fix: prevent save button from becoming inactive in Modes settings (#12283)

- Pass checkUnsaveChanges from SettingsView to ModesView so API config
  changes in the Modes tab prompt for unsaved changes before applying
- Remove auto-save of current config when switching to a mode without
  a saved config, preventing config bleed across modes
- Update tests to match new behavior

Author: roomote

src/core/webview/ClineProvider.ts

@@ -1463,16 +1463,10 @@ export class ClineProvider
 				// The task will continue with the current/default configuration.
 			}
 		} else {
-			// If no saved config for this mode, save current config as default.
-			const currentApiConfigNameAfter = this.getGlobalState("currentApiConfigName")
-
-			if (currentApiConfigNameAfter) {
-				const config = listApiConfig.find((c) => c.name === currentApiConfigNameAfter)
-
-				if (config?.id) {
-					await this.providerSettingsManager.setModeConfig(newMode, config.id)
-				}
-			}
+			// No saved config for this mode — leave the current config active
+			// without persisting it as the mode's default. This prevents config
+			// "bleed" where switching modes silently inherits and saves the
+			// previous mode's API configuration.
 		}
 
 		await this.postStateToWebview()

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

@@ -890,7 +890,7 @@ describe("ClineProvider", () => {
 		expect(mockContext.globalState.update).toHaveBeenCalledWith("currentApiConfigName", "test-config")
 	})
 
-	it("saves current config when switching to mode without config", async () => {
+	it("does not auto-save current config when switching to mode without config", async () => {
 		await provider.resolveWebviewView(mockWebviewView)
 		const messageHandler = (mockWebviewView.webview.onDidReceiveMessage as any).mock.calls[0][0]
 
@@ -907,8 +907,8 @@ describe("ClineProvider", () => {
 		// Switch to architect mode
 		await messageHandler({ type: "mode", text: "architect" })
 
-		// Should save current config as default for architect mode
-		expect(provider.providerSettingsManager.setModeConfig).toHaveBeenCalledWith("architect", "current-id")
+		// Should NOT auto-save current config as default for the new mode
+		expect(provider.providerSettingsManager.setModeConfig).not.toHaveBeenCalled()
 	})
 
 	it("saves config as default for current mode when loading config", async () => {
@@ -1483,7 +1483,7 @@ describe("ClineProvider", () => {
 			expect(mockPostMessage).toHaveBeenCalledWith(expect.objectContaining({ type: "state" }))
 		})
 
-		test("saves current config when switching to mode without config", async () => {
+		test("does not auto-save current config when switching to mode without config", async () => {
 			;(provider as any).providerSettingsManager = {
 				getModeConfigId: vi.fn().mockResolvedValue(undefined),
 				listConfig: vi
@@ -1506,8 +1506,8 @@ describe("ClineProvider", () => {
 			// Verify mode was updated
 			expect(mockContext.globalState.update).toHaveBeenCalledWith("mode", "architect")
 
-			// Verify current config was saved as default for new mode
-			expect(provider.providerSettingsManager.setModeConfig).toHaveBeenCalledWith("architect", "current-id")
+			// Should NOT auto-save current config as default for the new mode
+			expect(provider.providerSettingsManager.setModeConfig).not.toHaveBeenCalled()
 
 			// Verify state was posted to webview
 			expect(mockPostMessage).toHaveBeenCalledWith(expect.objectContaining({ type: "state" }))

webview-ui/src/components/modes/ModesView.tsx

@@ -63,7 +63,11 @@ function getGroupName(group: GroupEntry): ToolGroup {
 	return Array.isArray(group) ? group[0] : group
 }
 
-const ModesView = () => {
+interface ModesViewProps {
+	checkUnsaveChanges?: (then: () => void) => void
+}
+
+const ModesView = ({ checkUnsaveChanges }: ModesViewProps) => {
 	const { t } = useAppTranslation()
 
 	const {
@@ -913,10 +917,16 @@ const ModesView = () => {
 							<Select
 								value={currentApiConfigName}
 								onValueChange={(value) => {
-									vscode.postMessage({
-										type: "loadApiConfiguration",
-										text: value,
-									})
+									const doSwitch = () =>
+										vscode.postMessage({
+											type: "loadApiConfiguration",
+											text: value,
+										})
+									if (checkUnsaveChanges) {
+										checkUnsaveChanges(doSwitch)
+									} else {
+										doSwitch()
+									}
 								}}>
 								<SelectTrigger className="w-full">
 									<SelectValue placeholder={t("settings:common.select")} />

webview-ui/src/components/settings/SettingsView.tsx

@@ -867,7 +867,7 @@ const SettingsView = forwardRef<SettingsViewRef, SettingsViewProps>(({ onDone, t
 						)}
 
 						{/* Modes Section */}
-						{renderTab === "modes" && <ModesView />}
+						{renderTab === "modes" && <ModesView checkUnsaveChanges={checkUnsaveChanges} />}
 
 						{/* MCP Section */}
 						{renderTab === "mcp" && <McpView />}