[groovy] follow up IDEA-CR-41748

plugins/groovy/test/org/jetbrains/plugins/groovy/lang/psi/GroovyPsiEventsTest.java

+// Copyright 2000-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package org.jetbrains.plugins.groovy.lang.psi;
 
 import com.intellij.openapi.application.ApplicationManager;
@@ -6,7 +7,6 @@ import com.intellij.openapi.editor.Document;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.util.Ref;
 import com.intellij.psi.PsiDocumentManager;
-import com.intellij.psi.PsiManager;
 import com.intellij.psi.PsiTreeChangeAdapter;
 import com.intellij.psi.PsiTreeChangeEvent;
 import com.intellij.testFramework.fixtures.LightCodeInsightFixtureTestCase;
@@ -24,28 +24,21 @@ public class GroovyPsiEventsTest extends LightCodeInsightFixtureTestCase {
         gotIt.set(true);
       }
     };
-    PsiManager manager = getPsiManager();
-    try {
-      manager.addPsiTreeChangeListener(listener);
-
-      Project project = getProject();
-      GroovyFile file = GroovyPsiElementFactory.getInstance(project).createGroovyFile("/** This is doc comment*/class C{}", true, null);
-      PsiDocumentManager docManager = PsiDocumentManager.getInstance(project);
-      Document doc = docManager.getDocument(file);
-      assertNotNull(doc);
-      CommandProcessor.getInstance().executeCommand(project,
-                                                    () -> ApplicationManager.getApplication().runWriteAction(() -> {
-                                                      doc.insertString(3, " ");
-                                                      docManager.commitDocument(doc);
-                                                    }),
-                                                    "file text set",
-                                                    this
-      );
-    }
-    finally {
-      manager.removePsiTreeChangeListener(listener);
-    }
-
+    getPsiManager().addPsiTreeChangeListener(listener, getTestRootDisposable());
+    Project project = getProject();
+    GroovyFile file = GroovyPsiElementFactory.getInstance(project).createGroovyFile("/** This is doc comment*/class C{}", true, null);
+    PsiDocumentManager docManager = PsiDocumentManager.getInstance(project);
+    Document doc = docManager.getDocument(file);
+    assertNotNull(doc);
+    CommandProcessor.getInstance().executeCommand(
+      project,
+      () -> ApplicationManager.getApplication().runWriteAction(() -> {
+        doc.insertString(3, " ");
+        docManager.commitDocument(doc);
+      }),
+      "file text set",
+      this
+    );
     assertTrue(gotIt.get());
   }
 }