diff --git a/compiler/backend-common/src/org/jetbrains/kotlin/backend/common/FunctionsFromAnyGenerator.kt b/compiler/backend-common/src/org/jetbrains/kotlin/backend/common/FunctionsFromAnyGenerator.kt
index f44ae11e293..ef6ea195151 100644
--- a/compiler/backend-common/src/org/jetbrains/kotlin/backend/common/FunctionsFromAnyGenerator.kt
+++ b/compiler/backend-common/src/org/jetbrains/kotlin/backend/common/FunctionsFromAnyGenerator.kt
@@ -60,7 +60,7 @@ abstract class FunctionsFromAnyGenerator(protected val declaration: KtClassOrObj
         generateEqualsMethod(function, properties)
     }
 
-    private val primaryConstructorProperties: List<PropertyDescriptor>
+    protected val primaryConstructorProperties: List<PropertyDescriptor>
         get() = primaryConstructorParameters
             .filter { it.hasValOrVar() }
             .map { bindingContext.get(BindingContext.PRIMARY_CONSTRUCTOR_PARAMETER, it)!! }
diff --git a/compiler/testData/codegen/box/unsignedTypes/iterateOverArrayOfUnsignedValues.kt b/compiler/testData/codegen/box/unsignedTypes/iterateOverArrayOfUnsignedValues.kt
index df9786ba0f3..ab642d56920 100644
--- a/compiler/testData/codegen/box/unsignedTypes/iterateOverArrayOfUnsignedValues.kt
+++ b/compiler/testData/codegen/box/unsignedTypes/iterateOverArrayOfUnsignedValues.kt
@@ -1,7 +1,6 @@
 // WITH_UNSIGNED
 // IGNORE_BACKEND: JVM_IR
 // IGNORE_BACKEND: JS_IR
-// IGNORE_BACKEND: JS
 
 fun box(): String {
     var sum = 0u
diff --git a/compiler/testData/codegen/box/unsignedTypes/varargsOfUnsignedTypes.kt b/compiler/testData/codegen/box/unsignedTypes/varargsOfUnsignedTypes.kt
index 7a51ebfa7de..48bb64a394d 100644
--- a/compiler/testData/codegen/box/unsignedTypes/varargsOfUnsignedTypes.kt
+++ b/compiler/testData/codegen/box/unsignedTypes/varargsOfUnsignedTypes.kt
@@ -1,6 +1,6 @@
 // IGNORE_BACKEND: JVM_IR
 // WITH_UNSIGNED
-// IGNORE_BACKEND: JS, JS_IR
+// IGNORE_BACKEND: JS_IR
 
 fun uint(vararg us: UInt): UIntArray = us
 
diff --git a/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/BoxJsTestGenerated.java b/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/BoxJsTestGenerated.java
index 8c39384bdc8..431cb0973c1 100644
--- a/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/BoxJsTestGenerated.java
+++ b/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/BoxJsTestGenerated.java
@@ -2495,6 +2495,11 @@ public class BoxJsTestGenerated extends AbstractBoxJsTest {
                 runTest("js/js.translator/testData/box/expression/function/vararg.kt");
             }
 
+            @TestMetadata("varargUInt.kt")
+            public void testVarargUInt() throws Exception {
+                runTest("js/js.translator/testData/box/expression/function/varargUInt.kt");
+            }
+
             @TestMetadata("whenFunction.kt")
             public void testWhenFunction() throws Exception {
                 runTest("js/js.translator/testData/box/expression/function/whenFunction.kt");
diff --git a/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/IrBoxJsTestGenerated.java b/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/IrBoxJsTestGenerated.java
index 34c38ecf302..f5e80e5b612 100644
--- a/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/IrBoxJsTestGenerated.java
+++ b/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/IrBoxJsTestGenerated.java
@@ -2495,6 +2495,11 @@ public class IrBoxJsTestGenerated extends AbstractIrBoxJsTest {
                 runTest("js/js.translator/testData/box/expression/function/vararg.kt");
             }
 
