diff --git a/java/execution/impl/src/com/intellij/execution/testDiscovery/indices/DiscoveredTestsIndex.java b/java/execution/impl/src/com/intellij/execution/testDiscovery/indices/DiscoveredTestsIndex.java
index c644bff2ea1e..1d697fcf9042 100644
--- a/java/execution/impl/src/com/intellij/execution/testDiscovery/indices/DiscoveredTestsIndex.java
+++ b/java/execution/impl/src/com/intellij/execution/testDiscovery/indices/DiscoveredTestsIndex.java
@@ -8,6 +8,8 @@ import com.intellij.util.indexing.IndexId;
 import com.intellij.util.indexing.impl.KeyCollectionBasedForwardIndex;
 import com.intellij.util.indexing.impl.MapIndexStorage;
 import com.intellij.util.indexing.impl.MapReduceIndex;
+import com.intellij.util.indexing.impl.forward.KeyCollectionForwardIndexAccessor;
+import com.intellij.util.indexing.impl.forward.PersistentMapBasedForwardIndex;
 import com.intellij.util.io.*;
 import gnu.trove.TIntArrayList;
 import org.jetbrains.annotations.NotNull;
@@ -18,14 +20,10 @@ import java.util.Collection;
 
 public class DiscoveredTestsIndex extends MapReduceIndex<Integer, TIntArrayList, UsedSources> {
   protected DiscoveredTestsIndex(@NotNull File file) throws IOException {
-    super(INDEX_EXTENSION, new MyIndexStorage(file), new MyForwardIndex() {
-      @NotNull
-      @Override
-      public PersistentHashMap<Integer, Collection<Integer>> createMap() throws IOException {
-        return new PersistentHashMap<>(new File(file, "forward.idx"), EnumeratorIntegerDescriptor.INSTANCE,
-                                       new IntCollectionDataExternalizer());
-      }
-    });
+    super(INDEX_EXTENSION,
+          new MyIndexStorage(file),
+          new PersistentMapBasedForwardIndex(new File(file, "forward.idx")),
+          new KeyCollectionForwardIndexAccessor<>(new IntCollectionDataExternalizer()));
   }
 
   @Override
@@ -39,7 +37,7 @@ public class DiscoveredTestsIndex extends MapReduceIndex<Integer, TIntArrayList,
   }
 
   public boolean containsDataFrom(int testId) throws IOException {
-    return ((MyForwardIndex)myForwardIndex).containsDataFrom(testId);
+    return getForwardIndexMap().get(testId) != null;
   }
 
   private static class MyIndexStorage extends MapIndexStorage<Integer, TIntArrayList> {
@@ -81,15 +79,4 @@ public class DiscoveredTestsIndex extends MapReduceIndex<Integer, TIntArrayList,
       return DiscoveredTestDataHolder.VERSION;
     }
   };
-
-
-  private abstract static class MyForwardIndex extends KeyCollectionBasedForwardIndex<Integer, TIntArrayList> {
-    protected MyForwardIndex() throws IOException {
-      super(INDEX_EXTENSION);
-    }
-
-    public boolean containsDataFrom(int testId) throws IOException {
-      return getInput(testId) != null;
-    }
-  }
 }
diff --git a/java/execution/impl/src/com/intellij/execution/testDiscovery/indices/TestFilesIndex.java b/java/execution/impl/src/com/intellij/execution/testDiscovery/indices/TestFilesIndex.java
index fc9cb3888292..ad96c0b44db2 100644
--- a/java/execution/impl/src/com/intellij/execution/testDiscovery/indices/TestFilesIndex.java
+++ b/java/execution/impl/src/com/intellij/execution/testDiscovery/indices/TestFilesIndex.java
@@ -6,6 +6,9 @@ import com.intellij.util.indexing.DataIndexer;
 import com.intellij.util.indexing.IndexExtension;
 import com.intellij.util.indexing.IndexId;
 import com.intellij.util.indexing.impl.*;
+import com.intellij.util.indexing.impl.forward.ForwardIndex;
+import com.intellij.util.indexing.impl.forward.KeyCollectionForwardIndexAccessor;
+import com.intellij.util.indexing.impl.forward.PersistentMapBasedForwardIndex;
 import com.intellij.util.io.*;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -16,14 +19,10 @@ import java.util.Collection;
 
