diff --git a/js/js.translator/testData/closure/cases/closureFunctionByInnerFunction.kt b/js/js.translator/testData/closure/cases/closureFunctionByInnerFunction.kt
index 8d835fcc16a..8f0623f09fe 100644
--- a/js/js.translator/testData/closure/cases/closureFunctionByInnerFunction.kt
+++ b/js/js.translator/testData/closure/cases/closureFunctionByInnerFunction.kt
@@ -1,7 +1,5 @@
 package foo
 
-fun run<T>(f: () -> T) = f()
-
 val r = "OK"
 
 fun simple(s: String? = null): String {
diff --git a/js/js.translator/testData/closure/cases/closureInNestedFunctions.kt b/js/js.translator/testData/closure/cases/closureInNestedFunctions.kt
index 18f50dee099..2e08626540e 100644
--- a/js/js.translator/testData/closure/cases/closureInNestedFunctions.kt
+++ b/js/js.translator/testData/closure/cases/closureInNestedFunctions.kt
@@ -1,7 +1,5 @@
 package foo
 
-fun run<T>(f: () -> T) = f()
-
 fun funfun(): Boolean {
     val result = true
 
diff --git a/js/js.translator/testData/closure/cases/closureInNestedFunctionsInMethod.kt b/js/js.translator/testData/closure/cases/closureInNestedFunctionsInMethod.kt
index 2e5cb5ab6b2..c3f4476274d 100644
--- a/js/js.translator/testData/closure/cases/closureInNestedFunctionsInMethod.kt
+++ b/js/js.translator/testData/closure/cases/closureInNestedFunctionsInMethod.kt
@@ -1,7 +1,5 @@
 package foo
 
-fun run<T>(f: () -> T) = f()
-
 class A {
     val a = 12
     var b = 1
diff --git a/js/js.translator/testData/closure/cases/closureInNestedFunctionsWhichMixedWithObject.kt b/js/js.translator/testData/closure/cases/closureInNestedFunctionsWhichMixedWithObject.kt
index 96747e834bc..6ecb93199cd 100644
--- a/js/js.translator/testData/closure/cases/closureInNestedFunctionsWhichMixedWithObject.kt
+++ b/js/js.translator/testData/closure/cases/closureInNestedFunctionsWhichMixedWithObject.kt
@@ -1,7 +1,5 @@
 package foo
 
-fun run<T>(f: () -> T) = f()
-
 fun box(): Boolean {
     val t = run {
         object {
diff --git a/js/js.translator/testData/closure/cases/closureLocalFunctionByInnerFunction.kt b/js/js.translator/testData/closure/cases/closureLocalFunctionByInnerFunction.kt
index 45b137825b1..fe6ec55e599 100644
--- a/js/js.translator/testData/closure/cases/closureLocalFunctionByInnerFunction.kt
+++ b/js/js.translator/testData/closure/cases/closureLocalFunctionByInnerFunction.kt
@@ -1,7 +1,5 @@
 package foo
 
-fun run<T>(f: () -> T) = f()
-
 fun box(): String {
     fun simple(s: String? = null): String {
         if (s != null) return s
diff --git a/js/js.translator/testData/closure/cases/closureLocalFunctionByInnerFunctionInConstructor.kt b/js/js.translator/testData/closure/cases/closureLocalFunctionByInnerFunctionInConstructor.kt
index b03de123a4e..eb83c4dcde5 100644
--- a/js/js.translator/testData/closure/cases/closureLocalFunctionByInnerFunctionInConstructor.kt
+++ b/js/js.translator/testData/closure/cases/closureLocalFunctionByInnerFunctionInConstructor.kt
@@ -1,7 +1,5 @@
 package foo
 
