test: enhance dataset tests with vitest integration

- Added vitest imports to various dataset test files for improved testing capabilities.
- Ensured consistency in test structure across files by incorporating beforeEach, describe, expect, and it functions.

web/__tests__/datasets/create-dataset-flow.test.tsx

@@ -8,6 +8,7 @@
 import type { CustomFile } from '@/models/datasets'
 import type { RetrievalConfig } from '@/types/app'
 import { act, renderHook } from '@testing-library/react'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
 import { ChunkingMode, DataSourceType, ProcessMode } from '@/models/datasets'
 import { RETRIEVE_METHOD } from '@/types/app'
 
@@ -69,7 +70,7 @@ describe('Create Dataset Flow - Cross-Step Data Contract', () => {
       expect(result.current.segmentIdentifier).toBe(DEFAULT_SEGMENT_IDENTIFIER)
       expect(result.current.maxChunkLength).toBe(DEFAULT_MAXIMUM_CHUNK_LENGTH)
       expect(result.current.overlap).toBe(DEFAULT_OVERLAP)
-      expect(result.current.segmentationType).toBe(ProcessMode.general) // 'custom'
+      expect(result.current.segmentationType).toBe(ProcessMode.general)
     })
 
     it('should produce valid process rule for general chunking', () => {

web/__tests__/datasets/document-management.test.tsx

@@ -8,6 +8,7 @@
 
 import type { SimpleDocumentDetail } from '@/models/datasets'
 import { act, renderHook } from '@testing-library/react'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
 import { DataSourceType } from '@/models/datasets'
 
 const mockPush = vi.fn()

web/__tests__/datasets/external-knowledge-base.test.tsx

@@ -6,6 +6,7 @@
  */
 
 import type { CreateKnowledgeBaseReq } from '@/app/components/datasets/external-knowledge-base/create/declarations'
+import { describe, expect, it } from 'vitest'
 
 // --- Factory ---
 const createFormData = (overrides?: Partial<CreateKnowledgeBaseReq>): CreateKnowledgeBaseReq => ({

web/__tests__/datasets/segment-crud.test.tsx

@@ -7,6 +7,7 @@
 
 import type { SegmentDetailModel } from '@/models/datasets'
 import { act, renderHook } from '@testing-library/react'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
 import { useModalState } from '@/app/components/datasets/documents/detail/completed/hooks/use-modal-state'
 import { useSearchFilter } from '@/app/components/datasets/documents/detail/completed/hooks/use-search-filter'
 import { useSegmentSelection } from '@/app/components/datasets/documents/detail/completed/hooks/use-segment-selection'