assertion to prohibit closeProject() call within write action because fireClosing() listeners must have a chance to do something useful (e.g. cancel and wait for VCSInitialization to complete)

+ allow tests to register custom project cleanups

platform/testFramework/src/_LastInSuiteTest.java

@@ -21,6 +21,7 @@ import com.intellij.openapi.application.impl.ApplicationImpl;
 import com.intellij.openapi.util.Disposer;
 import com.intellij.testFramework.LeakHunter;
 import com.intellij.testFramework.LightPlatformTestCase;
+import com.intellij.testFramework.PlatformTestUtil;
 import com.intellij.util.ReflectionUtil;
 import com.intellij.util.concurrency.AppExecutorUtil;
 import com.intellij.util.concurrency.AppScheduledExecutorService;
@@ -49,8 +50,8 @@ public class _LastInSuiteTest extends TestCase {
           throw new RuntimeException(e);
         }
 
-        // disposes default project too
-        LightPlatformTestCase.closeAndDeleteProject();
+        // disposes default projects too
+        PlatformTestUtil.cleanupAllProjects();
         ApplicationImpl application = (ApplicationImpl)ApplicationManager.getApplication();
         System.out.println(application.writeActionStatistics());
         System.out.println(ActionUtil.ACTION_UPDATE_PAUSES.statistics());

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

@@ -135,6 +135,10 @@ public abstract class LightPlatformTestCase extends UsefulTestCase implements Da
   private static LightProjectDescriptor ourProjectDescriptor;
 
   private ThreadTracker myThreadTracker;
+  
+  static {
+    PlatformTestUtil.registerProjectCleanup(LightPlatformTestCase::closeAndDeleteProject);
+  }
 
   /**
    * @return Project to be used in tests for example for project components retrieval.

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

@@ -76,6 +76,7 @@ import java.text.DecimalFormat;
 import java.text.DecimalFormatSymbols;
 import java.util.*;
 import java.util.List;
+import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.jar.JarFile;
 
@@ -88,6 +89,8 @@ public class PlatformTestUtil {
 
   public static final boolean SKIP_HEADLESS = GraphicsEnvironment.isHeadless();
   public static final boolean SKIP_SLOW = Boolean.getBoolean("skip.slow.tests.locally");
+  
+  private static final List<Runnable> ourProjectCleanups = new CopyOnWriteArrayList<>();
 
   @NotNull
   public static String getTestName(@NotNull String name, boolean lowercaseFirstLetter) {
@@ -956,4 +959,16 @@ public class PlatformTestUtil {
     });
     return refs;
   }
+  
+  public static void registerProjectCleanup(@NotNull Runnable cleanup) {
+    ourProjectCleanups.add(cleanup);
+  }
+  
+  public static void cleanupAllProjects() {
+    for (Runnable each : ourProjectCleanups) {
+      each.run();
+    }
+    ourProjectCleanups.clear();
+  }
+  
 }