-fun run<T>(f: () -> T) = f()
-
 class Foo {
     val OK = "OK";
     var result: String = ""
diff --git a/js/js.translator/testData/closure/cases/closureThisInExtLambdaInsideMethod.kt b/js/js.translator/testData/closure/cases/closureThisInExtLambdaInsideMethod.kt
index 22fa1762c78..70e6393dfcf 100644
--- a/js/js.translator/testData/closure/cases/closureThisInExtLambdaInsideMethod.kt
+++ b/js/js.translator/testData/closure/cases/closureThisInExtLambdaInsideMethod.kt
@@ -2,8 +2,6 @@
 
 package foo
 
-fun run<T>(f: Int.() -> T) = 1.f()
-
 public class Foo(val trigger: () -> Any) {
     fun test() = run {trigger()};
 }
diff --git a/js/js.translator/testData/closure/cases/withManyClosuresInNestedFunctionsAndObjects.kt b/js/js.translator/testData/closure/cases/withManyClosuresInNestedFunctionsAndObjects.kt
index 75975c3d6d8..48da444fd55 100644
--- a/js/js.translator/testData/closure/cases/withManyClosuresInNestedFunctionsAndObjects.kt
+++ b/js/js.translator/testData/closure/cases/withManyClosuresInNestedFunctionsAndObjects.kt
@@ -1,7 +1,5 @@
 package foo
 
-fun run<T>(f: ()->T) = f()
-
 fun box(): String {
     val t = run {
                 object {
diff --git a/js/js.translator/testData/dataClass/cases/hashcode.kt b/js/js.translator/testData/dataClass/cases/hashcode.kt
index 3cd444a5dde..0483105b300 100644
--- a/js/js.translator/testData/dataClass/cases/hashcode.kt
+++ b/js/js.translator/testData/dataClass/cases/hashcode.kt
@@ -38,46 +38,30 @@ fun box(): String {
 
     // Check that same Dat's have the same hashcode.
     val sameDs = listOf(Dat("a", "b"), Dat("a", "b"))
-    assertAllEqual(map(sameDs, hashCoder))
+    assertAllEqual(sameDs.map(hashCoder))
 
     // Check that different Dat's have different hashcodes (at least some of them).
     val differentDs = listOf(Dat("a", "b"), Dat("a", "c"), Dat("a", "d"))
-    assertSomeNotEqual(map(differentDs, hashCoder))
+    assertSomeNotEqual(differentDs.map(hashCoder))
 
     // Check the same on Obj's, which should be always different and with different hashcodes.
     val sameOs = listOf(Obj("a", "b"), Obj("a", "b"), Obj("a", "b"))
     val differentOs = listOf(Obj("a", "b"), Obj("a", "b"), Obj("a", "b"))
 
     // Obj's are always different.
-    assertSomeNotEqual(map(sameOs, hashCoder))
-    assertSomeNotEqual(map(differentOs, hashCoder))
+    assertSomeNotEqual(sameOs.map(hashCoder))
+    assertSomeNotEqual(differentOs.map(hashCoder))
 
     // Both Dat's and Obj's wrapped as Holder should retain their hashcode relations.
-    val sameHDs = map(sameDs, wrapInH)
-    assertAllEqual(map(sameHDs, hashCoder))
-    val differentHDs = map(differentDs, wrapInH)
-    assertSomeNotEqual(map(differentHDs, hashCoder))
+    val sameHDs = sameDs.map(wrapInH)
+    assertAllEqual(sameHDs.map(hashCoder))
+    val differentHDs = differentDs.map(wrapInH)
+    assertSomeNotEqual(differentHDs.map(hashCoder))
 
-    val sameHOs = map(sameOs, wrapInH)
-    assertSomeNotEqual(map(sameHOs, hashCoder))
-    val differentHOs = map(differentOs, wrapInH)
-    assertSomeNotEqual(map(differentHOs, hashCoder))
+    val sameHOs = sameOs.map(wrapInH)
+    assertSomeNotEqual(sameHOs.map(hashCoder))
+    val differentHOs = differentOs.map(wrapInH)
+    assertSomeNotEqual(differentHOs.map(hashCoder))
 
     return "OK"
 }
-
-fun listOf<T>(vararg a: T): List<T> {
-    val list = ArrayList<T>()
-    for (e in a) {
-        list.add(e)
-    }
-    return list
-}
-
-fun map<T, S>(c : Iterable<T>, transform : (T) -> S) : List<S> {
-    val list = ArrayList<S>()
-    for (t in c) {
-        list.add(transform(t))
-    }
-    return list
-}
diff --git a/js/js.translator/testData/expression/misc/cases/KT-2314.kt b/js/js.translator/testData/expression/misc/cases/KT-2314.kt
index b84258b1dc7..dd5277482bc 100644
--- a/js/js.translator/testData/expression/misc/cases/KT-2314.kt
+++ b/js/js.translator/testData/expression/misc/cases/KT-2314.kt
@@ -3,15 +3,15 @@ package foo
 import java.util.*
 
