diff --git a/plugins/amazonq/chat/jetbrains-community/tst/software/aws/toolkits/jetbrains/services/amazonqFeatureDev/session/SessionStateChangeTest.kt b/plugins/amazonq/chat/jetbrains-community/tst/software/aws/toolkits/jetbrains/services/amazonqFeatureDev/session/SessionStateChangeTest.kt
new file mode 100644
index 0000000000..83d0cc4837
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+++ b/plugins/amazonq/chat/jetbrains-community/tst/software/aws/toolkits/jetbrains/services/amazonqFeatureDev/session/SessionStateChangeTest.kt
@@ -0,0 +1,151 @@
+// Copyright 2024 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package software.aws.toolkits.jetbrains.services.amazonqFeatureDev.session
+
+import com.intellij.testFramework.RuleChain
+import com.intellij.testFramework.replaceService
+import io.mockk.coEvery
+import io.mockk.every
+import io.mockk.just
+import io.mockk.mockk
+import io.mockk.mockkObject
+import io.mockk.mockkStatic
+import io.mockk.runs
+import io.mockk.spyk
+import io.mockk.unmockkAll
+import io.mockk.verify
+import kotlinx.coroutines.test.runTest
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.After
+import org.junit.Before
+import org.junit.Rule
+import org.junit.Test
+import org.mockito.kotlin.mock
+import org.mockito.kotlin.whenever
+import software.aws.toolkits.jetbrains.services.amazonq.FeatureDevSessionContext
+import software.aws.toolkits.jetbrains.services.amazonq.ZipCreationResult
+import software.aws.toolkits.jetbrains.services.amazonq.messages.MessagePublisher
+import software.aws.toolkits.jetbrains.services.amazonqFeatureDev.FeatureDevTestBase
+import software.aws.toolkits.jetbrains.services.amazonqFeatureDev.clients.FeatureDevClient
+import software.aws.toolkits.jetbrains.services.amazonqFeatureDev.messages.sendAnswerPart
+import software.aws.toolkits.jetbrains.services.amazonqFeatureDev.messages.sendUpdatePlaceholder
+import software.aws.toolkits.jetbrains.services.amazonqFeatureDev.util.FeatureDevService
+import software.aws.toolkits.jetbrains.services.amazonqFeatureDev.util.deleteUploadArtifact
+import software.aws.toolkits.jetbrains.services.amazonqFeatureDev.util.uploadArtifactToS3
+import software.aws.toolkits.telemetry.AmazonqTelemetry
+import java.io.File
+
+class SessionStateChangeTest : FeatureDevTestBase() {
+    @Rule
+    @JvmField
+    val ruleChain = RuleChain(projectRule, disposableRule)
+
+    private lateinit var session: Session
+    private lateinit var sessionStateConfig: SessionStateConfig
+    private lateinit var repoContext: FeatureDevSessionContext
+    private lateinit var messenger: MessagePublisher
+    private lateinit var featureDevService: FeatureDevService
+    private lateinit var featureDevClient: FeatureDevClient
+
+    @Before
+    override fun setup() {
+        messenger = mock()
+        featureDevClient = mock()
+        featureDevService = mockk()
+        repoContext = mock()
+        sessionStateConfig = SessionStateConfig(testConversationId, repoContext, featureDevService)
+        every { featureDevService.proxyClient } returns featureDevClient
+        every { featureDevService.project } returns projectRule.project
+
+        projectRule.project.replaceService(FeatureDevService::class.java, featureDevService, disposableRule.disposable)
+        projectRule.project.replaceService(FeatureDevClient::class.java, featureDevClient, disposableRule.disposable)
+        projectRule.project.replaceService(SessionStateConfig::class.java, sessionStateConfig, disposableRule.disposable)
+        session = Session("tabId", projectRule.project)
+
+        var field = Session::class.java.getDeclaredField("featureDevService")
+        field.isAccessible = true
+        field.set(session, featureDevService)
+
+        mockkStatic("software.aws.toolkits.jetbrains.services.amazonqFeatureDev.util.UploadArtifactKt")
+        every { uploadArtifactToS3(any(), any(), any(), any(), any()) } just runs
+        every { deleteUploadArtifact(any()) } just runs
