/**
* mysql-mcp - MySQL Connection Mock
*
* Provides mock implementations of mysql2 connection pool
* for unit testing without database dependency.
*/
import { vi } from 'vitest';
import type { PoolConnection, FieldPacket, ResultSetHeader, Pool } from 'mysql2/promise';
/**
* Mock field packet for query results
*/
export function createMockFieldPacket(name: string, type = 253): FieldPacket {
return {
catalog: 'def',
db: 'testdb',
table: 'test_table',
orgTable: 'test_table',
name,
orgName: name,
charsetNr: 33,
length: 255,
type,
flags: 0,
decimals: 0
} as FieldPacket;
}
/**
* Mock result set header for write operations
*/
export function createMockResultSetHeader(affectedRows = 1, insertId = 0): ResultSetHeader {
return {
constructor: { name: 'ResultSetHeader' },
fieldCount: 0,
affectedRows,
insertId,
info: '',
serverStatus: 2,
warningStatus: 0,
changedRows: 0
} as ResultSetHeader;
}
/**
* Create a mock pool connection
*/
export function createMockPoolConnection(
queryResult: unknown[] = [],
executeResult: unknown[] = []
): PoolConnection {
const mockConnection = {
query: vi.fn().mockResolvedValue([queryResult, []]),
execute: vi.fn().mockResolvedValue([executeResult, []]),
release: vi.fn(),
beginTransaction: vi.fn().mockResolvedValue(undefined),
commit: vi.fn().mockResolvedValue(undefined),
rollback: vi.fn().mockResolvedValue(undefined),
ping: vi.fn().mockResolvedValue(undefined),
end: vi.fn().mockResolvedValue(undefined),
destroy: vi.fn(),
connection: {
serverVersion: '8.0.35'
},
threadId: 1
} as unknown as PoolConnection;
return mockConnection;
}
/**
* Create a mock connection pool
*/
export function createMockPool(
queryResult: unknown[] = [],
executeResult: unknown[] = []
): Pool {
const mockConnection = createMockPoolConnection(queryResult, executeResult);
const mockPool = {
getConnection: vi.fn().mockResolvedValue(mockConnection),
query: vi.fn().mockResolvedValue([queryResult, []]),
execute: vi.fn().mockResolvedValue([executeResult, []]),
end: vi.fn().mockResolvedValue(undefined),
pool: {
_allConnections: { length: 10 },
_freeConnections: { length: 5 },
_connectionQueue: { length: 0 }
}
} as unknown as Pool;
return mockPool;
}
/**
* Mock mysql2/promise module
*/
export function mockMysql2Module(): {
createPool: ReturnType<typeof vi.fn>;
resetMock: () => void;
} {
const mockPool = createMockPool();
const createPool = vi.fn().mockReturnValue(mockPool);
return {
createPool,
resetMock: () => {
vi.clearAllMocks();
}
};
}
/**
* Helper to set up mock query responses
*/
export function setupMockQueryResponse(
pool: Pool,
responses: Map<string, unknown[]>
): void {
const queryFn = pool.query as ReturnType<typeof vi.fn>;
const executeFn = pool.execute as ReturnType<typeof vi.fn>;
const mockImplementation = (sql: string): Promise<[unknown[], FieldPacket[]]> => {
for (const [pattern, result] of responses) {
if (sql.includes(pattern)) {
return Promise.resolve([result, []]);
}
}
return Promise.resolve([[], []]);
};
queryFn.mockImplementation(mockImplementation);
executeFn.mockImplementation(mockImplementation);
}
