diff --git a/libraries/stdlib/js/test/collections/ArraysJsTest.kt b/libraries/stdlib/js/test/collections/ArraysJsTest.kt
index c5aa9eaef64..2ade5ddf37e 100644
--- a/libraries/stdlib/js/test/collections/ArraysJsTest.kt
+++ b/libraries/stdlib/js/test/collections/ArraysJsTest.kt
@@ -1,9 +1,9 @@
 /*
- * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
-package test.js.collections
+package test.collections.js
 
 import kotlin.test.*
 
diff --git a/libraries/stdlib/js/test/core/PromiseTest.kt b/libraries/stdlib/js/test/core/PromiseTest.kt
index 54bc73ec208..4cc148240fd 100644
--- a/libraries/stdlib/js/test/core/PromiseTest.kt
+++ b/libraries/stdlib/js/test/core/PromiseTest.kt
@@ -1,9 +1,9 @@
 /*
- * Copyright 2010-2018 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
-package core
+package test.js
 
 import test.assertStaticAndRuntimeTypeIs
 import test.assertStaticTypeIs
diff --git a/libraries/stdlib/jvm/test/ExceptionJVMTest.kt b/libraries/stdlib/jvm/test/exceptions/ExceptionJVMTest.kt
similarity index 88%
rename from libraries/stdlib/jvm/test/ExceptionJVMTest.kt
rename to libraries/stdlib/jvm/test/exceptions/ExceptionJVMTest.kt
index 84e134a49f4..ec515323019 100644
--- a/libraries/stdlib/jvm/test/ExceptionJVMTest.kt
+++ b/libraries/stdlib/jvm/test/exceptions/ExceptionJVMTest.kt
@@ -1,27 +1,27 @@
 /*
- * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
 package test.exceptions
 
-import kotlin.test.*
 import test.collections.assertArrayNotSameButEquals
 import test.testOnJvm7AndAbove
-
-import java.io.PrintWriter
 import java.io.*
 import java.nio.charset.Charset
+import kotlin.test.*
 
 class ExceptionJVMTest {
 
-    @Test fun printStackTraceOnRuntimeException() {
+    @Test
+    fun printStackTraceOnRuntimeException() {
         assertPrintStackTrace(RuntimeException("Crikey!"))
         assertPrintStackTraceStream(RuntimeException("Crikey2"))
         assertToStringWithTrace(RuntimeException("ToString"))
     }
 
-    @Test fun printStackTraceOnError() {
+    @Test
+    fun printStackTraceOnError() {
         assertPrintStackTrace(Error("Oh dear"))
         assertPrintStackTraceStream(Error("Oh dear2"))
         assertToStringWithTrace(Error("ToString"))
@@ -66,7 +66,8 @@ class ExceptionJVMTest {
         }
     }
 
-    @Test fun changeStackTrace() {
+    @Test
+    fun changeStackTrace() {
         val exception = RuntimeException("Fail")
         var stackTrace = exception.stackTrace
         stackTrace = stackTrace.dropLast(1).toTypedArray()
@@ -74,19 +75,22 @@ class ExceptionJVMTest {
         assertArrayNotSameButEquals(stackTrace, exception.stackTrace)
     }
 
-    @Test fun addSuppressedDoesNotThrow() {
+    @Test
+    fun addSuppressedDoesNotThrow() {
         val e1 = Throwable()
         val e2 = Exception("Suppressed")
 
         e1.addSuppressed(e2)
     }
 
-    @Test fun addSuppressedSelfDoesNotThrow() {
+    @Test
+    fun addSuppressedSelfDoesNotThrow() {
         val e1 = Throwable()
         e1.addSuppressed(e1) // should not throw
     }
 