 fun box(): Boolean {
-    val data = arrayList("foo", "bar")
-    if (data.head != "foo") {
+    val data = myArrayList("foo", "bar")
+    if (data.myHead != "foo") {
         return false
     }
     return true
 }
 
 
-public fun arrayList<T>(vararg values: T): ArrayList<T> {
+inline public fun myArrayList<T>(vararg values: T): ArrayList<T> {
     val c = ArrayList<T>()
     for (v in values) {
         c.add(v)
@@ -19,7 +19,7 @@ public fun arrayList<T>(vararg values: T): ArrayList<T> {
     return c
 }
 
-public val <T> ArrayList<T>.head: T
+inline public val <T> ArrayList<T>.myHead: T
     get() {
         return get(0)
     }
diff --git a/js/js.translator/testData/expression/string/cases/stringSplit.kt b/js/js.translator/testData/expression/string/cases/stringSplit.kt
index 9362587f4a5..d3ea0ecb1a6 100644
--- a/js/js.translator/testData/expression/string/cases/stringSplit.kt
+++ b/js/js.translator/testData/expression/string/cases/stringSplit.kt
@@ -1,9 +1,5 @@
 package foo
 
-// todo drop
-class Pair<F, S>(val first: F, val second: S)
-fun <F, S> F.to(second: S): Pair<F, S> = Pair(this, second)
-
 fun box(): String {
     val testInput = "test data\t1foo  2 bar"
     val tests = array(
diff --git a/js/js.translator/testData/inline/cases/extension.kt b/js/js.translator/testData/inline/cases/extension.kt
index 9e9b19d25d1..00d7ce36eb7 100644
--- a/js/js.translator/testData/inline/cases/extension.kt
+++ b/js/js.translator/testData/inline/cases/extension.kt
@@ -5,8 +5,6 @@
 
 package foo
 
-inline fun <T, R> with(receiver: T, f: T.() -> R): R = receiver.f()
-
 inline fun Inline.calcExt(s: (Int) -> Int, p: Int) : Int {
     return s(p)
 }
diff --git a/js/js.translator/testData/inlineMultiFile/cases/with/with.2.kt b/js/js.translator/testData/inlineMultiFile/cases/with/with.2.kt
index f70ef2700fd..67c32c70e78 100644
--- a/js/js.translator/testData/inlineMultiFile/cases/with/with.2.kt
+++ b/js/js.translator/testData/inlineMultiFile/cases/with/with.2.kt
@@ -33,6 +33,4 @@ public fun Input.copyTo(output: Output, size: Int): Int {
     return output.doOutput(this.data())
 }
 
-public inline fun <T, R> with(receiver: T, f: T.() -> R): R = receiver.f()
-
 public inline fun with2<T>(receiver : T, inlineOptions(ONLY_LOCAL_RETURN) body :  T.() -> Unit) : Unit = {receiver.body()}()
diff --git a/js/js.translator/testData/java/arrayList/cases/containsAll.kt b/js/js.translator/testData/java/arrayList/cases/containsAll.kt
index 99f8f475269..3932f6e4ee7 100644
--- a/js/js.translator/testData/java/arrayList/cases/containsAll.kt
+++ b/js/js.translator/testData/java/arrayList/cases/containsAll.kt
@@ -2,18 +2,6 @@ package foo
 
 import java.util.ArrayList;
 
