class RenameImportAliasByReferenceHandler : AbstractReferenceSubstitutionRenameHandler(VariableInplaceRenameHandler()) {
     override fun getElementToRename(dataContext: DataContext): PsiElement? {
-        val refExpr = getReferenceExpression(dataContext) as? KtSimpleNameExpression ?: return null
+        val refExpr = getReferenceExpression(dataContext) ?: return null
         return refExpr.mainReference.getImportAlias()
     }
 }

idea/src/org/jetbrains/kotlin/idea/search/ideaExtensions/KotlinOverridingMethodsWithGenericsSearcher.kt

@@ -47,7 +47,7 @@ class KotlinOverridingMethodsWithGenericsSearcher : QueryExecutor<PsiMethod, Ove
         // we do additional search for such methods.
         if (!callDescriptor.valueParameters.any { it.type.constructor.declarationDescriptor is TypeParameterDescriptor }) return true
 
-        val parentClass = runReadAction { method.containingClass }!!
+        val parentClass = runReadAction { method.containingClass }
 
         return ClassInheritorsSearch.search(parentClass, p.scope, true).forEach(Processor { inheritor: PsiClass ->
             val found = runReadAction {

idea/tests/org/jetbrains/kotlin/idea/configuration/AbstractConfigureKotlinTest.kt

@@ -153,13 +153,10 @@ abstract class AbstractConfigureKotlinTest : PlatformTestCase() {
             collector.showNotification()
         }
 
-        private fun getPathToJar(runtimeState: FileState, jarFromDist: String, jarFromTemp: String): String {
-            when (runtimeState) {
-                KotlinWithLibraryConfigurator.FileState.EXISTS -> return jarFromDist
-                KotlinWithLibraryConfigurator.FileState.COPY -> return jarFromTemp
-                KotlinWithLibraryConfigurator.FileState.DO_NOT_COPY -> return jarFromDist
-            }
-            return jarFromDist
+        private fun getPathToJar(runtimeState: FileState, jarFromDist: String, jarFromTemp: String) = when (runtimeState) {
+            KotlinWithLibraryConfigurator.FileState.EXISTS -> jarFromDist
+            KotlinWithLibraryConfigurator.FileState.COPY -> jarFromTemp
+            KotlinWithLibraryConfigurator.FileState.DO_NOT_COPY -> jarFromDist
         }
 
         protected fun configure(module: Module, jarState: FileState, configurator: KotlinProjectConfigurator) {

idea/tests/org/jetbrains/kotlin/idea/refactoring/InplaceRenameTest.kt

@@ -102,7 +102,7 @@ class InplaceRenameTest : LightPlatformCodeInsightTestCase() {
         val element = file.findElementForRename<KtNameReferenceExpression>(editor.caretModel.offset)!!
         assertNotNull(element)
 
-        val dataContext = SimpleDataContext.getSimpleContext(CommonDataKeys.PSI_ELEMENT.name, element!!,
+        val dataContext = SimpleDataContext.getSimpleContext(CommonDataKeys.PSI_ELEMENT.name, element,
                                                              getCurrentEditorDataContext())
         val handler = RenameKotlinImplicitLambdaParameter()
 

idea/tests/org/jetbrains/kotlin/idea/refactoring/changeSignature/KotlinChangeSignatureTest.kt

@@ -157,7 +157,7 @@ class KotlinChangeSignatureTest : KotlinLightCodeInsightFixtureTestCase() {
             val message = when {
                 e is BaseRefactoringProcessor.ConflictsInTestsException -> StringUtil.join(e.messages.sorted(), "\n")
                 e is CommonRefactoringUtil.RefactoringErrorHintException -> e.message
-                e is RuntimeException && e.message!!.startsWith("Refactoring cannot be performed") -> e.message
+                e.message!!.startsWith("Refactoring cannot be performed") -> e.message
                 else -> throw e
             }
             val conflictsFile = File(testDataPath + getTestName(false) + "Messages.txt")