integration-tests/simple-mcp-server.test.js

/**
 * @license
 * Copyright 2025 Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */

import { test, describe, before, after } from 'node:test';
import { strict as assert } from 'node:assert';
import { TestRig } from './test-helper.js';
import { spawn } from 'child_process';
import { join } from 'path';
import { fileURLToPath } from 'url';
import { writeFileSync, unlinkSync } from 'fs';

const __dirname = fileURLToPath(new URL('.', import.meta.url));
const serverScriptPath = join(__dirname, './temp-server.js');

const serverScript = `
import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
import { StdioServerTransport } from '@modelcontextprotocol/sdk/server/stdio.js';
import { z } from 'zod';

const server = new McpServer({
  name: 'addition-server',
  version: '1.0.0',
});

server.registerTool(
  'add',
  {
    title: 'Addition Tool',
    description: 'Add two numbers',
    inputSchema: { a: z.number(), b: z.number() },
  },
  async ({ a, b }) => ({
    content: [{ type: 'text', text: String(a + b) }],
  }),
);

const transport = new StdioServerTransport();
await server.connect(transport);
`;

describe('simple-mcp-server', () => {
  const rig = new TestRig();
  let child;

  before(() => {
    writeFileSync(serverScriptPath, serverScript);
    child = spawn('node', [serverScriptPath], {
      stdio: ['pipe', 'pipe', 'pipe'],
    });
    child.stderr.on('data', (data) => {
      console.error(`stderr: ${data}`);
    });
    // Wait for the server to be ready
    return new Promise((resolve) => setTimeout(resolve, 500));
  });

  after(() => {
    child.kill();
    unlinkSync(serverScriptPath);
  });

  test('should add two numbers', () => {
    rig.setup('should add two numbers');
    const output = rig.run('add 5 and 10');
    assert.ok(output.includes('15'));
  });
});