diff --git a/platform/xdebugger-impl/testSrc/com/intellij/xdebugger/impl/hotswap/HotSwapSessionManagerTest.kt b/platform/xdebugger-impl/testSrc/com/intellij/xdebugger/impl/hotswap/HotSwapSessionManagerTest.kt
new file mode 100644
index 000000000000..4851ffb02ce2
--- /dev/null
+++ b/platform/xdebugger-impl/testSrc/com/intellij/xdebugger/impl/hotswap/HotSwapSessionManagerTest.kt
@@ -0,0 +1,185 @@
+// 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.xdebugger.impl.hotswap
+
+import com.intellij.mock.MockVirtualFile
+import com.intellij.openapi.actionSystem.DataContext
+import com.intellij.openapi.util.Disposer
+import com.intellij.testFramework.HeavyPlatformTestCase
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.runBlocking
+
+class HotSwapSessionManagerTest : HeavyPlatformTestCase() {
+  fun testCurrentSession() {
+    val manager = HotSwapSessionManager.getInstance(project)
+    val disposable = Disposer.newDisposable(testRootDisposable)
+    try {
+      assertNull(manager.currentSession)
+      val hotSwapSession = manager.createSession(MockHotSwapProvider(), disposable)
+      assertSame(hotSwapSession, manager.currentSession)
+    }
+    finally {
+      Disposer.dispose(disposable)
+    }
+    assertNull(manager.currentSession)
+  }
+
+  fun testListener() {
+    val manager = HotSwapSessionManager.getInstance(project)
+    val disposable = Disposer.newDisposable(testRootDisposable)
+    try {
+      val list = mutableListOf<HotSwapVisibleStatus>()
+      manager.addListener(HotSwapChangesListener { _, status ->
+        list.add(status)
+      }, disposable)
+      assertEmpty(list)
+      manager.createSession(MockHotSwapProvider(), disposable)
+    }
+    finally {
+      Disposer.dispose(disposable)
+    }
+  }
+
+  fun testListenerAfterSessionStart() {
+    val manager = HotSwapSessionManager.getInstance(project)
+    val list = mutableListOf<HotSwapVisibleStatus>()
+    val disposable1 = Disposer.newDisposable(testRootDisposable)
+    val disposable2 = Disposer.newDisposable(testRootDisposable)
+    try {
+      manager.createSession(MockHotSwapProvider(), disposable1)
+      manager.addListener(HotSwapChangesListener { _, status ->
+        list.add(status)
+      }, disposable2)
+      assertEquals(HotSwapVisibleStatus.NO_CHANGES, list.single())
+    }
+    finally {
+      Disposer.dispose(disposable1)
+      try {
+        assertEquals(2, list.size)
+        assertEquals(HotSwapVisibleStatus.SESSION_COMPLETED, list.last())
+      }
+      finally {
+        Disposer.dispose(disposable2)
+      }
+    }
+
+  }
+
+  fun testOnChangesChanges(): Unit = runBlocking {
+    val manager = HotSwapSessionManager.getInstance(project)
+    val disposable = Disposer.newDisposable(testRootDisposable)
+    try {
+      val list = mutableListOf<HotSwapVisibleStatus>()
+      manager.addListener(HotSwapChangesListener { _, status ->
+        list.add(status)
+      }, disposable)
+      assertEmpty(list)
+      val provider = MockHotSwapProvider()
+      val hotSwapSession = manager.createSession(provider, disposable)
+      assertEmpty(hotSwapSession.getChanges())
+      assertEmpty(list)
+
+      provider.collector.addFile(MockVirtualFile("a.txt"))
+      assertEquals(1, list.size)
+      assertEquals(HotSwapVisibleStatus.CHANGES_READY, list.last())
+      assertEquals(1, hotSwapSession.getChanges().size)
+
+      provider.collector.addFile(MockVirtualFile("b.txt"))
+      assertEquals(1, list.size)
+      assertEquals(2, hotSwapSession.getChanges().size)
+    }