+            @TestMetadata("varargUInt.kt")
+            public void testVarargUInt() throws Exception {
+                runTest("js/js.translator/testData/box/expression/function/varargUInt.kt");
+            }
+
             @TestMetadata("whenFunction.kt")
             public void testWhenFunction() throws Exception {
                 runTest("js/js.translator/testData/box/expression/function/whenFunction.kt");
diff --git a/js/js.translator/src/org/jetbrains/kotlin/js/translate/declaration/JsDataClassGenerator.java b/js/js.translator/src/org/jetbrains/kotlin/js/translate/declaration/JsDataClassGenerator.java
index de5857ac2e8..a91008e725e 100644
--- a/js/js.translator/src/org/jetbrains/kotlin/js/translate/declaration/JsDataClassGenerator.java
+++ b/js/js.translator/src/org/jetbrains/kotlin/js/translate/declaration/JsDataClassGenerator.java
@@ -18,13 +18,18 @@ package org.jetbrains.kotlin.js.translate.declaration;
 
 import com.intellij.psi.PsiElement;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.kotlin.backend.common.CodegenUtil;
 import org.jetbrains.kotlin.backend.common.DataClassMethodGenerator;
 import org.jetbrains.kotlin.descriptors.*;
+import org.jetbrains.kotlin.descriptors.annotations.Annotations;
+import org.jetbrains.kotlin.descriptors.impl.FunctionDescriptorImpl;
+import org.jetbrains.kotlin.descriptors.impl.SimpleFunctionDescriptorImpl;
 import org.jetbrains.kotlin.js.backend.ast.*;
 import org.jetbrains.kotlin.js.translate.context.Namer;
 import org.jetbrains.kotlin.js.translate.context.TranslationContext;
 import org.jetbrains.kotlin.js.translate.utils.JsAstUtils;
 import org.jetbrains.kotlin.js.translate.utils.UtilsKt;
+import org.jetbrains.kotlin.name.Name;
 import org.jetbrains.kotlin.psi.KtClassOrObject;
 import org.jetbrains.kotlin.psi.KtParameter;
 import org.jetbrains.kotlin.resolve.BindingContext;
@@ -49,6 +54,15 @@ class JsDataClassGenerator extends DataClassMethodGenerator {
         this.isInline = isInline;
     }
 
+    @Override
+    public void generate() {
+        if (isInline) {
+            generateUnboxFunction();
+        }
+
+        super.generate();
+    }
+
     @Override
     public void generateComponentFunction(@NotNull FunctionDescriptor function, @NotNull ValueParameterDescriptor parameter) {
         if (isInline) return;
@@ -213,6 +227,18 @@ class JsDataClassGenerator extends DataClassMethodGenerator {
         functionObj.getBody().getStatements().add(returnStatement);
     }
 
+    private void generateUnboxFunction() {
+        PropertyDescriptor boxee = getPrimaryConstructorProperties().get(0);
+
+        JsFunction unboxFunction = context.createRootScopedFunction("unbox");
+        JsExpression prototypeRef = JsAstUtils.prototypeOf(context.getInnerReference(getClassDescriptor()));
+        JsExpression functionRef = new JsNameRef("unbox", prototypeRef);
+
+        unboxFunction.getBody().getStatements().add(new JsReturn(JsAstUtils.pureFqn(context.getNameForDescriptor(boxee), new JsThisRef())));
+
+        context.addDeclarationStatement(JsAstUtils.assignment(functionRef, unboxFunction).makeStmt());
+    }
+
     private JsFunction generateJsMethod(@NotNull FunctionDescriptor functionDescriptor) {
         JsFunction functionObject = context.createRootScopedFunction(functionDescriptor);
         functionObject.setSource(getDeclaration());
diff --git a/js/js.translator/src/org/jetbrains/kotlin/js/translate/intrinsic/functions/factories/ArrayFIF.kt b/js/js.translator/src/org/jetbrains/kotlin/js/translate/intrinsic/functions/factories/ArrayFIF.kt
index 3d688519680..091b728d747 100644
--- a/js/js.translator/src/org/jetbrains/kotlin/js/translate/intrinsic/functions/factories/ArrayFIF.kt
+++ b/js/js.translator/src/org/jetbrains/kotlin/js/translate/intrinsic/functions/factories/ArrayFIF.kt
@@ -40,6 +40,8 @@ import org.jetbrains.kotlin.js.translate.intrinsic.functions.basic.FunctionIntri
 import org.jetbrains.kotlin.js.translate.utils.JsAstUtils
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.resolve.inline.InlineStrategy
+import org.jetbrains.kotlin.resolve.isInlineClassType
+import org.jetbrains.kotlin.types.KotlinType
 import java.util.*
 
