diff --git a/build.gradle b/build.gradle
index 04b320b..9f6b230 100644
--- a/build.gradle
+++ b/build.gradle
@@ -14,7 +14,6 @@ buildscript {
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:${kotlinVersion}"
         classpath "org.jetbrains.kotlin:kotlin-serialization:${kotlinVersion}"
         classpath "org.jetbrains.kotlin:kotlin-frontend-plugin:${frontendPluginVersion}"
-//        classpath "net.devrieze:xmlutil-serialization:0.12.0.0"
     }
 }
 
@@ -28,7 +27,6 @@ if (production) {
 }
 apply plugin: 'org.jetbrains.kotlin.frontend'
 apply plugin: 'kotlinx-serialization'
-//apply plugin: 'xmlutil-serialization-js'
 
 repositories {
     maven { url = "http://bintray.com/" }
@@ -58,14 +56,13 @@ dependencies {
     compile "pl.treksoft:kvision-moment:${kvisionVersion}"
     compile "pl.treksoft:kvision-tabulator:${kvisionVersion}"
     testCompile "org.jetbrains.kotlin:kotlin-test-js:${kotlinVersion}"
-//    compile "net.devrieze:xmlutil-serialization:0.12.0.0"
 }
 
 kotlinFrontend {
-    sourceMaps = true // CHANGE HERE
+    sourceMaps = true
     webpackBundle {
         bundleName = "main"
-        sourceMapEnabled = false // CHANGE HERE (it must be false!)
+        sourceMapEnabled = false
         contentPath = file('src/main/web')
         mode = production ? "production" : "development"
     }
@@ -78,7 +75,7 @@ compileKotlin2Js {
         outputFile = "$project.buildDir.path/js/${project.name}.js"
         sourceMap = !production
         sourceMapEmbedSources = "always"
-        moduleKind = 'umd'
+        moduleKind = 'commonjs'
     }
 }
 
@@ -88,7 +85,7 @@ compileTestKotlin2Js {
         outputFile = "$project.buildDir.path/js-tests/${project.name}-tests.js"
         sourceMap = !production
         sourceMapEmbedSources = "always"
-        moduleKind = 'umd'
+        moduleKind = 'commonjs'
     }
 }
 
@@ -96,17 +93,9 @@ task pot(type: GruntTask) {
     args = ["pot"]
 }
 
-task po2json(type: GruntTask) {
-    args = ["default"]
-    inputs.dir(file('translation'))
-    outputs.dir(file('build/js'))
-    outputs.dir(file('build/kotlin-js-min/main'))
-}
-
 pot.dependsOn 'installGrunt'
 pot.dependsOn 'npmInstall'
-po2json.dependsOn 'installGrunt'
-po2json.dependsOn 'npmInstall'
+
 