+    finally {
+      Disposer.dispose(disposable)
+    }
+  }
+
+  fun testHotSwap(): Unit = runBlocking {
+    val manager = HotSwapSessionManager.getInstance(project)
+    val disposable = Disposer.newDisposable(testRootDisposable)
+    try {
+      val list = mutableListOf<HotSwapVisibleStatus>()
+      manager.addListener(HotSwapChangesListener { _, status ->
+        list.add(status)
+      }, disposable)
+      assertEmpty(list)
+      val provider = MockHotSwapProvider()
+      val hotSwapSession = manager.createSession(provider, disposable)
+
+      run {
+        val start = 0
+        provider.collector.addFile(MockVirtualFile("a.txt"))
+        assertEquals(start + 1, list.size)
+        assertEquals(HotSwapVisibleStatus.CHANGES_READY, list.last())
+        val listener = provider.performHotSwap(hotSwapSession)
+        assertEquals(start + 2, list.size)
+        assertEquals(HotSwapVisibleStatus.IN_PROGRESS, list.last())
+        listener.onFinish()
+        assertEquals(start + 3, list.size)
+        assertEquals(HotSwapVisibleStatus.NO_CHANGES, list.last())
+        assertEmpty(hotSwapSession.getChanges())
+      }
+
+      run {
+        val start = 3
+        provider.collector.addFile(MockVirtualFile("a.txt"))
+        assertEquals(start + 1, list.size)
+        assertEquals(HotSwapVisibleStatus.CHANGES_READY, list.last())
+        val listener = provider.performHotSwap(hotSwapSession)
+        assertEquals(start + 2, list.size)
+        assertEquals(HotSwapVisibleStatus.IN_PROGRESS, list.last())
+        listener.onSuccessfulReload()
+        assertEquals(start + 3, list.size)
+        assertEquals(HotSwapVisibleStatus.NO_CHANGES, list.last())
+        assertEmpty(hotSwapSession.getChanges())
+      }
+
+      run {
+        val start = 6
+        provider.collector.addFile(MockVirtualFile("a.txt"))
+        assertEquals(start + 1, list.size)
+        assertEquals(HotSwapVisibleStatus.CHANGES_READY, list.last())
+        val listener = provider.performHotSwap(hotSwapSession)
+        assertEquals(start + 2, list.size)
+        assertEquals(HotSwapVisibleStatus.IN_PROGRESS, list.last())
+        listener.onCanceled()
+        assertEquals(start + 3, list.size)
+        assertEquals(HotSwapVisibleStatus.CHANGES_READY, list.last())
+        assertEquals(1, hotSwapSession.getChanges().size)
+      }
+    }
+    finally {
+      Disposer.dispose(disposable)
+    }
+  }
+}
+
+internal class MockHotSwapProvider : HotSwapProvider<MockVirtualFile> {
+  lateinit var collector: MockChangesCollector
+
+  override fun createChangesCollector(
+    session: HotSwapSession<MockVirtualFile>,
+    coroutineScope: CoroutineScope,
+    listener: SourceFileChangesListener<MockVirtualFile>,
+  ): SourceFileChangesCollector<MockVirtualFile> = MockChangesCollector(listener).also { collector = it }
+
+  fun performHotSwap(session: HotSwapSession<MockVirtualFile>) = session.startHotSwapListening()
+  override fun performHotSwap(context: DataContext, session: HotSwapSession<MockVirtualFile>) {
+    error("Not supported")
+  }
+}
+
+internal class MockChangesCollector(private val listener: SourceFileChangesListener<MockVirtualFile>) : SourceFileChangesCollector<MockVirtualFile> {
+  private val files = mutableSetOf<MockVirtualFile>()
+  fun addFile(file: MockVirtualFile) {
+    files.add(file)
+    listener.onFileChange(file)
+  }
+
+  override fun getChanges(): Set<MockVirtualFile> = files
+
+  override fun resetChanges() {
+    files.clear()
+  }
+
+  override fun dispose() {
+  }
+}