 object ArrayFIF : CompositeFIF() {
@@ -64,14 +66,38 @@ object ArrayFIF : CompositeFIF() {
     @JvmStatic
     fun typedArraysEnabled(config: JsConfig) = config.configuration.get(JSConfigurationKeys.TYPED_ARRAYS_ENABLED, true)
 
-    fun castOrCreatePrimitiveArray(ctx: TranslationContext, type: PrimitiveType?, arg: JsArrayLiteral): JsExpression {
-        if (type == null || !typedArraysEnabled(ctx.config)) return arg
+    fun unsignedPrimitiveToSigned(type: KotlinType): PrimitiveType? {
+        // short-circuit
+        if (!type.isInlineClassType() || type.isMarkedNullable) return null
 
-        return if (type in TYPED_ARRAY_MAP) {
-            createTypedArray(type, arg)
+        return when {
+            KotlinBuiltIns.isUByte(type) -> BYTE
+            KotlinBuiltIns.isUShort(type) -> SHORT
+            KotlinBuiltIns.isUInt(type) -> INT
+            KotlinBuiltIns.isULong(type) -> LONG
+            else -> null
+        }
+    }
+
+    fun castOrCreatePrimitiveArray(ctx: TranslationContext, type: KotlinType, arg: JsArrayLiteral): JsExpression {
+        if (type.isMarkedNullable) return arg
+
+        val unsignedPrimitiveType = unsignedPrimitiveToSigned(type)
+
+        if (unsignedPrimitiveType != null) {
+            val conversionFunction = "to${unsignedPrimitiveType.typeName}"
+            arg.expressions.replaceAll { JsInvocation(JsNameRef(conversionFunction, it)) }
+        }
+
+        val primitiveType = unsignedPrimitiveType ?: KotlinBuiltIns.getPrimitiveType(type)?.takeUnless { type.isMarkedNullable}
+
+        if (primitiveType == null || !typedArraysEnabled(ctx.config)) return arg
+
+        return if (primitiveType in TYPED_ARRAY_MAP) {
+            createTypedArray(primitiveType, arg)
         }
         else {
-            JsAstUtils.invokeKotlinFunction(type.lowerCaseName + "ArrayOf", *arg.expressions.toTypedArray())
+            JsAstUtils.invokeKotlinFunction(primitiveType.lowerCaseName + "ArrayOf", *arg.expressions.toTypedArray())
         }
     }
 
diff --git a/js/js.translator/src/org/jetbrains/kotlin/js/translate/reference/CallArgumentTranslator.kt b/js/js.translator/src/org/jetbrains/kotlin/js/translate/reference/CallArgumentTranslator.kt
index fc986f68062..ce7256a0b12 100644
--- a/js/js.translator/src/org/jetbrains/kotlin/js/translate/reference/CallArgumentTranslator.kt
+++ b/js/js.translator/src/org/jetbrains/kotlin/js/translate/reference/CallArgumentTranslator.kt
@@ -5,12 +5,13 @@
 
