diff --git a/platform/testFramework/src/com/intellij/testFramework/fixtures/IdeaTestFixtureFactory.java b/platform/testFramework/src/com/intellij/testFramework/fixtures/IdeaTestFixtureFactory.java
index 8f58847de195..3d5f01a364df 100644
--- a/platform/testFramework/src/com/intellij/testFramework/fixtures/IdeaTestFixtureFactory.java
+++ b/platform/testFramework/src/com/intellij/testFramework/fixtures/IdeaTestFixtureFactory.java
@@ -1,6 +1,7 @@
 // Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.testFramework.fixtures;
 
+import com.intellij.openapi.project.Project;
 import com.intellij.testFramework.LightProjectDescriptor;
 import com.intellij.testFramework.builders.ModuleFixtureBuilder;
 import com.intellij.testFramework.fixtures.impl.IdeaTestFixtureFactoryImpl;
@@ -55,4 +56,7 @@ public abstract class IdeaTestFixtureFactory {
   public abstract @NotNull TempDirTestFixture createTempDirTestFixture();
 
   public abstract @NotNull BareTestFixture createBareFixture();
+
+  public abstract @NotNull CodeInsightTestFixture createCodeInsightFixtureForExistingProject(@NotNull Project project);
+
 }
diff --git a/platform/testFramework/src/com/intellij/testFramework/fixtures/impl/IdeaTestFixtureFactoryImpl.java b/platform/testFramework/src/com/intellij/testFramework/fixtures/impl/IdeaTestFixtureFactoryImpl.java
index ab0c5458eb53..49fa7ef6b4f3 100644
--- a/platform/testFramework/src/com/intellij/testFramework/fixtures/impl/IdeaTestFixtureFactoryImpl.java
+++ b/platform/testFramework/src/com/intellij/testFramework/fixtures/impl/IdeaTestFixtureFactoryImpl.java
@@ -1,6 +1,9 @@
 // Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.testFramework.fixtures.impl;
 
+import com.intellij.openapi.module.Module;
+import com.intellij.openapi.module.ModuleManager;
+import com.intellij.openapi.project.Project;
 import com.intellij.testFramework.LightProjectDescriptor;
 import com.intellij.testFramework.builders.EmptyModuleFixtureBuilder;
 import com.intellij.testFramework.builders.ModuleFixtureBuilder;
@@ -94,6 +97,28 @@ public final class IdeaTestFixtureFactoryImpl extends IdeaTestFixtureFactory {
     return new BareTestFixtureImpl();
   }
 
+  @Override
+  public @NotNull CodeInsightTestFixture createCodeInsightFixtureForExistingProject(@NotNull Project project) {
+    IdeaProjectTestFixture projectTestFixture = new IdeaProjectTestFixture() {
+      @Override
+      public Project getProject() {
+        return project;
+      }
+
+      @Override
+      public Module getModule() {
+        return ModuleManager.getInstance(project).getModules()[0];
+      }
+
+      @Override
+      public void setUp() {}
+
+      @Override
+      public void tearDown() {}
+    };
+    return new CodeInsightTestFixtureImpl(projectTestFixture, new TempDirTestFixtureImpl());
+  }
+
   public static final class MyEmptyModuleFixtureBuilderImpl extends EmptyModuleFixtureBuilderImpl {
     public MyEmptyModuleFixtureBuilderImpl(@NotNull TestFixtureBuilder<? extends IdeaProjectTestFixture> testFixtureBuilder) {
       super(testFixtureBuilder);
diff --git a/platform/testFramework/src/com/intellij/testFramework/utils/inlays/InlayParameterHintsTest.kt b/platform/testFramework/src/com/intellij/testFramework/utils/inlays/InlayParameterHintsTest.kt
index 93852286a19b..fe72367b1807 100644
--- a/platform/testFramework/src/com/intellij/testFramework/utils/inlays/InlayParameterHintsTest.kt
+++ b/platform/testFramework/src/com/intellij/testFramework/utils/inlays/InlayParameterHintsTest.kt
@@ -18,7 +18,7 @@ import org.junit.Assert.assertFalse
 import java.util.regex.Pattern
 
 
-class InlayHintsChecker(private val myFixture: CodeInsightTestFixture) {
+open class InlayHintsChecker(private val myFixture: CodeInsightTestFixture) {
 
   companion object {
     val pattern: Pattern = Pattern.compile("(<caret>)|(<selection>)|(</selection>)|<(hint|HINT|Hint|hINT)\\s+text=\"([^\n\r]+?(?=\"\\s*/>))\"\\s*/>")
@@ -126,11 +126,13 @@ class InlayHintsChecker(private val myFixture: CodeInsightTestFixture) {
           isHighlighted = false
           isCurrent = false
         }
-        InlayInfo(it.offset, inlayPresenter(it),  isHighlighted, isCurrent)
+        InlayInfo(getInlayOffset(it), inlayPresenter(it), isHighlighted, isCurrent)
       }
       .sortedBy { it.offset }
   }
 
+  protected open fun getInlayOffset(inlay: Inlay<*>): Int = inlay.offset
+
   fun extractInlaysAndCaretInfo(document: Document): CaretAndInlaysInfo {
     val text = document.text
     val matcher = pattern.matcher(text)