index.test.ts

/* eslint-disable @typescript-eslint/no-unused-vars */
/* eslint-disable no-constant-binary-expression */
/* eslint-disable @typescript-eslint/no-unused-expressions */
import { Client, getSupportedElicitationModes } from '../../src/client/index.js';
import {
    RequestSchema,
    NotificationSchema,
    ResultSchema,
    LATEST_PROTOCOL_VERSION,
    SUPPORTED_PROTOCOL_VERSIONS,
    InitializeRequestSchema,
    ListResourcesRequestSchema,
    ListToolsRequestSchema,
    ListToolsResultSchema,
    ListPromptsRequestSchema,
    CallToolRequestSchema,
    CallToolResultSchema,
    CreateMessageRequestSchema,
    ElicitRequestSchema,
    ElicitResultSchema,
    ListRootsRequestSchema,
    ErrorCode,
    McpError,
    CreateTaskResultSchema,
    Tool,
    Prompt,
    Resource
} from '../../src/types.js';
import { Transport } from '../../src/shared/transport.js';
import { Server } from '../../src/server/index.js';
import { McpServer } from '../../src/server/mcp.js';
import { InMemoryTransport } from '../../src/inMemory.js';
import { InMemoryTaskStore } from '../../src/experimental/tasks/stores/in-memory.js';
import * as z3 from 'zod/v3';
import * as z4 from 'zod/v4';

describe('Zod v4', () => {
    /***
     * Test: Type Checking
     * Test that custom request/notification/result schemas can be used with the Client class.
     */
    test('should typecheck', () => {
        const GetWeatherRequestSchema = RequestSchema.extend({
            method: z4.literal('weather/get'),
            params: z4.object({
                city: z4.string()
            })
        });

        const GetForecastRequestSchema = RequestSchema.extend({
            method: z4.literal('weather/forecast'),
            params: z4.object({
                city: z4.string(),
                days: z4.number()
            })
        });

        const WeatherForecastNotificationSchema = NotificationSchema.extend({
            method: z4.literal('weather/alert'),
            params: z4.object({
                severity: z4.enum(['warning', 'watch']),
                message: z4.string()
            })
        });

        const WeatherRequestSchema = GetWeatherRequestSchema.or(GetForecastRequestSchema);
        const WeatherNotificationSchema = WeatherForecastNotificationSchema;
        const WeatherResultSchema = ResultSchema.extend({
            temperature: z4.number(),
            conditions: z4.string()
        });

        type WeatherRequest = z4.infer<typeof WeatherRequestSchema>;
        type WeatherNotification = z4.infer<typeof WeatherNotificationSchema>;
        type WeatherResult = z4.infer<typeof WeatherResultSchema>;

        // Create a typed Client for weather data
        const weatherClient = new Client<WeatherRequest, WeatherNotification, WeatherResult>(
            {
                name: 'WeatherClient',
                version: '1.0.0'
            },
            {
                capabilities: {
                    sampling: {}
                }
            }
        );

        // Typecheck that only valid weather requests/notifications/results are allowed
        false &&
            weatherClient.request(
                {
                    method: 'weather/get',
                    params: {
                        city: 'Seattle'
                    }
                },
                WeatherResultSchema
            );

        false &&
            weatherClient.notification({
                method: 'weather/alert',
                params: {
                    severity: 'warning',
                    message: 'Storm approaching'
                }
            });
    });
});

describe('Zod v3', () => {
    /***
     * Test: Type Checking
     * Test that custom request/notification/result schemas can be used with the Client class.
     */
    test('should typecheck', () => {
        const GetWeatherRequestSchema = z3.object({
            ...RequestSchema.shape,
            method: z3.literal('weather/get'),
            params: z3.object({
                city: z3.string()
            })
        });

        const GetForecastRequestSchema = z3.object({
            ...RequestSchema.shape,
            method: z3.literal('weather/forecast'),
            params: z3.object({
                city: z3.string(),
                days: z3.number()
            })
        });

        const WeatherForecastNotificationSchema = z3.object({
            ...NotificationSchema.shape,
            method: z3.literal('weather/alert'),
            params: z3.object({
                severity: z3.enum(['warning', 'watch']),
                message: z3.string()
            })
        });

        const WeatherRequestSchema = GetWeatherRequestSchema.or(GetForecastRequestSchema);
        const WeatherNotificationSchema = WeatherForecastNotificationSchema;
        const WeatherResultSchema = z3.object({
            ...ResultSchema.shape,
            _meta: z3.record(z3.string(), z3.unknown()).optional(),
            temperature: z3.number(),
            conditions: z3.string()
        });

        type WeatherRequest = z3.infer<typeof WeatherRequestSchema>;
        type WeatherNotification = z3.infer<typeof WeatherNotificationSchema>;
        type WeatherResult = z3.infer<typeof WeatherResultSchema>;

        // Create a typed Client for weather data
        const weatherClient = new Client<WeatherRequest, WeatherNotification, WeatherResult>(
            {
                name: 'WeatherClient',
                version: '1.0.0'
            },
            {
                capabilities: {
                    sampling: {}
                }
            }
        );

        // Typecheck that only valid weather requests/notifications/results are allowed
        false &&
            weatherClient.request(
                {
                    method: 'weather/get',
                    params: {
                        city: 'Seattle'
                    }
                },
                WeatherResultSchema
            );

        false &&
            weatherClient.notification({
                method: 'weather/alert',
                params: {
                    severity: 'warning',
                    message: 'Storm approaching'
                }
            });
    });
});

/***
 * Test: Initialize with Matching Protocol Version
 */
test('should initialize with matching protocol version', async () => {
    const clientTransport: Transport = {
        start: vi.fn().mockResolvedValue(undefined),
        close: vi.fn().mockResolvedValue(undefined),
        send: vi.fn().mockImplementation(message => {
            if (message.method === 'initialize') {
                clientTransport.onmessage?.({
                    jsonrpc: '2.0',
                    id: message.id,
                    result: {
                        protocolVersion: LATEST_PROTOCOL_VERSION,
                        capabilities: {},
                        serverInfo: {
                            name: 'test',
                            version: '1.0'
                        },
                        instructions: 'test instructions'
                    }
                });
            }
            return Promise.resolve();
        })
    };

    const client = new Client(
        {
            name: 'test client',
            version: '1.0'
        },
        {
            capabilities: {
                sampling: {}
            }
        }
    );

    await client.connect(clientTransport);

    // Should have sent initialize with latest version
    expect(clientTransport.send).toHaveBeenCalledWith(
        expect.objectContaining({
            method: 'initialize',
            params: expect.objectContaining({
                protocolVersion: LATEST_PROTOCOL_VERSION
            })
        }),
        expect.objectContaining({
            relatedRequestId: undefined
        })
    );

    // Should have the instructions returned
    expect(client.getInstructions()).toEqual('test instructions');
});

/***
 * Test: Initialize with Supported Older Protocol Version
 */
test('should initialize with supported older protocol version', async () => {
    const OLD_VERSION = SUPPORTED_PROTOCOL_VERSIONS[1];
    const clientTransport: Transport = {
        start: vi.fn().mockResolvedValue(undefined),
        close: vi.fn().mockResolvedValue(undefined),
        send: vi.fn().mockImplementation(message => {
            if (message.method === 'initialize') {
                clientTransport.onmessage?.({
                    jsonrpc: '2.0',
                    id: message.id,
                    result: {
                        protocolVersion: OLD_VERSION,
                        capabilities: {},
                        serverInfo: {
                            name: 'test',
                            version: '1.0'
                        }
                    }
                });
            }
            return Promise.resolve();
        })
    };

    const client = new Client(
        {
            name: 'test client',
            version: '1.0'
        },
        {
            capabilities: {
                sampling: {}
            }
        }
    );

    await client.connect(clientTransport);

    // Connection should succeed with the older version
    expect(client.getServerVersion()).toEqual({
        name: 'test',
        version: '1.0'
    });

    // Expect no instructions
    expect(client.getInstructions()).toBeUndefined();
});

/***
 * Test: Reject Unsupported Protocol Version
 */
test('should reject unsupported protocol version', async () => {
    const clientTransport: Transport = {
        start: vi.fn().mockResolvedValue(undefined),
        close: vi.fn().mockResolvedValue(undefined),
        send: vi.fn().mockImplementation(message => {
            if (message.method === 'initialize') {
                clientTransport.onmessage?.({
                    jsonrpc: '2.0',
                    id: message.id,
                    result: {
                        protocolVersion: 'invalid-version',
                        capabilities: {},
                        serverInfo: {
                            name: 'test',
                            version: '1.0'
                        }
                    }
                });
            }
            return Promise.resolve();
        })
    };

    const client = new Client(
        {
            name: 'test client',
            version: '1.0'
        },
        {
            capabilities: {
                sampling: {}
            }
        }
    );

    await expect(client.connect(clientTransport)).rejects.toThrow("Server's protocol version is not supported: invalid-version");

    expect(clientTransport.close).toHaveBeenCalled();
});

/***
 * Test: Connect New Client to Old Supported Server Version
 */
test('should connect new client to old, supported server version', async () => {
    const OLD_VERSION = SUPPORTED_PROTOCOL_VERSIONS[1];
    const server = new Server(
        {
            name: 'test server',
            version: '1.0'
        },
        {
            capabilities: {
                resources: {},
                tools: {}
            }
        }
    );

    server.setRequestHandler(InitializeRequestSchema, _request => ({
        protocolVersion: OLD_VERSION,
        capabilities: {
            resources: {},
            tools: {}
        },
        serverInfo: {
            name: 'old server',
            version: '1.0'
        }
    }));

    server.setRequestHandler(ListResourcesRequestSchema, () => ({
        resources: []
    }));

    server.setRequestHandler(ListToolsRequestSchema, () => ({
        tools: []
    }));

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    const client = new Client(
        {
            name: 'new client',
            version: '1.0'
        },
        {
            capabilities: {
                sampling: {}
            },
            enforceStrictCapabilities: true
        }
    );

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    expect(client.getServerVersion()).toEqual({
        name: 'old server',
        version: '1.0'
    });
});

/***
 * Test: Version Negotiation with Old Client and Newer Server
 */
test('should negotiate version when client is old, and newer server supports its version', async () => {
    const OLD_VERSION = SUPPORTED_PROTOCOL_VERSIONS[1];
    const server = new Server(
        {
            name: 'new server',
            version: '1.0'
        },
        {
            capabilities: {
                resources: {},
                tools: {}
            }
        }
    );

    server.setRequestHandler(InitializeRequestSchema, _request => ({
        protocolVersion: LATEST_PROTOCOL_VERSION,
        capabilities: {
            resources: {},
            tools: {}
        },
        serverInfo: {
            name: 'new server',
            version: '1.0'
        }
    }));

    server.setRequestHandler(ListResourcesRequestSchema, () => ({
        resources: []
    }));

    server.setRequestHandler(ListToolsRequestSchema, () => ({
        tools: []
    }));

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    const client = new Client(
        {
            name: 'old client',
            version: '1.0'
        },
        {
            capabilities: {
                sampling: {}
            },
            enforceStrictCapabilities: true
        }
    );

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    expect(client.getServerVersion()).toEqual({
        name: 'new server',
        version: '1.0'
    });
});