 package org.jetbrains.kotlin.js.translate.reference
 
-import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.builtins.PrimitiveType
 import org.jetbrains.kotlin.builtins.functions.FunctionInvokeDescriptor
 import org.jetbrains.kotlin.builtins.getFunctionalClassKind
+import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.FunctionDescriptor
 import org.jetbrains.kotlin.descriptors.TypeParameterDescriptor
+import org.jetbrains.kotlin.incremental.components.NoLookupLocation
 import org.jetbrains.kotlin.js.backend.ast.*
 import org.jetbrains.kotlin.js.backend.ast.metadata.SideEffectKind
 import org.jetbrains.kotlin.js.backend.ast.metadata.sideEffects
@@ -25,6 +26,8 @@ import org.jetbrains.kotlin.js.translate.utils.AnnotationsUtils
 import org.jetbrains.kotlin.js.translate.utils.JsAstUtils
 import org.jetbrains.kotlin.js.translate.utils.TranslationUtils
 import org.jetbrains.kotlin.js.translate.utils.getReferenceToJsClass
+import org.jetbrains.kotlin.name.FqNameUnsafe
+import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.ValueArgument
 import org.jetbrains.kotlin.resolve.DescriptorUtils
 import org.jetbrains.kotlin.resolve.calls.components.isVararg
@@ -33,6 +36,7 @@ import org.jetbrains.kotlin.resolve.calls.model.ResolvedCall
 import org.jetbrains.kotlin.resolve.calls.model.ResolvedValueArgument
 import org.jetbrains.kotlin.resolve.calls.model.VarargValueArgument
 import org.jetbrains.kotlin.types.KotlinType
+import org.jetbrains.kotlin.types.typeUtil.isPrimitiveNumberType
 import java.util.*
 
 class CallArgumentTranslator private constructor(
@@ -77,7 +81,7 @@ class CallArgumentTranslator private constructor(
         var argsBeforeVararg: List<JsExpression>? = null
         var concatArguments: MutableList<JsExpression>? = null
         val argsToJsExpr = translateUnresolvedArguments(context(), resolvedCall)
-        var varargPrimitiveType: PrimitiveType? = null
+        var varargElementType: KotlinType? = null
 
         for (parameterDescriptor in valueParameters) {
             val actualArgument = valueArgumentsByIndex[parameterDescriptor.index]
@@ -90,8 +94,7 @@ class CallArgumentTranslator private constructor(
                     hasSpreadOperator = arguments.any { it.getSpreadElement() != null }
                 }
 
-                val varargElementType = parameterDescriptor.original.varargElementType!!
-                varargPrimitiveType = KotlinBuiltIns.getPrimitiveType(varargElementType).takeUnless { varargElementType.isMarkedNullable }
+                varargElementType = parameterDescriptor.original.varargElementType!!
 
                 if (hasSpreadOperator) {
                     if (isNativeFunctionCall) {
@@ -102,10 +105,10 @@ class CallArgumentTranslator private constructor(
                                                                  null)
                     }
                     else {
-                        result.addAll(translateVarargArgument(actualArgument,
-                                                              argsToJsExpr,
-                                                              actualArgument.arguments.size > 1,
-                                                              varargPrimitiveType))
+                        translateVarargArgument(actualArgument,
+                                                argsToJsExpr,
+                                                actualArgument.arguments.size > 1,
+                                                varargElementType)?.let { result.add(it) }
                     }
                 }
                 else {
@@ -113,7 +116,7 @@ class CallArgumentTranslator private constructor(
                         result.addAll(translateResolvedArgument(actualArgument, argsToJsExpr))
                     }
                     else {
-                        result.addAll(translateVarargArgument(actualArgument, argsToJsExpr, true, varargPrimitiveType))
+                        translateVarargArgument(actualArgument, argsToJsExpr, true, varargElementType)?.let { result.add(it) }
                     }
                 }
             }
@@ -134,7 +137,7 @@ class CallArgumentTranslator private constructor(
                 concatArguments!!.add(0, toArray(null, argsBeforeVararg))
             }
 
-            result = mutableListOf(concatArgumentsIfNeeded(concatArguments!!, varargPrimitiveType, true))
+            result = mutableListOf(concatArgumentsIfNeeded(concatArguments!!, varargElementType, true))
 
             if (receiver != null) {
                 cachedReceiver = context().getOrDeclareTemporaryConstVariable(receiver)
@@ -207,44 +210,64 @@ class CallArgumentTranslator private constructor(
         return result
     }
 
