[Gradle, JS] Add using Debuggable non headless chrome

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/subtargets/KotlinBrowserJs.kt

@@ -43,8 +43,8 @@ open class KotlinBrowserJs @Inject constructor(target: KotlinJsTarget) :
     override val testTaskDescription: String
         get() = "Run all ${target.name} tests inside browser using karma and webpack"
 
-    override fun configureDefaultTestFramework(it: KotlinJsTest) {
+    override fun configureDefaultTestFramework(testTask: KotlinJsTest) {
-        it.useKarma {
+        testTask.useKarma {
             useChromeHeadless()
         }
     }

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/subtargets/KotlinJsSubTarget.kt

@@ -120,7 +120,7 @@ abstract class KotlinJsSubTarget(
         }
     }
 
-    protected abstract fun configureDefaultTestFramework(it: KotlinJsTest)
+    protected abstract fun configureDefaultTestFramework(testTask: KotlinJsTest)
 
     private fun configureMain() {
         target.compilations.all { compilation ->

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/subtargets/KotlinNodeJs.kt

@@ -24,8 +24,8 @@ open class KotlinNodeJs @Inject constructor(target: KotlinJsTarget) :
         (project.tasks.getByName(runTaskName) as NodeJsExec).body()
     }
 
-    override fun configureDefaultTestFramework(it: KotlinJsTest) {
+    override fun configureDefaultTestFramework(testTask: KotlinJsTest) {
-        it.useMocha { }
+        testTask.useMocha { }
     }
 
     override fun configureMain(compilation: KotlinJsCompilation) {

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/testing/karma/KotlinKarma.kt

@@ -56,6 +56,9 @@ class KotlinKarma(override val compilation: KotlinJsCompilation) : KotlinJsTestF
         useMocha()
         useWebpack()
         useSourceMapSupport()
+
+        // necessary for debug as a fallback when no debuggable browsers found
+        addChromeLauncher()
     }
 
     private fun useKotlinReporter() {
@@ -98,6 +101,19 @@ class KotlinKarma(override val compilation: KotlinJsCompilation) : KotlinJsTestF
         )
     }
 
+    fun useDebuggableChrome() {
+        val debuggableChrome = "DebuggableChrome"
+
+        config.customLaunchers[debuggableChrome] = CustomLauncher("Chrome").apply {
+            flags.add("--remote-debugging-port=9222")
+        }
+
+        useBrowser(
+            id = debuggableChrome,
+            dependency = versions.karmaChromeLauncher
+        )
+    }
+
     fun useChromeHeadless() {
         useBrowser(
             id = "ChromeHeadless",
@@ -120,6 +136,10 @@ class KotlinKarma(override val compilation: KotlinJsCompilation) : KotlinJsTestF
         requiredDependencies.add(dependency)
     }
 
+    private fun addChromeLauncher() {
+        requiredDependencies.add(versions.karmaChromeLauncher)
+    }
+
     private fun useMocha() {
         requiredDependencies.add(versions.karmaMocha)
         requiredDependencies.add(versions.mocha)
@@ -322,7 +342,11 @@ class KotlinKarma(override val compilation: KotlinJsCompilation) : KotlinJsTestF
             confWriter.println()
 
             confWriter.print("config.set(")
-            GsonBuilder().setPrettyPrinting().create().toJson(config, confWriter)
+            GsonBuilder()
+                .setPrettyPrinting()
+                .disableHtmlEscaping()
+                .create()
+                .toJson(config, confWriter)
             confWriter.println(");")
 
             confJsWriters.forEach { it(confWriter) }