/***
 * Test: Throw when Old Client and Server Version Mismatch
 */
test("should throw when client is old, and server doesn't support its version", async () => {
    const OLD_VERSION = SUPPORTED_PROTOCOL_VERSIONS[1];
    const FUTURE_VERSION = 'FUTURE_VERSION';
    const server = new Server(
        {
            name: 'new server',
            version: '1.0'
        },
        {
            capabilities: {
                resources: {},
                tools: {}
            }
        }
    );

    server.setRequestHandler(InitializeRequestSchema, _request => ({
        protocolVersion: FUTURE_VERSION,
        capabilities: {
            resources: {},
            tools: {}
        },
        serverInfo: {
            name: 'new server',
            version: '1.0'
        }
    }));

    server.setRequestHandler(ListResourcesRequestSchema, () => ({
        resources: []
    }));

    server.setRequestHandler(ListToolsRequestSchema, () => ({
        tools: []
    }));

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    const client = new Client(
        {
            name: 'old client',
            version: '1.0'
        },
        {
            capabilities: {
                sampling: {}
            },
            enforceStrictCapabilities: true
        }
    );

    await Promise.all([
        expect(client.connect(clientTransport)).rejects.toThrow("Server's protocol version is not supported: FUTURE_VERSION"),
        server.connect(serverTransport)
    ]);
});

/***
 * Test: Respect Server Capabilities
 */
test('should respect server capabilities', async () => {
    const server = new Server(
        {
            name: 'test server',
            version: '1.0'
        },
        {
            capabilities: {
                resources: {},
                tools: {}
            }
        }
    );

    server.setRequestHandler(InitializeRequestSchema, _request => ({
        protocolVersion: LATEST_PROTOCOL_VERSION,
        capabilities: {
            resources: {},
            tools: {}
        },
        serverInfo: {
            name: 'test',
            version: '1.0'
        }
    }));

    server.setRequestHandler(ListResourcesRequestSchema, () => ({
        resources: []
    }));

    server.setRequestHandler(ListToolsRequestSchema, () => ({
        tools: []
    }));

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    const client = new Client(
        {
            name: 'test client',
            version: '1.0'
        },
        {
            capabilities: {
                sampling: {}
            },
            enforceStrictCapabilities: true
        }
    );

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    // Server supports resources and tools, but not prompts
    expect(client.getServerCapabilities()).toEqual({
        resources: {},
        tools: {}
    });

    // These should work
    await expect(client.listResources()).resolves.not.toThrow();
    await expect(client.listTools()).resolves.not.toThrow();

    // These should throw because prompts, logging, and completions are not supported
    await expect(client.listPrompts()).rejects.toThrow('Server does not support prompts');
    await expect(client.setLoggingLevel('error')).rejects.toThrow('Server does not support logging');
    await expect(
        client.complete({
            ref: { type: 'ref/prompt', name: 'test' },
            argument: { name: 'test', value: 'test' }
        })
    ).rejects.toThrow('Server does not support completions');
});

/***
 * Test: Respect Client Notification Capabilities
 */
test('should respect client notification capabilities', async () => {
    const server = new Server(
        {
            name: 'test server',
            version: '1.0'
        },
        {
            capabilities: {}
        }
    );

    const client = new Client(
        {
            name: 'test client',
            version: '1.0'
        },
        {
            capabilities: {
                roots: {
                    listChanged: true
                }
            }
        }
    );

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    // This should work because the client has the roots.listChanged capability
    await expect(client.sendRootsListChanged()).resolves.not.toThrow();

    // Create a new client without the roots.listChanged capability
    const clientWithoutCapability = new Client(
        {
            name: 'test client without capability',
            version: '1.0'
        },
        {
            capabilities: {},
            enforceStrictCapabilities: true
        }
    );

    await clientWithoutCapability.connect(clientTransport);

    // This should throw because the client doesn't have the roots.listChanged capability
    await expect(clientWithoutCapability.sendRootsListChanged()).rejects.toThrow(/^Client does not support/);
});

/***
 * Test: Respect Server Notification Capabilities
 */
test('should respect server notification capabilities', async () => {
    const server = new Server(
        {
            name: 'test server',
            version: '1.0'
        },
        {
            capabilities: {
                logging: {},
                resources: {
                    listChanged: true
                }
            }
        }
    );

    const client = new Client(
        {
            name: 'test client',
            version: '1.0'
        },
        {
            capabilities: {}
        }
    );

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    // These should work because the server has the corresponding capabilities
    await expect(server.sendLoggingMessage({ level: 'info', data: 'Test' })).resolves.not.toThrow();
    await expect(server.sendResourceListChanged()).resolves.not.toThrow();

    // This should throw because the server doesn't have the tools capability
    await expect(server.sendToolListChanged()).rejects.toThrow('Server does not support notifying of tool list changes');
});

/***
 * Test: Only Allow setRequestHandler for Declared Capabilities
 */
test('should only allow setRequestHandler for declared capabilities', () => {
    const client = new Client(
        {
            name: 'test client',
            version: '1.0'
        },
        {
            capabilities: {
                sampling: {}
            }
        }
    );

    // This should work because sampling is a declared capability
    expect(() => {
        client.setRequestHandler(CreateMessageRequestSchema, () => ({
            model: 'test-model',
            role: 'assistant',
            content: {
                type: 'text',
                text: 'Test response'
            }
        }));
    }).not.toThrow();

    // This should throw because roots listing is not a declared capability
    expect(() => {
        client.setRequestHandler(ListRootsRequestSchema, () => ({}));
    }).toThrow('Client does not support roots capability');
});

test('should allow setRequestHandler for declared elicitation capability', () => {
    const client = new Client(
        {
            name: 'test-client',
            version: '1.0.0'
        },
        {
            capabilities: {
                elicitation: {}
            }
        }
    );

    // This should work because elicitation is a declared capability
    expect(() => {
        client.setRequestHandler(ElicitRequestSchema, () => ({
            action: 'accept',
            content: {
                username: 'test-user',
                confirmed: true
            }
        }));
    }).not.toThrow();

    // This should throw because sampling is not a declared capability
    expect(() => {
        client.setRequestHandler(CreateMessageRequestSchema, () => ({
            model: 'test-model',
            role: 'assistant',
            content: {
                type: 'text',
                text: 'Test response'
            }
        }));
    }).toThrow('Client does not support sampling capability');
});

test('should accept form-mode elicitation request when client advertises empty elicitation object (back-compat)', async () => {
    const server = new Server(
        {
            name: 'test server',
            version: '1.0'
        },
        {
            capabilities: {
                prompts: {},
                resources: {},
                tools: {},
                logging: {}
            }
        }
    );

    const client = new Client(
        {
            name: 'test client',
            version: '1.0'
        },
        {
            capabilities: {
                elicitation: {}
            }
        }
    );

    // Set up client handler for form-mode elicitation
    client.setRequestHandler(ElicitRequestSchema, request => {
        expect(request.params.mode).toBe('form');
        return {
            action: 'accept',
            content: {
                username: 'test-user',
                confirmed: true
            }
        };
    });

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    // Server should be able to send form-mode elicitation request
    // This works because getSupportedElicitationModes defaults to form mode
    // when neither form nor url are explicitly declared
    const result = await server.elicitInput({
        mode: 'form',
        message: 'Please provide your username',
        requestedSchema: {
            type: 'object',
            properties: {
                username: {
                    type: 'string',
                    title: 'Username',
                    description: 'Your username'
                },
                confirmed: {
                    type: 'boolean',
                    title: 'Confirm',
                    description: 'Please confirm',
                    default: false
                }
            },
            required: ['username']
        }
    });

    expect(result.action).toBe('accept');
    expect(result.content).toEqual({
        username: 'test-user',
        confirmed: true
    });
});

test('should reject form-mode elicitation when client only supports URL mode', async () => {
    const client = new Client(
        {
            name: 'test-client',
            version: '1.0.0'
        },
        {
            capabilities: {
                elicitation: {
                    url: {}
                }
            }
        }
    );

    const handler = vi.fn().mockResolvedValue({
        action: 'cancel'
    });
    client.setRequestHandler(ElicitRequestSchema, handler);

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    let resolveResponse: ((message: unknown) => void) | undefined;
    const responsePromise = new Promise<unknown>(resolve => {
        resolveResponse = resolve;
    });

    serverTransport.onmessage = async message => {
        if ('method' in message) {
            if (message.method === 'initialize') {
                if (!('id' in message) || message.id === undefined) {
                    throw new Error('Expected initialize request to include an id');
                }
                const messageId = message.id;
                await serverTransport.send({
                    jsonrpc: '2.0',
                    id: messageId,
                    result: {
                        protocolVersion: LATEST_PROTOCOL_VERSION,
                        capabilities: {},
                        serverInfo: {
                            name: 'test-server',
                            version: '1.0.0'
                        }
                    }
                });
            } else if (message.method === 'notifications/initialized') {
                // ignore
            }
        } else {
            resolveResponse?.(message);
        }
    };

    await client.connect(clientTransport);

    // Server shouldn't send this, because the client capabilities
    // only advertised URL mode. Test that it's rejected by the client:
    const requestId = 1;
    await serverTransport.send({
        jsonrpc: '2.0',
        id: requestId,
        method: 'elicitation/create',
        params: {
            mode: 'form',
            message: 'Provide your username',
            requestedSchema: {
                type: 'object',
                properties: {
                    username: {
                        type: 'string'
                    }
                }
            }
        }
    });

    const response = (await responsePromise) as { id: number; error: { code: number; message: string } };

    expect(response.id).toBe(requestId);
    expect(response.error.code).toBe(ErrorCode.InvalidParams);
    expect(response.error.message).toContain('Client does not support form-mode elicitation requests');
    expect(handler).not.toHaveBeenCalled();

    await client.close();
});

test('should reject missing-mode elicitation when client only supports URL mode', async () => {
    const server = new Server(
        {
            name: 'test server',
            version: '1.0'
        },
        {
            capabilities: {}
        }
    );

    const client = new Client(
        {
            name: 'test client',
            version: '1.0'
        },
        {
            capabilities: {
                elicitation: {
                    url: {}
                }
            }
        }
    );

    const handler = vi.fn().mockResolvedValue({
        action: 'cancel'
    });
    client.setRequestHandler(ElicitRequestSchema, handler);

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();
    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    await expect(
        server.request(
            {
                method: 'elicitation/create',
                params: {
                    message: 'Please provide data',
                    requestedSchema: {
                        type: 'object',
                        properties: {
                            username: {
                                type: 'string'
                            }
                        }
                    }
                }
            },
            ElicitResultSchema
        )
    ).rejects.toThrow('Client does not support form-mode elicitation requests');

    expect(handler).not.toHaveBeenCalled();

    await Promise.all([client.close(), server.close()]);
});

test('should reject URL-mode elicitation when client only supports form mode', async () => {
    const client = new Client(
        {
            name: 'test-client',
            version: '1.0.0'
        },
        {
            capabilities: {
                elicitation: {
                    form: {}
                }
            }
        }
    );

    const handler = vi.fn().mockResolvedValue({
        action: 'cancel'
    });
    client.setRequestHandler(ElicitRequestSchema, handler);

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    let resolveResponse: ((message: unknown) => void) | undefined;
    const responsePromise = new Promise<unknown>(resolve => {
        resolveResponse = resolve;
    });

    serverTransport.onmessage = async message => {
        if ('method' in message) {
            if (message.method === 'initialize') {
                if (!('id' in message) || message.id === undefined) {
                    throw new Error('Expected initialize request to include an id');
                }
                const messageId = message.id;
                await serverTransport.send({
                    jsonrpc: '2.0',
                    id: messageId,
                    result: {
                        protocolVersion: LATEST_PROTOCOL_VERSION,
                        capabilities: {},
                        serverInfo: {
                            name: 'test-server',
                            version: '1.0.0'
                        }
                    }
                });
            } else if (message.method === 'notifications/initialized') {
                // ignore
            }
        } else {
            resolveResponse?.(message);
        }
    };

    await client.connect(clientTransport);