 public class TestFilesIndex extends MapReduceIndex<Integer, Void, UsedSources> {
   protected TestFilesIndex(@NotNull File file) throws IOException {
-    super(INDEX_EXTENSION, new MyIndexStorage(file), new MyForwardIndex() {
-      @NotNull
-      @Override
-      public PersistentHashMap<Integer, Collection<Integer>> createMap() throws IOException {
-        return new PersistentHashMap<>(new File(file, "forward.idx"), EnumeratorIntegerDescriptor.INSTANCE,
-                                       new IntCollectionDataExternalizer());
-      }
-    });
+    super(INDEX_EXTENSION,
+          new MyIndexStorage(file),
+          new PersistentMapBasedForwardIndex(new File(file, "forward.idx")),
+          new KeyCollectionForwardIndexAccessor<>(new IntCollectionDataExternalizer()));
   }
 
   @Override
@@ -38,7 +37,9 @@ public class TestFilesIndex extends MapReduceIndex<Integer, Void, UsedSources> {
 
   @Nullable
   Collection<Integer> getTestDataFor(int testId) throws IOException {
-    return ((MyForwardIndex)myForwardIndex).containsDataFrom(testId);
+    ForwardIndex forwardIndex = getForwardIndexMap();
+    KeyCollectionForwardIndexAccessor<Integer, Void, UsedSources> forwardIndexAccessor = (KeyCollectionForwardIndexAccessor<Integer, Void, UsedSources>)getForwardIndexAccessor();
+    return forwardIndexAccessor.deserializeData(forwardIndex.get(testId));
   }
 
   private static class MyIndexStorage extends MapIndexStorage<Integer, Void> {
@@ -80,16 +81,4 @@ public class TestFilesIndex extends MapReduceIndex<Integer, Void, UsedSources> {
       return DiscoveredTestDataHolder.VERSION;
     }
   };
-
-
-  private abstract static class MyForwardIndex extends KeyCollectionBasedForwardIndex<Integer, Void> {
-    protected MyForwardIndex() throws IOException {
-      super(INDEX_EXTENSION);
-    }
-
-    @Nullable
-    public Collection<Integer> containsDataFrom(int testId) throws IOException {
-      return getInput(testId);
-    }
-  }
 }
diff --git a/platform/util/src/com/intellij/util/indexing/impl/MapReduceIndex.java b/platform/util/src/com/intellij/util/indexing/impl/MapReduceIndex.java
index 88d4c0d25dea..0fc9fd59056f 100644
--- a/platform/util/src/com/intellij/util/indexing/impl/MapReduceIndex.java
+++ b/platform/util/src/com/intellij/util/indexing/impl/MapReduceIndex.java
@@ -79,7 +79,7 @@ public abstract class MapReduceIndex<Key,Value, Input> implements InvertedIndex<
                            @NotNull IndexStorage<Key, Value> storage,
                            @Nullable com.intellij.util.indexing.impl.forward.ForwardIndex forwardIndex,
                            @Nullable ForwardIndexAccessor<Key, Value, Input> forwardIndexAccessor) {
-    this(extension, storage, forwardIndex == null && forwardIndexAccessor == null ? null : wrapWithOldForwardIndex(forwardIndex, forwardIndexAccessor));
+    this(extension, storage, forwardIndex == null || forwardIndexAccessor == null ? null : new MyNewForwardIndexWrapper<>(forwardIndexAccessor, forwardIndex));
   }
 
   protected MapReduceIndex(@NotNull IndexExtension<Key, Value, Input> extension,
@@ -93,6 +93,16 @@ public abstract class MapReduceIndex<Key,Value, Input> implements InvertedIndex<
     myForwardIndex = forwardIndex;
   }
 
