PDF Reader MCP Server

import { describe, it, expect, vi, beforeEach, Mock } from 'vitest'; import { extractPagesTool, handleExtractPages } from './extract-pages.js'; import { TextExtractor } from '../services/text-extractor.js'; import { ExtractPagesParamsSchema } from '../types/mcp-types.js'; import { ValidationError } from '../utils/validation.js'; import { TestFixtures } from '../utils/test-helpers.js'; // Mock TextExtractor vi.mock('../services/text-extractor.js'); describe('Extract Pages Tool', () => { let mockTextExtractor: { extractFromPages: Mock; }; beforeEach(() => { mockTextExtractor = { extractFromPages: vi.fn() }; (TextExtractor as any).mockImplementation(() => mockTextExtractor); }); describe('Tool Definition', () => { it('should have correct MCP tool structure', () => { expect(extractPagesTool.name).toBe('extract_pdf_pages'); expect(extractPagesTool.description).toBe('Extract content from specific pages or page ranges of PDF documents'); expect(extractPagesTool.inputSchema).toBeDefined(); expect(extractPagesTool.inputSchema.type).toBe('object'); expect(extractPagesTool.inputSchema.required).toEqual(['file_path', 'page_range']); }); it('should define correct input schema properties', () => { const { properties } = extractPagesTool.inputSchema; expect(properties?.file_path).toEqual({ type: 'string', description: 'Path to the PDF file to extract pages from' }); expect(properties?.page_range).toEqual({ type: 'string', description: 'Page range to extract (e.g., "1-3", "2,4,6", or "all")' }); expect(properties?.output_format).toEqual({ type: 'string', description: 'Output format: "text" for plain text, "structured" for formatted text', enum: ['text', 'structured'], default: 'text' }); }); it('should follow MCP tool interface standards', () => { expect(extractPagesTool).toHaveProperty('name'); expect(extractPagesTool).toHaveProperty('description'); expect(extractPagesTool).toHaveProperty('inputSchema'); // Verify JSON Schema compliance expect(extractPagesTool.inputSchema.type).toBe('object'); expect(extractPagesTool.inputSchema).toHaveProperty('properties'); expect(extractPagesTool.inputSchema).toHaveProperty('required'); }); }); describe('Handler Function', () => { const mockPagesResult = { pages: [ { page_number: 1, content: 'First page content here...', word_count: 245 }, { page_number: 2, content: 'Second page content here...', word_count: 312 } ], total_pages_extracted: 2 }; it('should extract pages successfully with required parameters', async () => { mockTextExtractor.extractFromPages.mockResolvedValue(mockPagesResult); const args = { file_path: TestFixtures.SAMPLE_PDF(), page_range: '1-2' }; const result = await handleExtractPages(args); expect(TextExtractor).toHaveBeenCalled(); expect(mockTextExtractor.extractFromPages).toHaveBeenCalledWith( TestFixtures.SAMPLE_PDF(), '1-2', 'text' // default output_format ); expect(result).toEqual(mockPagesResult); }); it('should handle structured output format', async () => { mockTextExtractor.extractFromPages.mockResolvedValue(mockPagesResult); const args = { file_path: TestFixtures.SAMPLE_PDF(), page_range: '1,3,5', output_format: 'structured' as const }; await handleExtractPages(args); expect(mockTextExtractor.extractFromPages).toHaveBeenCalledWith( TestFixtures.SAMPLE_PDF(), '1,3,5', 'structured' ); }); it('should handle "all" page range', async () => { mockTextExtractor.extractFromPages.mockResolvedValue({ ...mockPagesResult, total_pages_extracted: 10 }); const args = { file_path: TestFixtures.SAMPLE_PDF(), page_range: 'all' }; const result = await handleExtractPages(args); expect(mockTextExtractor.extractFromPages).toHaveBeenCalledWith( TestFixtures.SAMPLE_PDF(), 'all', 'text' ); expect(result.total_pages_extracted).toBe(10); }); it('should validate input parameters using Zod schema', async () => { const invalidArgs = { file_path: TestFixtures.SAMPLE_PDF(), page_range: 123 // wrong type }; await expect(handleExtractPages(invalidArgs)).rejects.toThrow(); }); it('should require both file_path and page_range', async () => { const missingPageRange = { file_path: TestFixtures.SAMPLE_PDF() }; const missingFilePath = { page_range: '1-3' }; await expect(handleExtractPages(missingPageRange)).rejects.toThrow(); await expect(handleExtractPages(missingFilePath)).rejects.toThrow(); }); it('should handle processing errors with MCP error format', async () => { const processingError = new Error('Page extraction failed'); mockTextExtractor.extractFromPages.mockRejectedValue(processingError); const args = { file_path: TestFixtures.SAMPLE_PDF(), page_range: '1-3' }; try { await handleExtractPages(args); expect.fail('Should have thrown an error'); } catch (error) { expect(error).toBeInstanceOf(Error); // Verify MCP error format const errorData = JSON.parse((error as Error).message); expect(errorData).toHaveProperty('code'); expect(errorData).toHaveProperty('message'); expect(errorData).toHaveProperty('data'); } }); it('should handle validation errors for invalid page ranges', async () => { const validationError = new ValidationError('Invalid page range', 'INVALID_PAGE_RANGE'); mockTextExtractor.extractFromPages.mockRejectedValue(validationError); const args = { file_path: TestFixtures.SAMPLE_PDF(), page_range: '0-5' // invalid range }; await expect(handleExtractPages(args)).rejects.toThrow(); }); }); describe('Parameter Validation', () => { it('should accept valid page range formats', () => { const validParams = [ { file_path: '/test.pdf', page_range: 'all' }, { file_path: '/test.pdf', page_range: '1' }, { file_path: '/test.pdf', page_range: '1-5' }, { file_path: '/test.pdf', page_range: '1,3,5' }, { file_path: '/test.pdf', page_range: '1-2,4,6-8' } ]; validParams.forEach(params => { expect(() => ExtractPagesParamsSchema.parse(params)).not.toThrow(); }); }); it('should accept valid output formats', () => { const validParams = [ { file_path: '/test.pdf', page_range: '1-3', output_format: 'text' }, { file_path: '/test.pdf', page_range: '1-3', output_format: 'structured' } ]; validParams.forEach(params => { expect(() => ExtractPagesParamsSchema.parse(params)).not.toThrow(); }); }); it('should reject invalid output formats', () => { const invalidParams = { file_path: '/test.pdf', page_range: '1-3', output_format: 'invalid' }; expect(() => ExtractPagesParamsSchema.parse(invalidParams)).toThrow(); }); it('should apply default values correctly', () => { const minimalParams = { file_path: '/test.pdf', page_range: '1-3' }; const parsed = ExtractPagesParamsSchema.parse(minimalParams); expect(parsed.output_format).toBe('text'); }); it('should reject empty required fields', () => { const invalidParams = [ { file_path: '', page_range: '1-3' }, { file_path: '/test.pdf', page_range: '' }, { file_path: '', page_range: '' } ]; invalidParams.forEach(params => { expect(() => ExtractPagesParamsSchema.parse(params)).toThrow(); }); }); }); describe('Integration with MCP Standards', () => { it('should handle complex page extraction scenarios', async () => { const complexResult = { pages: [ { page_number: 1, content: 'Page 1', word_count: 100 }, { page_number: 5, content: 'Page 5', word_count: 150 }, { page_number: 7, content: 'Page 7', word_count: 200 }, { page_number: 8, content: 'Page 8', word_count: 175 } ], total_pages_extracted: 4 }; mockTextExtractor.extractFromPages.mockResolvedValue(complexResult); const args = { file_path: TestFixtures.COMPLEX_PDF(), page_range: '1,5,7-8', output_format: 'structured' as const }; const result = await handleExtractPages(args); expect(result.pages).toHaveLength(4); expect(result.total_pages_extracted).toBe(4); expect(result.pages[0].page_number).toBe(1); expect(result.pages[1].page_number).toBe(5); }); it('should preserve MCP error context in file path', async () => { const testError = new Error('Test error'); mockTextExtractor.extractFromPages.mockRejectedValue(testError); const args = { file_path: TestFixtures.SAMPLE_PDF(), page_range: '1-3' }; try { await handleExtractPages(args); expect.fail('Should have thrown an error'); } catch (error) { const errorData = JSON.parse((error as Error).message); expect(errorData.data.file_path).toBe(TestFixtures.SAMPLE_PDF()); } }); }); });