    // Server shouldn't send this, because the client capabilities
    // only advertised form mode. Test that it's rejected by the client:
    const requestId = 2;
    await serverTransport.send({
        jsonrpc: '2.0',
        id: requestId,
        method: 'elicitation/create',
        params: {
            mode: 'url',
            message: 'Open the authorization page',
            elicitationId: 'elicitation-123',
            url: 'https://example.com/authorize'
        }
    });

    const response = (await responsePromise) as { id: number; error: { code: number; message: string } };

    expect(response.id).toBe(requestId);
    expect(response.error.code).toBe(ErrorCode.InvalidParams);
    expect(response.error.message).toContain('Client does not support URL-mode elicitation requests');
    expect(handler).not.toHaveBeenCalled();

    await client.close();
});

test('should apply defaults for form-mode elicitation when applyDefaults is enabled', async () => {
    const server = new Server(
        {
            name: 'test server',
            version: '1.0'
        },
        {
            capabilities: {
                prompts: {},
                resources: {},
                tools: {},
                logging: {}
            }
        }
    );

    const client = new Client(
        {
            name: 'test client',
            version: '1.0'
        },
        {
            capabilities: {
                elicitation: {
                    form: {
                        applyDefaults: true
                    }
                }
            }
        }
    );

    client.setRequestHandler(ElicitRequestSchema, request => {
        expect(request.params.mode).toBe('form');
        return {
            action: 'accept',
            content: {}
        };
    });

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    const result = await server.elicitInput({
        mode: 'form',
        message: 'Please confirm your preferences',
        requestedSchema: {
            type: 'object',
            properties: {
                confirmed: {
                    type: 'boolean',
                    default: true
                }
            }
        }
    });

    expect(result.action).toBe('accept');
    expect(result.content).toEqual({
        confirmed: true
    });

    await client.close();
});

/***
 * Test: Handle Client Cancelling a Request
 */
test('should handle client cancelling a request', async () => {
    const server = new Server(
        {
            name: 'test server',
            version: '1.0'
        },
        {
            capabilities: {
                resources: {}
            }
        }
    );

    // Set up server to delay responding to listResources
    server.setRequestHandler(ListResourcesRequestSchema, async (request, extra) => {
        await new Promise(resolve => setTimeout(resolve, 1000));
        return {
            resources: []
        };
    });

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    const client = new Client(
        {
            name: 'test client',
            version: '1.0'
        },
        {
            capabilities: {}
        }
    );

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    // Set up abort controller
    const controller = new AbortController();

    // Issue request but cancel it immediately
    const listResourcesPromise = client.listResources(undefined, {
        signal: controller.signal
    });
    controller.abort('Cancelled by test');

    // Request should be rejected with an McpError
    await expect(listResourcesPromise).rejects.toThrow(McpError);
});

/***
 * Test: Handle Request Timeout
 */
test('should handle request timeout', async () => {
    const server = new Server(
        {
            name: 'test server',
            version: '1.0'
        },
        {
            capabilities: {
                resources: {}
            }
        }
    );

    // Set up server with a delayed response
    server.setRequestHandler(ListResourcesRequestSchema, async (_request, extra) => {
        const timer = new Promise(resolve => {
            const timeout = setTimeout(resolve, 100);
            extra.signal.addEventListener('abort', () => clearTimeout(timeout));
        });

        await timer;
        return {
            resources: []
        };
    });

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    const client = new Client(
        {
            name: 'test client',
            version: '1.0'
        },
        {
            capabilities: {}
        }
    );

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    // Request with 0 msec timeout should fail immediately
    await expect(client.listResources(undefined, { timeout: 0 })).rejects.toMatchObject({
        code: ErrorCode.RequestTimeout
    });
});

/***
 * Test: Handle Tool List Changed Notifications with Auto Refresh
 */
test('should handle tool list changed notification with auto refresh', async () => {
    // List changed notifications
    const notifications: [Error | null, Tool[] | null][] = [];

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

    // Register initial tool to enable the tools capability
    server.registerTool(
        'initial-tool',
        {
            description: 'Initial tool'
        },
        async () => ({ content: [] })
    );

    // Configure listChanged handler in constructor
    const client = new Client(
        {
            name: 'test-client',
            version: '1.0.0'
        },
        {
            listChanged: {
                tools: {
                    onChanged: (err, tools) => {
                        notifications.push([err, tools]);
                    }
                }
            }
        }
    );

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    const result1 = await client.listTools();
    expect(result1.tools).toHaveLength(1);

    // Register another tool - this triggers listChanged notification
    server.registerTool(
        'test-tool',
        {
            description: 'A test tool'
        },
        async () => ({ content: [] })
    );

    // Wait for the debounced notifications to be processed
    await new Promise(resolve => setTimeout(resolve, 1000));

    // Should be 1 notification with 2 tools because autoRefresh is true
    expect(notifications).toHaveLength(1);
    expect(notifications[0][0]).toBeNull();
    expect(notifications[0][1]).toHaveLength(2);
    expect(notifications[0][1]?.[1].name).toBe('test-tool');
});

/***
 * Test: Handle Tool List Changed Notifications with Manual Refresh
 */
test('should handle tool list changed notification with manual refresh', async () => {
    // List changed notifications
    const notifications: [Error | null, Tool[] | null][] = [];

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

    // Register initial tool to enable the tools capability
    server.registerTool('initial-tool', {}, async () => ({ content: [] }));

    // Configure listChanged handler with manual refresh (autoRefresh: false)
    const client = new Client(
        {
            name: 'test-client',
            version: '1.0.0'
        },
        {
            listChanged: {
                tools: {
                    autoRefresh: false,
                    debounceMs: 0,
                    onChanged: (err, tools) => {
                        notifications.push([err, tools]);
                    }
                }
            }
        }
    );

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    const result1 = await client.listTools();
    expect(result1.tools).toHaveLength(1);

    // Register another tool - this triggers listChanged notification
    server.registerTool(
        'test-tool',
        {
            description: 'A test tool'
        },
        async () => ({ content: [] })
    );

    // Wait for the notifications to be processed (no debounce)
    await new Promise(resolve => setTimeout(resolve, 100));

    // Should be 1 notification with no tool data because autoRefresh is false
    expect(notifications).toHaveLength(1);
    expect(notifications[0][0]).toBeNull();
    expect(notifications[0][1]).toBeNull();
});

/***
 * Test: Handle Prompt List Changed Notifications
 */
test('should handle prompt list changed notification with auto refresh', async () => {
    const notifications: [Error | null, Prompt[] | null][] = [];

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

    // Register initial prompt to enable the prompts capability
    server.registerPrompt(
        'initial-prompt',
        {
            description: 'Initial prompt'
        },
        async () => ({
            messages: [{ role: 'user', content: { type: 'text', text: 'Hello' } }]
        })
    );

    // Configure listChanged handler in constructor
    const client = new Client(
        {
            name: 'test-client',
            version: '1.0.0'
        },
        {
            listChanged: {
                prompts: {
                    onChanged: (err, prompts) => {
                        notifications.push([err, prompts]);
                    }
                }
            }
        }
    );

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    const result1 = await client.listPrompts();
    expect(result1.prompts).toHaveLength(1);

    // Register another prompt - this triggers listChanged notification
    server.registerPrompt('test-prompt', { description: 'A test prompt' }, async () => ({
        messages: [{ role: 'user', content: { type: 'text', text: 'Hello' } }]
    }));

    // Wait for the debounced notifications to be processed
    await new Promise(resolve => setTimeout(resolve, 1000));

    // Should be 1 notification with 2 prompts because autoRefresh is true
    expect(notifications).toHaveLength(1);
    expect(notifications[0][0]).toBeNull();
    expect(notifications[0][1]).toHaveLength(2);
    expect(notifications[0][1]?.[1].name).toBe('test-prompt');
});

/***
 * Test: Handle Resource List Changed Notifications
 */
test('should handle resource list changed notification with auto refresh', async () => {
    const notifications: [Error | null, Resource[] | null][] = [];

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

    // Register initial resource to enable the resources capability
    server.registerResource('initial-resource', 'file:///initial.txt', {}, async () => ({
        contents: [{ uri: 'file:///initial.txt', text: 'Hello' }]
    }));

    // Configure listChanged handler in constructor
    const client = new Client(
        {
            name: 'test-client',
            version: '1.0.0'
        },
        {
            listChanged: {
                resources: {
                    onChanged: (err, resources) => {
                        notifications.push([err, resources]);
                    }
                }
            }
        }
    );

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    const result1 = await client.listResources();
    expect(result1.resources).toHaveLength(1);

    // Register another resource - this triggers listChanged notification
    server.registerResource('test-resource', 'file:///test.txt', {}, async () => ({
        contents: [{ uri: 'file:///test.txt', text: 'Hello' }]
    }));

    // Wait for the debounced notifications to be processed
    await new Promise(resolve => setTimeout(resolve, 1000));

    // Should be 1 notification with 2 resources because autoRefresh is true
    expect(notifications).toHaveLength(1);
    expect(notifications[0][0]).toBeNull();
    expect(notifications[0][1]).toHaveLength(2);
    expect(notifications[0][1]?.[1].name).toBe('test-resource');
});

/***
 * Test: Handle Multiple List Changed Handlers
 */
test('should handle multiple list changed handlers configured together', async () => {
    const toolNotifications: [Error | null, Tool[] | null][] = [];
    const promptNotifications: [Error | null, Prompt[] | null][] = [];

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

    // Register initial tool and prompt to enable capabilities
    server.registerTool(
        'tool-1',
        {
            description: 'Tool 1'
        },
        async () => ({ content: [] })
    );
    server.registerPrompt(
        'prompt-1',
        {
            description: 'Prompt 1'
        },
        async () => ({
            messages: [{ role: 'user', content: { type: 'text', text: 'Hello' } }]
        })
    );

    // Configure multiple listChanged handlers in constructor
    const client = new Client(
        {
            name: 'test-client',
            version: '1.0.0'
        },
        {
            listChanged: {
                tools: {
                    debounceMs: 0,
                    onChanged: (err, tools) => {
                        toolNotifications.push([err, tools]);
                    }
                },
                prompts: {
                    debounceMs: 0,
                    onChanged: (err, prompts) => {
                        promptNotifications.push([err, prompts]);
                    }
                }
            }
        }
    );

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    // Register another tool and prompt to trigger notifications
    server.registerTool(
        'tool-2',
        {
            description: 'Tool 2'
        },
        async () => ({ content: [] })
    );
    server.registerPrompt(
        'prompt-2',
        {
            description: 'Prompt 2'
        },
        async () => ({
            messages: [{ role: 'user', content: { type: 'text', text: 'Hello' } }]
        })
    );

    // Wait for notifications to be processed
    await new Promise(resolve => setTimeout(resolve, 100));

    // Both handlers should have received their respective notifications
    expect(toolNotifications).toHaveLength(1);
    expect(toolNotifications[0][1]).toHaveLength(2);

    expect(promptNotifications).toHaveLength(1);
    expect(promptNotifications[0][1]).toHaveLength(2);
});

/***
 * Test: Handler not activated when server doesn't advertise listChanged capability
 */
test('should not activate listChanged handler when server does not advertise capability', async () => {
    const notifications: [Error | null, Tool[] | null][] = [];

