fix: resolve chat message edit/delete duplication issues

src/core/webview/__tests__/ClineProvider.spec.ts

@@ -1332,19 +1332,11 @@ describe("ClineProvider", () => {
 				text: "Edited message content",
 			})
 
-			// Verify correct messages were kept (only messages before the edited one)
-			expect(mockCline.overwriteClineMessages).toHaveBeenCalledWith([
-				mockMessages[0],
-				mockMessages[1],
-				mockMessages[2],
-			])
+			// Verify correct messages were kept - delete from the preceding user message to truly replace it
+			expect(mockCline.overwriteClineMessages).toHaveBeenCalledWith([])
 
-			// Verify correct API messages were kept (only messages before the edited one)
-			expect(mockCline.overwriteApiConversationHistory).toHaveBeenCalledWith([
-				mockApiHistory[0],
-				mockApiHistory[1],
-				mockApiHistory[2],
-			])
+			// Verify correct API messages were kept
+			expect(mockCline.overwriteApiConversationHistory).toHaveBeenCalledWith([])
 
 			// The new flow calls webviewMessageHandler recursively with askResponse
 			// We need to verify the recursive call happened by checking if the handler was called again
@@ -3016,7 +3008,7 @@ describe("ClineProvider - Comprehensive Edit/Delete Edge Cases", () => {
 			mockCline.apiConversationHistory = [{ ts: 1000 }, { ts: 2000 }, { ts: 3000 }] as any[]
 			mockCline.overwriteClineMessages = vi.fn()
 			mockCline.overwriteApiConversationHistory = vi.fn()
-			mockCline.handleWebviewAskResponse = vi.fn()
+			mockCline.submitUserMessage = vi.fn()
 
 			await provider.addClineToStack(mockCline)
 			;(provider as any).getTaskWithId = vi.fn().mockResolvedValue({
@@ -3046,9 +3038,11 @@ describe("ClineProvider - Comprehensive Edit/Delete Edge Cases", () => {
 				text: "Edited message with preserved images",
 			})
 
-			// Verify messages were edited correctly - messages up to the edited message should remain
-			expect(mockCline.overwriteClineMessages).toHaveBeenCalledWith([mockMessages[0], mockMessages[1]])
-			expect(mockCline.overwriteApiConversationHistory).toHaveBeenCalledWith([{ ts: 1000 }, { ts: 2000 }])
+			// Verify messages were edited correctly - the ORIGINAL user message and all subsequent messages are removed
+			expect(mockCline.overwriteClineMessages).toHaveBeenCalledWith([mockMessages[0]])
+			expect(mockCline.overwriteApiConversationHistory).toHaveBeenCalledWith([{ ts: 1000 }])
+			// Verify submitUserMessage was called with the edited content
+			expect(mockCline.submitUserMessage).toHaveBeenCalledWith("Edited message with preserved images", undefined)
 		})
 
 		test("handles editing messages with file attachments", async () => {
@@ -3070,7 +3064,7 @@ describe("ClineProvider - Comprehensive Edit/Delete Edge Cases", () => {
 			mockCline.apiConversationHistory = [{ ts: 1000 }, { ts: 2000 }, { ts: 3000 }] as any[]
 			mockCline.overwriteClineMessages = vi.fn()
 			mockCline.overwriteApiConversationHistory = vi.fn()
-			mockCline.handleWebviewAskResponse = vi.fn()
+			mockCline.submitUserMessage = vi.fn()
 
 			await provider.addClineToStack(mockCline)
 			;(provider as any).getTaskWithId = vi.fn().mockResolvedValue({
@@ -3101,11 +3095,7 @@ describe("ClineProvider - Comprehensive Edit/Delete Edge Cases", () => {
 			})
 
 			expect(mockCline.overwriteClineMessages).toHaveBeenCalled()
-			expect(mockCline.handleWebviewAskResponse).toHaveBeenCalledWith(
-				"messageResponse",
-				"Edited message with file attachment",
-				undefined,
-			)
+			expect(mockCline.submitUserMessage).toHaveBeenCalledWith("Edited message with file attachment", undefined)
 		})
 	})
 
@@ -3197,7 +3187,7 @@ describe("ClineProvider - Comprehensive Edit/Delete Edge Cases", () => {
 			await messageHandler({ type: "editMessageConfirm", messageTs: 2000, text: "Edited message" })
 