+    // Cache UTypeArray descriptor lookup
+    private val typeToUTypeArray = mutableMapOf<PrimitiveType, ClassDescriptor>()
+
+    private fun JsExpression.wrapInUArray(elementType: KotlinType): JsExpression {
+        return ArrayFIF.unsignedPrimitiveToSigned(elementType)?.let { primitiveType ->
+            val kotlinMemberScope = context.currentModule.getPackage(FqNameUnsafe("kotlin").toSafe()).memberScope
+            val classDescriptor = typeToUTypeArray.computeIfAbsent(primitiveType) {
+                val className = Name.identifier("U${primitiveType.typeName}Array")
+                kotlinMemberScope.getContributedClassifier(className, NoLookupLocation.FROM_BACKEND) as ClassDescriptor
+            }
+            JsNew(ReferenceTranslator.translateAsTypeReference(classDescriptor, context), listOf(this))
+        } ?: this
+    }
+
     private fun translateVarargArgument(
-            resolvedArgument: ResolvedValueArgument,
-            translatedArgs: Map<ValueArgument, JsExpression>,
-            shouldWrapVarargInArray: Boolean,
-            varargPrimitiveType: PrimitiveType?
-    ): List<JsExpression> {
+        resolvedArgument: ResolvedValueArgument,
+        translatedArgs: Map<ValueArgument, JsExpression>,
+        shouldWrapVarargInArray: Boolean,
+        varargElementType: KotlinType
+    ): JsExpression? {
         val arguments = resolvedArgument.arguments
         if (arguments.isEmpty()) {
             return if (shouldWrapVarargInArray) {
-                return listOf(toArray(varargPrimitiveType, listOf()))
-            }
-            else {
-                listOf()
+                return toArray(varargElementType, listOf()).wrapInUArray(varargElementType)
+            } else {
+                null
             }
         }
 
         val list = translateResolvedArgument(resolvedArgument, translatedArgs)
 
         return if (shouldWrapVarargInArray) {
-            val concatArguments = prepareConcatArguments(arguments, list, varargPrimitiveType)
-            val concatExpression = concatArgumentsIfNeeded(concatArguments, varargPrimitiveType, false)
-            listOf(concatExpression)
-        }
-        else {
-            listOf(JsAstUtils.invokeMethod(list[0], "slice"))
-        }
+            val concatArguments = prepareConcatArguments(arguments, list, varargElementType)
+            val concatExpression = concatArgumentsIfNeeded(concatArguments, varargElementType, false)
+            concatExpression
+        } else {
+            val arg = ArrayFIF.unsignedPrimitiveToSigned(varargElementType)?.let {type ->
+                JsInvocation(JsNameRef("unbox", list[0]))
+            } ?: list[0]
+            JsAstUtils.invokeMethod(arg, "slice")
+        }.wrapInUArray(varargElementType)
     }
 
-    private fun toArray(varargPrimitiveType: PrimitiveType?, elements: List<JsExpression>): JsExpression {
-        return ArrayFIF.castOrCreatePrimitiveArray(context(),
-                                                   varargPrimitiveType,
-                                                   JsArrayLiteral(elements).apply { sideEffects = SideEffectKind.PURE })
+    private fun toArray(varargElementType: KotlinType?, elements: List<JsExpression>): JsExpression {
+        val argument = JsArrayLiteral(elements).apply { sideEffects = SideEffectKind.PURE }
+
+        if (varargElementType == null) return argument
+
+        return ArrayFIF.castOrCreatePrimitiveArray(
+            context(),
+            varargElementType,
+            argument)
     }
 
     private fun prepareConcatArguments(
-            arguments: List<ValueArgument>,
-            list: List<JsExpression>,
-            varargPrimitiveType: PrimitiveType?
+        arguments: List<ValueArgument>,
+        list: List<JsExpression>,
+        varargElementType: KotlinType?
     ): MutableList<JsExpression> {
         assert(arguments.isNotEmpty()) { "arguments.size should not be 0" }
         assert(arguments.size == list.size) { "arguments.size: " + arguments.size + " != list.size: " + list.size }
@@ -259,17 +282,19 @@ class CallArgumentTranslator private constructor(
 