    // Server with tools capability but WITHOUT listChanged
    const server = new Server({ name: 'test-server', version: '1.0.0' }, { capabilities: { tools: {} } });

    server.setRequestHandler(InitializeRequestSchema, async request => ({
        protocolVersion: request.params.protocolVersion,
        capabilities: { tools: {} }, // No listChanged: true
        serverInfo: { name: 'test-server', version: '1.0.0' }
    }));

    server.setRequestHandler(ListToolsRequestSchema, async () => ({
        tools: [{ name: 'test-tool', inputSchema: { type: 'object' } }]
    }));

    // Configure listChanged handler that should NOT be activated
    const client = new Client(
        { name: 'test-client', version: '1.0.0' },
        {
            listChanged: {
                tools: {
                    debounceMs: 0,
                    onChanged: (err, tools) => {
                        notifications.push([err, tools]);
                    }
                }
            }
        }
    );

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    // Verify server doesn't have tools.listChanged capability
    expect(client.getServerCapabilities()?.tools?.listChanged).toBeFalsy();

    // Send a tool list changed notification manually
    await server.notification({ method: 'notifications/tools/list_changed' });
    await new Promise(resolve => setTimeout(resolve, 100));

    // Handler should NOT have been activated because server didn't advertise listChanged
    expect(notifications).toHaveLength(0);
});

/***
 * Test: Handler activated when server advertises listChanged capability
 */
test('should activate listChanged handler when server advertises capability', async () => {
    const notifications: [Error | null, Tool[] | null][] = [];

    // Server with tools.listChanged: true capability
    const server = new Server({ name: 'test-server', version: '1.0.0' }, { capabilities: { tools: { listChanged: true } } });

    server.setRequestHandler(InitializeRequestSchema, async request => ({
        protocolVersion: request.params.protocolVersion,
        capabilities: { tools: { listChanged: true } },
        serverInfo: { name: 'test-server', version: '1.0.0' }
    }));

    server.setRequestHandler(ListToolsRequestSchema, async () => ({
        tools: [{ name: 'test-tool', inputSchema: { type: 'object' } }]
    }));

    // Configure listChanged handler that SHOULD be activated
    const client = new Client(
        { name: 'test-client', version: '1.0.0' },
        {
            listChanged: {
                tools: {
                    debounceMs: 0,
                    onChanged: (err, tools) => {
                        notifications.push([err, tools]);
                    }
                }
            }
        }
    );

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    // Verify server has tools.listChanged capability
    expect(client.getServerCapabilities()?.tools?.listChanged).toBe(true);

    // Send a tool list changed notification
    await server.notification({ method: 'notifications/tools/list_changed' });
    await new Promise(resolve => setTimeout(resolve, 100));

    // Handler SHOULD have been called
    expect(notifications).toHaveLength(1);
    expect(notifications[0][0]).toBeNull();
    expect(notifications[0][1]).toHaveLength(1);
});

/***
 * Test: No handlers activated when server has no listChanged capabilities
 */
test('should not activate any handlers when server has no listChanged capabilities', async () => {
    const toolNotifications: [Error | null, Tool[] | null][] = [];
    const promptNotifications: [Error | null, Prompt[] | null][] = [];
    const resourceNotifications: [Error | null, Resource[] | null][] = [];

    // Server with capabilities but NO listChanged for any
    const server = new Server({ name: 'test-server', version: '1.0.0' }, { capabilities: { tools: {}, prompts: {}, resources: {} } });

    server.setRequestHandler(InitializeRequestSchema, async request => ({
        protocolVersion: request.params.protocolVersion,
        capabilities: { tools: {}, prompts: {}, resources: {} },
        serverInfo: { name: 'test-server', version: '1.0.0' }
    }));

    // Configure listChanged handlers for all three types
    const client = new Client(
        { name: 'test-client', version: '1.0.0' },
        {
            listChanged: {
                tools: {
                    debounceMs: 0,
                    onChanged: (err, tools) => toolNotifications.push([err, tools])
                },
                prompts: {
                    debounceMs: 0,
                    onChanged: (err, prompts) => promptNotifications.push([err, prompts])
                },
                resources: {
                    debounceMs: 0,
                    onChanged: (err, resources) => resourceNotifications.push([err, resources])
                }
            }
        }
    );

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    // Verify server has no listChanged capabilities
    const caps = client.getServerCapabilities();
    expect(caps?.tools?.listChanged).toBeFalsy();
    expect(caps?.prompts?.listChanged).toBeFalsy();
    expect(caps?.resources?.listChanged).toBeFalsy();

    // Send notifications for all three types
    await server.notification({ method: 'notifications/tools/list_changed' });
    await server.notification({ method: 'notifications/prompts/list_changed' });
    await server.notification({ method: 'notifications/resources/list_changed' });
    await new Promise(resolve => setTimeout(resolve, 100));

    // No handlers should have been activated
    expect(toolNotifications).toHaveLength(0);
    expect(promptNotifications).toHaveLength(0);
    expect(resourceNotifications).toHaveLength(0);
});

/***
 * Test: Partial capability support - some handlers activated, others not
 */
test('should handle partial listChanged capability support', async () => {
    const toolNotifications: [Error | null, Tool[] | null][] = [];
    const promptNotifications: [Error | null, Prompt[] | null][] = [];

    // Server with tools.listChanged: true but prompts without listChanged
    const server = new Server({ name: 'test-server', version: '1.0.0' }, { capabilities: { tools: { listChanged: true }, prompts: {} } });

    server.setRequestHandler(InitializeRequestSchema, async request => ({
        protocolVersion: request.params.protocolVersion,
        capabilities: { tools: { listChanged: true }, prompts: {} },
        serverInfo: { name: 'test-server', version: '1.0.0' }
    }));

    server.setRequestHandler(ListToolsRequestSchema, async () => ({
        tools: [{ name: 'tool-1', inputSchema: { type: 'object' } }]
    }));

    server.setRequestHandler(ListPromptsRequestSchema, async () => ({
        prompts: [{ name: 'prompt-1' }]
    }));

    const client = new Client(
        { name: 'test-client', version: '1.0.0' },
        {
            listChanged: {
                tools: {
                    debounceMs: 0,
                    onChanged: (err, tools) => toolNotifications.push([err, tools])
                },
                prompts: {
                    debounceMs: 0,
                    onChanged: (err, prompts) => promptNotifications.push([err, prompts])
                }
            }
        }
    );

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    // Verify capability state
    expect(client.getServerCapabilities()?.tools?.listChanged).toBe(true);
    expect(client.getServerCapabilities()?.prompts?.listChanged).toBeFalsy();

    // Send notifications for both
    await server.notification({ method: 'notifications/tools/list_changed' });
    await server.notification({ method: 'notifications/prompts/list_changed' });
    await new Promise(resolve => setTimeout(resolve, 100));

    // Tools handler should have been called
    expect(toolNotifications).toHaveLength(1);
    // Prompts handler should NOT have been called (no prompts.listChanged)
    expect(promptNotifications).toHaveLength(0);
});

describe('outputSchema validation', () => {
    /***
     * Test: Validate structuredContent Against outputSchema
     */
    test('should validate structuredContent against outputSchema', async () => {
        const server = new Server(
            {
                name: 'test-server',
                version: '1.0.0'
            },
            {
                capabilities: {
                    tools: {}
                }
            }
        );

        // Set up server handlers
        server.setRequestHandler(InitializeRequestSchema, async request => ({
            protocolVersion: request.params.protocolVersion,
            capabilities: {},
            serverInfo: {
                name: 'test-server',
                version: '1.0.0'
            }
        }));

        server.setRequestHandler(ListToolsRequestSchema, async () => ({
            tools: [
                {
                    name: 'test-tool',
                    description: 'A test tool',
                    inputSchema: {
                        type: 'object',
                        properties: {}
                    },
                    outputSchema: {
                        type: 'object',
                        properties: {
                            result: { type: 'string' },
                            count: { type: 'number' }
                        },
                        required: ['result', 'count'],
                        additionalProperties: false
                    }
                }
            ]
        }));

        server.setRequestHandler(CallToolRequestSchema, async request => {
            if (request.params.name === 'test-tool') {
                return {
                    structuredContent: { result: 'success', count: 42 }
                };
            }
            throw new Error('Unknown tool');
        });

        const client = new Client(
            {
                name: 'test-client',
                version: '1.0.0'
            },
            {
                capabilities: {
                    tasks: {
                        requests: {
                            tools: {
                                call: {}
                            },
                            tasks: {
                                get: true,
                                list: {},
                                result: true
                            }
                        }
                    }
                }
            }
        );

        const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

        await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

        // List tools to cache the schemas
        await client.listTools();

        // Call the tool - should validate successfully
        const result = await client.callTool({ name: 'test-tool' });
        expect(result.structuredContent).toEqual({ result: 'success', count: 42 });
    });

    /***
     * Test: Throw Error when structuredContent Does Not Match Schema
     */
    test('should throw error when structuredContent does not match schema', async () => {
        const server = new Server(
            {
                name: 'test-server',
                version: '1.0.0'
            },
            {
                capabilities: {
                    tools: {}
                }
            }
        );

        // Set up server handlers
        server.setRequestHandler(InitializeRequestSchema, async request => ({
            protocolVersion: request.params.protocolVersion,
            capabilities: {},
            serverInfo: {
                name: 'test-server',
                version: '1.0.0'
            }
        }));

        server.setRequestHandler(ListToolsRequestSchema, async () => ({
            tools: [
                {
                    name: 'test-tool',
                    description: 'A test tool',
                    inputSchema: {
                        type: 'object',
                        properties: {}
                    },
                    outputSchema: {
                        type: 'object',
                        properties: {
                            result: { type: 'string' },
                            count: { type: 'number' }
                        },
                        required: ['result', 'count'],
                        additionalProperties: false
                    }
                }
            ]
        }));

        server.setRequestHandler(CallToolRequestSchema, async request => {
            if (request.params.name === 'test-tool') {
                // Return invalid structured content (count is string instead of number)
                return {
                    structuredContent: { result: 'success', count: 'not a number' }
                };
            }
            throw new Error('Unknown tool');
        });

        const client = new Client(
            {
                name: 'test-client',
                version: '1.0.0'
            },
            {
                capabilities: {
                    tasks: {
                        requests: {
                            tools: {
                                call: {}
                            },
                            tasks: {
                                get: true,
                                list: {},
                                result: true
                            }
                        }
                    }
                }
            }
        );

        const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

        await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

        // List tools to cache the schemas
        await client.listTools();

        // Call the tool - should throw validation error
        await expect(client.callTool({ name: 'test-tool' })).rejects.toThrow(/Structured content does not match the tool's output schema/);
    });

    /***
     * Test: Throw Error when Tool with outputSchema Returns No structuredContent
     */
    test('should throw error when tool with outputSchema returns no structuredContent', async () => {
        const server = new Server(
            {
                name: 'test-server',
                version: '1.0.0'
            },
            {
                capabilities: {
                    tools: {}
                }
            }
        );