 			// The error should be caught and shown
-			expect(vscode.window.showErrorMessage).toHaveBeenCalledWith("Error editing message: Connection lost")
+			expect(vscode.window.showErrorMessage).toHaveBeenCalledWith("errors.message.error_editing_message")
 		})
 	})
 
@@ -3320,7 +3310,7 @@ describe("ClineProvider - Comprehensive Edit/Delete Edge Cases", () => {
 				text: "Edited message",
 			})
 
-			expect(vscode.window.showErrorMessage).toHaveBeenCalledWith("Error editing message: Unauthorized")
+			expect(vscode.window.showErrorMessage).toHaveBeenCalledWith("errors.message.error_editing_message")
 		})
 
 		describe("Malformed Requests and Invalid Formats", () => {
@@ -3544,7 +3534,7 @@ describe("ClineProvider - Comprehensive Edit/Delete Edge Cases", () => {
 
 				// Verify cleanup was attempted before failure
 				expect(cleanupSpy).toHaveBeenCalled()
-				expect(vscode.window.showErrorMessage).toHaveBeenCalledWith("Error editing message: Operation failed")
+				expect(vscode.window.showErrorMessage).toHaveBeenCalledWith("errors.message.error_editing_message")
 			})
 
 			test("validates proper cleanup during failed delete operations", async () => {
@@ -3584,9 +3574,7 @@ describe("ClineProvider - Comprehensive Edit/Delete Edge Cases", () => {
 
 				// Verify cleanup was attempted before failure
 				expect(cleanupSpy).toHaveBeenCalled()
-				expect(vscode.window.showErrorMessage).toHaveBeenCalledWith(
-					"Error deleting message: Delete operation failed",
-				)
+				expect(vscode.window.showErrorMessage).toHaveBeenCalledWith("errors.message.error_deleting_message")
 			})
 		})
 
@@ -3609,7 +3597,7 @@ describe("ClineProvider - Comprehensive Edit/Delete Edge Cases", () => {
 				mockCline.apiConversationHistory = [{ ts: 1000 }, { ts: 2000 }] as any[]
 				mockCline.overwriteClineMessages = vi.fn()
 				mockCline.overwriteApiConversationHistory = vi.fn()
-				mockCline.handleWebviewAskResponse = vi.fn()
+				mockCline.submitUserMessage = vi.fn()
 
 				await provider.addClineToStack(mockCline)
 				;(provider as any).getTaskWithId = vi.fn().mockResolvedValue({
@@ -3638,11 +3626,7 @@ describe("ClineProvider - Comprehensive Edit/Delete Edge Cases", () => {
 				await messageHandler({ type: "editMessageConfirm", messageTs: 2000, text: largeEditedContent })
 
 				expect(mockCline.overwriteClineMessages).toHaveBeenCalled()
-				expect(mockCline.handleWebviewAskResponse).toHaveBeenCalledWith(
-					"messageResponse",
-					largeEditedContent,
-					undefined,
-				)
+				expect(mockCline.submitUserMessage).toHaveBeenCalledWith(largeEditedContent, undefined)
 			})
 
 			test("handles deleting messages with large payloads", async () => {
@@ -3822,7 +3806,7 @@ describe("ClineProvider - Comprehensive Edit/Delete Edge Cases", () => {
 				] as any[]
 				mockCline.overwriteClineMessages = vi.fn()
 				mockCline.overwriteApiConversationHistory = vi.fn()
-				mockCline.handleWebviewAskResponse = vi.fn()
+				mockCline.submitUserMessage = vi.fn()
 
 				await provider.addClineToStack(mockCline)
 				;(provider as any).getTaskWithId = vi.fn().mockResolvedValue({
@@ -3855,7 +3839,7 @@ describe("ClineProvider - Comprehensive Edit/Delete Edge Cases", () => {
 
 				// Should handle future timestamps correctly
 				expect(mockCline.overwriteClineMessages).toHaveBeenCalled()
-				expect(mockCline.handleWebviewAskResponse).toHaveBeenCalled()
+				expect(mockCline.submitUserMessage).toHaveBeenCalled()
 			})
 		})
 	})

