diff --git a/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/testing/karma/KarmaStackTraceProcessor.kt b/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/testing/karma/KarmaStackTraceProcessor.kt
new file mode 100644
index 00000000000..01b41ce744a
--- /dev/null
+++ b/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/testing/karma/KarmaStackTraceProcessor.kt
@@ -0,0 +1,51 @@
+/*
+ * Copyright 2010-2019 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 org.jetbrains.kotlin.gradle.targets.js.testing.karma
+
+private const val WEBPACK_PROTOCOL = "webpack://"
+private const val KARMA_SOURCE_MAP_DELIMITER = " <-"
+
+private const val STACK_TRACE_DELIMITER = "at "
+private const val WEBPACK_LOCAL_DELIMITER = ".."
+
+fun processKarmaStackTrace(stackTrace: String): String {
+    return stackTrace.lines()
+        .map(::processWebpackName)
+        .joinToString("\n") { line ->
+            val index = line.indexOf(KARMA_SOURCE_MAP_DELIMITER)
+            if (index == -1)
+                line
+            else
+                line
+                    .removeRange(index, line.length - 1)
+                    .replace(WEBPACK_PROTOCOL, "")
+        }
+}
+
+fun processWebpackName(line: String): String {
+    // example: "at MyTest../kotlin/check-js-test-test.js.MyTest.foo (/src/test/kotlin/MyTest.kt:7:8)"
+    // should be "at MyTest.foo (/src/test/kotlin/MyTest.kt:7:8)"
+    val stackTraceDelimiter = line.indexOf(STACK_TRACE_DELIMITER)
+    val webpackLocalDelimiter = line.indexOf(WEBPACK_LOCAL_DELIMITER)
+    if (stackTraceDelimiter == -1 || webpackLocalDelimiter == -1) {
+        return line
+    }
+
+    val traceStartIndex = stackTraceDelimiter + STACK_TRACE_DELIMITER.length
+    val name = line.substring(
+        traceStartIndex,
+        webpackLocalDelimiter
+    ) // MyTest
+    val fileStart = line.indexOf("(")
+    val fullJsName = line.substring(webpackLocalDelimiter, fileStart) // ../kotlin/check-js-test-test.js.MyTest.foo
+
+    val nameIndex = fullJsName.indexOf(name)
+    if (nameIndex == -1) {
+        return line
+    }
+
+    return line.replaceRange(traceStartIndex, fileStart, fullJsName.substring(nameIndex))
+}
\ No newline at end of file
diff --git a/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/testing/karma/KotlinKarma.kt b/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/testing/karma/KotlinKarma.kt
index 701bf9678e5..886290d2da7 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/testing/karma/KotlinKarma.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/testing/karma/KotlinKarma.kt
@@ -354,45 +354,8 @@ class KotlinKarma(override val compilation: KotlinJsCompilation) : KotlinJsTestF
                         parseConsole(value)
                     }
 
-                    override fun processStackTrace(stackTrace: String): String {
-                        return stackTrace.lines()
-                            .map(::processName)
-                            .joinToString("\n") { line ->
-                                val index = line.indexOf(KARMA_SOURCE_MAP_DELIMITER)
-                                if (index == -1)
-                                    line
-                                else
-                                    line
-                                        .removeRange(index, line.length - 1)
-                                        .replace(WEBPACK_PROTOCOL, "")
-                            }
-
-                    }
-
-                    private fun processName(line: String): String {
-                        // example: "at MyTest../kotlin/check-js-test-test.js.MyTest.foo (/src/test/kotlin/MyTest.kt:7:8)"
-                        // should be "at MyTest.foo (/src/test/kotlin/MyTest.kt:7:8)"
-                        val stackTraceDelimiter = line.indexOf(STACK_TRACE_DELIMITER)
-                        val webpackLocalDelimiter = line.indexOf(WEBPACK_LOCAL_DELIMITER)
-                        if (stackTraceDelimiter == -1 || webpackLocalDelimiter == -1) {
-                            return line
-                        }
-
-                        val traceStartIndex = stackTraceDelimiter + STACK_TRACE_DELIMITER.length
-                        val name = line.substring(
-                            traceStartIndex,
-                            webpackLocalDelimiter
-                        ) // MyTest
-                        val fileStart = line.indexOf("(")
-                        val fullJsName = line.substring(webpackLocalDelimiter, fileStart) // ../kotlin/check-js-test-test.js.MyTest.foo
-
-                        val nameIndex = fullJsName.indexOf(name)
-                        if (nameIndex == -1) {
-                            return line
-                        }
-
-                        return line.replaceRange(traceStartIndex, fileStart, fullJsName.substring(nameIndex))
-                    }
+                    override fun processStackTrace(stackTrace: String): String =
+                        processKarmaStackTrace(stackTrace)
 
                     override fun getSuiteName(message: BaseTestSuiteMessage): String {
                         val src = message.suiteName.trim()
@@ -449,12 +412,6 @@ class KotlinKarma(override val compilation: KotlinJsCompilation) : KotlinJsTestF
         const val CHROME_BIN = "CHROME_BIN"
         const val CHROME_CANARY_BIN = "CHROME_CANARY_BIN"
 