             if (valueArgument.getSpreadElement() != null) {
                 if (lastArrayContent.size > 0) {
-                    concatArguments.add(toArray(varargPrimitiveType, lastArrayContent))
+                    concatArguments.add(toArray(varargElementType, lastArrayContent))
                     lastArrayContent = mutableListOf()
                 }
-                concatArguments.add(expressionArgument)
-            }
-            else {
+                val e = if (varargElementType != null && ArrayFIF.unsignedPrimitiveToSigned(varargElementType) != null) {
+                    JsInvocation(JsNameRef("unbox", expressionArgument))
+                } else expressionArgument
+                concatArguments.add(e)
+            } else {
                 lastArrayContent.add(expressionArgument)
             }
         }
         if (lastArrayContent.size > 0) {
-            concatArguments.add(toArray(varargPrimitiveType, lastArrayContent))
+            concatArguments.add(toArray(varargElementType, lastArrayContent))
         }
 
         return concatArguments
@@ -306,23 +331,23 @@ class CallArgumentTranslator private constructor(
         }
 
         private fun concatArgumentsIfNeeded(
-                concatArguments: List<JsExpression>,
-                varargPrimitiveType: PrimitiveType?,
-                isMixed: Boolean
+            concatArguments: List<JsExpression>,
+            varargElementType: KotlinType?,
+            isMixed: Boolean
         ): JsExpression {
             assert(concatArguments.isNotEmpty()) { "concatArguments.size should not be 0" }
 
