mcp-graphql-forge

import { describe, it, expect, beforeAll, afterAll } from 'vitest'; import { GraphQLClient } from 'graphql-request'; import { generateMCPToolsFromSchema, MCPTool } from '../tool-generator.js'; import { introspectGraphQLSchema } from '../introspect.js'; import { createMockGraphQLService } from './fixtures/mock-graphql-service.js'; // Mock MCP Server class for testing class TestGraphQLMCPServer { private graphqlClient: GraphQLClient; private tools: MCPTool[] = []; constructor(graphqlEndpoint: string) { this.graphqlClient = new GraphQLClient(graphqlEndpoint); } async loadTools() { const introspectionResult = await introspectGraphQLSchema({ endpoint: this.graphqlClient.url }); this.tools = generateMCPToolsFromSchema(introspectionResult); } private executeCall(tool: MCPTool, args: any) { const query = this.buildGraphQLOperation(tool._graphql!, args); return this.graphqlClient.request(query, args); } private buildGraphQLOperation(graphqlInfo: NonNullable<MCPTool['_graphql']>): string { const { fieldName, operationType, args, fieldSelection } = graphqlInfo; const variableDeclarations = args .map(arg => `$${arg.name}: ${arg.type}`) .join(', '); const variableUsage = args .map(arg => `${arg.name}: $${arg.name}`) .join(', '); const operation = ` ${operationType} ${fieldName}Operation${variableDeclarations ? `(${variableDeclarations})` : ''} { ${fieldName}${variableUsage ? `(${variableUsage})` : ''} ${fieldSelection} } `; return operation.trim(); } // Test helper methods async callTool(toolName: string, args: any = {}) { const tool = this.tools.find(t => t.name === toolName); if (!tool || !tool._graphql) { return { content: [ { type: 'text', text: `Unknown tool: ${toolName}` } ], isError: true }; } try { const result = await this.executeCall(tool, args); return { content: [ { type: 'text', text: JSON.stringify(result, null, 2) } ] }; } catch (error) { const errorMessage = error instanceof Error ? error.message : 'Unknown error'; return { content: [ { type: 'text', text: `Error executing ${toolName}: ${errorMessage}` } ], isError: true }; } } async listTools() { return { tools: this.tools }; } getTools() { return this.tools; } } describe('MCP Server Execution Tests', () => { const mockServer = createMockGraphQLService(4003); let mcpServer: TestGraphQLMCPServer; beforeAll(async () => { await mockServer.start(); mcpServer = new TestGraphQLMCPServer(mockServer.url); await mcpServer.loadTools(); }); afterAll(async () => { await mockServer.stop(); }); describe('Tool Generation and Structure', () => { it('should generate tools with proper GraphQL metadata', async () => { const tools = mcpServer.getTools(); expect(tools.length).toBeGreaterThan(0); // Check that tools have _graphql metadata tools.forEach(tool => { expect(tool._graphql).toBeDefined(); expect(tool._graphql?.fieldName).toBeDefined(); expect(tool._graphql?.operationType).toMatch(/^(query|mutation)$/); expect(tool._graphql?.args).toBeDefined(); expect(tool._graphql?.fieldSelection).toBeDefined(); }); }); it('should generate proper field selections for complex types', async () => { const tools = mcpServer.getTools(); const userTool = tools.find(t => t.name === 'query_user'); expect(userTool?._graphql?.fieldSelection).toContain('id'); expect(userTool?._graphql?.fieldSelection).toContain('name'); expect(userTool?._graphql?.fieldSelection).toContain('email'); expect(userTool?._graphql?.fieldSelection).toContain('role'); }); }); describe('Query Tool Execution', () => { it('should execute query_user tool successfully', async () => { const result = await mcpServer.callTool('query_user', { id: '1' }); expect(result).toBeDefined(); expect(result.content).toBeDefined(); expect(result.content[0].type).toBe('text'); const data = JSON.parse(result.content[0].text); expect(data.user).toBeDefined(); expect(data.user.id).toBe('1'); expect(data.user.name).toBe('Alice'); expect(data.user.email).toBe('alice@example.com'); }); it('should execute query_users tool successfully', async () => { const result = await mcpServer.callTool('query_users', { limit: 2, offset: 0 }); expect(result).toBeDefined(); expect(result.content).toBeDefined(); expect(result.content[0].type).toBe('text'); const data = JSON.parse(result.content[0].text); expect(data.users).toBeDefined(); expect(Array.isArray(data.users)).toBe(true); expect(data.users.length).toBe(2); expect(data.users[0].name).toBe('Alice'); expect(data.users[1].name).toBe('Bob'); }); it('should handle query_users with no parameters', async () => { const result = await mcpServer.callTool('query_users', {}); expect(result).toBeDefined(); expect(result.content).toBeDefined(); const data = JSON.parse(result.content[0].text); expect(data.users).toBeDefined(); expect(Array.isArray(data.users)).toBe(true); }); }); describe('Mutation Tool Execution', () => { it('should execute mutation_createUser tool successfully', async () => { const newUserInput = { name: 'Charlie', email: 'charlie@example.com', role: 'USER' }; const result = await mcpServer.callTool('mutation_createUser', { input: newUserInput }); expect(result).toBeDefined(); expect(result.content).toBeDefined(); expect(result.content[0].type).toBe('text'); const data = JSON.parse(result.content[0].text); expect(data.createUser).toBeDefined(); expect(data.createUser.name).toBe('Charlie'); expect(data.createUser.email).toBe('charlie@example.com'); expect(data.createUser.role).toBe('USER'); expect(data.createUser.id).toBeDefined(); }); }); describe('Error Handling', () => { it('should handle unknown tool names gracefully', async () => { const result = await mcpServer.callTool('unknown_tool', {}); expect(result).toBeDefined(); expect(result.content).toBeDefined(); expect(result.content[0].text).toContain('Unknown tool: unknown_tool'); expect(result.isError).toBe(true); }); it('should handle missing required parameters', async () => { // Try to call query_user without required id parameter const result = await mcpServer.callTool('query_user', {}); expect(result).toBeDefined(); expect(result.content).toBeDefined(); if (result.isError) { expect(result.content[0].text).toContain('Error executing query_user'); } else { const data = JSON.parse(result.content[0].text); expect(data.user).toBeNull(); } }); }); describe('GraphQL Query Generation', () => { it('should generate valid GraphQL queries with proper types', async () => { const tools = mcpServer.getTools(); // Check user query tool const userTool = tools.find(t => t.name === 'query_user'); expect(userTool?._graphql?.args[0].name).toBe('id'); // Check users query tool const usersTool = tools.find(t => t.name === 'query_users'); expect(usersTool?._graphql?.args.some(arg => arg.name === 'limit')).toBe(true); expect(usersTool?._graphql?.args.some(arg => arg.name === 'offset')).toBe(true); // Check createUser mutation tool const createUserTool = tools.find(t => t.name === 'mutation_createUser'); expect(createUserTool?._graphql?.args[0].name).toBe('input'); }); it('should include all available fields in field selections', async () => { const tools = mcpServer.getTools(); const userTool = tools.find(t => t.name === 'query_user'); const fieldSelection = userTool?._graphql?.fieldSelection || ''; // Should include all User fields expect(fieldSelection).toContain('id'); expect(fieldSelection).toContain('name'); expect(fieldSelection).toContain('email'); expect(fieldSelection).toContain('role'); // Should be properly formatted expect(fieldSelection).toMatch(/\{[\s\S]*\}/); // Contains braces }); }); describe('Tool List Functionality', () => { it('should list all available tools', async () => { const result = await mcpServer.listTools(); expect(result).toBeDefined(); expect(result.tools).toBeDefined(); expect(Array.isArray(result.tools)).toBe(true); expect(result.tools.length).toBeGreaterThan(0); // Should have both query and mutation tools const queryTools = result.tools.filter((t: any) => t.name.startsWith('query_')); const mutationTools = result.tools.filter((t: any) => t.name.startsWith('mutation_')); expect(queryTools.length).toBeGreaterThan(0); expect(mutationTools.length).toBeGreaterThan(0); }); it('should provide proper tool schemas', async () => { const result = await mcpServer.listTools(); result.tools.forEach((tool: any) => { expect(tool.name).toBeDefined(); expect(tool.description).toBeDefined(); expect(tool.inputSchema).toBeDefined(); expect(tool.inputSchema.type).toBe('object'); expect(tool.inputSchema.properties).toBeDefined(); }); }); }); });