+    }
+
+    @After
+    fun clear() {
+        unmockkAll()
+    }
+
+    @Test
+    fun `test complete successful workflow`() = runTest {
+        // Spy on the session to allow mocking private methods
+        val sessionSpy = spyk(session, recordPrivateCalls = true)
+
+        // Start from ConversationNotStartedState
+        assertThat(sessionSpy.sessionState).isInstanceOf(ConversationNotStartedState::class.java)
+        assertThat(sessionSpy.isAuthenticating).isFalse()
+        assertThat(sessionSpy.sessionState.phase).isEqualTo(SessionStatePhase.INIT)
+
+        // Mocking FeatureDevClient methods
+        whenever(featureDevClient.createTaskAssistConversation()).thenReturn(exampleCreateTaskAssistConversationResponse)
+        whenever(featureDevClient.sendFeatureDevTelemetryEvent(testConversationId)).thenReturn(exampleSendTelemetryEventResponse)
+
+        // Mocking FeatureDevService methods
+        every { featureDevService.createConversation() } returns testConversationId
+        every { featureDevService.startTaskAssistCodeGeneration(any(), any(), any(), any(), any()) } returns exampleStartTaskAssistConversationResponse
+        every { featureDevService.getTaskAssistCodeGeneration(any(), any()) } returns exampleCompleteGetTaskAssistCodeGenerationResponse
+        coEvery { featureDevService.exportTaskAssistArchiveResult(any()) } returns exampleExportTaskAssistResultArchiveResponse
+        every { featureDevService.sendFeatureDevEvent(any()) } just runs
+
+        // Mocking AmazonQTelemetry
+        mockkObject(AmazonqTelemetry)
+        every {
+            AmazonqTelemetry.createUpload(
+                amazonqConversationId = any(),
+                amazonqRepositorySize = any(),
+                amazonqUploadIntent = any(),
+                result = any(),
+                reason = any(),
+                reasonDesc = any(),
+                duration = any(),
+                credentialStartUrl = any()
+            )
+        } just runs
+
+        // Mock the private function
+        every { sessionSpy["getSessionStateConfig"]() } returns sessionStateConfig
+
+        // Mocking MessagePublisher
+        mockkStatic(MessagePublisher::sendAnswerPart)
+        coEvery { messenger.sendAnswerPart(any(), any()) } just runs
+        coEvery { messenger.sendUpdatePlaceholder(any(), any()) } just runs
+
+        // Preloading session to transition to PrepareCodeGenerationState
+        sessionSpy.preloader("Test Message", messenger)
+        assertThat(sessionSpy.sessionState).isInstanceOf(PrepareCodeGenerationState::class.java)
+
+        // Simulating code generation and transitioning back to PrepareCodeGenerationState
+        val mockFile: File = mock()
+        val repoZipResult = ZipCreationResult(mockFile, testChecksumSha, testContentLength)
+        val action = SessionStateAction("test-task", "Test Message")
+
+        whenever(repoContext.getProjectZip()).thenReturn(repoZipResult)
+        every { featureDevService.createUploadUrl(any(), any(), any(), any()) } returns exampleCreateUploadUrlResponse
+
+        val prepareState = sessionSpy.sessionState as PrepareCodeGenerationState
+        assertThat(prepareState.currentIteration).isEqualTo(1)
+
+        val actual = prepareState.interact(action)
+        assertThat(actual.nextState).isInstanceOf(PrepareCodeGenerationState::class.java)
+        val nextState = actual.nextState as PrepareCodeGenerationState
+
+        verify(exactly = 1) { featureDevService.createConversation() }
+        assertThat(nextState.phase).isEqualTo(SessionStatePhase.CODEGEN)
+        assertThat(nextState.codeGenerationRemainingIterationCount).isEqualTo(2)
+        assertThat(nextState.currentIteration).isEqualTo(1)
+        assertThat(nextState.codeGenerationTotalIterationCount).isEqualTo(3)
+        assertThat(actual.interaction.interactionSucceeded).isEqualTo(true)
+        assertThat(actual.interaction.content).isEqualTo("")
+    }
+}