             return if (concatArguments.size > 1) {
-                if (varargPrimitiveType != null) {
+                if (varargElementType != null && (varargElementType.isPrimitiveNumberType() || ArrayFIF.unsignedPrimitiveToSigned(varargElementType) != null)) {
                     val method = if (isMixed) "arrayConcat" else "primitiveArrayConcat"
-                    JsAstUtils.invokeKotlinFunction(method, concatArguments[0],
-                                                    *concatArguments.subList(1, concatArguments.size).toTypedArray())
-                }
-                else {
+                    JsAstUtils.invokeKotlinFunction(
+                        method, concatArguments[0],
+                        *concatArguments.subList(1, concatArguments.size).toTypedArray()
+                    )
+                } else {
                     JsInvocation(JsNameRef("concat", concatArguments[0]), concatArguments.subList(1, concatArguments.size))
                 }
-            }
-            else {
+            } else {
                 concatArguments[0]
             }
         }
diff --git a/js/js.translator/testData/box/expression/function/varargUInt.kt b/js/js.translator/testData/box/expression/function/varargUInt.kt
new file mode 100644
index 00000000000..530b2772332
--- /dev/null
+++ b/js/js.translator/testData/box/expression/function/varargUInt.kt
@@ -0,0 +1,113 @@
+// LANGUAGE_VERSION: 1.3
+// IGNORE_BACKEND: JS_IR
+// EXPECTED_REACHABLE_NODES: 1566
+package foo
+
+fun testSize(expectedSize: Int, vararg i: UInt): Boolean {
+    return (i.size == expectedSize)
+}
+
+fun testSum(expectedSum: UInt, vararg i: UInt): Boolean {
+    var sum = 0u
+    for (j in i) {
+        sum += j
+    }
+
+    return (expectedSum == sum)
+}
+
+fun testSpreadOperator(vararg args: UInt): Boolean {
+    var sum = 0u
+    for (a in args) sum += a
+
+    return testSize(args.size, *args) && testSum(sum, *args)
+}
+
+class Bar(val size: Int, val sum: UInt) {
+    fun test(vararg args: UInt) = testSize(size, *args) && testSum(sum, *args)
+}
+
+object obj {
+    fun test(size: Int, sum: UInt, vararg args: UInt) = testSize(size, *args) && testSum(sum, *args)
+}
+
+fun spreadInMethodCall(size: Int, sum: UInt, vararg args: UInt) = Bar(size, sum).test(*args)
+
+fun spreadInObjectMethodCall(size: Int, sum: UInt, vararg args: UInt) = obj.test(size, sum, *args)
+
+fun testVarargWithFunLit(vararg args: UInt, f: (a: UIntArray) -> Boolean): Boolean = f(args)
+
+fun <T> idVarArgs(vararg a: T) = a
+
+fun <T> idArrayVarArg(vararg a: Array<T>) = a
+
+fun sumFunValuesOnParameters(x: UInt, y: UInt, vararg a: UInt, f: (UInt) -> UInt): UInt {
+    var result = f(x) + f(y)
+    for(u in a) {
+        result += f(u)
+    }
+    return result
+}
+
+fun box(): String {
+    if (!testSize(0))
+        return "wrong vararg size when call function without args"
+
+    if (!testSum(0u))
+        return "wrong vararg sum (arguments) when call function without args"
+
+    if (!testSize(6, 1u, 1u, 1u, 2u, 3u, 4u))
+        return "wrong vararg size when call function with some args (1)"
+
+    if (!testSum(30, 10u, 20u, 0u))
+        return "wrong vararg sum (arguments) when call function with some args (1)"
+
+    if (!testSpreadOperator(30u, 10u, 20u, 0u))
+        return "failed when call function using spread operator"
+
+    if (!Bar(3, 30u).test(10u, 20u, 0u))
+        return "failed when call method"
+
+    if (!spreadInMethodCall(2, 3u, 1u, 2u))
+        return "failed when call method using spread operator"
+
+    if (!obj.test(5, 15u, 1u, 2u, 3u, 4u, 5u))
+        return "failed when call method of object"
+
+    if (!spreadInObjectMethodCall(2, 3u, 1u, 2u))
+        return "failed when call method of object using spread operator"
+
+    if (!testVarargWithFunLit(1u, 2u, 3u) { args -> args.size == 3 })
+        return "failed when call function with vararg and fun literal"
+
+    val a = arrayOf(1u, 2u, 3u)
+    val b = arrayOf(4u, 5u)
+
+    assertEquals(5, arrayOf(*a, *b).size)
+    assertEquals(8, arrayOf(10u, *a, 20u,  *b, 30u).size)
+
+    assertEquals(5, idVarArgs(*a, *b).size)
+    assertEquals(8, idVarArgs(10u, *a, 20u,  *b, 30u).size)
+
+    assertEquals(9, arrayOf(1u, *a, *a, 1u, 2u).size)
+    assertEquals(9, idVarArgs(1u, *a, *a, 1u, 2u).size)
+
+    assertEquals(9, arrayOf(1u, *a, *arrayOf(1u, 2u, 3u), 1u, 2u).size)
+    assertEquals(9, idVarArgs(1u, *a, *arrayOf(1u, 2u, 3u), 1u, 2u).size)
+
+    assertEquals(90u, sumFunValuesOnParameters(1u, 2u, 3u, 4u, 5u, 6u, 7u, 8u, 9u) { 2u*it })
+    assertEquals(90u, sumFunValuesOnParameters(1u, 2u, *uintArrayOf(3u, 4u, 5u, 6u, 7u, 8u, 9u)) { 2u*it })
+    assertEquals(90u, sumFunValuesOnParameters(1u, 2u, 3u, 4u, *uintArrayOf(5u, 6u, 7u, 8u, 9u)) { 2u*it })
+    assertEquals(90u, sumFunValuesOnParameters(1u, 2u, *uintArrayOf(3u, 4u, 5u, 6u, 7u), 8u, 9u) { 2u*it })
+    assertEquals(90u, sumFunValuesOnParameters(1u, 2u, *uintArrayOf(3u, 4u, 5u), *uintArrayOf(6u, 7u, 8u, 9u)) { 2u*it })
+    assertEquals(90u, sumFunValuesOnParameters(1u, 2u, *uintArrayOf(3u, 4u), 5u, 6u, *uintArrayOf(7u, 8u, 9u)) { 2u*it })
+
+    assertEquals(2, idArrayVarArg(arrayOf(1u), *arrayOf(arrayOf(2u, 3u, 4u))).size)
+    assertEquals(3, idArrayVarArg(arrayOf(1u, 2u), *arrayOf(arrayOf(3u, 4u), arrayOf(5u, 6u))).size)
+    assertEquals(6, idArrayVarArg(arrayOf(1u, 2u), *arrayOf(arrayOf(3u, 4u), arrayOf(5u, 6u)), arrayOf(7u), *arrayOf(arrayOf(8u, 9u), arrayOf(10u, 11u))).size)
+
+    val c = arrayOf(*a)
+    assertFalse(a === c, "Spread operator should copy its argument")
+
+    return "OK"
+}
\ No newline at end of file