src/core/webview/__tests__/webviewMessageHandler.delete.spec.ts

@@ -0,0 +1,245 @@
+import { describe, it, expect, beforeEach, vi } from "vitest"
+import { webviewMessageHandler } from "../webviewMessageHandler"
+import * as vscode from "vscode"
+import { ClineProvider } from "../ClineProvider"
+
+// Mock the saveTaskMessages function
+vi.mock("../../task-persistence", () => ({
+	saveTaskMessages: vi.fn(),
+}))
+
+// Mock the i18n module
+vi.mock("../../../i18n", () => ({
+	t: vi.fn((key: string) => key),
+	changeLanguage: vi.fn(),
+}))
+
+vi.mock("vscode", () => ({
+	window: {
+		showErrorMessage: vi.fn(),
+		showWarningMessage: vi.fn(),
+		showInformationMessage: vi.fn(),
+	},
+	workspace: {
+		workspaceFolders: undefined,
+		getConfiguration: vi.fn(() => ({
+			get: vi.fn(),
+			update: vi.fn(),
+		})),
+	},
+	ConfigurationTarget: {
+		Global: 1,
+		Workspace: 2,
+		WorkspaceFolder: 3,
+	},
+	Uri: {
+		parse: vi.fn((str) => ({ toString: () => str })),
+		file: vi.fn((path) => ({ fsPath: path })),
+	},
+	env: {
+		openExternal: vi.fn(),
+		clipboard: {
+			writeText: vi.fn(),
+		},
+	},
+	commands: {
+		executeCommand: vi.fn(),
+	},
+}))
+
+describe("webviewMessageHandler delete functionality", () => {
+	let provider: any
+	let getCurrentTaskMock: any
+
+	beforeEach(() => {
+		// Reset all mocks
+		vi.clearAllMocks()
+
+		// Create mock task
+		getCurrentTaskMock = {
+			clineMessages: [],
+			apiConversationHistory: [],
+			overwriteClineMessages: vi.fn(async () => {}),
+			overwriteApiConversationHistory: vi.fn(async () => {}),
+			taskId: "test-task-id",
+		}
+
+		// Create mock provider
+		provider = {
+			getCurrentTask: vi.fn(() => getCurrentTaskMock),
+			postMessageToWebview: vi.fn(),
+			contextProxy: {
+				getValue: vi.fn(),
+				setValue: vi.fn(async () => {}),
+				globalStorageUri: { fsPath: "/test/path" },
+			},
+			log: vi.fn(),
+			cwd: "/test/cwd",
+		}
+	})
+
+	describe("handleDeleteMessageConfirm", () => {
+		it("should handle deletion when apiConversationHistoryIndex is -1 (message not in API history)", async () => {
+			// Setup test data with a user message and assistant response
+			const userMessageTs = 1000
+			const assistantMessageTs = 1001
+
+			getCurrentTaskMock.clineMessages = [
+				{ ts: userMessageTs, say: "user", text: "Hello" },
+				{ ts: assistantMessageTs, say: "assistant", text: "Hi there" },
+			]
+
+			// API history has the assistant message but not the user message
+			// This simulates the case where the user message wasn't in API history
+			getCurrentTaskMock.apiConversationHistory = [
+				{ ts: assistantMessageTs, role: "assistant", content: { type: "text", text: "Hi there" } },
+				{
+					ts: 1002,
+					role: "assistant",
+					content: { type: "text", text: "attempt_completion" },
+					name: "attempt_completion",
+				},
+			]
+
+			// Call delete for the user message
+			await webviewMessageHandler(provider, {
+				type: "deleteMessageConfirm",
+				messageTs: userMessageTs,
+			})
+
+			// Verify that clineMessages was truncated at the correct index
+			expect(getCurrentTaskMock.overwriteClineMessages).toHaveBeenCalledWith([])
+
+			// When message is not found in API history (index is -1),
+			// API history should be truncated from the first API message at/after the deleted timestamp (fallback)
+			expect(getCurrentTaskMock.overwriteApiConversationHistory).toHaveBeenCalledWith([])
+		})
+
+		it("should handle deletion when exact apiConversationHistoryIndex is found", async () => {
+			// Setup test data where message exists in both arrays
+			const messageTs = 1000
+
+			getCurrentTaskMock.clineMessages = [
+				{ ts: 900, say: "user", text: "Previous message" },
+				{ ts: messageTs, say: "user", text: "Delete this" },
+				{ ts: 1100, say: "assistant", text: "Response" },
+			]
+
+			getCurrentTaskMock.apiConversationHistory = [
+				{ ts: 900, role: "user", content: { type: "text", text: "Previous message" } },
+				{ ts: messageTs, role: "user", content: { type: "text", text: "Delete this" } },
+				{ ts: 1100, role: "assistant", content: { type: "text", text: "Response" } },
+			]
+
