Build: Workaround java-rt loading into Gradle daemon

Fixes IDEA diff for tests not showing diff transfer buttons in the
 "Click to see difference" window for a failed test

build.gradle.kts

@@ -114,6 +114,7 @@ rootProject.apply {
     from(rootProject.file("gradle/checkCacheability.gradle.kts"))
     from(rootProject.file("gradle/retryPublishing.gradle.kts"))
     from(rootProject.file("gradle/modularizedTestConfigurations.gradle.kts"))
+    from(rootProject.file("gradle/ideaRtHack.gradle.kts"))
 }
 
 IdeVersionConfigurator.setCurrentIde(project)

gradle/ideaRtHack.gradle.kts

@@ -0,0 +1,23 @@
+// Remove this hack when IDEA-285445 (Gradle plugin doesn't handle java-rt from IDEA maven repo the same way as idea_rt.jar) is fixed
+// https://github.com/JetBrains/intellij-community/blob/0e2aa4030ee763c9b0c828f0b5119f4cdcc66f35/plugins/gradle/java/resources/org/jetbrains/plugins/gradle/java/addTestListener.groovy#L11
+if (isIdeaActive) {
+    gradle.taskGraph.whenReady {
+        allTasks.filterIsInstance<Test>().forEach { task ->
+            task.doFirst {
+                task.classpath.files.find { it.name.startsWith("java-rt") }?.let { javaRtJar ->
+                    try {
+                        val urlClassLoader =
+                            Class.forName("org.gradle.launcher.daemon.bootstrap.DaemonMain").classLoader as? java.net.URLClassLoader
+
+                        urlClassLoader?.let {
+                            it::class.java.getMethod("addURL", java.net.URL::class.java)
+                                .invoke(it, javaRtJar.toURI().toURL())
+                        }
+                    } catch (e: RuntimeException) {
+                        logger.log(LogLevel.WARN, "Failed to load java-rt into Gradle daemon", e)
+                    }
+                }
+            }
+        }
+    }
+}