        // Set up server handlers
        server.setRequestHandler(InitializeRequestSchema, async request => ({
            protocolVersion: request.params.protocolVersion,
            capabilities: {},
            serverInfo: {
                name: 'test-server',
                version: '1.0.0'
            }
        }));

        server.setRequestHandler(ListToolsRequestSchema, async () => ({
            tools: [
                {
                    name: 'test-tool',
                    description: 'A test tool',
                    inputSchema: {
                        type: 'object',
                        properties: {}
                    },
                    outputSchema: {
                        type: 'object',
                        properties: {
                            result: { type: 'string' }
                        },
                        required: ['result']
                    }
                }
            ]
        }));

        server.setRequestHandler(CallToolRequestSchema, async request => {
            if (request.params.name === 'test-tool') {
                // Return content instead of structuredContent
                return {
                    content: [{ type: 'text', text: 'This should be structured content' }]
                };
            }
            throw new Error('Unknown tool');
        });

        const client = new Client(
            {
                name: 'test-client',
                version: '1.0.0'
            },
            {
                capabilities: {
                    tasks: {
                        requests: {
                            tools: {
                                call: {}
                            },
                            tasks: {
                                get: true,
                                list: {},
                                result: true
                            }
                        }
                    }
                }
            }
        );

        const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

        await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

        // List tools to cache the schemas
        await client.listTools();

        // Call the tool - should throw error
        await expect(client.callTool({ name: 'test-tool' })).rejects.toThrow(
            /Tool test-tool has an output schema but did not return structured content/
        );
    });

    /***
     * Test: Handle Tools Without outputSchema Normally
     */
    test('should handle tools without outputSchema normally', async () => {
        const server = new Server(
            {
                name: 'test-server',
                version: '1.0.0'
            },
            {
                capabilities: {
                    tools: {}
                }
            }
        );

        // Set up server handlers
        server.setRequestHandler(InitializeRequestSchema, async request => ({
            protocolVersion: request.params.protocolVersion,
            capabilities: {},
            serverInfo: {
                name: 'test-server',
                version: '1.0.0'
            }
        }));

        server.setRequestHandler(ListToolsRequestSchema, async () => ({
            tools: [
                {
                    name: 'test-tool',
                    description: 'A test tool',
                    inputSchema: {
                        type: 'object',
                        properties: {}
                    }
                    // No outputSchema
                }
            ]
        }));

        server.setRequestHandler(CallToolRequestSchema, async request => {
            if (request.params.name === 'test-tool') {
                // Return regular content
                return {
                    content: [{ type: 'text', text: 'Normal response' }]
                };
            }
            throw new Error('Unknown tool');
        });

        const client = new Client(
            {
                name: 'test-client',
                version: '1.0.0'
            },
            {
                capabilities: {
                    tasks: {
                        requests: {
                            tools: {
                                call: {}
                            },
                            tasks: {
                                get: true,
                                list: {},
                                result: true
                            }
                        }
                    }
                }
            }
        );

        const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

        await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

        // List tools to cache the schemas
        await client.listTools();

        // Call the tool - should work normally without validation
        const result = await client.callTool({ name: 'test-tool' });
        expect(result.content).toEqual([{ type: 'text', text: 'Normal response' }]);
    });

    /***
     * Test: Handle Complex JSON Schema Validation
     */
    test('should handle complex JSON schema validation', async () => {
        const server = new Server(
            {
                name: 'test-server',
                version: '1.0.0'
            },
            {
                capabilities: {
                    tools: {}
                }
            }
        );

        // Set up server handlers
        server.setRequestHandler(InitializeRequestSchema, async request => ({
            protocolVersion: request.params.protocolVersion,
            capabilities: {},
            serverInfo: {
                name: 'test-server',
                version: '1.0.0'
            }
        }));

        server.setRequestHandler(ListToolsRequestSchema, async () => ({
            tools: [
                {
                    name: 'complex-tool',
                    description: 'A tool with complex schema',
                    inputSchema: {
                        type: 'object',
                        properties: {}
                    },
                    outputSchema: {
                        type: 'object',
                        properties: {
                            name: { type: 'string', minLength: 3 },
                            age: { type: 'integer', minimum: 0, maximum: 120 },
                            active: { type: 'boolean' },
                            tags: {
                                type: 'array',
                                items: { type: 'string' },
                                minItems: 1
                            },
                            metadata: {
                                type: 'object',
                                properties: {
                                    created: { type: 'string' }
                                },
                                required: ['created']
                            }
                        },
                        required: ['name', 'age', 'active', 'tags', 'metadata'],
                        additionalProperties: false
                    }
                }
            ]
        }));

        server.setRequestHandler(CallToolRequestSchema, async request => {
            if (request.params.name === 'complex-tool') {
                return {
                    structuredContent: {
                        name: 'John Doe',
                        age: 30,
                        active: true,
                        tags: ['user', 'admin'],
                        metadata: {
                            created: '2023-01-01T00:00:00Z'
                        }
                    }
                };
            }
            throw new Error('Unknown tool');
        });

        const client = new Client(
            {
                name: 'test-client',
                version: '1.0.0'
            },
            {
                capabilities: {
                    tasks: {
                        requests: {
                            tools: {
                                call: {}
                            },
                            tasks: {
                                get: true,
                                list: {},
                                result: true
                            }
                        }
                    }
                }
            }
        );

        const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

        await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

        // List tools to cache the schemas
        await client.listTools();

        // Call the tool - should validate successfully
        const result = await client.callTool({ name: 'complex-tool' });
        expect(result.structuredContent).toBeDefined();
        const structuredContent = result.structuredContent as { name: string; age: number };
        expect(structuredContent.name).toBe('John Doe');
        expect(structuredContent.age).toBe(30);
    });

    /***
     * Test: Fail Validation with Additional Properties When Not Allowed
     */
    test('should fail validation with additional properties when not allowed', async () => {
        const server = new Server(
            {
                name: 'test-server',
                version: '1.0.0'
            },
            {
                capabilities: {
                    tools: {}
                }
            }
        );

        // Set up server handlers
        server.setRequestHandler(InitializeRequestSchema, async request => ({
            protocolVersion: request.params.protocolVersion,
            capabilities: {},
            serverInfo: {
                name: 'test-server',
                version: '1.0.0'
            }
        }));

        server.setRequestHandler(ListToolsRequestSchema, async () => ({
            tools: [
                {
                    name: 'strict-tool',
                    description: 'A tool with strict schema',
                    inputSchema: {
                        type: 'object',
                        properties: {}
                    },
                    outputSchema: {
                        type: 'object',
                        properties: {
                            name: { type: 'string' }
                        },
                        required: ['name'],
                        additionalProperties: false
                    }
                }
            ]
        }));

        server.setRequestHandler(CallToolRequestSchema, async request => {
            if (request.params.name === 'strict-tool') {
                // Return structured content with extra property
                return {
                    structuredContent: {
                        name: 'John',
                        extraField: 'not allowed'
                    }
                };
            }
            throw new Error('Unknown tool');
        });

        const client = new Client({
            name: 'test-client',
            version: '1.0.0'
        });

        const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

        await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

        // List tools to cache the schemas
        await client.listTools();

        // Call the tool - should throw validation error due to additional property
        await expect(client.callTool({ name: 'strict-tool' })).rejects.toThrow(
            /Structured content does not match the tool's output schema/
        );
    });
});

describe('Task-based execution', () => {
    describe('Client calling server', () => {
        let serverTaskStore: InMemoryTaskStore;

        beforeEach(() => {
            serverTaskStore = new InMemoryTaskStore();
        });

        afterEach(() => {
            serverTaskStore?.cleanup();
        });

        test('should create task on server via tool call', async () => {
            const server = new McpServer(
                {
                    name: 'test-server',
                    version: '1.0.0'
                },
                {
                    capabilities: {
                        tasks: {
                            requests: {
                                tools: {
                                    call: {}
                                }
                            }
                        }
                    },
                    taskStore: serverTaskStore
                }
            );

            server.experimental.tasks.registerToolTask(
                'test-tool',
                {
                    description: 'A test tool',
                    inputSchema: {}
                },
                {
                    async createTask(_args, extra) {
                        const task = await extra.taskStore.createTask({
                            ttl: extra.taskRequestedTtl
                        });

                        const result = {
                            content: [{ type: 'text', text: 'Tool executed successfully!' }]
                        };
                        await extra.taskStore.storeTaskResult(task.taskId, 'completed', result);

                        return { task };
                    },
                    async getTask(extra) {
                        const task = await extra.taskStore.getTask(extra.taskId);
                        if (!task) {
                            throw new Error(`Task ${extra.taskId} not found`);
                        }
                        return task;
                    },
                    async getTaskResult(extra) {
                        const result = await extra.taskStore.getTaskResult(extra.taskId);
                        return result as { content: Array<{ type: 'text'; text: string }> };
                    }
                }
            );

            const client = new Client({
                name: 'test-client',
                version: '1.0.0'
            });

            const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

            await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

            // Client creates task on server via tool call
            await client.callTool({ name: 'test-tool', arguments: {} }, CallToolResultSchema, {
                task: {
                    ttl: 60000
                }
            });

            // Verify task was created successfully by listing tasks
            const taskList = await client.experimental.tasks.listTasks();
            expect(taskList.tasks.length).toBeGreaterThan(0);
            const task = taskList.tasks[0];
            expect(task.status).toBe('completed');
        });

        test('should query task status from server using getTask', async () => {
            const server = new McpServer(
                {
                    name: 'test-server',
                    version: '1.0.0'
                },
                {
                    capabilities: {
                        tasks: {
                            requests: {
                                tools: {
                                    call: {}
                                }
                            }
                        }
                    },
                    taskStore: serverTaskStore
                }
            );

            server.experimental.tasks.registerToolTask(
                'test-tool',
                {
                    description: 'A test tool',
                    inputSchema: {}
                },
                {
                    async createTask(_args, extra) {
                        const task = await extra.taskStore.createTask({
                            ttl: extra.taskRequestedTtl
                        });

                        const result = {
                            content: [{ type: 'text', text: 'Success!' }]
                        };
                        await extra.taskStore.storeTaskResult(task.taskId, 'completed', result);

                        return { task };
                    },
                    async getTask(extra) {
                        const task = await extra.taskStore.getTask(extra.taskId);
                        if (!task) {
                            throw new Error(`Task ${extra.taskId} not found`);
                        }
                        return task;
                    },
                    async getTaskResult(extra) {
                        const result = await extra.taskStore.getTaskResult(extra.taskId);
                        return result as { content: Array<{ type: 'text'; text: string }> };
                    }
                }
            );

            const client = new Client({
                name: 'test-client',
                version: '1.0.0'
            });

            const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

            await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

            // Create a task
            await client.callTool({ name: 'test-tool', arguments: {} }, CallToolResultSchema, {
                task: { ttl: 60000 }
            });

            // Query task status by listing tasks and getting the first one
            const taskList = await client.experimental.tasks.listTasks();
            expect(taskList.tasks.length).toBeGreaterThan(0);
            const task = taskList.tasks[0];
            expect(task).toBeDefined();
            expect(task.taskId).toBeDefined();
            expect(task.status).toBe('completed');
        });

        test('should query task result from server using getTaskResult', async () => {
            const server = new McpServer(
                {
                    name: 'test-server',
                    version: '1.0.0'
                },
                {
                    capabilities: {
                        tasks: {
                            requests: {
                                tools: {
                                    call: {},
                                    list: {}
                                }
                            }
                        }
                    },
                    taskStore: serverTaskStore
                }
            );

            server.experimental.tasks.registerToolTask(
                'test-tool',
                {
                    description: 'A test tool',
                    inputSchema: {}
                },
                {
                    async createTask(_args, extra) {
                        const task = await extra.taskStore.createTask({
                            ttl: extra.taskRequestedTtl
                        });

