From b281b931f5ceff213a4a8f7156f99ee6df1d58dc Mon Sep 17 00:00:00 2001
From: SSU-WEI HUANG <stanley.yellow1@gmail.com>
Date: Wed, 29 Jul 2026 10:02:46 +0800
Subject: [PATCH] fix(web): prevent duplicate session creation (#1222)

---
 web/src/components/NewSession/index.test.tsx | 33 +++++++++++++++++++-
 web/src/components/NewSession/index.tsx      | 13 ++++++--
 2 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/web/src/components/NewSession/index.test.tsx b/web/src/components/NewSession/index.test.tsx
index 08283b5f..c7685fed 100644
--- a/web/src/components/NewSession/index.test.tsx
+++ b/web/src/components/NewSession/index.test.tsx
@@ -13,6 +13,7 @@ const mocks = vi.hoisted(() => ({
     spawnSession: vi.fn(),
     onSuccess: vi.fn(),
     notification: vi.fn(),
+    checkPathsExists: vi.fn(),
     codexModelsLoading: false,
     directoryExists: undefined as boolean | undefined
 }))
@@ -44,7 +45,7 @@ vi.mock('@/hooks/useRecentPaths', () => ({
 vi.mock('@/hooks/useMachinePathsExists', () => ({
     useMachinePathsExists: () => ({
         pathExistence: { 'C:\\repo': mocks.directoryExists },
-        checkPathsExists: async () => ({ 'C:\\repo': mocks.directoryExists })
+        checkPathsExists: mocks.checkPathsExists
     })
 }))
 vi.mock('@/hooks/useDirectorySuggestions', () => ({
@@ -152,6 +153,8 @@ describe('NewSession launch preferences', () => {
         mocks.spawnSession.mockReset()
         mocks.onSuccess.mockReset()
         mocks.notification.mockReset()
+        mocks.checkPathsExists.mockReset()
+        mocks.checkPathsExists.mockImplementation(async () => ({ 'C:\\repo': mocks.directoryExists }))
         mocks.codexModelsLoading = false
         mocks.directoryExists = true
         savePreferredAgent('codex')
@@ -276,6 +279,34 @@ describe('NewSession launch preferences', () => {
         })
     })
 
+    it('spawns only once when Create is activated twice during directory validation', async () => {
+        let finishDirectoryCheck!: (result: Record<string, boolean>) => void
+        mocks.checkPathsExists.mockReturnValue(new Promise((resolve) => {
+            finishDirectoryCheck = resolve
+        }))
+        mocks.spawnSession.mockResolvedValue({ type: 'success', sessionId: 'session-1' })
+
+        render(
+            <NewSession
+                api={api}
+                machines={[machine]}
+                initialMachineId="machine-1"
+                initialDirectory="C:\\repo"
+                onSuccess={mocks.onSuccess}
+                onCancel={() => {}}
+            />
+        )
+
+        const create = screen.getByTestId('create')
+        fireEvent.click(create)
+        fireEvent.click(create)
+        finishDirectoryCheck({ 'C:\\repo': true })
+
+        await waitFor(() => expect(mocks.onSuccess).toHaveBeenCalledWith('session-1'))
+        expect(mocks.checkPathsExists).toHaveBeenCalledTimes(1)
+        expect(mocks.spawnSession).toHaveBeenCalledTimes(1)
+    })
+
     it('does not save changed launch settings when creation fails', async () => {
         mocks.spawnSession.mockResolvedValue({ type: 'error', message: 'spawn failed' })
 
diff --git a/web/src/components/NewSession/index.tsx b/web/src/components/NewSession/index.tsx
index 7fde36b2..8d4d8c91 100644
--- a/web/src/components/NewSession/index.tsx
+++ b/web/src/components/NewSession/index.tsx
@@ -147,7 +147,9 @@ export function NewSession(props: {
     const [codexImportError, setCodexImportError] = useState<string | null>(null)
     const [isImportingCodexSession, setIsImportingCodexSession] = useState(false)
     const [isCodexImportDialogOpen, setIsCodexImportDialogOpen] = useState(false)
-    const isFormDisabled = Boolean(isPending || props.isLoading || isImportingCodexSession)
+    const [isCreating, setIsCreating] = useState(false)
+    const createInFlightRef = useRef(false)
+    const isFormDisabled = Boolean(isCreating || isPending || props.isLoading || isImportingCodexSession)
     const worktreeInputRef = useRef<HTMLInputElement>(null)
     const preserveRestoredDraftRef = useRef(false)
 
@@ -877,8 +879,10 @@ export function NewSession(props: {
     }, [suggestions, selectedIndex, moveUp, moveDown, clearSuggestions, handleSuggestionSelect])
 
     async function handleCreate() {
-        if (!machineId || !trimmedDirectory) return
+        if (!machineId || !trimmedDirectory || createInFlightRef.current) return
 
+        createInFlightRef.current = true
+        setIsCreating(true)
         setError(null)
         try {
             const existsResult = await checkPathsExists([trimmedDirectory])
@@ -998,6 +1002,9 @@ export function NewSession(props: {
             setIsImportingCodexSession(false)
             haptic.notification('error')
             setError(e instanceof Error ? e.message : 'Failed to create session')
+        } finally {
+            createInFlightRef.current = false
+            setIsCreating(false)
         }
     }
 
@@ -1217,7 +1224,7 @@ export function NewSession(props: {
             ) : null}
 
             <ActionButtons
-                isPending={isPending || isImportingCodexSession}
+                isPending={isCreating || isPending || isImportingCodexSession}
                 canCreate={canCreate}
                 isDisabled={isFormDisabled}
                 createLabel={createLabel}