-        const val WEBPACK_PROTOCOL = "webpack://"
-        const val KARMA_SOURCE_MAP_DELIMITER = " <-"
-
-        const val STACK_TRACE_DELIMITER = "at "
-        const val WEBPACK_LOCAL_DELIMITER = ".."
-
         val KARMA_PROBLEM = "(?m)^.*\\d{2} \\d{2} \\d{4,} \\d{2}:\\d{2}:\\d{2}.\\d{3}:(ERROR|WARN) \\[.*]: (.*)\$".toRegex()
     }
 }
\ No newline at end of file
diff --git a/libraries/tools/kotlin-gradle-plugin/src/test/kotlin/org/jetbrains/kotlin/gradle/targets/js/testing/karma/KarmaStackTraceProcessorKtTest.kt b/libraries/tools/kotlin-gradle-plugin/src/test/kotlin/org/jetbrains/kotlin/gradle/targets/js/testing/karma/KarmaStackTraceProcessorKtTest.kt
new file mode 100644
index 00000000000..a23c394d3dc
--- /dev/null
+++ b/libraries/tools/kotlin-gradle-plugin/src/test/kotlin/org/jetbrains/kotlin/gradle/targets/js/testing/karma/KarmaStackTraceProcessorKtTest.kt
@@ -0,0 +1,69 @@
+/*
+ * Copyright 2010-2019 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 org.jetbrains.kotlin.gradle.targets.js.testing.karma
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class KarmaStackTraceProcessorKtTest {
+
+    @Test
+    fun processKarmaStackTrace() {
+        val stackTrace = """AssertionError: Expected value to be true.
+    at AssertionError_init_0 (webpack:///kotlin/exceptions.kt:102:36 <- /Users/ilya.goncharov/repos/check-kotlin-js-test/build/js/packages/check-kotlin-js-test-test/adapter.js:33390:22)
+    at DefaultJsAsserter.failWithMessage_0 (webpack:///src/main/kotlin/kotlin/test/DefaultJsAsserter.kt:80:18 <- /Users/ilya.goncharov/repos/check-kotlin-js-test/build/js/packages/check-kotlin-js-test-test/adapter.js:1569:13)
+    at DefaultJsAsserter.assertTrue_o10pc4${'$'} (webpack:///src/main/kotlin/kotlin/test/DefaultJsAsserter.kt:60:12 <- /Users/ilya.goncharov/repos/check-kotlin-js-test/build/js/packages/check-kotlin-js-test-test/adapter.js:1536:12)
+    at DefaultJsAsserter.assertTrue_4mavae${'$'} (webpack:///src/main/kotlin/kotlin/test/DefaultJsAsserter.kt:67:8 <- /Users/ilya.goncharov/repos/check-kotlin-js-test/build/js/packages/check-kotlin-js-test-test/adapter.js:1548:10)
+    at assertTrue_0 (webpack:///Assertions.kt:37:20 <- /Users/ilya.goncharov/repos/check-kotlin-js-test/build/js/packages/check-kotlin-js-test-test/adapter.js:1182:27)
+    at assertTrue (webpack:///Assertions.kt:32:70 <- /Users/ilya.goncharov/repos/check-kotlin-js-test/build/js/packages/check-kotlin-js-test-test/adapter.js:1177:5)
+    at MyTest../kotlin/check-kotlin-js-test-test.js.MyTest.foo (webpack:///src/test/kotlin/MyTest.kt:7:8 <- /Users/ilya.goncharov/repos/check-kotlin-js-test/build/js/packages/check-kotlin-js-test-test/adapter.js:53047:5)
+    at Context.<anonymous> (/Users/ilya.goncharov/repos/check-kotlin-js-test/build/js/packages/check-kotlin-js-test-test/adapter.js:53080:31)""".trimIndent()
+
+        val expected = """AssertionError: Expected value to be true.
+    at AssertionError_init_0 (/kotlin/exceptions.kt:102:36)
+    at DefaultJsAsserter.failWithMessage_0 (/src/main/kotlin/kotlin/test/DefaultJsAsserter.kt:80:18)
+    at DefaultJsAsserter.assertTrue_o10pc4${'$'} (/src/main/kotlin/kotlin/test/DefaultJsAsserter.kt:60:12)
+    at DefaultJsAsserter.assertTrue_4mavae${'$'} (/src/main/kotlin/kotlin/test/DefaultJsAsserter.kt:67:8)
+    at assertTrue_0 (/Assertions.kt:37:20)
+    at assertTrue (/Assertions.kt:32:70)
+    at MyTest.foo (/src/test/kotlin/MyTest.kt:7:8)
+    at Context.<anonymous> (/Users/ilya.goncharov/repos/check-kotlin-js-test/build/js/packages/check-kotlin-js-test-test/adapter.js:53080:31)""".trimIndent()
+
+        assertEquals(
+            expected,
+            processKarmaStackTrace(stackTrace)
+        )
+    }
+
+    @Test
+    fun processWebpackName() {
+        val processedLine = processWebpackName(
+            "at MyTest../kotlin/check-js-test-test.js.MyTest.foo (/src/test/kotlin/MyTest.kt:7:8)"
+        )
+        assertEquals(
+            "at MyTest.foo (/src/test/kotlin/MyTest.kt:7:8)",
+            processedLine
+        )
+    }
+
+    @Test
+    fun notProcessNotWebpackName() {
+        val line = "at DefaultJsAsserter.assertTrue(/src/main/kotlin/kotlin/test/DefaultJsAsserter.kt:67)"
+        assertEquals(
+            line,
+            processWebpackName(line)
+        )
+    }
+
+    @Test
+    fun notProcessMessage() {
+        val line = "AssertionError: Expected value to be true."
+        assertEquals(
+            line,
+            processWebpackName(line)
+        )
+    }
+}
\ No newline at end of file