+  public com.intellij.util.indexing.impl.forward.ForwardIndex getForwardIndexMap() {
+    //TODO simplify and rename (inheritors already have getForwardIndex() method) when will be rewritting
+    return myForwardIndex instanceof MyNewForwardIndexWrapper<?, ?, ?> ? ((MyNewForwardIndexWrapper)myForwardIndex).myForwardIndex : null;
+  }
+
+  public ForwardIndexAccessor<Key, Value, Input> getForwardIndexAccessor() {
+    //TODO simplify when will be rewritting
+    return myForwardIndex instanceof MyNewForwardIndexWrapper<?, ?, ?> ? ((MyNewForwardIndexWrapper)myForwardIndex).myForwardIndexAccessor : null;
+  }
+
   @NotNull
   public IndexStorage<Key, Value> getStorage() {
     return myStorage;
@@ -364,38 +374,41 @@ public abstract class MapReduceIndex<Key,Value, Input> implements InvertedIndex<
     }
   }
 
-  @NotNull
-  private static <Key, Value, Input> ForwardIndex<Key, Value> wrapWithOldForwardIndex(com.intellij.util.indexing.impl.forward.ForwardIndex forwardIndex,
-                                                                                      ForwardIndexAccessor<Key, Value, Input> forwardIndexAccessor) {
-    LOG.assertTrue(forwardIndex != null);
-    LOG.assertTrue(forwardIndexAccessor != null);
-    return new ForwardIndex<Key, Value>() {
-      @NotNull
-      @Override
-      public InputDataDiffBuilder<Key, Value> getDiffBuilder(int inputId) throws IOException {
-        return forwardIndexAccessor.getDiffBuilder(inputId, forwardIndex.get(inputId));
-      }
+  private static class MyNewForwardIndexWrapper<Key, Value, Input> implements ForwardIndex<Key, Value> {
+    private final ForwardIndexAccessor<Key, Value, Input> myForwardIndexAccessor;
+    private final com.intellij.util.indexing.impl.forward.ForwardIndex myForwardIndex;
 
-      @Override
-      public void putInputData(int inputId, @NotNull Map<Key, Value> data) throws IOException {
-        forwardIndex.put(inputId, forwardIndexAccessor.serializeIndexedData(data, null));
-      }
+    MyNewForwardIndexWrapper(@NotNull ForwardIndexAccessor<Key, Value, Input> forwardIndexAccessor,
+                                    @NotNull com.intellij.util.indexing.impl.forward.ForwardIndex forwardIndex) {
+      myForwardIndexAccessor = forwardIndexAccessor;
+      myForwardIndex = forwardIndex;
+    }
 
-      @Override
-      public void flush() {
-        forwardIndex.force();
-      }
+    @NotNull
+    @Override
+    public InputDataDiffBuilder<Key, Value> getDiffBuilder(int inputId) throws IOException {
+      return myForwardIndexAccessor.getDiffBuilder(inputId, myForwardIndex.get(inputId));
+    }
 
-      @Override
-      public void clear() throws IOException {
-        forwardIndex.clear();
-      }
+    @Override
+    public void putInputData(int inputId, @NotNull Map<Key, Value> data) throws IOException {
+      myForwardIndex.put(inputId, myForwardIndexAccessor.serializeIndexedData(data, null));
+    }
 
-      @Override
-      public void close() throws IOException {
-        forwardIndex.close();
-      }
-    };
+    @Override
+    public void flush() {
+      myForwardIndex.force();
+    }
+
+    @Override
+    public void clear() throws IOException {
+      myForwardIndex.clear();
+    }
+
+    @Override
+    public void close() throws IOException {
+      myForwardIndex.close();
+    }
   }
 }
 
diff --git a/platform/util/src/com/intellij/util/indexing/impl/forward/AbstractForwardIndexAccessor.java b/platform/util/src/com/intellij/util/indexing/impl/forward/AbstractForwardIndexAccessor.java
index 9a59d1b8224a..cc6f193725d9 100644
--- a/platform/util/src/com/intellij/util/indexing/impl/forward/AbstractForwardIndexAccessor.java
+++ b/platform/util/src/com/intellij/util/indexing/impl/forward/AbstractForwardIndexAccessor.java
@@ -30,10 +30,16 @@ public abstract class AbstractForwardIndexAccessor<Key, Value, DataType, Input>
 
   protected abstract DataType convertToDataType(@Nullable Map<Key, Value> map, @Nullable Input content) throws IOException;
 