                        const result = {
                            content: [{ type: 'text', text: 'Result data!' }]
                        };
                        await extra.taskStore.storeTaskResult(task.taskId, 'completed', result);

                        return { task };
                    },
                    async getTask(extra) {
                        const task = await extra.taskStore.getTask(extra.taskId);
                        if (!task) {
                            throw new Error(`Task ${extra.taskId} not found`);
                        }
                        return task;
                    },
                    async getTaskResult(extra) {
                        const result = await extra.taskStore.getTaskResult(extra.taskId);
                        return result as { content: Array<{ type: 'text'; text: string }> };
                    }
                }
            );

            const client = new Client({
                name: 'test-client',
                version: '1.0.0'
            });

            const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

            await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

            // Create a task using callToolStream to capture the task ID
            let taskId: string | undefined;
            const stream = client.experimental.tasks.callToolStream({ name: 'test-tool', arguments: {} }, CallToolResultSchema, {
                task: { ttl: 60000 }
            });

            for await (const message of stream) {
                if (message.type === 'taskCreated') {
                    taskId = message.task.taskId;
                }
            }

            expect(taskId).toBeDefined();

            // Query task result using the captured task ID
            const result = await client.experimental.tasks.getTaskResult(taskId!, CallToolResultSchema);
            expect(result.content).toEqual([{ type: 'text', text: 'Result data!' }]);
        });

        test('should query task list from server using listTasks', async () => {
            const server = new McpServer(
                {
                    name: 'test-server',
                    version: '1.0.0'
                },
                {
                    capabilities: {
                        tasks: {
                            requests: {
                                tools: {
                                    call: {}
                                }
                            }
                        }
                    },
                    taskStore: serverTaskStore
                }
            );

            server.experimental.tasks.registerToolTask(
                'test-tool',
                {
                    description: 'A test tool',
                    inputSchema: {}
                },
                {
                    async createTask(_args, extra) {
                        const task = await extra.taskStore.createTask({
                            ttl: extra.taskRequestedTtl
                        });

                        const result = {
                            content: [{ type: 'text', text: 'Success!' }]
                        };
                        await extra.taskStore.storeTaskResult(task.taskId, 'completed', result);

                        return { task };
                    },
                    async getTask(extra) {
                        const task = await extra.taskStore.getTask(extra.taskId);
                        if (!task) {
                            throw new Error(`Task ${extra.taskId} not found`);
                        }
                        return task;
                    },
                    async getTaskResult(extra) {
                        const result = await extra.taskStore.getTaskResult(extra.taskId);
                        return result as { content: Array<{ type: 'text'; text: string }> };
                    }
                }
            );

            const client = new Client({
                name: 'test-client',
                version: '1.0.0'
            });

            const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

            await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

            // Create multiple tasks
            const createdTaskIds: string[] = [];

            for (let i = 0; i < 2; i++) {
                await client.callTool({ name: 'test-tool', arguments: {} }, CallToolResultSchema, {
                    task: { ttl: 60000 }
                });

                // Get the task ID from the task list
                const taskList = await client.experimental.tasks.listTasks();
                const newTask = taskList.tasks.find(t => !createdTaskIds.includes(t.taskId));
                if (newTask) {
                    createdTaskIds.push(newTask.taskId);
                }
            }

            // Query task list
            const taskList = await client.experimental.tasks.listTasks();
            expect(taskList.tasks.length).toBeGreaterThanOrEqual(2);
            for (const taskId of createdTaskIds) {
                expect(taskList.tasks).toContainEqual(
                    expect.objectContaining({
                        taskId,
                        status: 'completed'
                    })
                );
            }
        });
    });

    describe('Server calling client', () => {
        let clientTaskStore: InMemoryTaskStore;

        beforeEach(() => {
            clientTaskStore = new InMemoryTaskStore();
        });

        afterEach(() => {
            clientTaskStore?.cleanup();
        });

        test('should create task on client via server elicitation', async () => {
            const client = new Client(
                {
                    name: 'test-client',
                    version: '1.0.0'
                },
                {
                    capabilities: {
                        elicitation: {},
                        tasks: {
                            requests: {
                                elicitation: {
                                    create: {}
                                }
                            }
                        }
                    },
                    taskStore: clientTaskStore
                }
            );

            client.setRequestHandler(ElicitRequestSchema, async (request, extra) => {
                const result = {
                    action: 'accept',
                    content: { username: 'list-user' }
                };

                // Check if task creation is requested
                if (request.params.task && extra.taskStore) {
                    const task = await extra.taskStore.createTask({
                        ttl: extra.taskRequestedTtl
                    });
                    await extra.taskStore.storeTaskResult(task.taskId, 'completed', result);
                    // Return CreateTaskResult when task creation is requested
                    return { task };
                }

                // Return ElicitResult for non-task requests
                return result;
            });

            const server = new Server(
                {
                    name: 'test-server',
                    version: '1.0.0'
                },
                {
                    capabilities: {
                        tasks: {
                            requests: {
                                elicitation: {
                                    create: {}
                                }
                            }
                        }
                    }
                }
            );

            const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

            await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

            // Server creates task on client via elicitation
            const createTaskResult = await server.request(
                {
                    method: 'elicitation/create',
                    params: {
                        mode: 'form',
                        message: 'Please provide your username',
                        requestedSchema: {
                            type: 'object',
                            properties: {
                                username: { type: 'string' }
                            },
                            required: ['username']
                        }
                    }
                },
                CreateTaskResultSchema,
                { task: { ttl: 60000 } }
            );

            // Verify CreateTaskResult structure
            expect(createTaskResult.task).toBeDefined();
            expect(createTaskResult.task.taskId).toBeDefined();
            const taskId = createTaskResult.task.taskId;

            // Verify task was created
            const task = await server.experimental.tasks.getTask(taskId);
            expect(task.status).toBe('completed');
        });

        test('should query task status from client using getTask', async () => {
            const client = new Client(
                {
                    name: 'test-client',
                    version: '1.0.0'
                },
                {
                    capabilities: {
                        elicitation: {},
                        tasks: {
                            requests: {
                                elicitation: {
                                    create: {}
                                }
                            }
                        }
                    },
                    taskStore: clientTaskStore
                }
            );

            client.setRequestHandler(ElicitRequestSchema, async (request, extra) => {
                const result = {
                    action: 'accept',
                    content: { username: 'list-user' }
                };

                // Check if task creation is requested
                if (request.params.task && extra.taskStore) {
                    const task = await extra.taskStore.createTask({
                        ttl: extra.taskRequestedTtl
                    });
                    await extra.taskStore.storeTaskResult(task.taskId, 'completed', result);
                    // Return CreateTaskResult when task creation is requested
                    return { task };
                }

                // Return ElicitResult for non-task requests
                return result;
            });

            const server = new Server(
                {
                    name: 'test-server',
                    version: '1.0.0'
                },
                {
                    capabilities: {
                        tasks: {
                            requests: {
                                elicitation: {
                                    create: {}
                                }
                            }
                        }
                    }
                }
            );

            const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

            await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

            // Create a task on client and wait for CreateTaskResult
            const createTaskResult = await server.request(
                {
                    method: 'elicitation/create',
                    params: {
                        mode: 'form',
                        message: 'Please provide info',
                        requestedSchema: {
                            type: 'object',
                            properties: { username: { type: 'string' } }
                        }
                    }
                },
                CreateTaskResultSchema,
                { task: { ttl: 60000 } }
            );

            // Verify CreateTaskResult structure
            expect(createTaskResult.task).toBeDefined();
            expect(createTaskResult.task.taskId).toBeDefined();
            const taskId = createTaskResult.task.taskId;

            // Query task status
            const task = await server.experimental.tasks.getTask(taskId);
            expect(task).toBeDefined();
            expect(task.taskId).toBe(taskId);
            expect(task.status).toBe('completed');
        });

        test('should query task result from client using getTaskResult', async () => {
            const client = new Client(
                {
                    name: 'test-client',
                    version: '1.0.0'
                },
                {
                    capabilities: {
                        elicitation: {},
                        tasks: {
                            requests: {
                                elicitation: {
                                    create: {}
                                }
                            }
                        }
                    },
                    taskStore: clientTaskStore
                }
            );

            client.setRequestHandler(ElicitRequestSchema, async (request, extra) => {
                const result = {
                    action: 'accept',
                    content: { username: 'result-user' }
                };

                // Check if task creation is requested
                if (request.params.task && extra.taskStore) {
                    const task = await extra.taskStore.createTask({
                        ttl: extra.taskRequestedTtl
                    });
                    await extra.taskStore.storeTaskResult(task.taskId, 'completed', result);
                    // Return CreateTaskResult when task creation is requested
                    return { task };
                }

                // Return ElicitResult for non-task requests
                return result;
            });

            const server = new Server(
                {
                    name: 'test-server',
                    version: '1.0.0'
                },
                {
                    capabilities: {
                        tasks: {
                            requests: {
                                elicitation: {
                                    create: {}
                                }
                            }
                        }
                    }
                }
            );

            const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

            await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

            // Create a task on client and wait for CreateTaskResult
            const createTaskResult = await server.request(
                {
                    method: 'elicitation/create',
                    params: {
                        mode: 'form',
                        message: 'Please provide info',
                        requestedSchema: {
                            type: 'object',
                            properties: { username: { type: 'string' } }
                        }
                    }
                },
                CreateTaskResultSchema,
                { task: { ttl: 60000 } }
            );

            // Verify CreateTaskResult structure
            expect(createTaskResult.task).toBeDefined();
            expect(createTaskResult.task.taskId).toBeDefined();
            const taskId = createTaskResult.task.taskId;

            // Query task result using getTaskResult
            const taskResult = await server.experimental.tasks.getTaskResult(taskId, ElicitResultSchema);
            expect(taskResult.action).toBe('accept');
            expect(taskResult.content).toEqual({ username: 'result-user' });
        });

        test('should query task list from client using listTasks', async () => {
            const client = new Client(
                {
                    name: 'test-client',
                    version: '1.0.0'
                },
                {
                    capabilities: {
                        elicitation: {},
                        tasks: {
                            requests: {
                                elicitation: {
                                    create: {}
                                }
                            }
                        }
                    },
                    taskStore: clientTaskStore
                }
            );

            client.setRequestHandler(ElicitRequestSchema, async (request, extra) => {
                const result = {
                    action: 'accept',
                    content: { username: 'list-user' }
                };

                // Check if task creation is requested
                if (request.params.task && extra.taskStore) {
                    const task = await extra.taskStore.createTask({
                        ttl: extra.taskRequestedTtl
                    });
                    await extra.taskStore.storeTaskResult(task.taskId, 'completed', result);
                    // Return CreateTaskResult when task creation is requested
                    return { task };
                }

                // Return ElicitResult for non-task requests
                return result;
            });

            const server = new Server(
                {
                    name: 'test-server',
                    version: '1.0.0'
                },
                {
                    capabilities: {
                        tasks: {
                            requests: {
                                elicitation: {
                                    create: {}
                                }
                            }
                        }
                    }
                }
            );

            const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

            await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

            // Create multiple tasks on client
            const createdTaskIds: string[] = [];
            for (let i = 0; i < 2; i++) {
                const createTaskResult = await server.request(
                    {
                        method: 'elicitation/create',
                        params: {
                            mode: 'form',
                            message: 'Please provide info',
                            requestedSchema: {
                                type: 'object',
                                properties: { username: { type: 'string' } }
                            }
                        }
                    },
                    CreateTaskResultSchema,
                    { task: { ttl: 60000 } }
                );