 task copyResources(type: Copy) {
     from "src/main/resources"
@@ -147,8 +136,8 @@ afterEvaluate {
         tasks.getByName("copyResourcesForDce") { dependsOn(runDceKotlinJs) }
     }
     tasks.getByName("webpack-bundle") {
-        dependsOn(/*po2json,*/ copyResources, copyResourcesForDce)
+        dependsOn(copyResources, copyResourcesForDce)
     }
-    tasks.getByName("webpack-run") { dependsOn(/*po2json,*/ copyResources) }
-    tasks.getByName("karma-start") { dependsOn(/*po2json,*/ copyResources) }
+    tasks.getByName("webpack-run") { dependsOn(copyResources) }
+    tasks.getByName("karma-start") { dependsOn(copyResources) }
 }
diff --git a/gradle.properties b/gradle.properties
index cb4380d..c692834 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -2,7 +2,3 @@ kotlinVersion=1.3.50
 kvisionVersion=1.0.0
 serializationVersion=0.11.0
 frontendPluginVersion=0.0.45
-kotlin.incremental.js=false
-#kotlin.parallel.tasks.in.project=true
-systemProp.sonar.host.url=http://localhost:9000
-systemProp.sonar.login=a3d5c3d3fd7ec307158740001e8c04c3f437ff93
diff --git a/karma.conf.js b/karma.conf.js
index b38aba8..cc79baa 100644
--- a/karma.conf.js
+++ b/karma.conf.js
@@ -1,68 +1,34 @@
-// see https://github.com/mkraynov/kfsad/blob/master/karma.conf.js
+// Example: see https://github.com/mkraynov/kfsad/blob/master/karma.conf.js
+// Doc: see http://karma-runner.github.io/4.0/config/configuration-file.html
 module.exports = function (config) {
   config.set({
-    basePath: '',
-    // all plugins have to be installed before via
-    // npm install <plugin> --save-dev
-    plugins: [
-      'karma-webpack',
-      'karma-browserify',
-      'karma-jasmine',
-      'karma-mocha',
-      'karma-mocha-reporter',
-      'karma-chrome-launcher',
-      'karma-phantomjs-launcher',
-      'karma-coverage'],
-    frameworks: ['mocha'],
-    files: [
-      'build/js-tests/kroviz-tests.js'
-    ],
-    exclude: [],
-    preprocessors: {
-      'build/**/*_test.js': ['webpack']
-    },
-//    webpack: require('./webpack.karma'),
-    webpack: {
-      entry: './build/js-tests/kroviz-tests.js',
-      output: {
-        filename: 'bundle.js'
-      }
-    },
-    webpackMiddleware: {
-      noInfo: true
-    },
-    // available reporters: https://npmjs.org/browse/keyword/karma-reporter
-    reporters: ['coverage'],
-    port: 9876,
-    colors: true,
-    logLevel: config.LOG_INFO,
-    autoWatch: true,
-    browsers: ['ChromeHeadlessNoSandbox'],
-    customLaunchers: {
-      // https://github.com/karma-runner/karma-chrome-launcher/issues/158#issuecomment-339265457
-      ChromeHeadlessNoSandbox: {
-        base: 'ChromeHeadless',
-        flags: ['--no-sandbox']
-      }
-    },
-    singleRun: true,
-    concurrency: Infinity,
-    client: {
-      mocha: {
-        timeout: 6000
-      }
-    }
+      files: ['./build/**/*.js'],
+      excludes: ['./**/*.css'],
+      preprocessors: {
+//        'build/**/*_test.js': ['webpack']
+      },
+      frameworks: ['jasmine'],
+      plugins: [
+        require('karma-chrome-launcher'),
+        require('karma-coverage-istanbul-reporter'),
+        require('istanbul-instrumenter-loader'),
+        require('karma-jasmine'),
+        require('karma-jasmine-html-reporter'),
+        require('karma-webpack')
+      ],
+      reporters: ['coverage-istanbul'],
+      coverageIstanbulReporter: {
+        reports: ['html', 'lcovonly', 'text-summary'],
+        // if using webpack and pre-loaders, work around webpack breaking the source path
+        fixWebpackSourcePaths: true
+      },
+      browsers: ['ChromeHeadless'],
 
-   /* plugins: [
-      'karma-browserify',
-      'karma-mocha',
-      'karma-mocha-reporter',
-      'karma-chrome-launcher',
-      'karma-phantomjs-launcher',
-      'karma-coverage'],
-    browserify: ({
-      entries: ['./build/js/kroviz.js'], */
-//      noParse: ['./node_modules_imported/**/*js']
-//    }),
-  })
+//      logLevel: config.LOG_DEBUG,
+      autoWatch: true,
+      singleRun: true,
+      concurrency: Infinity,
+      color: false
+    }
+  )
 };
diff --git a/package.json b/package.json
index 33aedd5..3ba673a 100644
--- a/package.json
+++ b/package.json
@@ -39,6 +39,8 @@
   "dependencies": {
     "default-passive-events": "^1.0.10",
     "grunt-cli": "^1.3.2",
+    "istanbul-instrumenter-loader": "^3.0.1",
+    "karma-coverage-istanbul-reporter": "^2.1.0",
     "karma-jasmine-html-reporter": "^1.4.2",
     "kotlinx-serialization-runtime-js": "^0.5.0",
     "progress": "^2.0.3",