+  @Nullable
+  public DataType deserializeData(@Nullable ByteArraySequence sequence) throws IOException {
+    if (sequence == null) return null;
+    return deserializeFromByteSeq(sequence, myDataTypeExternalizer);
+  }
+
   @NotNull
   @Override
   public InputDataDiffBuilder<Key, Value> getDiffBuilder(int inputId, @Nullable ByteArraySequence sequence) throws IOException {
-    return createDiffBuilder(inputId, sequence == null ? null : deserializeFromByteSeq(sequence, myDataTypeExternalizer));
+    return createDiffBuilder(inputId, deserializeData(sequence));
   }
 
   @Nullable
diff --git a/plugins/junit5_rt_tests/test/com/intellij/testDiscovery/TestDiscoveryJUnitIntegrationTest.java b/plugins/junit5_rt_tests/test/com/intellij/testDiscovery/TestDiscoveryJUnitIntegrationTest.java
index b21733197587..e0991951f19c 100644
--- a/plugins/junit5_rt_tests/test/com/intellij/testDiscovery/TestDiscoveryJUnitIntegrationTest.java
+++ b/plugins/junit5_rt_tests/test/com/intellij/testDiscovery/TestDiscoveryJUnitIntegrationTest.java
@@ -2,6 +2,8 @@
 package com.intellij.testDiscovery;
 
 import com.intellij.execution.ExecutionException;
+import com.intellij.execution.Location;
+import com.intellij.execution.PsiLocation;
 import com.intellij.execution.configurations.RunConfiguration;
 import com.intellij.execution.configurations.RunConfigurationBase;
 import com.intellij.execution.junit.JUnitConfiguration;
@@ -21,6 +23,7 @@ import com.intellij.openapi.vfs.VfsUtilCore;
 import com.intellij.psi.PsiClass;
 import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiMethod;
+import com.intellij.psi.util.PsiTreeUtil;
 import com.intellij.testFramework.EdtRule;
 import com.intellij.testFramework.MapDataContext;
 import com.intellij.testFramework.PlatformTestUtil;
@@ -37,8 +40,10 @@ import org.junit.rules.TestName;
 import org.junit.runner.RunWith;
 import org.junit.runners.Parameterized;
 
+import java.io.File;
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.Iterator;
 import java.util.Set;
 import java.util.stream.Collectors;
 
@@ -146,6 +151,12 @@ public class TestDiscoveryJUnitIntegrationTest extends AbstractTestFrameworkComp
       .collect(Collectors.toSet());
     String module = assertOneElement(modules);
     assertEquals(myModule.getName(), module);
+
+    for (Pair<String, String> test : expectedTests) {
+      assertTrue(testDiscoveryIndex.hasTestTrace(test.getFirst(), test.getSecond(), JUnitConfiguration.FRAMEWORK_ID));
+    }
+    assertFalse(testDiscoveryIndex.hasTestTrace("dummy test name", "123", JUnitConfiguration.FRAMEWORK_ID));
+
   }
 
   private static Pair<String, String> t(String testClassName, String testMethodName) {
@@ -155,12 +166,12 @@ public class TestDiscoveryJUnitIntegrationTest extends AbstractTestFrameworkComp
   private void runTestConfiguration(@NotNull PsiElement psiElement) throws ExecutionException {
     MapDataContext context = new MapDataContext();
     context.put(LangDataKeys.MODULE, myModule);
-    RunConfiguration configuration = createConfiguration(psiElement, context);
+    JUnitConfiguration configuration = createConfiguration(psiElement, context);
     ProcessOutput processOutput = doStartTestsProcess(configuration);
     TestDiscoveryDataSocketListener socketListener =
-      ((RunConfigurationBase)configuration).getUserData(TestDiscoveryExtension.SOCKET_LISTENER_KEY);
+      configuration.getUserData(TestDiscoveryExtension.SOCKET_LISTENER_KEY);
     socketListener.awaitTermination();
-    ((RunConfigurationBase)configuration).putUserData(TestDiscoveryExtension.SOCKET_LISTENER_KEY, null);
+    configuration.putUserData(TestDiscoveryExtension.SOCKET_LISTENER_KEY, null);
     assertEmpty(processOutput.err);
   }