diff --git a/libraries/tools/kotlin-test-js-runner/karma-debug.js b/libraries/tools/kotlin-test-js-runner/karma-debug.js
index ffa29928ce6..5d6c356be41 100644
--- a/libraries/tools/kotlin-test-js-runner/karma-debug.js
+++ b/libraries/tools/kotlin-test-js-runner/karma-debug.js
@@ -5,6 +5,8 @@
 
 'use strict';
 
+import {configureBrowsers, fixMochaTimeout} from "./src/DebugConfigurator";
+
 const karma = require('karma');
 
 const cfg = karma.config;
@@ -33,88 +35,4 @@ server.on('browsers_ready', function () {
     }, 1000)
 });
 
-server.start();
-
-function configureBrowsers(config) {
-    let newBrowsers = config.browsers;
-    if (!Array.isArray(newBrowsers)) {
-        newBrowsers = [];
-    }
-
-    let browser = newBrowsers.find(browserName => isDebuggableBrowser(browserName, config));
-
-    if (!browser) {
-        console.warn(
-            'Unable to find debuggable browser: Only Google Chrome with 9222 remote debugging port supported\n',
-            'Fallback on Chrome Headless'
-        );
-        browser = 'ChromeHeadless'
-    }
-
-    config.browsers = [browser];
-}
-
-const REMOTE_DEBUGGING_PORT = '--remote-debugging-port';
-
-function isDebuggableBrowser(browserName, config) {
-    if ([
-        'ChromeHeadless',
-        'ChromeCanaryHeadless',
-        'ChromiumHeadless'
-    ].includes(browserName)) {
-        return true
-    }
-
-    const customLaunchers = config.customLaunchers;
-    if (!customLaunchers) {
-        return false;
-    }
-
-    let customLauncher = customLaunchers[browserName];
-    if (!customLauncher) {
-        return false;
-    }
-
-    const flags = customLauncher.flags;
-    if (!Array.isArray(flags)) {
-        return false;
-    }
-
-    const prefix = REMOTE_DEBUGGING_PORT + '=';
-    const value = flags.find(flag => typeof flag === 'string' && flag.indexOf(prefix) === 0);
-    if (value == null) {
-        return false;
-    }
-
-    const port = parseInt(value.substring(prefix.length), 10);
-    if (isNaN(port) || port !== 9222) {
-        console.error(`Debugger expect 9222 port, but ${port} found`);
-        return false;
-    }
-
-    return true;
-}
-
-function fixMochaTimeout(config) {
-    let client = config.client;
-    if (typeof client === 'undefined') {
-        config.client = client = {};
-    }
-    if (client === Object(client)) {
-        let mocha = client.mocha;
-        if (typeof mocha === 'undefined') {
-            client.mocha = mocha = {};
-        }
-        if (mocha === Object(mocha)) {
-            mocha.timeout = 0;
-        }
-        else {
-            console.error('config.client.mocha is not an object');
-            process.exit(1);
-        }
-    }
-    else {
-        console.error('config.client is not an object');
-        process.exit(1);
-    }
-}
\ No newline at end of file
+server.start();
\ No newline at end of file
diff --git a/libraries/tools/kotlin-test-js-runner/src/DebugConfigurator.js b/libraries/tools/kotlin-test-js-runner/src/DebugConfigurator.js
new file mode 100644
index 00000000000..574c5fc26e6
--- /dev/null
+++ b/libraries/tools/kotlin-test-js-runner/src/DebugConfigurator.js
@@ -0,0 +1,88 @@
+/*
+ * 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.
+ */
+
+const REMOTE_DEBUGGING_PORT = '--remote-debugging-port';
+
+export function configureBrowsers(config) {
+    let newBrowsers = config.browsers;
+    if (!Array.isArray(newBrowsers)) {
+        newBrowsers = [];
+    }
+
+    let browser = newBrowsers.find(browserName => isDebuggableBrowser(browserName, config));
+
+    if (!browser) {
+        console.warn(
+            'Unable to find debuggable browser: Only Google Chrome with 9222 remote debugging port supported\n',
+            'Fallback on Chrome Headless'
+        );
+        browser = 'ChromeHeadless'
+    }
+
+    config.browsers = [browser];
+}
+
+function isDebuggableBrowser(browserName, config) {
+    if ([
+        'ChromeHeadless',
+        'ChromeCanaryHeadless',
+        'ChromiumHeadless'
+    ].includes(browserName)) {
+        return true
+    }
+
+    const customLaunchers = config.customLaunchers;
+    if (!customLaunchers) {
+        return false;
+    }
+
+    let customLauncher = customLaunchers[browserName];
+    if (!customLauncher) {
+        return false;
+    }
+
+    const flags = customLauncher.flags;
+    if (!Array.isArray(flags)) {
+        return false;
+    }
+
+    const prefix = REMOTE_DEBUGGING_PORT + '=';
+    const value = flags.find(flag => typeof flag === 'string' && flag.indexOf(prefix) === 0);
+    if (value == null) {
+        return false;
+    }
+
+    const port = parseInt(value.substring(prefix.length), 10);
+    if (isNaN(port) || port !== 9222) {
+        console.error(`Debugger expect 9222 port, but ${port} found`);
+        return false;
+    }
+
+    return true;
+}
+
+export function fixMochaTimeout(config) {
+    let client = config.client;
+    if (typeof client === 'undefined') {
+        config.client = client = {};
+    }
+    if (client === Object(client)) {
+        let mocha = client.mocha;
+        if (typeof mocha === 'undefined') {
+            client.mocha = mocha = {};
+        }
+        if (mocha === Object(mocha)) {
+            mocha.timeout = 0;
+        }
+        else {
+            console.error('config.client.mocha is not an object');
+            process.exit(1);
+        }
+    }
+    else {
+        console.error('config.client is not an object');
+        process.exit(1);
+    }
+}
\ No newline at end of file