                // Verify CreateTaskResult structure and capture taskId
                expect(createTaskResult.task).toBeDefined();
                expect(createTaskResult.task.taskId).toBeDefined();
                createdTaskIds.push(createTaskResult.task.taskId);
            }

            // Query task list
            const taskList = await server.experimental.tasks.listTasks();
            expect(taskList.tasks.length).toBeGreaterThanOrEqual(2);
            for (const taskId of createdTaskIds) {
                expect(taskList.tasks).toContainEqual(
                    expect.objectContaining({
                        taskId,
                        status: 'completed'
                    })
                );
            }
        });
    });

    test('should list tasks from server with pagination', async () => {
        const serverTaskStore = new InMemoryTaskStore();

        const server = new McpServer(
            {
                name: 'test-server',
                version: '1.0.0'
            },
            {
                capabilities: {
                    tasks: {
                        requests: {
                            tools: {
                                call: {}
                            }
                        }
                    }
                },
                taskStore: serverTaskStore
            }
        );

        server.experimental.tasks.registerToolTask(
            'test-tool',
            {
                description: 'A test tool',
                inputSchema: {
                    id: z4.string()
                }
            },
            {
                async createTask({ id }, extra) {
                    const task = await extra.taskStore.createTask({
                        ttl: extra.taskRequestedTtl
                    });

                    const result = {
                        content: [{ type: 'text', text: `Result for ${id || 'unknown'}` }]
                    };
                    await extra.taskStore.storeTaskResult(task.taskId, 'completed', result);

                    return { task };
                },
                async getTask(extra) {
                    const task = await extra.taskStore.getTask(extra.taskId);
                    if (!task) {
                        throw new Error(`Task ${extra.taskId} not found`);
                    }
                    return task;
                },
                async getTaskResult(extra) {
                    const result = await extra.taskStore.getTaskResult(extra.taskId);
                    return result as { content: Array<{ type: 'text'; text: string }> };
                }
            }
        );

        const client = new Client(
            {
                name: 'test-client',
                version: '1.0.0'
            },
            {
                capabilities: {
                    tasks: {
                        requests: {
                            tools: {
                                call: {}
                            }
                        }
                    }
                }
            }
        );

        const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

        await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

        // Create multiple tasks
        const createdTaskIds: string[] = [];

        for (let i = 0; i < 3; i++) {
            await client.callTool({ name: 'test-tool', arguments: { id: `task-${i + 1}` } }, CallToolResultSchema, {
                task: { ttl: 60000 }
            });

            // Get the task ID from the task list
            const taskList = await client.experimental.tasks.listTasks();
            const newTask = taskList.tasks.find(t => !createdTaskIds.includes(t.taskId));
            if (newTask) {
                createdTaskIds.push(newTask.taskId);
            }
        }

        // List all tasks without cursor
        const firstPage = await client.experimental.tasks.listTasks();
        expect(firstPage.tasks.length).toBeGreaterThan(0);
        expect(firstPage.tasks.map(t => t.taskId)).toEqual(expect.arrayContaining(createdTaskIds));

        // If there's a cursor, test pagination
        if (firstPage.nextCursor) {
            const secondPage = await client.experimental.tasks.listTasks(firstPage.nextCursor);
            expect(secondPage.tasks).toBeDefined();
        }

        serverTaskStore.cleanup();
    });

    describe('Error scenarios', () => {
        let serverTaskStore: InMemoryTaskStore;
        let clientTaskStore: InMemoryTaskStore;

        beforeEach(() => {
            serverTaskStore = new InMemoryTaskStore();
            clientTaskStore = new InMemoryTaskStore();
        });

        afterEach(() => {
            serverTaskStore?.cleanup();
            clientTaskStore?.cleanup();
        });

        test('should throw error when querying non-existent task from server', async () => {
            const server = new Server(
                {
                    name: 'test-server',
                    version: '1.0.0'
                },
                {
                    capabilities: {
                        tools: {},
                        tasks: {
                            requests: {
                                tools: {
                                    call: {}
                                }
                            }
                        }
                    },
                    taskStore: serverTaskStore
                }
            );

            const client = new Client(
                {
                    name: 'test-client',
                    version: '1.0.0'
                },
                {
                    capabilities: {
                        tasks: {
                            requests: {
                                tools: {
                                    call: {}
                                }
                            }
                        }
                    }
                }
            );

            const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

            await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

            // Try to get a task that doesn't exist
            await expect(client.experimental.tasks.getTask('non-existent-task')).rejects.toThrow();
        });

        test('should throw error when querying result of non-existent task from server', async () => {
            const server = new Server(
                {
                    name: 'test-server',
                    version: '1.0.0'
                },
                {
                    capabilities: {
                        tools: {},
                        tasks: {
                            requests: {
                                tools: {
                                    call: {}
                                }
                            }
                        }
                    },
                    taskStore: serverTaskStore
                }
            );

            const client = new Client(
                {
                    name: 'test-client',
                    version: '1.0.0'
                },
                {
                    capabilities: {
                        tasks: {
                            requests: {
                                tools: {
                                    call: {}
                                }
                            }
                        }
                    }
                }
            );

            const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

            await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

            // Try to get result of a task that doesn't exist
            await expect(client.experimental.tasks.getTaskResult('non-existent-task', CallToolResultSchema)).rejects.toThrow();
        });

        test('should throw error when server queries non-existent task from client', async () => {
            const client = new Client(
                {
                    name: 'test-client',
                    version: '1.0.0'
                },
                {
                    capabilities: {
                        elicitation: {},
                        tasks: {
                            requests: {
                                elicitation: {
                                    create: {}
                                }
                            }
                        }
                    },
                    taskStore: clientTaskStore
                }
            );

            client.setRequestHandler(ElicitRequestSchema, async () => ({
                action: 'accept',
                content: { username: 'test' }
            }));

            const server = new Server(
                {
                    name: 'test-server',
                    version: '1.0.0'
                },
                {
                    capabilities: {
                        tasks: {
                            requests: {
                                elicitation: {
                                    create: {}
                                }
                            }
                        }
                    }
                }
            );

            const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

            await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

            // Try to query a task that doesn't exist on client
            await expect(server.experimental.tasks.getTask('non-existent-task')).rejects.toThrow();
        });
    });
});

test('should respect server task capabilities', async () => {
    const serverTaskStore = new InMemoryTaskStore();
    const server = new McpServer(
        {
            name: 'test-server',
            version: '1.0.0'
        },
        {
            capabilities: {
                tasks: {
                    requests: {
                        tools: {
                            call: {}
                        }
                    }
                }
            },
            taskStore: serverTaskStore
        }
    );

    server.experimental.tasks.registerToolTask(
        'test-tool',
        {
            description: 'A test tool',
            inputSchema: {}
        },
        {
            async createTask(_args, extra) {
                const task = await extra.taskStore.createTask({
                    ttl: extra.taskRequestedTtl
                });

                const result = {
                    content: [{ type: 'text', text: 'Success!' }]
                };
                await extra.taskStore.storeTaskResult(task.taskId, 'completed', result);

                return { task };
            },
            async getTask(extra) {
                const task = await extra.taskStore.getTask(extra.taskId);
                if (!task) {
                    throw new Error(`Task ${extra.taskId} not found`);
                }
                return task;
            },
            async getTaskResult(extra) {
                const result = await extra.taskStore.getTaskResult(extra.taskId);
                return result as { content: Array<{ type: 'text'; text: string }> };
            }
        }
    );

    const client = new Client(
        {
            name: 'test-client',
            version: '1.0.0'
        },
        {
            enforceStrictCapabilities: true
        }
    );

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();
    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    // Server supports task creation for tools/call
    expect(client.getServerCapabilities()).toEqual({
        tools: {
            listChanged: true
        },
        tasks: {
            requests: {
                tools: {
                    call: {}
                }
            }
        }
    });

    // These should work because server supports tasks
    await expect(
        client.callTool({ name: 'test-tool', arguments: {} }, CallToolResultSchema, {
            task: { ttl: 60000 }
        })
    ).resolves.not.toThrow();
    await expect(client.experimental.tasks.listTasks()).resolves.not.toThrow();

    // tools/list doesn't support task creation, but it shouldn't throw - it should just ignore the task metadata
    await expect(
        client.request(
            {
                method: 'tools/list',
                params: {}
            },
            ListToolsResultSchema
        )
    ).resolves.not.toThrow();

    serverTaskStore.cleanup();
});

/**
 * Test: requestStream() method
 */
test('should expose requestStream() method for streaming responses', async () => {
    const server = new Server(
        {
            name: 'test-server',
            version: '1.0.0'
        },
        {
            capabilities: {
                tools: {}
            }
        }
    );

    server.setRequestHandler(CallToolRequestSchema, async () => {
        return {
            content: [{ type: 'text', text: 'Tool result' }]
        };
    });

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    const client = new Client(
        {
            name: 'test-client',
            version: '1.0.0'
        },
        {
            capabilities: {}
        }
    );

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    // First verify that regular request() works
    const regularResult = await client.callTool({ name: 'test-tool', arguments: {} });
    expect(regularResult.content).toEqual([{ type: 'text', text: 'Tool result' }]);

    // Test requestStream with non-task request (should yield only result)
    const stream = client.experimental.tasks.requestStream(
        {
            method: 'tools/call',
            params: { name: 'test-tool', arguments: {} }
        },
        CallToolResultSchema
    );

    const messages = [];
    for await (const message of stream) {
        messages.push(message);
    }

    // Should have received only a result message (no task messages)
    expect(messages.length).toBe(1);
    expect(messages[0].type).toBe('result');
    if (messages[0].type === 'result') {
        expect(messages[0].result.content).toEqual([{ type: 'text', text: 'Tool result' }]);
    }

    await client.close();
    await server.close();
});

/**
 * Test: callToolStream() method
 */
test('should expose callToolStream() method for streaming tool calls', async () => {
    const server = new Server(
        {
            name: 'test-server',
            version: '1.0.0'
        },
        {
            capabilities: {
                tools: {}
            }
        }
    );

    server.setRequestHandler(CallToolRequestSchema, async () => {
        return {
            content: [{ type: 'text', text: 'Tool result' }]
        };
    });

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    const client = new Client(
        {
            name: 'test-client',
            version: '1.0.0'
        },
        {
            capabilities: {}
        }
    );

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    // Test callToolStream
    const stream = client.experimental.tasks.callToolStream({ name: 'test-tool', arguments: {} });

    const messages = [];
    for await (const message of stream) {
        messages.push(message);
    }

    // Should have received messages ending with result
    expect(messages.length).toBe(1);
    expect(messages[0].type).toBe('result');
    if (messages[0].type === 'result') {
        expect(messages[0].result.content).toEqual([{ type: 'text', text: 'Tool result' }]);
    }

    await client.close();
    await server.close();
});

/**
 * Test: callToolStream() with output schema validation
 */
test('should validate structured output in callToolStream()', async () => {
    const server = new Server(
        {
            name: 'test-server',
            version: '1.0.0'
        },
        {
            capabilities: {
                tools: {}
            }
        }
    );

    server.setRequestHandler(ListToolsRequestSchema, async () => {
        return {
            tools: [
                {
                    name: 'structured-tool',
                    description: 'A tool with output schema',
                    inputSchema: {
                        type: 'object',
                        properties: {}
                    },
                    outputSchema: {
                        type: 'object',
                        properties: {
                            value: { type: 'number' }
                        },
                        required: ['value']
                    }
                }
            ]
        };
    });

    server.setRequestHandler(CallToolRequestSchema, async () => {
        return {
            content: [{ type: 'text', text: 'Result' }],
            structuredContent: { value: 42 }
        };
    });

