fix: centralize rules folder deletion and add error notifications

- Remove duplicate rules folder deletion logic from SimpleInstaller.ts
- Centralize rules management in CustomModesManager.deleteCustomMode()
- Add user-visible error notifications for marketplace removal failures
- Clean up unused imports from SimpleInstaller.ts

Addresses review feedback in PR #6136 for marketplace mode removal cleanup.

Author: hannesrudolph

src/core/config/CustomModesManager.ts

@@ -1,6 +1,7 @@
 import * as vscode from "vscode"
 import * as path from "path"
 import * as fs from "fs/promises"
+import * as os from "os"
 
 import * as yaml from "yaml"
 import stripBom from "strip-bom"
@@ -517,6 +518,9 @@ export class CustomModesManager {
 				throw new Error(t("common:customModes.errors.modeNotFound"))
 			}
 
+			// Determine which mode to use for rules folder path calculation
+			const modeToDelete = projectMode || globalMode
+
 			await this.queueWrite(async () => {
 				// Delete from project first if it exists there
 				if (projectMode && roomodesPath) {
@@ -528,6 +532,11 @@ export class CustomModesManager {
 					await this.updateModesInFile(settingsPath, (modes) => modes.filter((m) => m.slug !== slug))
 				}
 
+				// Delete associated rules folder
+				if (modeToDelete) {
+					await this.deleteRulesFolder(slug, modeToDelete)
+				}
+
 				// Clear cache when modes are deleted
 				this.clearCache()
 				await this.refreshMergedState()
@@ -538,6 +547,49 @@ export class CustomModesManager {
 		}
 	}
 
+	/**
+	 * Deletes the rules folder for a specific mode
+	 * @param slug - The mode slug
+	 * @param mode - The mode configuration to determine the scope
+	 */
+	private async deleteRulesFolder(slug: string, mode: ModeConfig): Promise<void> {
+		try {
+			// Determine the scope based on source (project or global)
+			const scope = mode.source || "global"
+
+			// Determine the rules folder path
+			let rulesFolderPath: string
+			if (scope === "project") {
+				const workspacePath = getWorkspacePath()
+				if (workspacePath) {
+					rulesFolderPath = path.join(workspacePath, ".roo", `rules-${slug}`)
+				} else {
+					return // No workspace, can't delete project rules
+				}
+			} else {
+				// Global scope - use OS home directory
+				const homeDir = os.homedir()
+				rulesFolderPath = path.join(homeDir, ".roo", `rules-${slug}`)
+			}
+
+			// Check if the rules folder exists and delete it
+			const rulesFolderExists = await fileExistsAtPath(rulesFolderPath)
+			if (rulesFolderExists) {
+				try {
+					await fs.rm(rulesFolderPath, { recursive: true, force: true })
+					logger.info(`Deleted rules folder for mode ${slug}: ${rulesFolderPath}`)
+				} catch (error) {
+					logger.error(`Failed to delete rules folder for mode ${slug}: ${error}`)
+					// Continue even if folder deletion fails
+				}
+			}
+		} catch (error) {
+			logger.error(`Error deleting rules folder for mode ${slug}`, {
+				error: error instanceof Error ? error.message : String(error),
+			})
+		}
+	}
+
 	public async resetCustomModes(): Promise<void> {
 		try {
 			const filePath = await this.getCustomModesFilePath()

src/core/webview/webviewMessageHandler.ts

@@ -2238,6 +2238,12 @@ export const webviewMessageHandler = async (
 					})
 				} catch (error) {
 					console.error(`Error removing marketplace item: ${error}`)
+
+					// Show error message to user
+					vscode.window.showErrorMessage(
+						`Failed to remove marketplace item: ${error instanceof Error ? error.message : String(error)}`,
+					)
+
 					// Send error message to webview
 					provider.postMessageToWebview({
 						type: "marketplaceRemoveResult",

src/services/marketplace/SimpleInstaller.ts

@@ -2,7 +2,6 @@ import * as vscode from "vscode"
 import * as path from "path"
 import * as fs from "fs/promises"
 import * as yaml from "yaml"
-import * as os from "os"
 import type { MarketplaceItem, MarketplaceItemType, InstallMarketplaceItemOptions, McpParameter } from "@roo-code/types"
 import { GlobalFileNames } from "../../shared/globalFileNames"
 import { ensureSettingsDirectoryExists } from "../../utils/globalContext"
@@ -321,45 +320,8 @@ export class SimpleInstaller {
 			throw new Error("Mode missing slug identifier")
 		}
 
-		// Get the mode details before deletion to determine source and rules folder path
-		const customModes = await this.customModesManager.getCustomModes()
-		const modeToDelete = customModes.find((mode) => mode.slug === modeSlug)
-
-		// Use CustomModesManager to delete the mode configuration
+		// Use CustomModesManager to delete the mode configuration and associated rules folder
 		await this.customModesManager.deleteCustomMode(modeSlug)
-
-		// Handle rules folder deletion separately (similar to webviewMessageHandler)
-		if (modeToDelete) {
-			// Determine the scope based on source (project or global)
-			const scope = modeToDelete.source || "global"
-
-			// Determine the rules folder path
-			let rulesFolderPath: string
-			if (scope === "project") {
-				const workspaceFolder = vscode.workspace.workspaceFolders?.[0]
-				if (workspaceFolder) {
-					rulesFolderPath = path.join(workspaceFolder.uri.fsPath, ".roo", `rules-${modeSlug}`)
-				} else {
-					return // No workspace, can't delete project rules
-				}
-			} else {
-				// Global scope - use OS home directory
-				const homeDir = os.homedir()
-				rulesFolderPath = path.join(homeDir, ".roo", `rules-${modeSlug}`)
-			}
-
-			// Check if the rules folder exists and delete it
-			const rulesFolderExists = await fileExistsAtPath(rulesFolderPath)
-			if (rulesFolderExists) {
-				try {
-					await fs.rm(rulesFolderPath, { recursive: true, force: true })
-					console.log(`Deleted rules folder for mode ${modeSlug}: ${rulesFolderPath}`)
-				} catch (error) {
-					console.error(`Failed to delete rules folder for mode ${modeSlug}: ${error}`)
-					// Continue even if folder deletion fails
-				}
-			}
-		}
 	}
 
 	private async removeMcp(item: MarketplaceItem, target: "project" | "global"): Promise<void> {