tests: decrease "Caused by" chain by using runInEdtAndWaitRethrowing

platform/testFramework/src/com/intellij/testFramework/EdtTestUtil.kt

@@ -17,6 +17,7 @@ package com.intellij.testFramework
 
 import com.intellij.openapi.application.ApplicationManager
 import com.intellij.openapi.application.impl.ApplicationImpl
+import com.intellij.util.ExceptionUtil
 import com.intellij.util.ThrowableRunnable
 import org.jetbrains.annotations.TestOnly
 import java.lang.reflect.InvocationTargetException
@@ -24,9 +25,25 @@ import javax.swing.SwingUtilities
 
 class EdtTestUtil {
   companion object {
-    @JvmStatic fun runInEdtAndWait(runnable: ThrowableRunnable<Throwable>) {
+    @TestOnly @JvmStatic fun runInEdtAndWait(runnable: ThrowableRunnable<Throwable>) {
       runInEdtAndWait { runnable.run() }
     }
+
+    /**
+     * Same as {@link #runInEdtAndWait}, but when an unchecked exception happens inside runnable, its just rethrown without being wrapped.
+     * Can be useful to decrease "Caused by" chain for cases when the stack trace of the calling thread is not important or obvious.
+     */
+    @TestOnly @JvmStatic fun runInEdtAndWaitRethrowing(runnable: ThrowableRunnable<Throwable>) {
+      var exception: Throwable? = null
+      runInEdtAndWait {
+        try {
+          runnable.run()
+        } catch (e: Throwable) {
+          exception = e
+        }
+      }
+      ExceptionUtil.rethrowAllAsUnchecked(exception)
+    }
   }
 }
 

platform/testFramework/src/com/intellij/testFramework/LightPlatformTestCase.java

@@ -496,7 +496,7 @@ public abstract class LightPlatformTestCase extends UsefulTestCase implements Da
     }
 
     TestRunnerUtil.replaceIdeEventQueueSafely();
-    EdtTestUtil.runInEdtAndWait(() -> {
+    EdtTestUtil.runInEdtAndWaitRethrowing(() -> {
       try {
         ourTestThread = Thread.currentThread();
         startRunAndTear();

platform/testFramework/src/com/intellij/testFramework/UsefulTestCase.java

@@ -414,7 +414,7 @@ public abstract class UsefulTestCase extends TestCase {
 
     if (runInDispatchThread()) {
       TestRunnerUtil.replaceIdeEventQueueSafely();
-      EdtTestUtil.runInEdtAndWait(this::defaultRunBare);
+      EdtTestUtil.runInEdtAndWaitRethrowing(this::defaultRunBare);
     }
     else {
       defaultRunBare();