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    const client = new Client(
        {
            name: 'test-client',
            version: '1.0.0'
        },
        {
            capabilities: {}
        }
    );

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    // List tools to cache the output schema
    await client.listTools();

    // Test callToolStream with valid structured output
    const stream = client.experimental.tasks.callToolStream({ name: 'structured-tool', arguments: {} });

    const messages = [];
    for await (const message of stream) {
        messages.push(message);
    }

    // Should have received result with validated structured content
    expect(messages.length).toBe(1);
    expect(messages[0].type).toBe('result');
    if (messages[0].type === 'result') {
        expect(messages[0].result.structuredContent).toEqual({ value: 42 });
    }

    await client.close();
    await server.close();
});

test('callToolStream() should yield error when structuredContent does not match schema', async () => {
    const server = new Server(
        {
            name: 'test-server',
            version: '1.0.0'
        },
        {
            capabilities: {
                tools: {}
            }
        }
    );

    server.setRequestHandler(ListToolsRequestSchema, async () => ({
        tools: [
            {
                name: 'test-tool',
                description: 'A test tool',
                inputSchema: {
                    type: 'object',
                    properties: {}
                },
                outputSchema: {
                    type: 'object',
                    properties: {
                        result: { type: 'string' },
                        count: { type: 'number' }
                    },
                    required: ['result', 'count'],
                    additionalProperties: false
                }
            }
        ]
    }));

    server.setRequestHandler(CallToolRequestSchema, async () => {
        // Return invalid structured content (count is string instead of number)
        return {
            structuredContent: { result: 'success', count: 'not a number' }
        };
    });

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    const client = new Client(
        {
            name: 'test-client',
            version: '1.0.0'
        },
        {
            capabilities: {}
        }
    );

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    // List tools to cache the schemas
    await client.listTools();

    const stream = client.experimental.tasks.callToolStream({ name: 'test-tool', arguments: {} });

    const messages = [];
    for await (const message of stream) {
        messages.push(message);
    }

    expect(messages.length).toBe(1);
    expect(messages[0].type).toBe('error');
    if (messages[0].type === 'error') {
        expect(messages[0].error.message).toMatch(/Structured content does not match the tool's output schema/);
    }

    await client.close();
    await server.close();
});

test('callToolStream() should yield error when tool with outputSchema returns no structuredContent', async () => {
    const server = new Server(
        {
            name: 'test-server',
            version: '1.0.0'
        },
        {
            capabilities: {
                tools: {}
            }
        }
    );

    server.setRequestHandler(ListToolsRequestSchema, async () => ({
        tools: [
            {
                name: 'test-tool',
                description: 'A test tool',
                inputSchema: {
                    type: 'object',
                    properties: {}
                },
                outputSchema: {
                    type: 'object',
                    properties: {
                        result: { type: 'string' }
                    },
                    required: ['result']
                }
            }
        ]
    }));

    server.setRequestHandler(CallToolRequestSchema, async () => {
        return {
            content: [{ type: 'text', text: 'This should be structured content' }]
        };
    });

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    const client = new Client(
        {
            name: 'test-client',
            version: '1.0.0'
        },
        {
            capabilities: {}
        }
    );

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    await client.listTools();

    const stream = client.experimental.tasks.callToolStream({ name: 'test-tool', arguments: {} });

    const messages = [];
    for await (const message of stream) {
        messages.push(message);
    }

    expect(messages.length).toBe(1);
    expect(messages[0].type).toBe('error');
    if (messages[0].type === 'error') {
        expect(messages[0].error.message).toMatch(/Tool test-tool has an output schema but did not return structured content/);
    }

    await client.close();
    await server.close();
});

test('callToolStream() should handle tools without outputSchema normally', async () => {
    const server = new Server(
        {
            name: 'test-server',
            version: '1.0.0'
        },
        {
            capabilities: {
                tools: {}
            }
        }
    );

    server.setRequestHandler(ListToolsRequestSchema, async () => ({
        tools: [
            {
                name: 'test-tool',
                description: 'A test tool',
                inputSchema: {
                    type: 'object',
                    properties: {}
                }
            }
        ]
    }));

    server.setRequestHandler(CallToolRequestSchema, async () => {
        return {
            content: [{ type: 'text', text: 'Normal response' }]
        };
    });

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    const client = new Client(
        {
            name: 'test-client',
            version: '1.0.0'
        },
        {
            capabilities: {}
        }
    );

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    await client.listTools();

    const stream = client.experimental.tasks.callToolStream({ name: 'test-tool', arguments: {} });

    const messages = [];
    for await (const message of stream) {
        messages.push(message);
    }

    expect(messages.length).toBe(1);
    expect(messages[0].type).toBe('result');
    if (messages[0].type === 'result') {
        expect(messages[0].result.content).toEqual([{ type: 'text', text: 'Normal response' }]);
    }

    await client.close();
    await server.close();
});

test('callToolStream() should handle complex JSON schema validation', async () => {
    const server = new Server(
        {
            name: 'test-server',
            version: '1.0.0'
        },
        {
            capabilities: {
                tools: {}
            }
        }
    );

    server.setRequestHandler(ListToolsRequestSchema, async () => ({
        tools: [
            {
                name: 'complex-tool',
                description: 'A tool with complex schema',
                inputSchema: {
                    type: 'object',
                    properties: {}
                },
                outputSchema: {
                    type: 'object',
                    properties: {
                        name: { type: 'string', minLength: 3 },
                        age: { type: 'integer', minimum: 0, maximum: 120 },
                        active: { type: 'boolean' },
                        tags: {
                            type: 'array',
                            items: { type: 'string' },
                            minItems: 1
                        },
                        metadata: {
                            type: 'object',
                            properties: {
                                created: { type: 'string' }
                            },
                            required: ['created']
                        }
                    },
                    required: ['name', 'age', 'active', 'tags', 'metadata'],
                    additionalProperties: false
                }
            }
        ]
    }));

    server.setRequestHandler(CallToolRequestSchema, async () => {
        return {
            structuredContent: {
                name: 'John Doe',
                age: 30,
                active: true,
                tags: ['user', 'admin'],
                metadata: {
                    created: '2023-01-01T00:00:00Z'
                }
            }
        };
    });

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    const client = new Client(
        {
            name: 'test-client',
            version: '1.0.0'
        },
        {
            capabilities: {}
        }
    );

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    await client.listTools();

    const stream = client.experimental.tasks.callToolStream({ name: 'complex-tool', arguments: {} });

    const messages = [];
    for await (const message of stream) {
        messages.push(message);
    }

    expect(messages.length).toBe(1);
    expect(messages[0].type).toBe('result');
    if (messages[0].type === 'result') {
        expect(messages[0].result.structuredContent).toBeDefined();
        const structuredContent = messages[0].result.structuredContent as { name: string; age: number };
        expect(structuredContent.name).toBe('John Doe');
        expect(structuredContent.age).toBe(30);
    }

    await client.close();
    await server.close();
});

test('callToolStream() should yield error with additional properties when not allowed', async () => {
    const server = new Server(
        {
            name: 'test-server',
            version: '1.0.0'
        },
        {
            capabilities: {
                tools: {}
            }
        }
    );

    server.setRequestHandler(ListToolsRequestSchema, async () => ({
        tools: [
            {
                name: 'strict-tool',
                description: 'A tool with strict schema',
                inputSchema: {
                    type: 'object',
                    properties: {}
                },
                outputSchema: {
                    type: 'object',
                    properties: {
                        name: { type: 'string' }
                    },
                    required: ['name'],
                    additionalProperties: false
                }
            }
        ]
    }));

    server.setRequestHandler(CallToolRequestSchema, async () => {
        return {
            structuredContent: {
                name: 'John',
                extraField: 'not allowed'
            }
        };
    });

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    const client = new Client(
        {
            name: 'test-client',
            version: '1.0.0'
        },
        {
            capabilities: {}
        }
    );

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    await client.listTools();

    const stream = client.experimental.tasks.callToolStream({ name: 'strict-tool', arguments: {} });

    const messages = [];
    for await (const message of stream) {
        messages.push(message);
    }

    expect(messages.length).toBe(1);
    expect(messages[0].type).toBe('error');
    if (messages[0].type === 'error') {
        expect(messages[0].error.message).toMatch(/Structured content does not match the tool's output schema/);
    }

    await client.close();
    await server.close();
});

test('callToolStream() should not validate structuredContent when isError is true', async () => {
    const server = new Server(
        {
            name: 'test-server',
            version: '1.0.0'
        },
        {
            capabilities: {
                tools: {}
            }
        }
    );

    server.setRequestHandler(ListToolsRequestSchema, async () => ({
        tools: [
            {
                name: 'test-tool',
                description: 'A test tool',
                inputSchema: {
                    type: 'object',
                    properties: {}
                },
                outputSchema: {
                    type: 'object',
                    properties: {
                        result: { type: 'string' }
                    },
                    required: ['result']
                }
            }
        ]
    }));

    server.setRequestHandler(CallToolRequestSchema, async () => {
        // Return isError with content (no structuredContent) - should NOT trigger validation error
        return {
            isError: true,
            content: [{ type: 'text', text: 'Something went wrong' }]
        };
    });

    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

    const client = new Client(
        {
            name: 'test-client',
            version: '1.0.0'
        },
        {
            capabilities: {}
        }
    );

    await Promise.all([client.connect(clientTransport), server.connect(serverTransport)]);

    await client.listTools();

    const stream = client.experimental.tasks.callToolStream({ name: 'test-tool', arguments: {} });

    const messages = [];
    for await (const message of stream) {
        messages.push(message);
    }

    // Should have received result (not error), with isError flag set
    expect(messages.length).toBe(1);
    expect(messages[0].type).toBe('result');
    if (messages[0].type === 'result') {
        expect(messages[0].result.isError).toBe(true);
        expect(messages[0].result.content).toEqual([{ type: 'text', text: 'Something went wrong' }]);
    }

    await client.close();
    await server.close();
});

describe('getSupportedElicitationModes', () => {
    test('should support nothing when capabilities are undefined', () => {
        const result = getSupportedElicitationModes(undefined);
        expect(result.supportsFormMode).toBe(false);
        expect(result.supportsUrlMode).toBe(false);
    });

    test('should default to form mode when capabilities are an empty object', () => {
        const result = getSupportedElicitationModes({});
        expect(result.supportsFormMode).toBe(true);
        expect(result.supportsUrlMode).toBe(false);
    });

    test('should support form mode when form is explicitly declared', () => {
        const result = getSupportedElicitationModes({ form: {} });
        expect(result.supportsFormMode).toBe(true);
        expect(result.supportsUrlMode).toBe(false);
    });

    test('should support url mode when url is explicitly declared', () => {
        const result = getSupportedElicitationModes({ url: {} });
        expect(result.supportsFormMode).toBe(false);
        expect(result.supportsUrlMode).toBe(true);
    });

    test('should support both modes when both are explicitly declared', () => {
        const result = getSupportedElicitationModes({ form: {}, url: {} });
        expect(result.supportsFormMode).toBe(true);
        expect(result.supportsUrlMode).toBe(true);
    });

    test('should support form mode when form declares applyDefaults', () => {
        const result = getSupportedElicitationModes({ form: { applyDefaults: true } });
        expect(result.supportsFormMode).toBe(true);
        expect(result.supportsUrlMode).toBe(false);
    });
});