-    @Test fun circularCauseStackTrace() {
+    @Test
+    fun circularCauseStackTrace() {
         val e1 = Exception("cause")
         val e2 = Error("induced", e1)
         e1.initCause(e2)
diff --git a/libraries/stdlib/jvm/test/random/RandomSerializationTest.kt b/libraries/stdlib/jvm/test/random/RandomSerializationTest.kt
index c5193e7c58d..dd513e5b00d 100644
--- a/libraries/stdlib/jvm/test/random/RandomSerializationTest.kt
+++ b/libraries/stdlib/jvm/test/random/RandomSerializationTest.kt
@@ -1,9 +1,9 @@
 /*
- * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
-package random
+package test.random
 
 import test.io.*
 import kotlin.random.*
diff --git a/libraries/stdlib/test/OrderingTest.kt b/libraries/stdlib/test/comparisons/OrderingTest.kt
similarity index 99%
rename from libraries/stdlib/test/OrderingTest.kt
rename to libraries/stdlib/test/comparisons/OrderingTest.kt
index 48fa0a3af79..e03bc6617d4 100644
--- a/libraries/stdlib/test/OrderingTest.kt
+++ b/libraries/stdlib/test/comparisons/OrderingTest.kt
@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2018 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
diff --git a/libraries/stdlib/test/coroutines/cancellation/CancellationExceptionTest.kt b/libraries/stdlib/test/coroutines/cancellation/CancellationExceptionTest.kt
index 5efbce2f359..7cfdb1714c3 100644
--- a/libraries/stdlib/test/coroutines/cancellation/CancellationExceptionTest.kt
+++ b/libraries/stdlib/test/coroutines/cancellation/CancellationExceptionTest.kt
@@ -1,9 +1,9 @@
 /*
- * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
-package coroutines.cancellation
+package test.coroutines.cancellation
 
 import kotlin.coroutines.cancellation.CancellationException
 import kotlin.test.Test
diff --git a/libraries/stdlib/test/ExceptionTest.kt b/libraries/stdlib/test/exceptions/ExceptionTest.kt
similarity index 98%
rename from libraries/stdlib/test/ExceptionTest.kt
rename to libraries/stdlib/test/exceptions/ExceptionTest.kt
index 612bf2e70e5..0c44ea831ba 100644
--- a/libraries/stdlib/test/ExceptionTest.kt
+++ b/libraries/stdlib/test/exceptions/ExceptionTest.kt
@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
@@ -8,6 +8,7 @@ package test.exceptions
 import test.supportsSuppressedExceptions
 import kotlin.test.*
 
+@Suppress("Reformat") // author's formatting
 class ExceptionTest {
     private val cause = Exception("cause")
 
diff --git a/libraries/stdlib/test/numbers/NaNPropagationTest.kt b/libraries/stdlib/test/numbers/NaNPropagationTest.kt
index bdc8e71170d..a4483056f57 100644
--- a/libraries/stdlib/test/numbers/NaNPropagationTest.kt
+++ b/libraries/stdlib/test/numbers/NaNPropagationTest.kt
@@ -1,9 +1,9 @@
 /*
- * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
-package numbers
+package test.numbers
 
 import kotlin.test.*
 
diff --git a/libraries/stdlib/test/ranges/URangeTest.kt b/libraries/stdlib/test/ranges/URangeTest.kt
index 68bbdf3c79d..7ed7ce8fb31 100644
--- a/libraries/stdlib/test/ranges/URangeTest.kt
+++ b/libraries/stdlib/test/ranges/URangeTest.kt
@@ -1,9 +1,9 @@
 /*
- * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
-package ranges
+package test.ranges
 
 import kotlin.test.*
 
diff --git a/libraries/stdlib/test/unsigned/UComparisonsTest.kt b/libraries/stdlib/test/unsigned/UComparisonsTest.kt
index a8fc24b0578..f1b9413c4e1 100644
--- a/libraries/stdlib/test/unsigned/UComparisonsTest.kt
+++ b/libraries/stdlib/test/unsigned/UComparisonsTest.kt
@@ -1,9 +1,9 @@
 /*
- * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
-package unsigned
+package test.unsigned
 
 import kotlin.test.Test
 import kotlin.test.expect
diff --git a/libraries/stdlib/test/TuplesTest.kt b/libraries/stdlib/test/utils/TuplesTest.kt
similarity index 97%
rename from libraries/stdlib/test/TuplesTest.kt
rename to libraries/stdlib/test/utils/TuplesTest.kt
index c1e6704a499..189a8c5863c 100644
--- a/libraries/stdlib/test/TuplesTest.kt
+++ b/libraries/stdlib/test/utils/TuplesTest.kt
@@ -1,9 +1,9 @@
 /*
- * Copyright 2010-2018 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
-package test.tuples
+package test.utils
 
 import kotlin.test.*