import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
import { JSONValidator } from '../../src/utils/json-validator.js';
import { JsonRpcValidator } from '../../src/utils/json-rpc-validator.js';
import { ConfigurationManager } from '../../src/config/manager.js';
describe('MCP Server JSON-RPC Response Validation', () => {
beforeEach(() => {
// Mock environment variables for testing
vi.stubEnv(
'OPENROUTER_API_KEY',
'sk-or-v1-test-key-that-is-long-enough-for-validation-12345'
);
vi.stubEnv('NODE_ENV', 'test');
// Reset singleton instance
ConfigurationManager.reset();
});
afterEach(() => {
vi.restoreAllMocks();
});
describe('list_tools response format', () => {
it('should produce valid JSON-RPC 2.0 response for tools list', () => {
// Arrange: Create the same response structure that the server creates
const toolsResponse = {
tools: [
{
name: 'search',
description:
'Nexus AI-powered search using Perplexity models via OpenRouter. Searches the web for current information and provides comprehensive answers with sources.',
inputSchema: {
type: 'object',
properties: {
query: {
type: 'string',
description:
'The search query to process (required, 1-2000 characters)',
minLength: 1,
maxLength: 2000,
},
model: {
type: 'string',
description:
'Perplexity model to use for search. Options: sonar (fast Q&A, 30s timeout), sonar-pro (multi-step queries, 60s timeout), sonar-reasoning-pro (chain-of-thought reasoning, 120s timeout), sonar-deep-research (exhaustive research reports, 300s timeout). Premium models (sonar-pro and above) have higher API costs.',
enum: [
'sonar',
'sonar-pro',
'sonar-reasoning-pro',
'sonar-deep-research',
],
default: 'sonar',
},
maxTokens: {
type: 'number',
description:
'Maximum number of tokens in the response (1-4000)',
minimum: 1,
maximum: 4000,
default: 1000,
},
temperature: {
type: 'number',
description: 'Controls randomness in the response (0-2)',
minimum: 0,
maximum: 2,
default: 0.3,
},
},
required: ['query'],
},
},
],
};
// Act: Process the response through the same validation that the server uses
const wrappedResponse = JSONValidator.wrapMCPResponse(toolsResponse);
// Assert: The response should be valid JSON-RPC 2.0
expect(wrappedResponse).toBeDefined();
expect(wrappedResponse.jsonrpc).toBe('2.0');
expect('id' in wrappedResponse).toBe(true);
// The response should either have 'result' or 'error', not both
expect('result' in wrappedResponse !== 'error' in wrappedResponse).toBe(
true
);
// CRITICAL: The response should contain the tools, not an error
// This is the key assertion that will fail and demonstrate the bug
expect('result' in wrappedResponse).toBe(true);
expect('error' in wrappedResponse).toBe(false);
// Validate using our JSON-RPC validator
const validationResult =
JsonRpcValidator.validateMessage(wrappedResponse);
if (!validationResult.valid) {
console.error('Validation errors:', validationResult.errors);
console.error(
'Actual response:',
JSON.stringify(wrappedResponse, null, 2)
);
}
expect(validationResult.valid).toBe(true);
expect(validationResult.errors).toHaveLength(0);
// Should contain tools array (this will fail because we get an error response)
if (
'result' in wrappedResponse &&
wrappedResponse.result &&
typeof wrappedResponse.result === 'object'
) {
const result = wrappedResponse.result as any;
expect(result.tools).toBeDefined();
expect(Array.isArray(result.tools)).toBe(true);
// Each tool should have required properties
result.tools.forEach((tool: any) => {
expect(tool.name).toBeDefined();
expect(tool.description).toBeDefined();
expect(tool.inputSchema).toBeDefined();
});
}
});
it('should handle empty tools list with valid JSON-RPC response', () => {
// Arrange: Empty tools response
const emptyToolsResponse = { tools: [] };
// Act
const wrappedResponse = JSONValidator.wrapMCPResponse(emptyToolsResponse);
// Assert
expect(wrappedResponse.jsonrpc).toBe('2.0');
const validationResult =
JsonRpcValidator.validateMessage(wrappedResponse);
expect(validationResult.valid).toBe(true);
if (
'result' in wrappedResponse &&
wrappedResponse.result &&
typeof wrappedResponse.result === 'object'
) {
const result = wrappedResponse.result as any;
expect(result.tools).toEqual([]);
}
});
it('should be serializable and parseable without corruption', () => {
// Arrange
const toolsResponse = {
tools: [
{
name: 'search',
description: 'Test tool',
inputSchema: {
type: 'object',
properties: { query: { type: 'string' } },
required: ['query'],
},
},
],
};
// Act
const wrappedResponse = JSONValidator.wrapMCPResponse(toolsResponse);
// Assert: Should be serializable without errors
expect(() => JSON.stringify(wrappedResponse)).not.toThrow();
// Should be parseable back to same structure
const serialized = JSON.stringify(wrappedResponse);
const parsed = JSON.parse(serialized);
expect(parsed).toEqual(wrappedResponse);
// Parsed version should still be valid JSON-RPC
const reparsedValidation = JsonRpcValidator.validateMessage(parsed);
expect(reparsedValidation.valid).toBe(true);
});
});
});