+			// Call delete
+			await webviewMessageHandler(provider, {
+				type: "deleteMessageConfirm",
+				messageTs: messageTs,
+			})
+
+			// Verify truncation at correct indices
+			expect(getCurrentTaskMock.overwriteClineMessages).toHaveBeenCalledWith([
+				{ ts: 900, say: "user", text: "Previous message" },
+			])
+
+			expect(getCurrentTaskMock.overwriteApiConversationHistory).toHaveBeenCalledWith([
+				{ ts: 900, role: "user", content: { type: "text", text: "Previous message" } },
+			])
+		})
+
+		it("should handle deletion when message not found in clineMessages", async () => {
+			getCurrentTaskMock.clineMessages = [{ ts: 1000, say: "user", text: "Some message" }]
+
+			getCurrentTaskMock.apiConversationHistory = []
+
+			// Call delete with non-existent timestamp
+			await webviewMessageHandler(provider, {
+				type: "deleteMessageConfirm",
+				messageTs: 9999,
+			})
+
+			// Verify error message was shown (expecting translation key since t() is mocked to return the key)
+			expect(vscode.window.showErrorMessage).toHaveBeenCalledWith("common:errors.message.message_not_found")
+
+			// Verify no truncation occurred
+			expect(getCurrentTaskMock.overwriteClineMessages).not.toHaveBeenCalled()
+			expect(getCurrentTaskMock.overwriteApiConversationHistory).not.toHaveBeenCalled()
+		})
+
+		it("should handle deletion with attempt_completion in API history", async () => {
+			// Setup test data with attempt_completion
+			const userMessageTs = 1000
+			const attemptCompletionTs = 1001
+
+			getCurrentTaskMock.clineMessages = [
+				{ ts: userMessageTs, say: "user", text: "Fix the bug" },
+				{ ts: attemptCompletionTs, say: "assistant", text: "I've fixed the bug" },
+			]
+
+			// API history has attempt_completion but user message is missing
+			getCurrentTaskMock.apiConversationHistory = [
+				{
+					ts: attemptCompletionTs,
+					role: "assistant",
+					content: {
+						type: "text",
+						text: "I've fixed the bug in the code",
+					},
+					name: "attempt_completion",
+				},
+				{
+					ts: 1002,
+					role: "user",
+					content: { type: "text", text: "Looks good, but..." },
+				},
+			]
+
+			// Call delete for the user message
+			await webviewMessageHandler(provider, {
+				type: "deleteMessageConfirm",
+				messageTs: userMessageTs,
+			})
+
+			// Verify that clineMessages was truncated
+			expect(getCurrentTaskMock.overwriteClineMessages).toHaveBeenCalledWith([])
+
+			// API history should be truncated from first message at/after deleted timestamp (fallback)
+			expect(getCurrentTaskMock.overwriteApiConversationHistory).toHaveBeenCalledWith([])
+		})
+
+		it("should preserve messages before the deleted one", async () => {
+			const messageTs = 2000
+
+			getCurrentTaskMock.clineMessages = [
+				{ ts: 1000, say: "user", text: "First message" },
+				{ ts: 1500, say: "assistant", text: "First response" },
+				{ ts: messageTs, say: "user", text: "Delete this" },
+				{ ts: 2500, say: "assistant", text: "Response to delete" },
+			]
+
+			getCurrentTaskMock.apiConversationHistory = [
+				{ ts: 1000, role: "user", content: { type: "text", text: "First message" } },
+				{ ts: 1500, role: "assistant", content: { type: "text", text: "First response" } },
+				{ ts: messageTs, role: "user", content: { type: "text", text: "Delete this" } },
+				{ ts: 2500, role: "assistant", content: { type: "text", text: "Response to delete" } },
+			]
+
+			await webviewMessageHandler(provider, {
+				type: "deleteMessageConfirm",
+				messageTs: messageTs,
+			})
+
+			// Should preserve messages before the deleted one
+			expect(getCurrentTaskMock.overwriteClineMessages).toHaveBeenCalledWith([
+				{ ts: 1000, say: "user", text: "First message" },
+				{ ts: 1500, say: "assistant", text: "First response" },
+			])
+
+			// API history should be truncated at the exact index
+			expect(getCurrentTaskMock.overwriteApiConversationHistory).toHaveBeenCalledWith([
+				{ ts: 1000, role: "user", content: { type: "text", text: "First message" } },
+				{ ts: 1500, role: "assistant", content: { type: "text", text: "First response" } },
+			])
+		})
+	})
+})