chore: add integration tests for import/save route regression coverage

frontend/src/hooks/__tests__/useJSONImport.test.tsx

@@ -29,6 +29,86 @@ describe('useJSONImport', () => {
     vi.clearAllMocks()
   })
 
+  it('sets preview and sessionId after successful upload', async () => {
+    const uploadResponse = {
+      session: {
+        id: 'json-session-upload',
+        state: 'reviewing',
+        source: 'json',
+      },
+      preview: {
+        hosts: [],
+        conflicts: [],
+        errors: [],
+      },
+      conflict_details: {},
+    }
+
+    vi.mocked(api.uploadJSONExport).mockResolvedValue(uploadResponse)
+
+    const { result } = renderHook(() => useJSONImport(), { wrapper: createWrapper() })
+
+    await act(async () => {
+      await result.current.upload('{"proxy_hosts":[]}')
+    })
+
+    await waitFor(() => {
+      expect(result.current.sessionId).toBe('json-session-upload')
+      expect(result.current.preview).toEqual(uploadResponse)
+    })
+  })
+
+  it('commits active session and clears preview/session state', async () => {
+    const uploadResponse = {
+      session: {
+        id: 'json-session-commit',
+        state: 'reviewing',
+        source: 'json',
+      },
+      preview: {
+        hosts: [],
+        conflicts: [],
+        errors: [],
+      },
+      conflict_details: {},
+    }
+    const commitResponse = {
+      created: 1,
+      updated: 0,
+      skipped: 0,
+      errors: [],
+    }
+
+    vi.mocked(api.uploadJSONExport).mockResolvedValue(uploadResponse)
+    vi.mocked(api.commitJSONImport).mockResolvedValue(commitResponse)
+
+    const { result } = renderHook(() => useJSONImport(), { wrapper: createWrapper() })
+
+    await act(async () => {
+      await result.current.upload('{"proxy_hosts":[]}')
+    })
+
+    await waitFor(() => {
+      expect(result.current.sessionId).toBe('json-session-commit')
+    })
+
+    await act(async () => {
+      await result.current.commit({ 'json.example.com': 'replace' }, { 'json.example.com': 'JSON Example' })
+    })
+
+    expect(api.commitJSONImport).toHaveBeenCalledWith(
+      'json-session-commit',
+      { 'json.example.com': 'replace' },
+      { 'json.example.com': 'JSON Example' }
+    )
+
+    await waitFor(() => {
+      expect(result.current.sessionId).toBeNull()
+      expect(result.current.preview).toBeNull()
+      expect(result.current.commitResult).toEqual(commitResponse)
+    })
+  })
+
   it('passes active session UUID to cancelJSONImport', async () => {
     const sessionId = 'json-session-123'
     vi.mocked(api.uploadJSONExport).mockResolvedValue({
@@ -66,4 +146,45 @@ describe('useJSONImport', () => {
       expect(result.current.sessionId).toBeNull()
     })
   })
+
+  it('returns No active session and skips cancel API call when session is missing', async () => {
+    const { result } = renderHook(() => useJSONImport(), { wrapper: createWrapper() })
+
+    await expect(result.current.cancel()).rejects.toThrow('No active session')
+    expect(api.cancelJSONImport).not.toHaveBeenCalled()
+  })
+
+  it('exposes commit error and preserves session on commit failure', async () => {
+    const uploadResponse = {
+      session: {
+        id: 'json-session-error',
+        state: 'reviewing',
+        source: 'json',
+      },
+      preview: {
+        hosts: [],
+        conflicts: [],
+        errors: [],
+      },
+      conflict_details: {},
+    }
+    const commitError = new Error('404 Not Found')
+
+    vi.mocked(api.uploadJSONExport).mockResolvedValue(uploadResponse)
+    vi.mocked(api.commitJSONImport).mockRejectedValue(commitError)
+
+    const { result } = renderHook(() => useJSONImport(), { wrapper: createWrapper() })
+
+    await act(async () => {
+      await result.current.upload('{"proxy_hosts":[]}')
+    })
+
+    await expect(result.current.commit({}, {})).rejects.toBe(commitError)
+
+    await waitFor(() => {
+      expect(result.current.commitError).toBe(commitError)
+      expect(result.current.sessionId).toBe('json-session-error')
+      expect(result.current.preview).not.toBeNull()
+    })
+  })
 })