diff --git a/native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/TestInfra_OutputFilterTest.kt b/native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/TestInfra_OutputFilterTest.kt
new file mode 100644
index 00000000000..e9668be37ec
--- /dev/null
+++ b/native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/TestInfra_OutputFilterTest.kt
@@ -0,0 +1,166 @@
+/*
+ * 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 org.jetbrains.kotlin.konan.blackboxtest.support
+
+import org.jetbrains.kotlin.konan.blackboxtest.support.util.TestOutputFilter
+import org.jetbrains.kotlin.konan.blackboxtest.support.util.TCTestOutputFilter
+import org.junit.jupiter.api.Assertions.*
+import org.junit.jupiter.api.Test
+
+@Suppress("ClassName")
+class TestInfra_OutputFilterTest {
+    @Test
+    fun noFiltering() {
+        val randomTestOutput = List(100) { (Char.MIN_VALUE..Char.MAX_VALUE).random() }.joinToString("")
+
+        val (filteredOutput, testReport) = TestOutputFilter.NO_FILTERING.filter(randomTestOutput)
+
+        assertEquals(null, testReport)
+        assertTrue(randomTestOutput === filteredOutput)
+    }
+
+    @Test
+    fun noTCMessages() {
+        val testOutput = """
+            1
+            2
+            3
+            4
+            5
+        """.trimIndent()
+
+        val (filteredOutput, testReport) = TCTestOutputFilter.filter(testOutput)
+        testReport ?: throw AssertionError("Test report expected")
+
+        assertTrue(testReport.isEmpty())
+        assertTrue(testOutput == filteredOutput)
+    }
+
+    @Test
+    fun mixedTCMessages() {
+        val testOutput = """
+            1
+            ##teamcity[testSuiteStarted name='sample.test.Foo']
+            2
+            ##teamcity[testStarted name='passed']
+            3
+            ##teamcity[testFinished name='passed']
+            4
+            ##teamcity[testStarted name='failed']
+            5
+            ##teamcity[testFailed name='failed' details='foo: something went wrong!|n']
+            6
+            ##teamcity[testFinished name='failed']
+            7
+            ##teamcity[testIgnored name='ignored']
+            8
+            ##teamcity[testSuiteFinished name='sample.test.Foo']
+            9
+            ##teamcity[testSuiteStarted name='sample.test.Bar']
+            10
+            ##teamcity[testSuiteFinished name='sample.test.Bar']
+            11
+            ##teamcity[testSuiteStarted name='sample.test.Baz']
+            12
+            ##teamcity[testStarted name='passed']
+            13
+            ##teamcity[testFinished name='passed']
+            14
+            ##teamcity[testStarted name='failed']
+            15
+            ##teamcity[testFailed name='failed' details='baz: something went wrong!|n']
+            16
+            ##teamcity[testFinished name='failed']
+            17
+            ##teamcity[testIgnored name='ignored']
+            18
+            ##teamcity[testSuiteFinished name='sample.test.Baz']
+            19
+            
+        """.trimIndent()
+
+        val (filteredOutput, testReport) = TCTestOutputFilter.filter(testOutput)
+        testReport ?: throw AssertionError("Test report expected")
+
+        assertTrue(!testReport.isEmpty())
+        assertEquals(
+            listOf("sample.test.Foo.passed", "sample.test.Baz.passed"),
+            testReport.passedTests.map(TestName::toString)
+        )
+        assertEquals(
+            listOf("sample.test.Foo.failed", "sample.test.Baz.failed"),
+            testReport.failedTests.map(TestName::toString)
+        )
+        assertEquals(
+            listOf("sample.test.Foo.ignored", "sample.test.Baz.ignored"),
+            testReport.ignoredTests.map(TestName::toString)
+        )
+
+        assertEquals(
+            """
+                |1
+                |2
+                |3
+                |4
+                |5
+                |foo: something went wrong!
+                |6
+                |7
+                |8
+                |9
+                |10
+                |11
+                |12
+                |13
+                |14
+                |15
+                |baz: something went wrong!
+                |16
+                |17
+                |18
+                |19
+                |
+            """.trimMargin(),
+            filteredOutput
+        )
+    }
+
+    @Test
+    fun interruptedTestTCMessage() {
+        val testOutput = """
+            1
+            ##teamcity[testSuiteStarted name='sample.test.Foo']
+            2
+            ##teamcity[testStarted name='passed']
+            3
+            ##teamcity[testFinished name='passed']
+            4
+            ##teamcity[testStarted name='failed']
+            5
+            
+        """.trimIndent()
+
+        val (filteredOutput, testReport) = TCTestOutputFilter.filter(testOutput)
+        testReport ?: throw AssertionError("Test report expected")
+
+        assertTrue(!testReport.isEmpty())
+        assertEquals(listOf("sample.test.Foo.passed"), testReport.passedTests.map(TestName::toString))
+        assertEquals(listOf("sample.test.Foo.failed"), testReport.failedTests.map(TestName::toString))
+        assertTrue(testReport.ignoredTests.isEmpty())
+
+        assertEquals(
+            """
+                |1
+                |2
+                |3
+                |4
+                |5
+                |
+            """.trimMargin(),
+            filteredOutput
+        )
+    }
+}
diff --git a/native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/util/TestOutput.kt b/native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/util/TestOutput.kt
index 85e029569b5..f636f540638 100644
--- a/native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/util/TestOutput.kt
+++ b/native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/util/TestOutput.kt
@@ -24,7 +24,7 @@ internal class TestReport(
 internal interface TestOutputFilter {
     fun filter(testOutput: String): FilteredOutput
 
-    class FilteredOutput(val filteredOutput: String, val testReport: TestReport?)
+    data class FilteredOutput(val filteredOutput: String, val testReport: TestReport?)
 
     companion object {
         val NO_FILTERING = object : TestOutputFilter {