Local RAG

// DocumentChunker Unit Test - Test error propagation for Fail-fast principle // Created: 2025-10-31 // Purpose: Verify proper error handling in chunking process import { beforeEach, describe, expect, it, vi } from 'vitest' import { DocumentChunker } from '../index.js' describe('DocumentChunker', () => { let chunker: DocumentChunker beforeEach(async () => { chunker = new DocumentChunker({ chunkSize: 512, chunkOverlap: 100, }) await chunker.initialize() }) // -------------------------------------------- // Normal Case: Successful chunking // -------------------------------------------- describe('Normal chunking behavior', () => { it('should split text into chunks successfully', async () => { const text = 'This is a test. '.repeat(50) // ~800 characters const chunks = await chunker.chunkText(text) expect(chunks).toBeDefined() expect(Array.isArray(chunks)).toBe(true) expect(chunks.length).toBeGreaterThan(0) // Verify chunk structure for (const chunk of chunks) { expect(chunk).toHaveProperty('text') expect(chunk).toHaveProperty('index') expect(typeof chunk.text).toBe('string') expect(typeof chunk.index).toBe('number') } }) it('should return empty array for empty string (valid empty input)', async () => { const chunks = await chunker.chunkText('') expect(chunks).toBeDefined() expect(Array.isArray(chunks)).toBe(true) expect(chunks.length).toBe(0) }) }) // -------------------------------------------- // Error Case: RecursiveCharacterTextSplitter failure // RED PHASE: This test should FAIL with current implementation // Current behavior: chunkText() catches error and returns [] // Expected behavior: chunkText() should propagate error // -------------------------------------------- describe('Error propagation (Fail-fast principle)', () => { it('should propagate error when RecursiveCharacterTextSplitter.splitText() fails', async () => { // Mock the splitter to throw an error const mockError = new Error('RecursiveCharacterTextSplitter failure') const mockSplitter = { splitText: vi.fn().mockRejectedValue(mockError), } // Replace the internal splitter with our mock // @ts-expect-error - accessing private property for testing chunker['splitter'] = mockSplitter // Act & Assert: Verify error is propagated (not caught and converted to []) await expect(chunker.chunkText('test input')).rejects.toThrow( 'RecursiveCharacterTextSplitter failure' ) // Verify splitText was called expect(mockSplitter.splitText).toHaveBeenCalledWith('test input') }) it('should not initialize without calling initialize()', async () => { const uninitializedChunker = new DocumentChunker({ chunkSize: 512, chunkOverlap: 100, }) // Should throw error when trying to chunk without initialization await expect(uninitializedChunker.chunkText('test')).rejects.toThrow( 'DocumentChunker not initialized' ) }) }) })