-
-// TODO: drop when arrayListOf will be available here.
-fun arrayListOf<T>(vararg a: T): ArrayList<T> {
-    val list = ArrayList<T>();
-
-    for (e in a) {
-        list.add(e)
-    }
-
-    return list
-}
-
 fun box(): String {
     val list = arrayListOf(3, "2", -1, null, 0, 8, 5, "3", 77, -15)
     val subset = arrayListOf(3, "2", -1, null)
diff --git a/js/js.translator/testData/java/arrayList/cases/indexOf.kt b/js/js.translator/testData/java/arrayList/cases/indexOf.kt
index 0ee14825c89..2816a3f5a5a 100644
--- a/js/js.translator/testData/java/arrayList/cases/indexOf.kt
+++ b/js/js.translator/testData/java/arrayList/cases/indexOf.kt
@@ -2,17 +2,6 @@ package foo
 
 import java.util.ArrayList;
 
-// TODO: drop when listOf will be available here.
-fun listOf<T>(vararg a: T): List<T> {
-    val list = ArrayList<T>();
-
-    for (e in a) {
-        list.add(e)
-    }
-
-    return list
-}
-
 fun test<T>(list: List<T>, elements: List<T>, expected: List<Int>, method: List<T>.(T) -> Int, methodName: String): String? {
     for (i in 0..elements.size() - 1) {
         val actual = list.method(elements[i])
diff --git a/js/js.translator/testData/java/arrayList/cases/removeAll.kt b/js/js.translator/testData/java/arrayList/cases/removeAll.kt
index d60a09b8bef..90f7c44e120 100644
--- a/js/js.translator/testData/java/arrayList/cases/removeAll.kt
+++ b/js/js.translator/testData/java/arrayList/cases/removeAll.kt
@@ -3,17 +3,6 @@ package foo
 import java.util.ArrayList;
 
 
-// TODO: drop when listOf will be available here.
-fun listOf<T>(vararg a: T): List<T> {
-    val list = ArrayList<T>();
-
-    for (e in a) {
-        list.add(e)
-    }
-
-    return list
-}
-
 fun test<T>(a: List<T>, b: List<T>, removed: Boolean, expected: List<T>): String? {
     val t = ArrayList<T>(a.size())
     t.addAll(a)
diff --git a/js/js.translator/testData/java/arrayList/cases/retainAll.kt b/js/js.translator/testData/java/arrayList/cases/retainAll.kt
index 57454603d7e..76990dbb6e9 100644
--- a/js/js.translator/testData/java/arrayList/cases/retainAll.kt
+++ b/js/js.translator/testData/java/arrayList/cases/retainAll.kt
@@ -2,18 +2,6 @@ package foo
 
 import java.util.ArrayList;
 
-
-// TODO: drop when listOf will be available here.
-fun listOf<T>(vararg a: T): List<T> {
-    val list = ArrayList<T>();
-
-    for (e in a) {
-        list.add(e)
-    }
-
-    return list
-}
-
 fun test<T>(a: List<T>, b: List<T>, removed: Boolean, expected: List<T>): String? {
     val t = ArrayList<T>(a.size())
     t.addAll(a)
diff --git a/js/js.translator/testData/operatorOverloading/cases/overloadPlusAssignViaExtensionFunction.kt b/js/js.translator/testData/operatorOverloading/cases/overloadPlusAssignViaExtensionFunction.kt
index 2720b4c31fc..0ca71493344 100644
--- a/js/js.translator/testData/operatorOverloading/cases/overloadPlusAssignViaExtensionFunction.kt
+++ b/js/js.translator/testData/operatorOverloading/cases/overloadPlusAssignViaExtensionFunction.kt
@@ -2,15 +2,22 @@ package foo
 
 import java.util.*
 
-fun <T> ArrayList<T>.plusAssign(other: Collection<T>) {
+class A<T>(val list: MutableList<T>) {
+    fun addAll(c: Collection<T>) {
+        list.addAll(c)
+    }
+}
+
+fun <T> A<T>.plusAssign(other: Collection<T>) {
     addAll(other)
 }
 
 fun box(): Boolean {
-    var v1 = ArrayList<String>()
-    val v2 = ArrayList<String>()
-    v1.add("foo")
-    v2.add("bar")
-    v1 += v2
+    var v1 = arrayListOf("foo")
+    val v2 = listOf("bar")
+
+    val a = A(v1)
+    a += v2
+
     return (v1.size() == 2 && v1[0] == "foo" && v1[1] == "bar")
 }